def run(self):
"""
Main method. All work is done here.
"""
self.start_timer('total')
self.transport = MulticurlTransport(self.thread_number)
try:
self.setup_default_queue()
self.prepare()
self.start_timer('task_generator')
if not self.slave:
if not self.ng:
self.init_task_generator()
self.stop_timer('task_generator')
while self.work_allowed:
now = int(time.time())
if now - self.last_snapshot_values['timestamp'] > self.snapshot_interval:
snapshot = {'timestamp': now}
for key in ('download-size', 'upload-size',
'download-size-with-cache'):
snapshot[key] = self.counters[key] - self.last_snapshot_values[key]
self.last_snapshot_values[key] = self.counters[key]
snapshot['request-count'] = self.counters['request'] -\
self.last_snapshot_values['request-count']
self.last_snapshot_values['request-count'] = self.counters['request']
self.last_snapshot_values['timestamp'] = now
self.snapshots[now] = snapshot
self.snapshot_timestamps.append(now)
if self.snapshot_file:
with open(self.snapshot_file, 'a') as out:
out.write(json.dumps(snapshot) + '\n')
# FIXIT: REMOVE
# Run update task handler which
# updates database object which stores
# info about current scraping process
if self.dump_spider_stats:
self.dump_spider_stats(self)
if self.controller.enabled:
self.controller.process_commands()
if not self.ng:
# NG
self.start_timer('task_generator')
# star
if self.task_generator_enabled:
self.process_task_generator()
self.stop_timer('task_generator')
if self.transport.ready_for_task():
logger_verbose.debug('Transport has free resources. '
'Trying to add new task (if exists)')
# Try five times to get new task and proces task generator
# because slave parser could agressively consume
# tasks from task queue
for x in xrange(5):
task = self.load_new_task()
if task is None:
if not self.transport.active_task_number():
self.process_task_generator()
elif task is True:
# If only delayed tasks in queue
break
else:
# If got some task
break
if not task:
if not self.transport.active_task_number():
logger_verbose.debug('Network transport has no '
'active tasks')
# NG
if self.ng:
self.waiting_shutdown_event.set()
if self.shutdown_event.is_set():
logger_verbose.debug('Got shutdown signal')
self.stop()
else:
logger_verbose.debug('Shutdown event has'
' not been set yet')
else:
if not self.task_generator_enabled:
self.stop()
else:
logger_verbose.debug('Transport active tasks: %d' %
self.transport.active_task_number())
elif isinstance(task, NullTask):
logger_verbose.debug('Got NullTask')
if not self.transport.active_task_number():
if task.sleep:
logger.debug('Got NullTask with sleep '
'instruction. Sleeping for'
' %.2f seconds' % task.sleep)
time.sleep(task.sleep)
elif isinstance(task, bool) and (task is True):
pass
else:
if self.ng:
if self.waiting_shutdown_event.is_set():
self.waiting_shutdown_event.clear()
logger_verbose.debug('Got new task from task queue: %s'
% task)
self.process_task_counters(task)
is_valid, reason = self.check_task_limits(task)
if not is_valid:
logger_verbose.debug('Task %s is rejected due to '
'%s limit'
% (task.name, reason))
if reason == 'task-try-count':
self.add_item('task-count-rejected', task.url)
elif reason == 'network-try-count':
self.add_item('network-count-rejected', task.url)
else:
raise Exception('Unknown response from '
'check_task_limits: %s'
% reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
# TODO: not do following line
# TODO: middleware: TaskFails
else:
self.process_new_task(task)
self.transport.process_handlers()
with self.save_timer('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Iterate over network trasport ready results
# Each result could be valid or failed
# Result format: {ok, grab, grab_config_backup, task, emsg}
#print '[transport iterate results - start]'
for result in self.transport.iterate_results():
if self.is_valid_for_cache(result):
with self.save_timer('cache'):
with self.save_timer('cache.write'):
self.cache.save_response(result['task'].url,
result['grab'])
#print '[process network results]'
self.process_network_result(result)
#print '[done]'
self.inc_count('request')
#print '[transport iterate results - end]'
logger_verbose.debug('Work done')
except KeyboardInterrupt:
print('\nGot ^C signal. Stopping.')
raise
finally:
# This code is executed when main cycles is breaked
self.stop_timer('total')
self.shutdown()
class Spider(SpiderMetaClassMixin, SpiderPattern, SpiderStat):
"""
Asynchronous scraping framework.
"""
# You can define here some urls and initial tasks
# with name "initial" will be created from these
# urls
# If the logic of generating initial tasks is complex
# then consider to use `task_generator` method instead of
# `initial_urls` attribute
initial_urls = None
# The base url which is used to resolve all relative urls
# The resolving takes place in `add_task` method
base_url = None
middlewares = []
middleware_points = {
'response': [],
}
class Meta:
# Meta.abstract means that this class will not be
# collected to spider registry by `grab crawl` CLI command.
# The Meta is inherited by descendant classes BUT
# Meta.abstract is reset to False in each descendant
abstract = True
def __init__(self, thread_number=3,
network_try_limit=10, task_try_limit=10,
request_pause=NULL,
priority_mode='random',
meta=None,
only_cache=False,
config=None,
slave=False,
max_task_generator_chunk=None,
args=None,
# New options start here
waiting_shutdown_event=None,
taskq=None,
result_queue=None,
network_response_queue=None,
shutdown_event=None,
generator_done_event=None,
ng=False,
):
"""
Arguments:
* thread-number - Number of concurrent network streams
* network_try_limit - How many times try to send request
again if network error was occurred, use 0 to disable
* network_try_limit - Limit of tries to execute some task
this is not the same as network_try_limit
network try limit limits the number of tries which
are performed automatically in case of network timeout
of some other physical error
but task_try_limit limits the number of attempts which
are scheduled manually in the spider business logic
* priority_mode - could be "random" or "const"
* meta - arbitrary user data
* retry_rebuild_user_agent - generate new random user-agent for each
network request which is performed again due to network error
* args - command line arguments parsed with `setup_arg_parser` method
New options:
* waiting_shutdown_event=None,
* taskq=None,
* result_queue=None,
* newtork_response_queue=None,
* shutdown_event=None,
* generator_done_event=None):
"""
# New options starts
self.waiting_shutdown_event = waiting_shutdown_event
self.taskq = taskq
self.result_queue = result_queue
self.shutdown_event = shutdown_event
self.generator_done_event = generator_done_event
self.network_response_queue = network_response_queue
self.ng = ng
# New options ends
if args is None:
self.args = {}
else:
self.args = args
self.slave = slave
self.max_task_generator_chunk = max_task_generator_chunk
self.timers = {
'network-name-lookup': 0,
'network-connect': 0,
'network-total': 0,
}
self.time_points = {}
self.start_timer('total')
if config is not None:
self.config = config
else:
# Fix circular import error
from grab.util.config import Config
self.config = Config()
if meta:
self.meta = meta
else:
self.meta = {}
self.task_generator_enabled = False
self.only_cache = only_cache
self.thread_number = thread_number
self.counters = defaultdict(int)
self._grab_config = {}
self.items = {}
self.task_try_limit = task_try_limit
self.network_try_limit = network_try_limit
if priority_mode not in ['random', 'const']:
raise SpiderMisuseError('Value of priority_mode option should be '
'"random" or "const"')
else:
self.priority_mode = priority_mode
try:
signal.signal(signal.SIGUSR1, self.sigusr1_handler)
except (ValueError, AttributeError):
pass
try:
signal.signal(signal.SIGUSR2, self.sigusr2_handler)
except (ValueError, AttributeError):
pass
# Initial cache-subsystem values
self.cache_enabled = False
self.cache = None
self.work_allowed = True
if request_pause is not NULL:
logger.error('Option `request_pause` is deprecated and is not '
'supported anymore')
self.proxylist_enabled = None
self.proxylist = None
self.proxy = None
self.proxy_auto_change = False
# FIXIT: REMOVE
self.dump_spider_stats = None
self.controller = CommandController(self)
# snapshots contains information about spider's state
# for each 10 seconds interval
self.snapshots = {}
self.last_snapshot_values = {
'timestamp': 0,
'download-size': 0,
'upload-size': 0,
'download-size-with-cache': 0,
'request-count': 0,
}
self.snapshot_timestamps = []
self.snapshot_interval = self.config.get('GRAB_SNAPSHOT_CONFIG', {}).get('interval', 10)
self.snapshot_file = self.config.get('GRAB_SNAPSHOT_CONFIG', {}).get('file', None)
if self.snapshot_file:
open(self.snapshot_file, 'w').write('')
def get_grab_config(self):
logger.error('Using `grab_config` attribute is deprecated. Override '
'`create_grab_instance method instead.')
return self._grab_config
def set_grab_config(self, val):
logger.error('Using `grab_config` attribute is deprecated. Override '
'`create_grab_instance method instead.')
self._grab_config = val
grab_config = property(get_grab_config, set_grab_config)
def setup_middleware(self, middleware_list):
for item in middleware_list:
self.middlewares.append(item)
mod_path, cls_name = item.rsplit('.', 1)
mod = __import__(mod_path, None, None, ['foo'])
cls = getattr(mod, cls_name)
mid = cls()
if hasattr(mid, 'process_response'):
self.middleware_points['response'].append(mid)
def setup_cache(self, backend='mongo', database=None, use_compression=True,
**kwargs):
if database is None:
raise SpiderMisuseError('setup_cache method requires database '
'option')
self.cache_enabled = True
mod = __import__('grab.spider.cache_backend.%s' % backend,
globals(), locals(), ['foo'])
self.cache = mod.CacheBackend(database=database,
use_compression=use_compression,
spider=self, **kwargs)
def setup_queue(self, backend='memory', **kwargs):
logger.debug('Using %s backend for task queue' % backend)
mod = __import__('grab.spider.queue_backend.%s' % backend,
globals(), locals(), ['foo'])
self.taskq = mod.QueueBackend(spider_name=self.get_name(),
**kwargs)
def prepare(self):
"""
You can do additional spider customization here
before it has started working. Simply redefine
this method in your Spider class.
"""
def sigusr1_handler(self, signal, frame):
"""
Catches SIGUSR1 signal and dumps current state
to temporary file
"""
with open('/tmp/spider.state', 'w') as out:
out.write(self.render_stats())
def sigusr2_handler(self, signal, frame):
"""
Catches SIGUSR1 signal and shutdowns spider.
"""
logger.error('Received SIGUSR2 signal. Doing shutdown')
self.stop()
def setup_grab(self, **kwargs):
logging.error('This method is deprecated. Instead override '
'`create_grab_instance` method in you spider sub-class')
self.grab_config.update(**kwargs)
def check_task_limits(self, task):
"""
Check that network/try counters are OK.
Returns:
* if success: (True, None)
* if error: (False, reason)
"""
if task.task_try_count > self.task_try_limit:
logger.debug('Task tries (%d) ended: %s / %s' % (
self.task_try_limit, task.name, task.url))
return False, 'task-try-count'
if task.network_try_count > self.network_try_limit:
logger.debug('Network tries (%d) ended: %s / %s' % (
self.network_try_limit, task.name, task.url))
return False, 'network-try-count'
return True, None
def generate_task_priority(self):
if self.priority_mode == 'const':
return DEFAULT_TASK_PRIORITY
else:
return randint(*RANDOM_TASK_PRIORITY_RANGE)
def add_task(self, task):
"""
Add task to the task queue.
"""
if self.taskq is None:
raise SpiderMisuseError('You should configure task queue before '
'adding tasks. Use `setup_queue` method.')
if task.priority is None or not task.priority_is_custom:
task.priority = self.generate_task_priority()
task.priority_is_custom = False
else:
task.priority_is_custom = True
if not isinstance(task, NullTask):
if not task.url.startswith(('http://', 'https://', 'ftp://', 'file://', 'feed://')):
if self.base_url is None:
msg = 'Could not resolve relative URL because base_url ' \
'is not specified. Task: %s, URL: %s'\
% (task.name, task.url)
logger.error(msg)
self.add_item('task-with-invalid-url', task.url)
return False
else:
task.url = urljoin(self.base_url, task.url)
# If task has grab_config object then update it too
if task.grab_config:
task.grab_config['url'] = task.url
# TODO: keep original task priority if it was set explicitly
self.taskq.put(task, task.priority, schedule_time=task.schedule_time)
is_valid = True
return is_valid
def load_initial_urls(self):
"""
Create initial tasks from `self.initial_urls`.
Tasks are created with name "initial".
"""
if self.initial_urls:
for url in self.initial_urls:
self.add_task(Task('initial', url=url))
def setup_default_queue(self):
"""
If task queue is not configured explicitly
then create task queue with default parameters
This method is not the same as `self.setup_queue` because
`self.setup_queue` works by default with in-memory queue.
You can override `setup_default_queue` in your custom
Spider and use other storage engines for you
default task queue.
"""
# If queue is still not configured
# then configure it with default backend
if self.taskq is None:
self.setup_queue()
def process_task_generator(self):
"""
Load new tasks from `self.task_generator_object`
Create new tasks.
If task queue size is less than some value
then load new tasks from tasks file.
"""
if self.task_generator_enabled:
if hasattr(self.taskq, 'qsize'):
qsize = self.taskq.qsize()
else:
qsize = self.taskq.size()
if self.max_task_generator_chunk is not None:
min_limit = min(self.max_task_generator_chunk,
self.thread_number * 10)
else:
min_limit = self.thread_number * 10
if qsize < min_limit:
logger_verbose.debug('Task queue contains less tasks than '
'limit. Trying to add new tasks')
try:
for x in xrange(min_limit - qsize):
item = next(self.task_generator_object)
logger_verbose.debug('Got new item from generator. '
'Processing it.')
#self.add_task(item)
self.process_handler_result(item)
except StopIteration:
# If generator have no values to yield
# then disable it
logger_verbose.debug('Task generator has no more tasks. '
'Disabling it')
self.task_generator_enabled = False
def init_task_generator(self):
"""
Process `initial_urls` and `task_generator`.
Generate first portion of tasks.
TODO: task generator should work in separate OS process
"""
self.task_generator_object = self.task_generator()
self.task_generator_enabled = True
logger_verbose.debug('Processing initial urls')
self.load_initial_urls()
# Initial call to task generator
# before main cycle
self.process_task_generator()
def load_new_task(self):
start = time.time()
while True:
try:
with self.save_timer('task_queue'):
return self.taskq.get()
except queue.Empty:
if self.taskq.size():
logger_verbose.debug('Waiting for scheduled task')
return True
if not self.slave:
logger_verbose.debug('Task queue is empty.')
return None
else:
# Temporarily hack which force slave crawler
# to wait 5 seconds for new tasks, this solves
# the problem that sometimes slave crawler stop
# its work because it could not receive new
# tasks immediately
if not self.transport.active_task_number():
if time.time() - start < 5:
time.sleep(0.1)
logger.debug('Slave sleeping')
else:
break
else:
break
logger_verbose.debug('Task queue is empty.')
return None
def process_task_counters(self, task):
task.network_try_count += 1
if task.task_try_count == 0:
task.task_try_count = 1
def create_grab_instance(self, **kwargs):
# Back-ward compatibility for deprecated `grab_config` attribute
# Use _grab_config to not trigger warning messages
if self._grab_config and kwargs:
merged_config = deepcopy(self._grab_config)
merged_config.update(kwargs)
return Grab(**merged_config)
elif self._grab_config and not kwargs:
return Grab(**self._grab_config)
else:
return Grab(**kwargs)
def setup_grab_for_task(self, task):
grab = self.create_grab_instance()
if task.grab_config:
grab.load_config(task.grab_config)
else:
grab.setup(url=task.url)
# Generate new common headers
grab.config['common_headers'] = grab.common_headers()
return grab
def is_task_cacheable(self, task, grab):
if ( # cache is disabled for all tasks
not self.cache_enabled
# cache data should be refreshed
or task.get('refresh_cache', False)
# cache could not be used
or task.get('disable_cache', False)
# request type is not cacheable
or grab.detect_request_method() != 'GET'):
return False
else:
return True
def load_task_from_cache(self, transport, task, grab, grab_config_backup):
cache_item = self.cache.get_item(grab.config['url'],
timeout=task.cache_timeout)
if cache_item is None:
return None
else:
with self.save_timer('cache.read.prepare_request'):
grab.prepare_request()
with self.save_timer('cache.read.load_response'):
self.cache.load_response(grab, cache_item)
grab.log_request('CACHED')
self.inc_count('request')
self.inc_count('request-cache')
return {'ok': True, 'grab': grab,
'grab_config_backup': grab_config_backup,
'task': task, 'emsg': None}
def valid_response_code(self, code, task):
"""
Answer the question: if the response could be handled via
usual task handler or the task faield and should be processed as error.
"""
return (code < 400 or code == 404 or
code in task.valid_status)
def process_handler_error(self, func_name, ex, task, error_tb=None):
self.inc_count('error-%s' % ex.__class__.__name__.lower())
if error_tb is not None:
logger.error('Error in %s function' % func_name)
logger.error(error_tb)
else:
logger.error('Error in %s function' % func_name,
exc_info=ex)
# Looks strange but I really have some problems with
# serializing exception into string
try:
ex_str = unicode(ex)
except TypeError:
try:
ex_str = unicode(ex, 'utf-8', 'ignore')
except TypeError:
ex_str = str(ex)
task_url = task.url if task is not None else None
self.add_item('fatal', '%s|%s|%s|%s' % (
func_name, ex.__class__.__name__, ex_str, task_url))
if isinstance(ex, FatalError):
raise
def find_data_handler(self, data):
try:
return getattr(data, 'handler')
except AttributeError:
try:
handler = getattr(self, 'data_%s' % data.handler_key)
except AttributeError:
raise NoDataHandler('No handler defined for Data %s'
% data.handler_key)
else:
return handler
def execute_task_handler(self, res, handler):
"""
Apply `handler` function to the network result.
If network result is failed then submit task again
to the network task queue.
"""
try:
handler_name = handler.__name__
except AttributeError:
handler_name = 'NONE'
if (res['task'].get('raw') or (
res['ok'] and self.valid_response_code(res['grab'].response.code,
res['task']))):
try:
with self.save_timer('response_handler'):
with self.save_timer('response_handler.%s' % handler_name):
result = handler(res['grab'], res['task'])
if result is None:
pass
else:
for item in result:
self.process_handler_result(item, res['task'])
except NoDataHandler as ex:
raise
except Exception as ex:
self.process_handler_error(handler_name, ex, res['task'])
else:
self.inc_count('task-%s-ok' % res['task'].name)
else:
# Log the error
if res['ok']:
msg = res['emsg'] = 'HTTP %s' % res['grab'].response.code
else:
msg = res['emsg']
# TODO: REMOVE
#if 'Operation timed out after' in msg:
#num = int(msg.split('Operation timed out after')[1].strip().split(' ')[0])
#if num > 20000:
#import pdb; pdb.set_trace()
self.inc_count('network-error-%s' % res['emsg'][:20])
logger.error(u'Network error: %s' % msg)
# Try to repeat the same network query
if self.network_try_limit > 0:
task = res['task']
task.refresh_cache = True
# Should use task.grab_config or backup of grab_config
task.setup_grab_config(res['grab_config_backup'])
self.add_task(task)
# TODO: allow to write error handlers
def find_task_handler(self, task):
callback = task.get('callback')
if callback:
return callback
else:
try:
handler = getattr(self, 'task_%s' % task.name)
except AttributeError:
raise NoTaskHandler('No handler or callback defined for '
'task %s' % task.name)
else:
return handler
def process_network_result(self, res, from_cache=False):
"""
Handle result received from network transport of
from the cache layer.
Find handler function for that task and call it.
"""
# Increase stat counters
self.inc_count('request-processed')
self.inc_count('task')
self.inc_count('task-%s' % res['task'].name)
if (res['task'].network_try_count == 1 and
res['task'].task_try_count == 1):
self.inc_count('task-%s-initial' % res['task'].name)
# Update traffic statistics
if res['grab'] and res['grab'].response:
self.timers['network-name-lookup'] += res['grab'].response.name_lookup_time
self.timers['network-connect'] += res['grab'].response.connect_time
self.timers['network-total'] += res['grab'].response.total_time
if not from_cache:
self.inc_count('download-size', res['grab'].response.download_size)
self.inc_count('upload-size', res['grab'].response.upload_size)
self.inc_count('download-size-with-cache', res['grab'].response.download_size)
self.inc_count('upload-size-with-cache', res['grab'].response.upload_size)
#self.inc_count('traffic-in
# NG
# FIX: Understand how it should work in NG spider
# TOFIX: start
stop = False
for mid in self.middleware_points['response']:
try:
mid_response = mid.process_response(self, res)
except StopTaskProcessing:
logger.debug('Got StopTaskProcessing exception')
stop = True
break
else:
if isinstance(mid_response, Task):
logger.debug('Got task from middleware')
self.add_task(mid_response)
stop = True
break
elif mid_response is None:
pass
else:
raise Exception('Unknown response from middleware %s' % mid)
# TOFIX: end
if stop:
return
if self.ng:
logger_verbose.debug('Submitting result for task %s to response'
' queue' % res['task'])
self.network_response_queue.put(res)
else:
handler = self.find_task_handler(res['task'])
self.execute_task_handler(res, handler)
def change_proxy(self, task, grab):
"""
Assign new proxy from proxylist to the task.
"""
if task.use_proxylist and self.proxylist_enabled:
if self.proxy_auto_change:
self.proxy = self.proxylist.get_random()
if self.proxy:
proxy, proxy_userpwd, proxy_type = self.proxy
grab.setup(proxy=proxy, proxy_userpwd=proxy_userpwd,
proxy_type=proxy_type)
def process_new_task(self, task):
"""
Handle new task.
1) Setup Grab object for that task
2) Try to load task from the cache
3) If no cached data then submit task to network transport
"""
grab = self.setup_grab_for_task(task)
grab_config_backup = grab.dump_config()
cache_result = None
if self.is_task_cacheable(task, grab):
with self.save_timer('cache'):
with self.save_timer('cache.read'):
cache_result = self.load_task_from_cache(
self.transport, task, grab, grab_config_backup)
if cache_result:
logger_verbose.debug('Task data is loaded from the cache. '
'Yielding task result.')
self.process_network_result(cache_result, from_cache=True)
self.inc_count('task-%s-cache' % task.name)
else:
if self.only_cache:
logger.debug('Skipping network request to %s' % grab.config['url'])
else:
self.inc_count('request-network')
self.inc_count('task-%s-network' % task.name)
self.change_proxy(task, grab)
with self.save_timer('network_transport'):
logger_verbose.debug('Submitting task to the transport '
'layer')
try:
self.transport.process_task(task, grab, grab_config_backup)
except GrabInvalidUrl as ex:
logger.debug('Task %s has invalid URL: %s' % (
task.name, task.url))
self.add_item('invalid-url', task.url)
else:
logger_verbose.debug('Asking transport layer to do '
'something')
def is_valid_for_cache(self, res):
"""
Check if network transport result could
be saved to cache layer.
res: {ok, grab, grab_config_backup, task, emsg}
"""
if res['ok']:
if self.cache_enabled:
if res['grab'].request_method == 'GET':
if not res['task'].get('disable_cache'):
if self.valid_response_code(res['grab'].response.code,
res['task']):
return True
return False
def stop(self):
"""
This method set internal flag which signal spider
to stop processing new task and shuts down.
"""
logger_verbose.debug('Method `stop` was called')
self.work_allowed = False
def run(self):
"""
Main method. All work is done here.
"""
self.start_timer('total')
self.transport = MulticurlTransport(self.thread_number)
try:
self.setup_default_queue()
self.prepare()
self.start_timer('task_generator')
if not self.slave:
if not self.ng:
self.init_task_generator()
self.stop_timer('task_generator')
while self.work_allowed:
now = int(time.time())
if now - self.last_snapshot_values['timestamp'] > self.snapshot_interval:
snapshot = {'timestamp': now}
for key in ('download-size', 'upload-size',
'download-size-with-cache'):
snapshot[key] = self.counters[key] - self.last_snapshot_values[key]
self.last_snapshot_values[key] = self.counters[key]
snapshot['request-count'] = self.counters['request'] -\
self.last_snapshot_values['request-count']
self.last_snapshot_values['request-count'] = self.counters['request']
self.last_snapshot_values['timestamp'] = now
self.snapshots[now] = snapshot
self.snapshot_timestamps.append(now)
if self.snapshot_file:
with open(self.snapshot_file, 'a') as out:
out.write(json.dumps(snapshot) + '\n')
# FIXIT: REMOVE
# Run update task handler which
# updates database object which stores
# info about current scraping process
if self.dump_spider_stats:
self.dump_spider_stats(self)
if self.controller.enabled:
self.controller.process_commands()
if not self.ng:
# NG
self.start_timer('task_generator')
# star
if self.task_generator_enabled:
self.process_task_generator()
self.stop_timer('task_generator')
if self.transport.ready_for_task():
logger_verbose.debug('Transport has free resources. '
'Trying to add new task (if exists)')
# Try five times to get new task and proces task generator
# because slave parser could agressively consume
# tasks from task queue
for x in xrange(5):
task = self.load_new_task()
if task is None:
if not self.transport.active_task_number():
self.process_task_generator()
elif task is True:
# If only delayed tasks in queue
break
else:
# If got some task
break
if not task:
if not self.transport.active_task_number():
logger_verbose.debug('Network transport has no '
'active tasks')
# NG
if self.ng:
self.waiting_shutdown_event.set()
if self.shutdown_event.is_set():
logger_verbose.debug('Got shutdown signal')
self.stop()
else:
logger_verbose.debug('Shutdown event has'
' not been set yet')
else:
if not self.task_generator_enabled:
self.stop()
else:
logger_verbose.debug('Transport active tasks: %d' %
self.transport.active_task_number())
elif isinstance(task, NullTask):
logger_verbose.debug('Got NullTask')
if not self.transport.active_task_number():
if task.sleep:
logger.debug('Got NullTask with sleep '
'instruction. Sleeping for'
' %.2f seconds' % task.sleep)
time.sleep(task.sleep)
elif isinstance(task, bool) and (task is True):
pass
else:
if self.ng:
if self.waiting_shutdown_event.is_set():
self.waiting_shutdown_event.clear()
logger_verbose.debug('Got new task from task queue: %s'
% task)
self.process_task_counters(task)
is_valid, reason = self.check_task_limits(task)
if not is_valid:
logger_verbose.debug('Task %s is rejected due to '
'%s limit'
% (task.name, reason))
if reason == 'task-try-count':
self.add_item('task-count-rejected', task.url)
elif reason == 'network-try-count':
self.add_item('network-count-rejected', task.url)
else:
raise Exception('Unknown response from '
'check_task_limits: %s'
% reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
# TODO: not do following line
# TODO: middleware: TaskFails
else:
self.process_new_task(task)
self.transport.process_handlers()
with self.save_timer('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Iterate over network trasport ready results
# Each result could be valid or failed
# Result format: {ok, grab, grab_config_backup, task, emsg}
#print '[transport iterate results - start]'
for result in self.transport.iterate_results():
if self.is_valid_for_cache(result):
with self.save_timer('cache'):
with self.save_timer('cache.write'):
self.cache.save_response(result['task'].url,
result['grab'])
#print '[process network results]'
self.process_network_result(result)
#print '[done]'
self.inc_count('request')
#print '[transport iterate results - end]'
logger_verbose.debug('Work done')
except KeyboardInterrupt:
print('\nGot ^C signal. Stopping.')
raise
finally:
# This code is executed when main cycles is breaked
self.stop_timer('total')
self.shutdown()
def load_proxylist(self, source, source_type, proxy_type='http',
auto_init=True, auto_change=True,
**kwargs):
self.proxylist = ProxyList(source, source_type, proxy_type=proxy_type,
**kwargs)
self.proxylist_enabled = True
self.proxy = None
if not auto_change and auto_init:
self.proxy = self.proxylist.get_random()
self.proxy_auto_change = auto_change
def get_name(self):
if hasattr(self, 'spider_name'):
return self.spider_name
else:
return camel_case_to_underscore(self.__class__.__name__)
# ****************
# Abstract methods
# ****************
def shutdown(self):
"""
You can override this method to do some final actions
after parsing has been done.
"""
logger.debug('Job done!')
def task_generator(self):
"""
You can override this method to load new tasks smoothly.
It will be used each time as number of tasks
in task queue is less then number of threads multiplied on 2
This allows you to not overload all free memory if total number of
tasks is big.
"""
if False:
# Some magic to make this function empty generator
yield ':-)'
return
def process_handler_result(self, result, task=None):
"""
Process result received from the task handler.
Result could be:
* None
* Task instance
* Data instance.
"""
if isinstance(result, Task):
self.add_task(result)
elif isinstance(result, Data):
handler = self.find_data_handler(result)
try:
data_result = handler(**result.storage)
if data_result is None:
pass
else:
for something in data_result:
self.process_handler_result(something, task)
except Exception as ex:
self.process_handler_error('data_%s' % result.handler_key, ex,
task)
elif result is None:
pass
else:
raise SpiderError('Unknown result type: %s' % result)
@classmethod
def get_spider_name(cls):
if hasattr(cls, 'spider_name'):
return cls.spider_name
else:
return camel_case_to_underscore(cls.__name__)
@classmethod
def setup_spider_config(cls, config):
pass
# ***********
# NG Features
# ***********
def run_generator(self):
"""
Generate tasks and put them into Task Queue.
This is main method for Generator Process
"""
self.init_task_generator()
while True:
if not self.task_generator_enabled:
self.generator_done_event.set()
if self.shutdown_event.is_set():
logger.info('Got shutdown event')
break
time.sleep(1)
self.process_task_generator()
def run_parser(self):
"""
Process items received from Network Response Queue.
Network Response Queue are filled by Downloader Process.
This is main method for Parser Process.
"""
should_work = True
while should_work:
try:
response = self.network_response_queue.get(True, 0.1)
except queue.Empty:
logger_verbose.debug('Response queue is empty.')
response = None
if not response:
self.waiting_shutdown_event.set()
if self.shutdown_event.is_set():
logger_verbose.debug('Got shutdown signal')
should_work = False
else:
logger_verbose.debug('Shutdown event has not been set yet')
else:
if self.waiting_shutdown_event.is_set():
self.waiting_shutdown_event.clear()
logger_verbose.debug('Got new response from response '
'queue: %s' % response['task'].url)
handler = self.find_task_handler(response['task'])
self.execute_task_handler(response, handler)
logger_verbose.debug('Work done')
# TODO:
# Develop Manager Process which contains logic of accepting or rejecting
# task objects received from Parser Processes
# Maybe Manager Process also should controls the Data flow
# TODO2:
# Data handler process
#def run_manager(self):
#try:
#self.start_time = time.time()
#self.prepare()
#res_count = 0
#while True:
#try:
#res = self.result_queue.get(block=True, timeout=2)
#except Queue.Empty:
##pass
#res = None
#if res is None:
#logging.error('res is None: stopping')
#break
#if self.should_stop:
#break
#if self.task_generator_enabled:
#self.process_task_generator()
#for task, original_task in res['task_list']:
#logging.debug('Processing task items from result queue')
#self.process_handler_result(task)
##for data, original_task in res['data_list']:
##logging.debug('Processing data items from result queue')
##self.process_handler_result(data)
#except KeyboardInterrupt:
#print '\nGot ^C signal. Stopping.'
#print self.render_stats()
#raise
#finally:
## This code is executed when main cycles is breaked
#self.shutdown()
def command_get_stats(self, command):
return {'data': self.render_stats()}
@classmethod
def get_available_command_names(cls):
spider = cls()
clist = []
for key in dir(spider):
if key.startswith('command_'):
clist.append(key.split('command_', 1)[1])
return sorted(clist)
class Spider(object):
"""
Asynchronous scraping framework.
"""
# You can define here some urls and initial tasks
# with name "initial" will be created from these
# urls
# If the logic of generating initial tasks is complex
# then consider to use `task_generator` method instead of
# `initial_urls` attribute
initial_urls = None
# The base url which is used to resolve all relative urls
# The resolving takes place in `add_task` method
base_url = None
class Meta:
# Meta.abstract means that this class will not be
# collected to spider registry by `grab crawl` CLI command.
# The Meta is inherited by descendant classes BUT
# Meta.abstract is reset to False in each descendant
abstract = True
# *************
# Class Methods
# *************
@classmethod
def setup_spider_config(cls, config):
pass
@classmethod
def get_spider_name(cls):
if hasattr(cls, "spider_name"):
return cls.spider_name
else:
return camel_case_to_underscore(cls.__name__)
# **************
# Public Methods
# **************
def __init__(
self,
thread_number=None,
network_try_limit=None,
task_try_limit=None,
request_pause=NULL,
priority_mode="random",
meta=None,
only_cache=False,
config=None,
slave=None,
max_task_generator_chunk=None,
args=None,
# New options start here
taskq=None,
# MP:
network_result_queue=None,
parser_result_queue=None,
waiting_shutdown_event=None,
shutdown_event=None,
mp_mode=False,
parser_pool_size=None,
parser_mode=False,
parser_requests_per_process=10000,
# http api
http_api_port=None,
):
"""
Arguments:
* thread-number - Number of concurrent network streams
* network_try_limit - How many times try to send request
again if network error was occurred, use 0 to disable
* network_try_limit - Limit of tries to execute some task
this is not the same as network_try_limit
network try limit limits the number of tries which
are performed automatically in case of network timeout
of some other physical error
but task_try_limit limits the number of attempts which
are scheduled manually in the spider business logic
* priority_mode - could be "random" or "const"
* meta - arbitrary user data
* retry_rebuild_user_agent - generate new random user-agent for each
network request which is performed again due to network error
* args - command line arguments parsed with `setup_arg_parser` method
New options:
* taskq=None,
* newtork_response_queue=None,
"""
if slave is not None:
raise SpiderConfigurtionError(
"Slave mode is not supported anymore. "
"Use `mp_mode=True` option to run multiple HTML"
" parser processes."
)
# API:
self.http_api_port = http_api_port
# MP:
self.mp_mode = mp_mode
if self.mp_mode:
from multiprocessing import Process, Event, Queue
else:
from multiprocessing.dummy import Process, Event, Queue
if network_result_queue is not None:
self.network_result_queue = network_result_queue
else:
self.network_result_queue = Queue()
self.parser_result_queue = parser_result_queue
self.waiting_shutdown_event = waiting_shutdown_event
if shutdown_event is not None:
self.shutdown_event = shutdown_event
else:
self.shutdown_event = Event()
if not self.mp_mode and parser_pool_size and parser_pool_size > 1:
raise SpiderConfigurationError("Parser pool size could be only 1 in " "non-multiprocess mode")
self.parser_pool_size = parser_pool_size
self.parser_mode = parser_mode
self.parser_requests_per_process = parser_requests_per_process
self.stat = Stat()
self.timer = Timer()
self.task_queue = taskq
if args is None:
self.args = {}
else:
self.args = args
self.max_task_generator_chunk = max_task_generator_chunk
self.timer.start("total")
if config is not None:
self.config = config
else:
self.config = {}
if meta:
self.meta = meta
else:
self.meta = {}
self.task_generator_enabled = False
self.only_cache = only_cache
self.thread_number = thread_number or int(self.config.get("thread_number", DEFAULT_NETWORK_STREAM_NUMBER))
self.task_try_limit = task_try_limit or int(self.config.get("task_try_limit", DEFAULT_TASK_TRY_LIMIT))
self.network_try_limit = network_try_limit or int(
self.config.get("network_try_limit", DEFAULT_NETWORK_TRY_LIMIT)
)
self._grab_config = {}
if priority_mode not in ["random", "const"]:
raise SpiderMisuseError("Value of priority_mode option should be " '"random" or "const"')
else:
self.priority_mode = priority_mode
# Initial cache-subsystem values
self.cache_enabled = False
self.cache = None
self.work_allowed = True
if request_pause is not NULL:
logger.error("Option `request_pause` is deprecated and is not " "supported anymore")
self.proxylist_enabled = None
self.proxylist = None
self.proxy = None
self.proxy_auto_change = False
self.interrupted = False
def setup_cache(self, backend="mongo", database=None, use_compression=True, **kwargs):
if database is None:
raise SpiderMisuseError("setup_cache method requires database " "option")
self.cache_enabled = True
mod = __import__("grab.spider.cache_backend.%s" % backend, globals(), locals(), ["foo"])
self.cache = mod.CacheBackend(database=database, use_compression=use_compression, spider=self, **kwargs)
def setup_queue(self, backend="memory", **kwargs):
logger.debug("Using %s backend for task queue" % backend)
mod = __import__("grab.spider.queue_backend.%s" % backend, globals(), locals(), ["foo"])
self.task_queue = mod.QueueBackend(spider_name=self.get_spider_name(), **kwargs)
def add_task(self, task, raise_error=False):
"""
Add task to the task queue.
"""
# MP:
# ***
if self.parser_mode:
self.parser_result_queue.put((task, None))
return
if self.task_queue is None:
raise SpiderMisuseError("You should configure task queue before " "adding tasks. Use `setup_queue` method.")
if task.priority is None or not task.priority_is_custom:
task.priority = self.generate_task_priority()
task.priority_is_custom = False
else:
task.priority_is_custom = True
try:
if not task.url.startswith(("http://", "https://", "ftp://", "file://", "feed://")):
if self.base_url is None:
msg = "Could not resolve relative URL because base_url " "is not specified. Task: %s, URL: %s" % (
task.name,
task.url,
)
raise SpiderError(msg)
else:
task.url = urljoin(self.base_url, task.url)
# If task has grab_config object then update it too
if task.grab_config:
task.grab_config["url"] = task.url
except Exception as ex:
self.stat.collect("task-with-invalid-url", task.url)
if raise_error:
raise
else:
logger.error("", exc_info=ex)
return False
# TODO: keep original task priority if it was set explicitly
self.task_queue.put(task, task.priority, schedule_time=task.schedule_time)
return True
def stop(self):
"""
This method set internal flag which signal spider
to stop processing new task and shuts down.
"""
logger_verbose.debug("Method `stop` was called")
self.work_allowed = False
def load_proxylist(self, source, source_type=None, proxy_type="http", auto_init=True, auto_change=True, **kwargs):
self.proxylist = ProxyList()
if isinstance(source, BaseProxySource):
self.proxylist.set_source(source)
elif isinstance(source, six.string_types):
if source_type == "text_file":
self.proxylist.load_file(source, proxy_type=proxy_type)
elif source_type == "url":
self.proxylist.load_url(source, proxy_type=proxy_type)
else:
raise SpiderMisuseError(
"Method `load_proxylist` received " "invalid `source_type` argument: %s" % source_type
)
else:
raise SpiderMisuseError("Method `load_proxylist` received " "invalid `source` argument: %s" % source)
self.proxylist_enabled = True
self.proxy = None
if not auto_change and auto_init:
self.proxy = self.proxylist.get_random_proxy()
self.proxy_auto_change = auto_change
def process_next_page(self, grab, task, xpath, resolve_base=False, **kwargs):
"""
Generate task for next page.
:param grab: Grab instance
:param task: Task object which should be assigned to next page url
:param xpath: xpath expression which calculates list of URLS
:param **kwargs: extra settings for new task object
Example::
self.follow_links(grab, 'topic', '//div[@class="topic"]/a/@href')
"""
try:
# next_url = grab.xpath_text(xpath)
next_url = grab.doc.select(xpath).text()
except IndexError:
return False
else:
url = grab.make_url_absolute(next_url, resolve_base=resolve_base)
page = task.get("page", 1) + 1
grab2 = grab.clone()
grab2.setup(url=url)
task2 = task.clone(task_try_count=1, grab=grab2, page=page, **kwargs)
self.add_task(task2)
return True
def render_stats(self, timing=True):
out = ["------------ Stats: ------------"]
out.append("Counters:")
# Process counters
items = sorted(self.stat.counters.items(), key=lambda x: x[0], reverse=True)
for item in items:
out.append(" %s: %s" % item)
out.append("")
out.append("Lists:")
# Process collections sorted by size desc
col_sizes = [(x, len(y)) for x, y in self.stat.collections.items()]
col_sizes = sorted(col_sizes, key=lambda x: x[1], reverse=True)
for col_size in col_sizes:
out.append(" %s: %d" % col_size)
out.append("")
# Process extra metrics
if "download-size" in self.stat.counters:
out.append("Network download: %s" % metric.format_traffic_value(self.stat.counters["download-size"]))
out.append("Queue size: %d" % self.task_queue.size() if self.task_queue else "NA")
out.append("Network streams: %d" % self.thread_number)
if timing:
out.append("")
out.append(self.render_timing())
return "\n".join(out) + "\n"
def render_timing(self):
out = ["Timers:"]
out.append(" DOM: %.3f" % GLOBAL_STATE["dom_build_time"])
time_items = [(x, y) for x, y in self.timer.timers.items()]
time_items = sorted(time_items, key=lambda x: x[1])
for time_item in time_items:
out.append(" %s: %.03f" % time_item)
return "\n".join(out) + "\n"
# ********************************
# Methods for spider customization
# ********************************
def prepare(self):
"""
You can do additional spider customization here
before it has started working. Simply redefine
this method in your Spider class.
"""
def prepare_parser(self):
"""
You can do additional spider customization here
before it has started working. Simply redefine
this method in your Spider class.
This method is called only from Spider working in parser mode
that, in turn, is spawned automatically by main spider proces
working in multiprocess mode.
"""
def shutdown(self):
"""
You can override this method to do some final actions
after parsing has been done.
"""
pass
def update_grab_instance(self, grab):
"""
Use this method to automatically update config of any
`Grab` instance created by the spider.
"""
pass
def create_grab_instance(self, **kwargs):
# Back-ward compatibility for deprecated `grab_config` attribute
# Here I use `_grab_config` to not trigger warning messages
if self._grab_config and kwargs:
merged_config = deepcopy(self._grab_config)
merged_config.update(kwargs)
grab = Grab(**merged_config)
elif self._grab_config and not kwargs:
grab = Grab(**self._grab_config)
else:
grab = Grab(**kwargs)
return grab
def task_generator(self):
"""
You can override this method to load new tasks smoothly.
It will be used each time as number of tasks
in task queue is less then number of threads multiplied on 2
This allows you to not overload all free memory if total number of
tasks is big.
"""
if False:
# Some magic to make this function empty generator
yield ":-)"
return
# ***************
# Private Methods
# ***************
def check_task_limits(self, task):
"""
Check that task's network & try counters do not exceed limits.
Returns:
* if success: (True, None)
* if error: (False, reason)
"""
if task.task_try_count > self.task_try_limit:
logger.debug("Task tries (%d) ended: %s / %s" % (self.task_try_limit, task.name, task.url))
return False, "task-try-count"
if task.network_try_count > self.network_try_limit:
logger.debug("Network tries (%d) ended: %s / %s" % (self.network_try_limit, task.name, task.url))
return False, "network-try-count"
return True, None
def generate_task_priority(self):
if self.priority_mode == "const":
return DEFAULT_TASK_PRIORITY
else:
return randint(*RANDOM_TASK_PRIORITY_RANGE)
def process_task_generator(self):
"""
Load new tasks from `self.task_generator_object`
Create new tasks.
If task queue size is less than some value
then load new tasks from tasks file.
"""
if self.task_generator_enabled:
queue_size = self.task_queue.size()
if self.max_task_generator_chunk is not None:
min_limit = min(self.max_task_generator_chunk, self.thread_number * 10)
else:
min_limit = self.thread_number * 10
if queue_size < min_limit:
logger_verbose.debug(
"Task queue contains less tasks (%d) than "
"allowed limit (%d). Trying to add "
"new tasks." % (queue_size, min_limit)
)
try:
for x in six.moves.range(min_limit - queue_size):
item = next(self.task_generator_object)
logger_verbose.debug("Got new item from generator. " "Processing it.")
self.process_handler_result(item)
except StopIteration:
# If generator have no values to yield
# then disable it
logger_verbose.debug("Task generator has no more tasks. " "Disabling it")
self.task_generator_enabled = False
def start_task_generator(self):
"""
Process `self.initial_urls` list and `self.task_generator`
method. Generate first portion of tasks.
"""
logger_verbose.debug("Processing initial urls")
if self.initial_urls:
for url in self.initial_urls:
self.add_task(Task("initial", url=url))
self.task_generator_object = self.task_generator()
self.task_generator_enabled = True
# Initial call to task generator before spider has started working
self.process_task_generator()
def get_task_from_queue(self):
start = time.time()
try:
with self.timer.log_time("task_queue"):
return self.task_queue.get()
except queue.Empty:
size = self.task_queue.size()
if size:
logger_verbose.debug("No ready-to-go tasks, Waiting for " "scheduled tasks (%d)" % size)
return True
else:
logger_verbose.debug("Task queue is empty.")
return None
def setup_grab_for_task(self, task):
grab = self.create_grab_instance()
if task.grab_config:
grab.load_config(task.grab_config)
else:
grab.setup(url=task.url)
# Generate new common headers
grab.config["common_headers"] = grab.common_headers()
self.update_grab_instance(grab)
return grab
def is_task_cacheable(self, task, grab):
if ( # cache is disabled for all tasks
not self.cache_enabled
# cache data should be refreshed
or task.get("refresh_cache", False)
# cache could not be used
or task.get("disable_cache", False)
# request type is not cacheable
or grab.detect_request_method() != "GET"
):
return False
else:
return True
def load_task_from_cache(self, task, grab, grab_config_backup):
with self.timer.log_time("cache"):
with self.timer.log_time("cache.read"):
cache_item = self.cache.get_item(grab.config["url"], timeout=task.cache_timeout)
if cache_item is None:
return None
else:
with self.timer.log_time("cache.read.prepare_request"):
grab.prepare_request()
with self.timer.log_time("cache.read.load_response"):
self.cache.load_response(grab, cache_item)
grab.log_request("CACHED")
self.stat.inc("spider:request-cache")
return {
"ok": True,
"grab": grab,
"grab_config_backup": grab_config_backup,
"task": task,
"emsg": None,
}
def is_valid_network_response_code(self, code, task):
"""
Answer the question: if the response could be handled via
usual task handler or the task faield and should be processed as error.
"""
return code < 400 or code == 404 or code in task.valid_status
def process_handler_error(self, func_name, ex, task):
self.stat.inc("spider:error-%s" % ex.__class__.__name__.lower())
if hasattr(ex, "tb"):
logger.error("Error in %s function" % func_name)
logger.error(ex.tb)
else:
logger.error("Error in %s function" % func_name, exc_info=ex)
# Looks strange but I really have some problems with
# serializing exception into string
try:
ex_str = six.text_type(ex)
except TypeError:
try:
ex_str = ex.decode("utf-8", "ignore")
except TypeError:
ex_str = str(ex)
task_url = task.url if task is not None else None
self.stat.collect("fatal", "%s|%s|%s|%s" % (func_name, ex.__class__.__name__, ex_str, task_url))
if isinstance(ex, FatalError):
# raise FatalError()
# six.reraise(FatalError, ex)
# logger.error(ex.tb)
raise ex
def find_data_handler(self, data):
try:
return getattr(data, "handler")
except AttributeError:
try:
handler = getattr(self, "data_%s" % data.handler_key)
except AttributeError:
raise NoDataHandler("No handler defined for Data %s" % data.handler_key)
else:
return handler
def is_valid_network_result(self, res):
if res["task"].get("raw"):
return True
if res["ok"]:
res_code = res["grab"].response.code
if self.is_valid_network_response_code(res_code, res["task"]):
return True
return False
def run_parser(self):
"""
Main work cycle of spider process working in parser-mode.
"""
# Use Stat instance that does not print any logging messages
if self.parser_mode:
self.stat = Stat(logging_period=None)
self.prepare_parser()
process_request_count = 0
try:
recent_task_time = time.time()
while True:
try:
result = self.network_result_queue.get(True, 0.1)
except queue.Empty:
logger_verbose.debug("Network result queue is empty")
# Set `waiting_shutdown_event` only after 1 seconds
# of waiting for tasks to avoid
# race-condition issues
if time.time() - recent_task_time > 1:
self.waiting_shutdown_event.set()
if self.shutdown_event.is_set():
logger_verbose.debug("Got shutdown event")
return
else:
process_request_count += 1
recent_task_time = time.time()
if self.parser_mode:
self.stat.reset()
if self.waiting_shutdown_event.is_set():
self.waiting_shutdown_event.clear()
try:
handler = self.find_task_handler(result["task"])
except NoTaskHandler as ex:
ex.tb = format_exc()
self.parser_result_queue.put((ex, result["task"]))
self.stat.inc("parser:handler-not-found")
else:
self.process_network_result_with_handler_mp(result, handler)
self.stat.inc("parser:handler-processed")
finally:
if self.parser_mode:
data = {
"type": "stat",
"counters": self.stat.counters,
"collections": self.stat.collections,
}
self.parser_result_queue.put((data, result["task"]))
if self.parser_mode:
if self.parser_requests_per_process:
if process_request_count >= self.parser_requests_per_process:
break
except Exception as ex:
logging.error("", exc_info=ex)
raise
finally:
self.waiting_shutdown_event.set()
def process_network_result_with_handler_mp(self, result, handler):
"""
This is like `process_network_result_with_handler` but
for multiprocessing version
"""
handler_name = getattr(handler, "__name__", "NONE")
try:
with self.timer.log_time("response_handler"):
with self.timer.log_time("response_handler.%s" % handler_name):
handler_result = handler(result["grab"], result["task"])
if handler_result is None:
pass
else:
for something in handler_result:
self.parser_result_queue.put((something, result["task"]))
except NoDataHandler as ex:
ex.tb = format_exc()
self.parser_result_queue.put((ex, result["task"]))
except Exception as ex:
ex.tb = format_exc()
self.parser_result_queue.put((ex, result["task"]))
def find_task_handler(self, task):
if task.origin_task_generator is not None:
return self.handler_for_inline_task
callback = task.get("callback")
if callback:
return callback
else:
try:
handler = getattr(self, "task_%s" % task.name)
except AttributeError:
raise NoTaskHandler("No handler or callback defined for " "task %s" % task.name)
else:
return handler
def handler_for_inline_task(self, grab, task):
# It can be subroutine for the first call,
# So we should check it
if isinstance(task, types.GeneratorType):
coroutines_stack = []
sendval = None
origin_task_generator = task
target = origin_task_generator
else:
coroutines_stack = task.coroutines_stack
sendval = grab
origin_task_generator = task.origin_task_generator
target = origin_task_generator
while True:
try:
result = target.send(sendval)
# If it is subroutine we have to initialize it and
# save coroutine in the coroutines stack
if isinstance(result, types.GeneratorType):
coroutines_stack.append(target)
sendval = None
target = result
origin_task_generator = target
else:
new_task = result
new_task.origin_task_generator = origin_task_generator
new_task.coroutines_stack = coroutines_stack
self.add_task(new_task)
return
except StopIteration:
# If coroutine is over we should check coroutines stack,
# may be it is subroutine
if coroutines_stack:
target = coroutines_stack.pop()
origin_task_generator = target
else:
return
def log_network_result_stats(self, res, from_cache=False):
# Increase stat counters
self.stat.inc("spider:request-processed")
self.stat.inc("spider:task")
self.stat.inc("spider:task-%s" % res["task"].name)
if res["task"].network_try_count == 1 and res["task"].task_try_count == 1:
self.stat.inc("spider:task-%s-initial" % res["task"].name)
# Update traffic statistics
if res["grab"] and res["grab"].response:
resp = res["grab"].response
self.timer.inc_timer("network-name-lookup", resp.name_lookup_time)
self.timer.inc_timer("network-connect", resp.connect_time)
self.timer.inc_timer("network-total", resp.total_time)
if from_cache:
self.stat.inc("spider:download-size-with-cache", resp.download_size)
self.stat.inc("spider:upload-size-with-cache", resp.upload_size)
else:
self.stat.inc("spider:download-size", resp.download_size)
self.stat.inc("spider:upload-size", resp.upload_size)
def process_grab_proxy(self, task, grab):
"Assign new proxy from proxylist to the task"
if task.use_proxylist:
if self.proxylist_enabled:
# Need this to work around
# pycurl feature/bug:
# pycurl instance uses previously connected proxy server
# even if `proxy` options is set with another proxy server
grab.setup(connection_reuse=False)
if self.proxy_auto_change:
self.proxy = self.change_proxy(task, grab)
def change_proxy(self, task, grab):
proxy = self.proxylist.get_random_proxy()
grab.setup(proxy=proxy.get_address(), proxy_userpwd=proxy.get_userpwd(), proxy_type=proxy.proxy_type)
return proxy
def submit_task_to_transport(self, task, grab, grab_config_backup):
self.stat.inc("spider:request-network")
self.stat.inc("spider:task-%s-network" % task.name)
with self.timer.log_time("network_transport"):
logger_verbose.debug("Submitting task to the transport " "layer")
try:
self.transport.start_task_processing(task, grab, grab_config_backup)
except GrabInvalidUrl:
logger.debug("Task %s has invalid URL: %s" % (task.name, task.url))
self.stat.collect("invalid-url", task.url)
def is_valid_for_cache(self, res):
"""
Check if network transport result could
be saved to cache layer.
res: {ok, grab, grab_config_backup, task, emsg}
"""
if res["ok"]:
if self.cache_enabled:
if res["grab"].request_method == "GET":
if not res["task"].get("disable_cache"):
if self.is_valid_network_response_code(res["grab"].response.code, res["task"]):
return True
return False
def start_api_thread(self):
from grab.spider.http_api import HttpApiThread
proc = HttpApiThread(self)
proc.start()
return proc
def is_ready_to_shutdown(self):
# Things should be true to shutdown spider
# 1) No active network connections
# 2) Network result queue is empty
# 3) Task queue is empty
# 4) Parser pipeline is ready to shutdown
# 5) Task generator has completed
return (
self.parser_pipeline.is_waiting_shutdown()
and not self.task_generator_enabled
and not self.transport.get_active_threads_number()
and not self.task_queue.size()
and not self.network_result_queue.qsize()
)
def run(self):
"""
Main method. All work is done here.
"""
if self.mp_mode:
from multiprocessing import Process, Event, Queue
else:
from multiprocessing.dummy import Process, Event, Queue
self.timer.start("total")
self.transport = MulticurlTransport(self.thread_number)
if self.http_api_port:
http_api_proc = self.start_api_thread()
else:
http_api_proc = None
self.parser_pipeline = ParserPipeline(
bot=self,
mp_mode=self.mp_mode,
pool_size=self.parser_pool_size,
shutdown_event=self.shutdown_event,
network_result_queue=self.network_result_queue,
requests_per_process=self.parser_requests_per_process,
)
network_result_queue_limit = max(10, self.thread_number * 2)
try:
# Run custom things defined by this specific spider
# By defaut it does nothing
self.prepare()
# Setup task queue if it has not been configured yet
if self.task_queue is None:
self.setup_queue()
# Initiate task generator. Only in main process!
with self.timer.log_time("task_generator"):
self.start_task_generator()
while self.work_allowed:
with self.timer.log_time("task_generator"):
if self.task_generator_enabled:
self.process_task_generator()
result_from_cache = None
free_threads = self.transport.get_free_threads_number()
# Load new task only if self.network_result_queue is not full
if self.transport.get_free_threads_number() and (
self.network_result_queue.qsize() < network_result_queue_limit
):
logger_verbose.debug(
"Transport and parser have free resources. " "Trying to load new task from task queue."
)
task = self.get_task_from_queue()
# If no task received from task queue
# try to query task generator
# and then check if spider could be shuted down
if task is None:
if not self.transport.get_active_threads_number():
self.process_task_generator()
if task is None:
# If no task received from task queue
# check if spider could be shut down
if self.is_ready_to_shutdown():
self.shutdown_event.set()
self.stop()
break # Break `if self.work_allowed` cycle
elif isinstance(task, bool) and (task is True):
# Take some sleep to not load CPU
if not self.transport.get_active_threads_number():
time.sleep(0.1)
else:
logger_verbose.debug("Got new task from task queue: %s" % task)
task.network_try_count += 1
is_valid, reason = self.check_task_limits(task)
if is_valid:
grab = self.setup_grab_for_task(task)
grab_config_backup = grab.dump_config()
result_from_cache = None
if self.is_task_cacheable(task, grab):
result_from_cache = self.load_task_from_cache(task, grab, grab_config_backup)
if result_from_cache:
logger_verbose.debug("Task data is loaded from the cache. ")
else:
if self.only_cache:
logger.debug("Skipping network request to " "%s" % grab.config["url"])
else:
self.process_grab_proxy(task, grab)
self.submit_task_to_transport(task, grab, grab_config_backup)
else:
self.log_rejected_task(task, reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
with self.timer.log_time("network_transport"):
logger_verbose.debug("Asking transport layer to do " "something")
self.transport.process_handlers()
logger_verbose.debug("Processing network results (if any).")
# Collect completed network results
# Each result could be valid or failed
# Result is dict {ok, grab, grab_config_backup, task, emsg}
results = [(x, False) for x in self.transport.iterate_results()]
if result_from_cache:
results.append((result_from_cache, True))
# Some sleep to avoid thousands of iterations per second.
# If no results from network transport
if not results:
# If task queue is empty (or if there are only
# delayed tasks)
if task is None or bool(task) == True:
# If no network activity
if not self.transport.get_active_threads_number():
# If parser result queue is empty
if not self.parser_pipeline.has_results():
# Just sleep some time, do not kill CPU
time.sleep(0.1)
for result, from_cache in results:
if not from_cache:
if self.is_valid_for_cache(result):
with self.timer.log_time("cache"):
with self.timer.log_time("cache.write"):
self.cache.save_response(result["task"].url, result["grab"])
self.log_network_result_stats(result, from_cache=from_cache)
if self.is_valid_network_result(result):
# handler = self.find_task_handler(result['task'])
# self.process_network_result_with_handler(
# result, handler)
# MP:
# ***
self.network_result_queue.put(result)
else:
self.log_failed_network_result(result)
# Try to do network request one more time
if self.network_try_limit > 0:
result["task"].refresh_cache = True
result["task"].setup_grab_config(result["grab_config_backup"])
self.add_task(result["task"])
if from_cache:
self.stat.inc("spider:task-%s-cache" % task.name)
self.stat.inc("spider:request")
# MP:
# ***
while True:
try:
p_res, p_task = self.parser_pipeline.get_result()
except queue.Empty:
break
else:
self.stat.inc("spider:parser-result")
self.process_handler_result(p_res, p_task)
if not self.shutdown_event.is_set():
self.parser_pipeline.check_pool_health()
logger_verbose.debug("Work done")
except KeyboardInterrupt:
logger.info("\nGot ^C signal in process %d. Stopping." % os.getpid())
self.interrupted = True
raise
finally:
# This code is executed when main cycles is breaked
self.timer.stop("total")
self.stat.print_progress_line()
self.shutdown()
# Stop HTTP API process
if http_api_proc:
http_api_proc.server.shutdown()
http_api_proc.join()
self.task_queue.clear()
# Stop parser processes
self.shutdown_event.set()
self.parser_pipeline.shutdown()
logger.debug("Main process [pid=%s]: work done" % os.getpid())
def log_failed_network_result(self, res):
# Log the error
if res["ok"]:
msg = "http-%s" % res["grab"].response.code
else:
msg = res["error_abbr"]
self.stat.inc("error:%s" % msg)
# logger.error(u'Network error: %s' % msg)#%
# make_unicode(msg, errors='ignore'))
def log_rejected_task(self, task, reason):
logger_verbose.debug("Task %s is rejected due to " "%s limit" % (task.name, reason))
if reason == "task-try-count":
self.stat.collect("task-count-rejected", task.url)
elif reason == "network-try-count":
self.stat.collect("network-count-rejected", task.url)
else:
raise SpiderError("Unknown response from " "check_task_limits: %s" % reason)
def process_handler_result(self, result, task=None):
"""
Process result received from the task handler.
Result could be:
* None
* Task instance
* Data instance.
"""
if isinstance(result, Task):
self.add_task(result)
elif isinstance(result, Data):
handler = self.find_data_handler(result)
try:
data_result = handler(**result.storage)
if data_result is None:
pass
else:
for something in data_result:
self.process_handler_result(something, task)
except Exception as ex:
self.process_handler_error("data_%s" % result.handler_key, ex, task)
elif result is None:
pass
elif isinstance(result, Exception):
handler = self.find_task_handler(task)
handler_name = getattr(handler, "__name__", "NONE")
self.process_handler_error(handler_name, result, task)
elif isinstance(result, dict):
if result.get("type") == "stat":
for name, count in result["counters"].items():
self.stat.inc(name, count)
for name, items in result["collections"].items():
for item in items:
self.stat.collect(name, item)
else:
raise SpiderError("Unknown result type: %s" % result)
else:
raise SpiderError("Unknown result type: %s" % result)
# ******************
# Deprecated Methods
# ******************
def add_item(self, list_name, item):
logger.debug("Method `Spider::add_item` is deprecated. " "Use `Spider::stat.collect` method instead.")
self.stat.collect(list_name, item)
def inc_count(self, key, count=1):
logger.debug("Method `Spider::inc_count` is deprecated. " "Use `Spider::stat.inc` method instead.")
self.stat.inc(key, count)
def start_timer(self, key):
logger.debug("Method `Spider::start_timer` is deprecated. " "Use `Spider::timer.start` method instead.")
self.timer.start(key)
def stop_timer(self, key):
logger.debug("Method `Spider::stop_timer` is deprecated. " "Use `Spider::timer.stop` method instead.")
self.timer.stop(key)
@property
def items(self):
logger.debug("Attribute `Spider::items` is deprecated. " "Use `Spider::stat.collections` attribute instead.")
return self.stat.collections
@property
def counters(self):
logger.debug("Attribute `Spider::counters` is deprecated. " "Use `Spider::stat.counters` attribute instead.")
return self.stat.counters
@contextmanager
def save_timer(self, key):
logger.debug("Method `Spider::save_timer` is deprecated. " "Use `Spider::timer.log_time` method instead.")
self.timer.start(key)
try:
yield
finally:
self.timer.stop(key)
def get_grab_config(self):
logger.error("Using `grab_config` attribute is deprecated. Override " "`create_grab_instance method instead.")
return self._grab_config
def set_grab_config(self, val):
logger.error("Using `grab_config` attribute is deprecated. Override " "`create_grab_instance method instead.")
self._grab_config = val
grab_config = property(get_grab_config, set_grab_config)
def setup_grab(self, **kwargs):
logger.error(
"Method `Spider::setup_grab` is deprecated. "
"Define `Spider::create_grab_instance` or "
"Spider::update_grab_instance` methods in your "
"Spider sub-class."
)
self.grab_config.update(**kwargs)
def valid_response_code(self, code, task):
logger.error(
"Method `Spider::valid_response_code` is deprecated. "
"Use `Spider::is_valid_network_response_code` method or "
"`Spider::is_valid_network_result` method."
)
return self.is_valid_network_response_code(code, task)
@property
def taskq(self):
logger.error("Attribute `Spider::taskq` is deprecated. " "Use `Spider::task_queue` attribute.")
return self.task_queue
def run(self):
"""
Main method. All work is done here.
"""
if self.mp_mode:
from multiprocessing import Process, Event, Queue
else:
from multiprocessing.dummy import Process, Event, Queue
self.timer.start('total')
if self.transport_name == 'multicurl':
self.transport = MulticurlTransport(self, self.thread_number)
elif self.transport_name == 'threaded':
self.transport = ThreadedTransport(self, self.thread_number)
if self.http_api_port:
http_api_proc = self.start_api_thread()
else:
http_api_proc = None
self.parser_result_queue = Queue()
self.parser_pipeline = ParserPipeline(
bot=self,
mp_mode=self.mp_mode,
pool_size=self.parser_pool_size,
shutdown_event=self.shutdown_event,
network_result_queue=self.network_result_queue,
parser_result_queue=self.parser_result_queue,
requests_per_process=self.parser_requests_per_process,
)
network_result_queue_limit = max(10, self.thread_number * 2)
try:
# Run custom things defined by this specific spider
# By defaut it does nothing
self.prepare()
# Setup task queue if it has not been configured yet
if self.task_queue is None:
self.setup_queue()
# Initiate task generator. Only in main process!
with self.timer.log_time('task_generator'):
self.start_task_generators()
# Work in infinite cycle untill
# `self.work_allowed` flag is True
#shutdown_countdown = 0 # !!!
pending_tasks = deque()
while self.work_allowed:
free_threads = self.transport.get_free_threads_number()
# Load new task only if:
# 1) network transport has free threads
# 2) network result queue is not full
# 3) cache is disabled OR cache has free resources
if (self.transport.get_free_threads_number()
and (self.network_result_queue.qsize()
< network_result_queue_limit)
and (self.cache_pipeline is None
or self.cache_pipeline.has_free_resources())):
if pending_tasks:
task = pending_tasks.popleft()
else:
task = self.get_task_from_queue()
if task is None:
# If received task is None then
# check if spider is ready to be shut down
if not pending_tasks and self.is_ready_to_shutdown():
# I am afraid there is a bug in `is_ready_to_shutdown`
# because it tries to evaluate too many things
# includig things that are being set from other threads,
# so to ensure we are really ready to shutdown I call
# is_ready_to_shutdown a few more times.
# Without this hack some times really rarely times
# the Grab fails to do its job
# A good way to see this bug is to disable this hack
# and run:
# while ./runtest.py -t test.spider_data; do echo "ok"; done;
# And wait a few minutes
really_ready = True
for x in range(10):
if not self.is_ready_to_shutdown():
really_ready = False
break
time.sleep(0.001)
if really_ready:
self.shutdown_event.set()
self.stop()
break # Break from `while self.work_allowed` cycle
elif isinstance(task, bool) and (task is True):
# If received task is True
# and there is no active network threads then
# take some sleep
if not self.transport.get_active_threads_number():
time.sleep(0.01)
else:
logger_verbose.debug('Got new task from task queue: %s'
% task)
task.network_try_count += 1
is_valid, reason = self.check_task_limits(task)
if is_valid:
task_grab = self.setup_grab_for_task(task)
if self.cache_pipeline:
self.cache_pipeline.input_queue.put(
('load', (task, task_grab)),
)
else:
self.submit_task_to_transport(task, task_grab)
else:
self.log_rejected_task(task, reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
with self.timer.log_time('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Collect completed network results
# Each result could be valid or failed
# Result is dict {ok, grab, grab_config_backup, task, emsg}
results = [(x, False) for x in
self.transport.iterate_results()]
if self.cache_pipeline:
while True:
try:
action, result = self.cache_pipeline\
.result_queue.get(False)
except queue.Empty:
break
else:
assert action in ('network_result', 'task')
if action == 'network_result':
results.append((result, True))
elif action == 'task':
task = result
task_grab = self.setup_grab_for_task(task)
if (self.transport.get_free_threads_number()
and (self.network_result_queue.qsize()
< network_result_queue_limit)):
self.submit_task_to_transport(task, task_grab)
else:
pending_tasks.append(task)
# Take sleep to avoid millions of iterations per second.
# 1) If no results from network transport
# 2) If task queue is empty (or if there are only delayed tasks)
# 3) If no network activity
# 4) If parser result queue is empty
if (not results
and (task is None or bool(task) == True)
and not self.transport.get_active_threads_number()
and not self.parser_result_queue.qsize()
and (self.cache_pipeline is None
or (self.cache_pipeline.input_queue.qsize() == 0
and self.cache_pipeline.is_idle()
and self.cache_pipeline.result_queue.qsize() == 0))
):
time.sleep(0.001)
for result, from_cache in results:
if self.cache_pipeline and not from_cache:
if result['ok']:
self.cache_pipeline.input_queue.put(
('save', (result['task'], result['grab']))
)
self.log_network_result_stats(
result, from_cache=from_cache)
is_valid = False
if result['task'].get('raw'):
is_valid = True
elif result['ok']:
res_code = result['grab'].response.code
if self.is_valid_network_response_code(res_code, result['task']):
is_valid = True
if is_valid:
self.network_result_queue.put(result)
else:
self.log_failed_network_result(result)
# Try to do network request one more time
# TODO:
# Implement valid_try_limit
# Use it if request failed not because of network error
# But because of content integrity check
if self.network_try_limit > 0:
result['task'].refresh_cache = True
result['task'].setup_grab_config(
result['grab_config_backup'])
self.add_task(result['task'])
if from_cache:
self.stat.inc('spider:task-%s-cache' % result['task'].name)
self.stat.inc('spider:request')
while True:
try:
p_res, p_task = self.parser_result_queue.get(block=False)
except queue.Empty:
break
else:
self.stat.inc('spider:parser-result')
self.process_handler_result(p_res, p_task)
if not self.shutdown_event.is_set():
self.parser_pipeline.check_pool_health()
logger_verbose.debug('Work done')
except KeyboardInterrupt:
logger.info('\nGot ^C signal in process %d. Stopping.'
% os.getpid())
self.interrupted = True
raise
finally:
# This code is executed when main cycles is breaked
self.timer.stop('total')
self.stat.print_progress_line()
self.shutdown()
# Stop HTTP API process
if http_api_proc:
http_api_proc.server.shutdown()
http_api_proc.join()
if self.task_queue:
self.task_queue.clear()
# Stop parser processes
self.shutdown_event.set()
self.parser_pipeline.shutdown()
logger.debug('Main process [pid=%s]: work done' % os.getpid())
def run(self):
"""
Main method. All work is done here.
"""
self.start_timer('total')
self.transport = MulticurlTransport(self.thread_number)
try:
self.setup_default_queue()
self.prepare()
self.start_timer('task_generator')
if not self.slave:
self.init_task_generator()
self.stop_timer('task_generator')
while self.work_allowed:
self.start_timer('task_generator')
if self.task_generator_enabled:
self.process_task_generator()
self.stop_timer('task_generator')
free_threads = self.transport.get_free_threads_number()
if free_threads:
logger_verbose.debug(
'Transport has free resources (%d). '
'Trying to add new task (if exists).' % free_threads)
# Try five times to get new task and proces task generator
# because slave parser could agressively consume
# tasks from task queue
for x in six.moves.range(5):
task = self.load_new_task()
if task is None:
if not self.transport.active_task_number():
self.process_task_generator()
elif task is True:
# If only delayed tasks in queue
break
else:
# If got some task
break
if not task:
if not self.transport.active_task_number():
logger_verbose.debug('Network transport has no '
'active tasks')
if not self.task_generator_enabled:
self.stop()
else:
logger_verbose.debug(
'Transport active tasks: %d' %
self.transport.active_task_number())
elif isinstance(task, NullTask):
logger_verbose.debug('Got NullTask')
if not self.transport.active_task_number():
if task.sleep:
logger.debug('Got NullTask with sleep '
'instruction. Sleeping for'
' %.2f seconds' % task.sleep)
time.sleep(task.sleep)
elif isinstance(task, bool) and (task is True):
# Take some sleep to not load CPU
if not self.transport.active_task_number():
time.sleep(0.1)
else:
logger_verbose.debug(
'Got new task from task queue: %s' % task)
self.process_task_counters(task)
is_valid, reason = self.check_task_limits(task)
if not is_valid:
logger_verbose.debug('Task %s is rejected due to '
'%s limit' %
(task.name, reason))
if reason == 'task-try-count':
self.add_item('task-count-rejected', task.url)
elif reason == 'network-try-count':
self.add_item('network-count-rejected',
task.url)
else:
raise SpiderError('Unknown response from '
'check_task_limits: %s' %
reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
else:
self.process_new_task(task)
self.transport.process_handlers()
with self.save_timer('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Iterate over network trasport ready results
# Each result could be valid or failed
# Result format: {ok, grab, grab_config_backup, task, emsg}
# print '[transport iterate results - start]'
for result in self.transport.iterate_results():
if self.is_valid_for_cache(result):
with self.save_timer('cache'):
with self.save_timer('cache.write'):
self.cache.save_response(
result['task'].url, result['grab'])
# print '[process network results]'
self.process_network_result(result)
# print '[done]'
self.inc_count('request')
# print '[transport iterate results - end]'
logger_verbose.debug('Work done')
except KeyboardInterrupt:
print('\nGot ^C signal in process %d. Stopping.' % os.getpid())
self.interrupted = True
raise
finally:
# This code is executed when main cycles is breaked
self.stop_timer('total')
self.shutdown()
def run(self):
"""
Main method. All work is done here.
"""
if self.mp_mode:
from multiprocessing import Process, Event, Queue
else:
from multiprocessing.dummy import Process, Event, Queue
self.timer.start("total")
self.transport = MulticurlTransport(self.thread_number)
if self.http_api_port:
http_api_proc = self.start_api_thread()
else:
http_api_proc = None
self.parser_pipeline = ParserPipeline(
bot=self,
mp_mode=self.mp_mode,
pool_size=self.parser_pool_size,
shutdown_event=self.shutdown_event,
network_result_queue=self.network_result_queue,
requests_per_process=self.parser_requests_per_process,
)
network_result_queue_limit = max(10, self.thread_number * 2)
try:
# Run custom things defined by this specific spider
# By defaut it does nothing
self.prepare()
# Setup task queue if it has not been configured yet
if self.task_queue is None:
self.setup_queue()
# Initiate task generator. Only in main process!
with self.timer.log_time("task_generator"):
self.start_task_generator()
while self.work_allowed:
with self.timer.log_time("task_generator"):
if self.task_generator_enabled:
self.process_task_generator()
result_from_cache = None
free_threads = self.transport.get_free_threads_number()
# Load new task only if self.network_result_queue is not full
if self.transport.get_free_threads_number() and (
self.network_result_queue.qsize() < network_result_queue_limit
):
logger_verbose.debug(
"Transport and parser have free resources. " "Trying to load new task from task queue."
)
task = self.get_task_from_queue()
# If no task received from task queue
# try to query task generator
# and then check if spider could be shuted down
if task is None:
if not self.transport.get_active_threads_number():
self.process_task_generator()
if task is None:
# If no task received from task queue
# check if spider could be shut down
if self.is_ready_to_shutdown():
self.shutdown_event.set()
self.stop()
break # Break `if self.work_allowed` cycle
elif isinstance(task, bool) and (task is True):
# Take some sleep to not load CPU
if not self.transport.get_active_threads_number():
time.sleep(0.1)
else:
logger_verbose.debug("Got new task from task queue: %s" % task)
task.network_try_count += 1
is_valid, reason = self.check_task_limits(task)
if is_valid:
grab = self.setup_grab_for_task(task)
grab_config_backup = grab.dump_config()
result_from_cache = None
if self.is_task_cacheable(task, grab):
result_from_cache = self.load_task_from_cache(task, grab, grab_config_backup)
if result_from_cache:
logger_verbose.debug("Task data is loaded from the cache. ")
else:
if self.only_cache:
logger.debug("Skipping network request to " "%s" % grab.config["url"])
else:
self.process_grab_proxy(task, grab)
self.submit_task_to_transport(task, grab, grab_config_backup)
else:
self.log_rejected_task(task, reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
with self.timer.log_time("network_transport"):
logger_verbose.debug("Asking transport layer to do " "something")
self.transport.process_handlers()
logger_verbose.debug("Processing network results (if any).")
# Collect completed network results
# Each result could be valid or failed
# Result is dict {ok, grab, grab_config_backup, task, emsg}
results = [(x, False) for x in self.transport.iterate_results()]
if result_from_cache:
results.append((result_from_cache, True))
# Some sleep to avoid thousands of iterations per second.
# If no results from network transport
if not results:
# If task queue is empty (or if there are only
# delayed tasks)
if task is None or bool(task) == True:
# If no network activity
if not self.transport.get_active_threads_number():
# If parser result queue is empty
if not self.parser_pipeline.has_results():
# Just sleep some time, do not kill CPU
time.sleep(0.1)
for result, from_cache in results:
if not from_cache:
if self.is_valid_for_cache(result):
with self.timer.log_time("cache"):
with self.timer.log_time("cache.write"):
self.cache.save_response(result["task"].url, result["grab"])
self.log_network_result_stats(result, from_cache=from_cache)
if self.is_valid_network_result(result):
# handler = self.find_task_handler(result['task'])
# self.process_network_result_with_handler(
# result, handler)
# MP:
# ***
self.network_result_queue.put(result)
else:
self.log_failed_network_result(result)
# Try to do network request one more time
if self.network_try_limit > 0:
result["task"].refresh_cache = True
result["task"].setup_grab_config(result["grab_config_backup"])
self.add_task(result["task"])
if from_cache:
self.stat.inc("spider:task-%s-cache" % task.name)
self.stat.inc("spider:request")
# MP:
# ***
while True:
try:
p_res, p_task = self.parser_pipeline.get_result()
except queue.Empty:
break
else:
self.stat.inc("spider:parser-result")
self.process_handler_result(p_res, p_task)
if not self.shutdown_event.is_set():
self.parser_pipeline.check_pool_health()
logger_verbose.debug("Work done")
except KeyboardInterrupt:
logger.info("\nGot ^C signal in process %d. Stopping." % os.getpid())
self.interrupted = True
raise
finally:
# This code is executed when main cycles is breaked
self.timer.stop("total")
self.stat.print_progress_line()
self.shutdown()
# Stop HTTP API process
if http_api_proc:
http_api_proc.server.shutdown()
http_api_proc.join()
self.task_queue.clear()
# Stop parser processes
self.shutdown_event.set()
self.parser_pipeline.shutdown()
logger.debug("Main process [pid=%s]: work done" % os.getpid())
class Spider(object):
"""
Asynchronous scraping framework.
"""
# You can define here some urls and initial tasks
# with name "initial" will be created from these
# urls
# If the logic of generating initial tasks is complex
# then consider to use `task_generator` method instead of
# `initial_urls` attribute
initial_urls = None
class Meta:
# Meta.abstract means that this class will not be
# collected to spider registry by `grab crawl` CLI command.
# The Meta is inherited by descendant classes BUT
# Meta.abstract is reset to False in each descendant
abstract = True
# *************
# Class Methods
# *************
@classmethod
def update_spider_config(cls, config):
pass
@classmethod
def get_spider_name(cls):
if hasattr(cls, 'spider_name'):
return cls.spider_name
else:
return camel_case_to_underscore(cls.__name__)
# **************
# Public Methods
# **************
def __init__(
self,
thread_number=None,
network_try_limit=None,
task_try_limit=None,
request_pause=NULL,
priority_mode='random',
meta=None,
only_cache=False,
config=None,
slave=None,
args=None,
# New options start here
taskq=None,
# MP:
network_result_queue=None,
parser_result_queue=None,
is_parser_idle=None,
shutdown_event=None,
mp_mode=False,
parser_pool_size=None,
parser_mode=False,
parser_requests_per_process=10000,
# http api
http_api_port=None,
):
"""
Arguments:
* thread-number - Number of concurrent network streams
* network_try_limit - How many times try to send request
again if network error was occurred, use 0 to disable
* network_try_limit - Limit of tries to execute some task
this is not the same as network_try_limit
network try limit limits the number of tries which
are performed automatically in case of network timeout
of some other physical error
but task_try_limit limits the number of attempts which
are scheduled manually in the spider business logic
* priority_mode - could be "random" or "const"
* meta - arbitrary user data
* retry_rebuild_user_agent - generate new random user-agent for each
network request which is performed again due to network error
* args - command line arguments parsed with `setup_arg_parser` method
New options:
* taskq=None,
* newtork_response_queue=None,
"""
if slave is not None:
raise SpiderConfigurtionError(
'Slave mode is not supported anymore. '
'Use `mp_mode=True` option to run multiple HTML'
' parser processes.')
# API:
self.http_api_port = http_api_port
# MP:
self.mp_mode = mp_mode
if self.mp_mode:
from multiprocessing import Process, Event, Queue
else:
from multiprocessing.dummy import Process, Event, Queue
if network_result_queue is not None:
self.network_result_queue = network_result_queue
else:
self.network_result_queue = Queue()
self.parser_result_queue = parser_result_queue
self.is_parser_idle = is_parser_idle
if shutdown_event is not None:
self.shutdown_event = shutdown_event
else:
self.shutdown_event = Event()
if not self.mp_mode and parser_pool_size and parser_pool_size > 1:
raise SpiderConfigurationError(
'Parser pool size could be only 1 in '
'non-multiprocess mode')
self.parser_pool_size = parser_pool_size
self.parser_mode = parser_mode
self.parser_requests_per_process = parser_requests_per_process
self.stat = Stat()
self.timer = Timer()
self.task_queue = taskq
if args is None:
self.args = {}
else:
self.args = args
if config is not None:
self.config = config
else:
self.config = {}
if meta:
self.meta = meta
else:
self.meta = {}
self.thread_number = (thread_number or int(
self.config.get('thread_number', DEFAULT_NETWORK_STREAM_NUMBER)))
self.task_try_limit = (task_try_limit or int(
self.config.get('task_try_limit', DEFAULT_TASK_TRY_LIMIT)))
self.network_try_limit = (network_try_limit or int(
self.config.get('network_try_limit', DEFAULT_NETWORK_TRY_LIMIT)))
self._grab_config = {}
if priority_mode not in ['random', 'const']:
raise SpiderMisuseError('Value of priority_mode option should be '
'"random" or "const"')
else:
self.priority_mode = priority_mode
self.only_cache = only_cache
self.cache_pipeline = None
self.work_allowed = True
if request_pause is not NULL:
warn('Option `request_pause` is deprecated and is not '
'supported anymore')
self.proxylist_enabled = None
self.proxylist = None
self.proxy = None
self.proxy_auto_change = False
self.interrupted = False
def setup_cache(self,
backend='mongo',
database=None,
use_compression=True,
**kwargs):
if database is None:
raise SpiderMisuseError('setup_cache method requires database '
'option')
self.cache_enabled = True
mod = __import__('grab.spider.cache_backend.%s' % backend, globals(),
locals(), ['foo'])
cache = mod.CacheBackend(database=database,
use_compression=use_compression,
spider=self,
**kwargs)
self.cache_pipeline = CachePipeline(self, cache)
def setup_queue(self, backend='memory', **kwargs):
logger.debug('Using %s backend for task queue' % backend)
mod = __import__('grab.spider.queue_backend.%s' % backend, globals(),
locals(), ['foo'])
self.task_queue = mod.QueueBackend(spider_name=self.get_spider_name(),
**kwargs)
def add_task(self, task, raise_error=False):
"""
Add task to the task queue.
"""
# MP:
# ***
if self.parser_mode:
self.parser_result_queue.put((task, None))
return
if self.task_queue is None:
raise SpiderMisuseError('You should configure task queue before '
'adding tasks. Use `setup_queue` method.')
if task.priority is None or not task.priority_set_explicitly:
task.priority = self.generate_task_priority()
task.priority_set_explicitly = False
else:
task.priority_set_explicitly = True
if not task.url.startswith(
('http://', 'https://', 'ftp://', 'file://', 'feed://')):
self.stat.collect('task-with-invalid-url', task.url)
msg = ('It is not allowed to build Task object with '
'relative URL: %s' % task.url)
ex = SpiderError(msg)
if raise_error:
raise ex
else:
logger.error('', exc_info=ex)
return False
# TODO: keep original task priority if it was set explicitly
# WTF the previous comment means?
self.task_queue.put(task,
task.priority,
schedule_time=task.schedule_time)
return True
def stop(self):
"""
This method set internal flag which signal spider
to stop processing new task and shuts down.
"""
logger_verbose.debug('Method `stop` was called')
self.work_allowed = False
def load_proxylist(self,
source,
source_type=None,
proxy_type='http',
auto_init=True,
auto_change=True,
**kwargs):
self.proxylist = ProxyList()
if isinstance(source, BaseProxySource):
self.proxylist.set_source(source)
elif isinstance(source, six.string_types):
if source_type == 'text_file':
self.proxylist.load_file(source, proxy_type=proxy_type)
elif source_type == 'url':
self.proxylist.load_url(source, proxy_type=proxy_type)
else:
raise SpiderMisuseError('Method `load_proxylist` received '
'invalid `source_type` argument: %s' %
source_type)
else:
raise SpiderMisuseError('Method `load_proxylist` received '
'invalid `source` argument: %s' % source)
self.proxylist_enabled = True
self.proxy = None
if not auto_change and auto_init:
self.proxy = self.proxylist.get_random_proxy()
self.proxy_auto_change = auto_change
def process_next_page(self,
grab,
task,
xpath,
resolve_base=False,
**kwargs):
"""
Generate task for next page.
:param grab: Grab instance
:param task: Task object which should be assigned to next page url
:param xpath: xpath expression which calculates list of URLS
:param **kwargs: extra settings for new task object
Example::
self.follow_links(grab, 'topic', '//div[@class="topic"]/a/@href')
"""
try:
# next_url = grab.xpath_text(xpath)
next_url = grab.doc.select(xpath).text()
except IndexError:
return False
else:
url = grab.make_url_absolute(next_url, resolve_base=resolve_base)
page = task.get('page', 1) + 1
grab2 = grab.clone()
grab2.setup(url=url)
task2 = task.clone(task_try_count=1,
grab=grab2,
page=page,
**kwargs)
self.add_task(task2)
return True
def render_stats(self, timing=True):
out = ['------------ Stats: ------------']
out.append('Counters:')
# Process counters
items = sorted(self.stat.counters.items(),
key=lambda x: x[0],
reverse=True)
for item in items:
out.append(' %s: %s' % item)
out.append('')
out.append('Lists:')
# Process collections sorted by size desc
col_sizes = [(x, len(y)) for x, y in self.stat.collections.items()]
col_sizes = sorted(col_sizes, key=lambda x: x[1], reverse=True)
for col_size in col_sizes:
out.append(' %s: %d' % col_size)
out.append('')
# Process extra metrics
if 'download-size' in self.stat.counters:
out.append('Network download: %s' % metric.format_traffic_value(
self.stat.counters['download-size']))
out.append('Queue size: %d' %
self.task_queue.size() if self.task_queue else 'NA')
out.append('Network streams: %d' % self.thread_number)
elapsed = self.timer.timers['total']
hours, seconds = divmod(elapsed, 3600)
minutes, seconds = divmod(seconds, 60)
out.append('Time elapsed: %d:%d:%d (H:M:S)' %
(hours, minutes, seconds))
out.append('End time: %s' %
datetime.utcnow().strftime('%d %b %Y, %H:%M:%S UTC'))
if timing:
out.append('')
out.append(self.render_timing())
return '\n'.join(out) + '\n'
def render_timing(self):
out = ['Timers:']
out.append(' DOM: %.3f' % GLOBAL_STATE['dom_build_time'])
time_items = [(x, y) for x, y in self.timer.timers.items()]
time_items = sorted(time_items, key=lambda x: x[1])
for time_item in time_items:
out.append(' %s: %.03f' % time_item)
return '\n'.join(out) + '\n'
# ********************************
# Methods for spider customization
# ********************************
def prepare(self):
"""
You can do additional spider customization here
before it has started working. Simply redefine
this method in your Spider class.
"""
def prepare_parser(self):
"""
You can do additional spider customization here
before it has started working. Simply redefine
this method in your Spider class.
This method is called only from Spider working in parser mode
that, in turn, is spawned automatically by main spider proces
working in multiprocess mode.
"""
def shutdown(self):
"""
You can override this method to do some final actions
after parsing has been done.
"""
pass
def update_grab_instance(self, grab):
"""
Use this method to automatically update config of any
`Grab` instance created by the spider.
"""
pass
def create_grab_instance(self, **kwargs):
# Back-ward compatibility for deprecated `grab_config` attribute
# Here I use `_grab_config` to not trigger warning messages
if self._grab_config and kwargs:
merged_config = deepcopy(self._grab_config)
merged_config.update(kwargs)
grab = Grab(**merged_config)
elif self._grab_config and not kwargs:
grab = Grab(**self._grab_config)
else:
grab = Grab(**kwargs)
return grab
def task_generator(self):
"""
You can override this method to load new tasks smoothly.
It will be used each time as number of tasks
in task queue is less then number of threads multiplied on 2
This allows you to not overload all free memory if total number of
tasks is big.
"""
if False:
# Some magic to make this function empty generator
yield ':-)'
return
# ***************
# Private Methods
# ***************
def check_task_limits(self, task):
"""
Check that task's network & try counters do not exceed limits.
Returns:
* if success: (True, None)
* if error: (False, reason)
"""
if task.task_try_count > self.task_try_limit:
return False, 'task-try-count'
if task.network_try_count > self.network_try_limit:
return False, 'network-try-count'
return True, None
def generate_task_priority(self):
if self.priority_mode == 'const':
return DEFAULT_TASK_PRIORITY
else:
return randint(*RANDOM_TASK_PRIORITY_RANGE)
def task_generator_thread_wrapper(self, task_generator):
"""
Load new tasks from `self.task_generator_object`
Create new tasks.
If task queue size is less than some value
then load new tasks from tasks file.
"""
while True:
with self.timer.log_time('task_generator'):
queue_size = self.task_queue.size()
min_limit = self.thread_number * 10
if queue_size < min_limit:
with self.timer.log_time('task_generator'):
logger_verbose.debug(
'Task queue contains less tasks (%d) than '
'allowed limit (%d). Trying to add '
'new tasks.' % (queue_size, min_limit))
try:
for x in six.moves.range(min_limit - queue_size):
item = next(task_generator)
logger_verbose.debug(
'Got new item from generator. '
'Processing it.')
self.process_handler_result(item, None)
except StopIteration:
# If generator have no values to yield
# then disable it
logger_verbose.debug(
'Task generator has no more tasks. '
'Disabling it')
break
else:
time.sleep(0.1)
def start_task_generators(self):
"""
Process `self.initial_urls` list and `self.task_generator`
method.
"""
logger_verbose.debug('Processing initial urls')
if self.initial_urls:
for url in self.initial_urls:
self.add_task(Task('initial', url=url))
self._task_generator_list = []
th = Thread(target=self.task_generator_thread_wrapper,
args=[self.task_generator()])
th.daemon = True
th.start()
self._task_generator_list.append(th)
def get_task_from_queue(self):
start = time.time()
try:
with self.timer.log_time('task_queue'):
return self.task_queue.get()
except queue.Empty:
size = self.task_queue.size()
if size:
logger_verbose.debug('No ready-to-go tasks, Waiting for '
'scheduled tasks (%d)' % size)
return True
else:
logger_verbose.debug('Task queue is empty.')
return None
def setup_grab_for_task(self, task):
grab = self.create_grab_instance()
if task.grab_config:
grab.load_config(task.grab_config)
else:
grab.setup(url=task.url)
# Generate new common headers
grab.config['common_headers'] = grab.common_headers()
self.update_grab_instance(grab)
return grab
def is_valid_network_response_code(self, code, task):
"""
Answer the question: if the response could be handled via
usual task handler or the task faield and should be processed as error.
"""
return (code < 400 or code == 404 or code in task.valid_status)
def process_handler_error(self, func_name, ex, task):
self.stat.inc('spider:error-%s' % ex.__class__.__name__.lower())
if hasattr(ex, 'tb'):
logger.error('Error in %s function' % func_name)
logger.error(ex.tb)
else:
logger.error('Error in %s function' % func_name, exc_info=ex)
# Looks strange but I really have some problems with
# serializing exception into string
try:
ex_str = six.text_type(ex)
except TypeError:
try:
ex_str = ex.decode('utf-8', 'ignore')
except TypeError:
ex_str = str(ex)
task_url = task.url if task is not None else None
self.stat.collect(
'fatal', '%s|%s|%s|%s' %
(func_name, ex.__class__.__name__, ex_str, task_url))
if isinstance(ex, FatalError):
#raise FatalError()
#six.reraise(FatalError, ex)
#logger.error(ex.tb)
raise ex
def find_data_handler(self, data):
try:
return getattr(data, 'handler')
except AttributeError:
try:
handler = getattr(self, 'data_%s' % data.handler_key)
except AttributeError:
raise NoDataHandler('No handler defined for Data %s' %
data.handler_key)
else:
return handler
def run_parser(self):
"""
Main work cycle of spider process working in parser-mode.
"""
self.is_parser_idle.clear()
# Use Stat instance that does not print any logging messages
if self.parser_mode:
self.stat = Stat(logging_period=None)
self.prepare_parser()
process_request_count = 0
try:
recent_task_time = time.time()
while True:
try:
result = self.network_result_queue.get(block=False)
except queue.Empty:
self.is_parser_idle.set()
time.sleep(0.1)
self.is_parser_idle.clear()
logger_verbose.debug('Network result queue is empty')
# Set `waiting_shutdown_event` only after 1 seconds
# of waiting for tasks to avoid
# race-condition issues
#if time.time() - recent_task_time > 1:
# self.waiting_shutdown_event.set()
if self.shutdown_event.is_set():
logger_verbose.debug('Got shutdown event')
return
else:
process_request_count += 1
recent_task_time = time.time()
if self.parser_mode:
self.stat.reset()
#if self.waiting_shutdown_event.is_set():
# self.waiting_shutdown_event.clear()
try:
handler = self.find_task_handler(result['task'])
except NoTaskHandler as ex:
ex.tb = format_exc()
self.parser_result_queue.put((ex, result['task']))
self.stat.inc('parser:handler-not-found')
else:
self.process_network_result_with_handler(
result, handler)
self.stat.inc('parser:handler-processed')
finally:
if self.parser_mode:
data = {
'type': 'stat',
'counters': self.stat.counters,
'collections': self.stat.collections,
}
self.parser_result_queue.put(
(data, result['task']))
if self.parser_mode:
if self.parser_requests_per_process:
if (process_request_count >=
self.parser_requests_per_process):
break
except Exception as ex:
logging.error('', exc_info=ex)
raise
#finally:
# self.waiting_shutdown_event.set()
def process_network_result_with_handler(self, result, handler):
handler_name = getattr(handler, '__name__', 'NONE')
try:
with self.timer.log_time('response_handler'):
with self.timer.log_time('response_handler.%s' % handler_name):
handler_result = handler(result['grab'], result['task'])
if handler_result is None:
pass
else:
for something in handler_result:
self.parser_result_queue.put(
(something, result['task']))
except NoDataHandler as ex:
ex.tb = format_exc()
self.parser_result_queue.put((ex, result['task']))
except Exception as ex:
ex.tb = format_exc()
self.parser_result_queue.put((ex, result['task']))
def find_task_handler(self, task):
callback = task.get('callback')
if callback:
return callback
else:
try:
handler = getattr(self, 'task_%s' % task.name)
except AttributeError:
raise NoTaskHandler('No handler or callback defined for '
'task %s' % task.name)
else:
return handler
def log_network_result_stats(self, res, from_cache=False):
# Increase stat counters
self.stat.inc('spider:request-processed')
self.stat.inc('spider:task')
self.stat.inc('spider:task-%s' % res['task'].name)
if (res['task'].network_try_count == 1
and res['task'].task_try_count == 1):
self.stat.inc('spider:task-%s-initial' % res['task'].name)
# Update traffic statistics
if res['grab'] and res['grab'].response:
resp = res['grab'].response
self.timer.inc_timer('network-name-lookup', resp.name_lookup_time)
self.timer.inc_timer('network-connect', resp.connect_time)
self.timer.inc_timer('network-total', resp.total_time)
if from_cache:
self.stat.inc('spider:download-size-with-cache',
resp.download_size)
self.stat.inc('spider:upload-size-with-cache',
resp.upload_size)
else:
self.stat.inc('spider:download-size', resp.download_size)
self.stat.inc('spider:upload-size', resp.upload_size)
def process_grab_proxy(self, task, grab):
"Assign new proxy from proxylist to the task"
if task.use_proxylist:
if self.proxylist_enabled:
# Need this to work around
# pycurl feature/bug:
# pycurl instance uses previously connected proxy server
# even if `proxy` options is set with another proxy server
grab.setup(connection_reuse=False)
if self.proxy_auto_change:
self.change_active_proxy(task)
if self.proxy:
grab.setup(proxy=self.proxy.get_address(),
proxy_userpwd=self.proxy.get_userpwd(),
proxy_type=self.proxy.proxy_type)
def change_active_proxy(self, task, grab):
self.proxy = self.proxylist.get_random_proxy()
def submit_task_to_transport(self, task, grab):
if self.only_cache:
self.stat.inc('spider:request-network-disabled-only-cache')
else:
grab_config_backup = grab.dump_config()
self.process_grab_proxy(task, grab)
self.stat.inc('spider:request-network')
self.stat.inc('spider:task-%s-network' % task.name)
with self.timer.log_time('network_transport'):
logger_verbose.debug('Submitting task to the transport '
'layer')
try:
self.transport.start_task_processing(
task, grab, grab_config_backup)
except GrabInvalidUrl:
logger.debug('Task %s has invalid URL: %s' %
(task.name, task.url))
self.stat.collect('invalid-url', task.url)
def start_api_thread(self):
from grab.spider.http_api import HttpApiThread
proc = HttpApiThread(self)
proc.start()
return proc
def is_ready_to_shutdown(self):
# Things should be true to shutdown spider
# 1) No active task handlers (task_* functions)
# 2) All task generators has completed work
# 3) No active network threads
# 4) Task queue is empty
# 5) Network result queue is empty
# 6) Cache is disabled or is in idle mode
return (not self.parser_result_queue.qsize()
and all(x['is_parser_idle'].is_set()
for x in self.parser_pipeline.parser_pool)
and not any(x.isAlive()
for x in self._task_generator_list) # (2)
and not self.transport.get_active_threads_number() # (3)
and not self.task_queue.size() # (4)
and not self.network_result_queue.qsize() # (5)
and (self.cache_pipeline is None or
(self.cache_pipeline.is_idle()
and self.cache_pipeline.input_queue.qsize() == 0
and self.cache_pipeline.result_queue.qsize() == 0)))
def run(self):
"""
Main method. All work is done here.
"""
if self.mp_mode:
from multiprocessing import Process, Event, Queue
else:
from multiprocessing.dummy import Process, Event, Queue
self.timer.start('total')
self.transport = MulticurlTransport(self.thread_number)
if self.http_api_port:
http_api_proc = self.start_api_thread()
else:
http_api_proc = None
self.parser_result_queue = Queue()
self.parser_pipeline = ParserPipeline(
bot=self,
mp_mode=self.mp_mode,
pool_size=self.parser_pool_size,
shutdown_event=self.shutdown_event,
network_result_queue=self.network_result_queue,
parser_result_queue=self.parser_result_queue,
requests_per_process=self.parser_requests_per_process,
)
network_result_queue_limit = max(10, self.thread_number * 2)
try:
# Run custom things defined by this specific spider
# By defaut it does nothing
self.prepare()
# Setup task queue if it has not been configured yet
if self.task_queue is None:
self.setup_queue()
# Initiate task generator. Only in main process!
with self.timer.log_time('task_generator'):
self.start_task_generators()
# Work in infinite cycle untill
# `self.work_allowed` flag is True
#shutdown_countdown = 0 # !!!
pending_tasks = deque()
while self.work_allowed:
free_threads = self.transport.get_free_threads_number()
# Load new task only if:
# 1) network transport has free threads
# 2) network result queue is not full
# 3) cache is disabled OR cache has free resources
if (self.transport.get_free_threads_number()
and (self.network_result_queue.qsize() <
network_result_queue_limit)
and (self.cache_pipeline is None
or self.cache_pipeline.has_free_resources())):
if pending_tasks:
task = pending_tasks.popleft()
else:
task = self.get_task_from_queue()
if task is None:
# If received task is None then
# check if spider is ready to be shut down
if not pending_tasks and self.is_ready_to_shutdown():
# I am afraid there is a bug in `is_ready_to_shutdown`
# because it tries to evaluate too many things
# includig thigs that are being set from other threads,
# so to ensure we are really ready to shutdown I call
# is_ready_to_shutdown a few more times.
# Without this hack some times really rarely times
# the Grab fails to do its job
# A good way to see this bug is to disable this hack
# and run:
# while ./runtest.py -t test.spider_data; do echo "ok"; done;
# And wait a few minutes
really_ready = True
for x in range(10):
if not self.is_ready_to_shutdown():
really_ready = False
break
time.sleep(0.001)
if really_ready:
self.shutdown_event.set()
self.stop()
break # Break from `while self.work_allowed` cycle
elif isinstance(task, bool) and (task is True):
# If received task is True
# and there is no active network threads then
# take some sleep
if not self.transport.get_active_threads_number():
time.sleep(0.01)
else:
logger_verbose.debug(
'Got new task from task queue: %s' % task)
task.network_try_count += 1
is_valid, reason = self.check_task_limits(task)
if is_valid:
task_grab = self.setup_grab_for_task(task)
if self.cache_pipeline:
self.cache_pipeline.input_queue.put(
('load', (task, task_grab)), )
else:
self.submit_task_to_transport(task, task_grab)
else:
self.log_rejected_task(task, reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
with self.timer.log_time('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Collect completed network results
# Each result could be valid or failed
# Result is dict {ok, grab, grab_config_backup, task, emsg}
results = [(x, False)
for x in self.transport.iterate_results()]
if self.cache_pipeline:
while True:
try:
action, result = self.cache_pipeline\
.result_queue.get(False)
except queue.Empty:
break
else:
assert action in ('network_result', 'task')
if action == 'network_result':
results.append((result, True))
elif action == 'task':
task = result
task_grab = self.setup_grab_for_task(task)
if (self.transport.get_free_threads_number()
and (self.network_result_queue.qsize()
< network_result_queue_limit)):
self.submit_task_to_transport(
task, task_grab)
else:
pending_tasks.append(task)
# Take sleep to avoid millions of iterations per second.
# 1) If no results from network transport
# 2) If task queue is empty (or if there are only delayed tasks)
# 3) If no network activity
# 4) If parser result queue is empty
if (not results and (task is None or bool(task) == True)
and not self.transport.get_active_threads_number()
and not self.parser_result_queue.qsize() and
(self.cache_pipeline is None or
(self.cache_pipeline.input_queue.qsize() == 0
and self.cache_pipeline.is_idle()
and self.cache_pipeline.result_queue.qsize() == 0))):
time.sleep(0.001)
for result, from_cache in results:
if self.cache_pipeline and not from_cache:
if result['ok']:
self.cache_pipeline.input_queue.put(
('save', (result['task'], result['grab'])))
self.log_network_result_stats(result,
from_cache=from_cache)
is_valid = False
if result['task'].get('raw'):
is_valid = True
elif result['ok']:
res_code = result['grab'].response.code
if self.is_valid_network_response_code(
res_code, result['task']):
is_valid = True
if is_valid:
self.network_result_queue.put(result)
else:
self.log_failed_network_result(result)
# Try to do network request one more time
# TODO:
# Implement valid_try_limit
# Use it if request failed not because of network error
# But because of content integrity check
if self.network_try_limit > 0:
result['task'].refresh_cache = True
result['task'].setup_grab_config(
result['grab_config_backup'])
self.add_task(result['task'])
if from_cache:
self.stat.inc('spider:task-%s-cache' %
result['task'].name)
self.stat.inc('spider:request')
while True:
try:
p_res, p_task = self.parser_result_queue.get(
block=False)
except queue.Empty:
break
else:
self.stat.inc('spider:parser-result')
self.process_handler_result(p_res, p_task)
if not self.shutdown_event.is_set():
self.parser_pipeline.check_pool_health()
logger_verbose.debug('Work done')
except KeyboardInterrupt:
logger.info('\nGot ^C signal in process %d. Stopping.' %
os.getpid())
self.interrupted = True
raise
finally:
# This code is executed when main cycles is breaked
self.timer.stop('total')
self.stat.print_progress_line()
self.shutdown()
# Stop HTTP API process
if http_api_proc:
http_api_proc.server.shutdown()
http_api_proc.join()
if self.task_queue:
self.task_queue.clear()
# Stop parser processes
self.shutdown_event.set()
self.parser_pipeline.shutdown()
logger.debug('Main process [pid=%s]: work done' % os.getpid())
def log_failed_network_result(self, res):
# Log the error
if res['ok']:
msg = 'http-%s' % res['grab'].response.code
else:
msg = res['error_abbr']
self.stat.inc('error:%s' % msg)
#logger.error(u'Network error: %s' % msg)#%
#make_unicode(msg, errors='ignore'))
def log_rejected_task(self, task, reason):
logger_verbose.debug('Task %s is rejected due to '
'%s limit' % (task.name, reason))
if reason == 'task-try-count':
self.stat.collect('task-count-rejected', task.url)
elif reason == 'network-try-count':
self.stat.collect('network-count-rejected', task.url)
else:
raise SpiderError('Unknown response from '
'check_task_limits: %s' % reason)
def process_handler_result(self, result, task):
"""
Process result received from the task handler.
Result could be:
* None
* Task instance
* Data instance.
* dict:
* {type: "stat", counters: [], collections: []}
* ResponseNotValid-based exception
* Arbitrary exception
"""
if isinstance(result, Task):
self.add_task(result)
elif isinstance(result, Data):
handler = self.find_data_handler(result)
try:
data_result = handler(**result.storage)
if data_result is None:
pass
else:
for something in data_result:
self.process_handler_result(something, task)
except Exception as ex:
self.process_handler_error('data_%s' % result.handler_key, ex,
task)
elif result is None:
pass
elif isinstance(result, ResponseNotValid):
self.add_task(task.clone(refresh_cache=True))
error_code = result.__class__.__name__.replace('_', '-')
self.stat.inc('integrity:%s' % error_code)
elif isinstance(result, Exception):
handler = self.find_task_handler(task)
handler_name = getattr(handler, '__name__', 'NONE')
self.process_handler_error(handler_name, result, task)
elif isinstance(result, dict):
if result.get('type') == 'stat':
for name, count in result['counters'].items():
self.stat.inc(name, count)
for name, items in result['collections'].items():
for item in items:
self.stat.collect(name, item)
else:
raise SpiderError('Unknown result type: %s' % result)
else:
raise SpiderError('Unknown result type: %s' % result)
class Spider(SpiderMetaClassMixin, SpiderStat):
"""
Asynchronous scraping framework.
"""
# You can define here some urls and initial tasks
# with name "initial" will be created from these
# urls
# If the logic of generating initial tasks is complex
# then consider to use `task_generator` method instead of
# `initial_urls` attribute
initial_urls = None
# The base url which is used to resolve all relative urls
# The resolving takes place in `add_task` method
base_url = None
class Meta:
# Meta.abstract means that this class will not be
# collected to spider registry by `grab crawl` CLI command.
# The Meta is inherited by descendant classes BUT
# Meta.abstract is reset to False in each descendant
abstract = True
def __init__(
self,
thread_number=None,
network_try_limit=None,
task_try_limit=None,
request_pause=NULL,
priority_mode='random',
meta=None,
only_cache=False,
config=None,
slave=False,
max_task_generator_chunk=None,
args=None,
# New options start here
taskq=None,
):
"""
Arguments:
* thread-number - Number of concurrent network streams
* network_try_limit - How many times try to send request
again if network error was occurred, use 0 to disable
* network_try_limit - Limit of tries to execute some task
this is not the same as network_try_limit
network try limit limits the number of tries which
are performed automatically in case of network timeout
of some other physical error
but task_try_limit limits the number of attempts which
are scheduled manually in the spider business logic
* priority_mode - could be "random" or "const"
* meta - arbitrary user data
* retry_rebuild_user_agent - generate new random user-agent for each
network request which is performed again due to network error
* args - command line arguments parsed with `setup_arg_parser` method
New options:
* taskq=None,
* newtork_response_queue=None,
"""
self.taskq = taskq
if args is None:
self.args = {}
else:
self.args = args
self.slave = slave
self.max_task_generator_chunk = max_task_generator_chunk
self.timers = {
'network-name-lookup': 0,
'network-connect': 0,
'network-total': 0,
}
self.time_points = {}
self.start_timer('total')
if config is not None:
self.config = config
else:
self.config = {}
if meta:
self.meta = meta
else:
self.meta = {}
self.task_generator_enabled = False
self.only_cache = only_cache
self.thread_number = thread_number or\
int(self.config.get('thread_number', 3))
self.task_try_limit = task_try_limit or\
int(self.config.get('task_try_limit', 10))
self.network_try_limit = network_try_limit or \
int(self.config.get('network_try_limit', 10))
self.counters = defaultdict(int)
self._grab_config = {}
self.items = {}
if priority_mode not in ['random', 'const']:
raise SpiderMisuseError('Value of priority_mode option should be '
'"random" or "const"')
else:
self.priority_mode = priority_mode
try:
signal.signal(signal.SIGUSR1, self.sigusr1_handler)
except (ValueError, AttributeError):
pass
try:
signal.signal(signal.SIGUSR2, self.sigusr2_handler)
except (ValueError, AttributeError):
pass
# Initial cache-subsystem values
self.cache_enabled = False
self.cache = None
self.work_allowed = True
if request_pause is not NULL:
logger.error('Option `request_pause` is deprecated and is not '
'supported anymore')
self.proxylist_enabled = None
self.proxylist = None
self.proxy = None
self.proxy_auto_change = False
self.interrupted = False
def get_grab_config(self):
logger.error('Using `grab_config` attribute is deprecated. Override '
'`create_grab_instance method instead.')
return self._grab_config
def set_grab_config(self, val):
logger.error('Using `grab_config` attribute is deprecated. Override '
'`create_grab_instance method instead.')
self._grab_config = val
grab_config = property(get_grab_config, set_grab_config)
def setup_cache(self,
backend='mongo',
database=None,
use_compression=True,
**kwargs):
if database is None:
raise SpiderMisuseError('setup_cache method requires database '
'option')
self.cache_enabled = True
mod = __import__('grab.spider.cache_backend.%s' % backend, globals(),
locals(), ['foo'])
self.cache = mod.CacheBackend(database=database,
use_compression=use_compression,
spider=self,
**kwargs)
def setup_queue(self, backend='memory', **kwargs):
logger.debug('Using %s backend for task queue' % backend)
mod = __import__('grab.spider.queue_backend.%s' % backend, globals(),
locals(), ['foo'])
self.taskq = mod.QueueBackend(spider_name=self.get_spider_name(),
**kwargs)
def prepare(self):
"""
You can do additional spider customization here
before it has started working. Simply redefine
this method in your Spider class.
"""
def sigusr1_handler(self, signal, frame):
"""
Catches SIGUSR1 signal and dumps current state
to temporary file
"""
with open('/tmp/spider.state', 'w') as out:
out.write(self.render_stats())
def sigusr2_handler(self, signal, frame):
"""
Catches SIGUSR1 signal and shutdowns spider.
"""
logger.error('Received SIGUSR2 signal. Doing shutdown')
self.stop()
def setup_grab(self, **kwargs):
logging.error('This method is deprecated. Instead override '
'`create_grab_instance` method in you spider sub-class')
self.grab_config.update(**kwargs)
def check_task_limits(self, task):
"""
Check that network/try counters are OK.
Returns:
* if success: (True, None)
* if error: (False, reason)
"""
if task.task_try_count > self.task_try_limit:
logger.debug('Task tries (%d) ended: %s / %s' %
(self.task_try_limit, task.name, task.url))
return False, 'task-try-count'
if task.network_try_count > self.network_try_limit:
logger.debug('Network tries (%d) ended: %s / %s' %
(self.network_try_limit, task.name, task.url))
return False, 'network-try-count'
return True, None
def generate_task_priority(self):
if self.priority_mode == 'const':
return DEFAULT_TASK_PRIORITY
else:
return randint(*RANDOM_TASK_PRIORITY_RANGE)
def add_task(self, task, raise_error=False):
"""
Add task to the task queue.
"""
if self.taskq is None:
raise SpiderMisuseError('You should configure task queue before '
'adding tasks. Use `setup_queue` method.')
if task.priority is None or not task.priority_is_custom:
task.priority = self.generate_task_priority()
task.priority_is_custom = False
else:
task.priority_is_custom = True
if not isinstance(task, NullTask):
try:
if not task.url.startswith(
('http://', 'https://', 'ftp://', 'file://', 'feed://')):
if self.base_url is None:
msg = 'Could not resolve relative URL because base_url ' \
'is not specified. Task: %s, URL: %s'\
% (task.name, task.url)
raise SpiderError(msg)
else:
task.url = urljoin(self.base_url, task.url)
# If task has grab_config object then update it too
if task.grab_config:
task.grab_config['url'] = task.url
except Exception as ex:
self.add_item('task-with-invalid-url', task.url)
if raise_error:
raise
else:
logger.error('', exc_info=ex)
return False
# TODO: keep original task priority if it was set explicitly
self.taskq.put(task, task.priority, schedule_time=task.schedule_time)
return True
def load_initial_urls(self):
"""
Create initial tasks from `self.initial_urls`.
Tasks are created with name "initial".
"""
if self.initial_urls:
for url in self.initial_urls:
self.add_task(Task('initial', url=url))
def setup_default_queue(self):
"""
If task queue is not configured explicitly
then create task queue with default parameters
This method is not the same as `self.setup_queue` because
`self.setup_queue` works by default with in-memory queue.
You can override `setup_default_queue` in your custom
Spider and use other storage engines for you
default task queue.
"""
# If queue is still not configured
# then configure it with default backend
if self.taskq is None:
self.setup_queue()
def process_task_generator(self):
"""
Load new tasks from `self.task_generator_object`
Create new tasks.
If task queue size is less than some value
then load new tasks from tasks file.
"""
if self.task_generator_enabled:
if hasattr(self.taskq, 'qsize'):
qsize = self.taskq.qsize()
else:
qsize = self.taskq.size()
if self.max_task_generator_chunk is not None:
min_limit = min(self.max_task_generator_chunk,
self.thread_number * 10)
else:
min_limit = self.thread_number * 10
if qsize < min_limit:
logger_verbose.debug(
'Task queue contains less tasks (%d) than '
'allowed limit (%d). Trying to add '
'new tasks.' % (qsize, min_limit))
try:
for x in six.moves.range(min_limit - qsize):
item = next(self.task_generator_object)
logger_verbose.debug('Got new item from generator. '
'Processing it.')
# self.add_task(item)
self.process_handler_result(item)
except StopIteration:
# If generator have no values to yield
# then disable it
logger_verbose.debug('Task generator has no more tasks. '
'Disabling it')
self.task_generator_enabled = False
def init_task_generator(self):
"""
Process `initial_urls` and `task_generator`.
Generate first portion of tasks.
TODO: task generator should work in separate OS process
"""
self.task_generator_object = self.task_generator()
self.task_generator_enabled = True
logger_verbose.debug('Processing initial urls')
self.load_initial_urls()
# Initial call to task generator
# before main cycle
self.process_task_generator()
def load_new_task(self):
start = time.time()
while True:
try:
with self.save_timer('task_queue'):
return self.taskq.get()
except queue.Empty:
qsize = self.taskq.size()
if qsize:
logger_verbose.debug('No ready-to-go tasks, Waiting for '
'scheduled tasks (%d)' % qsize)
return True
if not self.slave:
logger_verbose.debug('Task queue is empty.')
return None
else:
# Temporarily hack which force slave crawler
# to wait 5 seconds for new tasks, this solves
# the problem that sometimes slave crawler stop
# its work because it could not receive new
# tasks immediately
if not self.transport.active_task_number():
if time.time() - start < 5:
time.sleep(0.1)
logger.debug('Slave sleeping')
else:
break
else:
break
logger_verbose.debug('Task queue is empty.')
return None
def process_task_counters(self, task):
task.network_try_count += 1
if task.task_try_count == 0:
task.task_try_count = 1
def create_grab_instance(self, **kwargs):
# Back-ward compatibility for deprecated `grab_config` attribute
# Here I use `_grab_config` to not trigger warning messages
if self._grab_config and kwargs:
merged_config = deepcopy(self._grab_config)
merged_config.update(kwargs)
grab = Grab(**merged_config)
elif self._grab_config and not kwargs:
grab = Grab(**self._grab_config)
else:
grab = Grab(**kwargs)
return grab
def update_grab_instance(self, grab):
"""
Use this method to automatically update config of any
`Grab` instance created by the spider.
"""
pass
def setup_grab_for_task(self, task):
grab = self.create_grab_instance()
if task.grab_config:
grab.load_config(task.grab_config)
else:
grab.setup(url=task.url)
# Generate new common headers
grab.config['common_headers'] = grab.common_headers()
self.update_grab_instance(grab)
return grab
def is_task_cacheable(self, task, grab):
if ( # cache is disabled for all tasks
not self.cache_enabled
# cache data should be refreshed
or task.get('refresh_cache', False)
# cache could not be used
or task.get('disable_cache', False)
# request type is not cacheable
or grab.detect_request_method() != 'GET'):
return False
else:
return True
def load_task_from_cache(self, transport, task, grab, grab_config_backup):
cache_item = self.cache.get_item(grab.config['url'],
timeout=task.cache_timeout)
if cache_item is None:
return None
else:
with self.save_timer('cache.read.prepare_request'):
grab.prepare_request()
with self.save_timer('cache.read.load_response'):
self.cache.load_response(grab, cache_item)
grab.log_request('CACHED')
self.inc_count('request')
self.inc_count('request-cache')
return {
'ok': True,
'grab': grab,
'grab_config_backup': grab_config_backup,
'task': task,
'emsg': None
}
def valid_response_code(self, code, task):
"""
Answer the question: if the response could be handled via
usual task handler or the task faield and should be processed as error.
"""
return (code < 400 or code == 404 or code in task.valid_status)
def process_handler_error(self, func_name, ex, task):
self.inc_count('error-%s' % ex.__class__.__name__.lower())
logger.error('Error in %s function' % func_name, exc_info=ex)
# Looks strange but I really have some problems with
# serializing exception into string
try:
ex_str = six.text_type(ex)
except TypeError:
try:
ex_str = ex.decode('utf-8', 'ignore')
except TypeError:
ex_str = str(ex)
task_url = task.url if task is not None else None
self.add_item(
'fatal', '%s|%s|%s|%s' %
(func_name, ex.__class__.__name__, ex_str, task_url))
if isinstance(ex, FatalError):
raise
def find_data_handler(self, data):
try:
return getattr(data, 'handler')
except AttributeError:
try:
handler = getattr(self, 'data_%s' % data.handler_key)
except AttributeError:
raise NoDataHandler('No handler defined for Data %s' %
data.handler_key)
else:
return handler
def execute_task_handler(self, res, handler):
"""
Apply `handler` function to the network result.
If network result is failed then submit task again
to the network task queue.
"""
try:
handler_name = handler.__name__
except AttributeError:
handler_name = 'NONE'
if (res['task'].get('raw') or (res['ok'] and self.valid_response_code(
res['grab'].response.code, res['task']))):
try:
with self.save_timer('response_handler'):
with self.save_timer('response_handler.%s' % handler_name):
result = handler(res['grab'], res['task'])
if result is None:
pass
else:
for item in result:
self.process_handler_result(item, res['task'])
except NoDataHandler as ex:
raise
except Exception as ex:
self.process_handler_error(handler_name, ex, res['task'])
else:
self.inc_count('task-%s-ok' % res['task'].name)
else:
# Log the error
if res['ok']:
msg = res['emsg'] = 'HTTP %s' % res['grab'].response.code
else:
msg = res['emsg']
self.inc_count('network-error-%s' %
make_str(res['emsg'][:20], errors='ignore'))
logger.error(u'Network error: %s' %
make_unicode(msg, errors='ignore'))
# Try to repeat the same network query
if self.network_try_limit > 0:
task = res['task']
task.refresh_cache = True
# Should use task.grab_config or backup of grab_config
task.setup_grab_config(res['grab_config_backup'])
self.add_task(task)
# TODO: allow to write error handlers
def find_task_handler(self, task):
if task.origin_task_generator is not None:
return self.handler_for_inline_task
callback = task.get('callback')
if callback:
return callback
else:
try:
handler = getattr(self, 'task_%s' % task.name)
except AttributeError:
raise NoTaskHandler('No handler or callback defined for '
'task %s' % task.name)
else:
return handler
def handler_for_inline_task(self, grab, task):
# It can be subroutine for the first call,
# So we should check it
if isinstance(task, types.GeneratorType):
coroutines_stack = []
sendval = None
origin_task_generator = task
target = origin_task_generator
else:
coroutines_stack = task.coroutines_stack
sendval = grab
origin_task_generator = task.origin_task_generator
target = origin_task_generator
while True:
try:
result = target.send(sendval)
# If it is subroutine we have to initialize it and
# save coroutine in the coroutines stack
if isinstance(result, types.GeneratorType):
coroutines_stack.append(target)
sendval = None
target = result
origin_task_generator = target
else:
new_task = result
new_task.origin_task_generator = origin_task_generator
new_task.coroutines_stack = coroutines_stack
self.add_task(new_task)
return
except StopIteration:
# If coroutine is over we should check coroutines stack,
# may be it is subroutine
if coroutines_stack:
target = coroutines_stack.pop()
origin_task_generator = target
else:
return
def process_network_result(self, res, from_cache=False):
"""
Handle result received from network transport of
from the cache layer.
Find handler function for that task and call it.
"""
# Increase stat counters
self.inc_count('request-processed')
self.inc_count('task')
self.inc_count('task-%s' % res['task'].name)
if (res['task'].network_try_count == 1
and res['task'].task_try_count == 1):
self.inc_count('task-%s-initial' % res['task'].name)
# Update traffic statistics
if res['grab'] and res['grab'].response:
self.timers['network-name-lookup'] +=\
res['grab'].response.name_lookup_time
self.timers['network-connect'] += res['grab'].response.connect_time
self.timers['network-total'] += res['grab'].response.total_time
if not from_cache:
self.inc_count('download-size',
res['grab'].response.download_size)
self.inc_count('upload-size', res['grab'].response.upload_size)
self.inc_count('download-size-with-cache',
res['grab'].response.download_size)
self.inc_count('upload-size-with-cache',
res['grab'].response.upload_size)
handler = self.find_task_handler(res['task'])
self.execute_task_handler(res, handler)
def change_proxy(self, task, grab):
"""
Assign new proxy from proxylist to the task.
"""
if task.use_proxylist and self.proxylist_enabled:
if self.proxy_auto_change:
self.proxy = self.proxylist.get_random()
if self.proxy:
proxy, proxy_userpwd, proxy_type = self.proxy
grab.setup(proxy=proxy,
proxy_userpwd=proxy_userpwd,
proxy_type=proxy_type)
def process_new_task(self, task):
"""
Handle new task.
1) Setup Grab object for that task
2) Try to load task from the cache
3) If no cached data then submit task to network transport
"""
grab = self.setup_grab_for_task(task)
grab_config_backup = grab.dump_config()
cache_result = None
if self.is_task_cacheable(task, grab):
with self.save_timer('cache'):
with self.save_timer('cache.read'):
cache_result = self.load_task_from_cache(
self.transport, task, grab, grab_config_backup)
if cache_result:
logger_verbose.debug('Task data is loaded from the cache. '
'Yielding task result.')
self.process_network_result(cache_result, from_cache=True)
self.inc_count('task-%s-cache' % task.name)
else:
if self.only_cache:
logger.debug('Skipping network request to %s' %
grab.config['url'])
else:
self.inc_count('request-network')
self.inc_count('task-%s-network' % task.name)
self.change_proxy(task, grab)
with self.save_timer('network_transport'):
logger_verbose.debug('Submitting task to the transport '
'layer')
try:
self.transport.process_task(task, grab,
grab_config_backup)
except GrabInvalidUrl:
logger.debug('Task %s has invalid URL: %s' %
(task.name, task.url))
self.add_item('invalid-url', task.url)
else:
logger_verbose.debug('Asking transport layer to do '
'something')
def is_valid_for_cache(self, res):
"""
Check if network transport result could
be saved to cache layer.
res: {ok, grab, grab_config_backup, task, emsg}
"""
if res['ok']:
if self.cache_enabled:
if res['grab'].request_method == 'GET':
if not res['task'].get('disable_cache'):
if self.valid_response_code(res['grab'].response.code,
res['task']):
return True
return False
def stop(self):
"""
This method set internal flag which signal spider
to stop processing new task and shuts down.
"""
logger_verbose.debug('Method `stop` was called')
self.work_allowed = False
def run(self):
"""
Main method. All work is done here.
"""
self.start_timer('total')
self.transport = MulticurlTransport(self.thread_number)
try:
self.setup_default_queue()
self.prepare()
self.start_timer('task_generator')
if not self.slave:
self.init_task_generator()
self.stop_timer('task_generator')
while self.work_allowed:
self.start_timer('task_generator')
if self.task_generator_enabled:
self.process_task_generator()
self.stop_timer('task_generator')
free_threads = self.transport.get_free_threads_number()
if free_threads:
logger_verbose.debug(
'Transport has free resources (%d). '
'Trying to add new task (if exists).' % free_threads)
# Try five times to get new task and proces task generator
# because slave parser could agressively consume
# tasks from task queue
for x in six.moves.range(5):
task = self.load_new_task()
if task is None:
if not self.transport.active_task_number():
self.process_task_generator()
elif task is True:
# If only delayed tasks in queue
break
else:
# If got some task
break
if not task:
if not self.transport.active_task_number():
logger_verbose.debug('Network transport has no '
'active tasks')
if not self.task_generator_enabled:
self.stop()
else:
logger_verbose.debug(
'Transport active tasks: %d' %
self.transport.active_task_number())
elif isinstance(task, NullTask):
logger_verbose.debug('Got NullTask')
if not self.transport.active_task_number():
if task.sleep:
logger.debug('Got NullTask with sleep '
'instruction. Sleeping for'
' %.2f seconds' % task.sleep)
time.sleep(task.sleep)
elif isinstance(task, bool) and (task is True):
# Take some sleep to not load CPU
if not self.transport.active_task_number():
time.sleep(0.1)
else:
logger_verbose.debug(
'Got new task from task queue: %s' % task)
self.process_task_counters(task)
is_valid, reason = self.check_task_limits(task)
if not is_valid:
logger_verbose.debug('Task %s is rejected due to '
'%s limit' %
(task.name, reason))
if reason == 'task-try-count':
self.add_item('task-count-rejected', task.url)
elif reason == 'network-try-count':
self.add_item('network-count-rejected',
task.url)
else:
raise SpiderError('Unknown response from '
'check_task_limits: %s' %
reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
else:
self.process_new_task(task)
self.transport.process_handlers()
with self.save_timer('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Iterate over network trasport ready results
# Each result could be valid or failed
# Result format: {ok, grab, grab_config_backup, task, emsg}
# print '[transport iterate results - start]'
for result in self.transport.iterate_results():
if self.is_valid_for_cache(result):
with self.save_timer('cache'):
with self.save_timer('cache.write'):
self.cache.save_response(
result['task'].url, result['grab'])
# print '[process network results]'
self.process_network_result(result)
# print '[done]'
self.inc_count('request')
# print '[transport iterate results - end]'
logger_verbose.debug('Work done')
except KeyboardInterrupt:
print('\nGot ^C signal in process %d. Stopping.' % os.getpid())
self.interrupted = True
raise
finally:
# This code is executed when main cycles is breaked
self.stop_timer('total')
self.shutdown()
def load_proxylist(self,
source,
source_type,
proxy_type='http',
auto_init=True,
auto_change=True,
**kwargs):
self.proxylist = ProxyList(source,
source_type,
proxy_type=proxy_type,
**kwargs)
self.proxylist_enabled = True
self.proxy = None
if not auto_change and auto_init:
self.proxy = self.proxylist.get_random()
self.proxy_auto_change = auto_change
# ****************
# Abstract methods
# ****************
def shutdown(self):
"""
You can override this method to do some final actions
after parsing has been done.
"""
logger.debug('Job done!')
def task_generator(self):
"""
You can override this method to load new tasks smoothly.
It will be used each time as number of tasks
in task queue is less then number of threads multiplied on 2
This allows you to not overload all free memory if total number of
tasks is big.
"""
if False:
# Some magic to make this function empty generator
yield ':-)'
return
def process_handler_result(self, result, task=None):
"""
Process result received from the task handler.
Result could be:
* None
* Task instance
* Data instance.
"""
if isinstance(result, Task):
self.add_task(result)
elif isinstance(result, Data):
handler = self.find_data_handler(result)
try:
data_result = handler(**result.storage)
if data_result is None:
pass
else:
for something in data_result:
self.process_handler_result(something, task)
except Exception as ex:
self.process_handler_error('data_%s' % result.handler_key, ex,
task)
elif result is None:
pass
elif isinstance(result, NullTask):
pass
else:
raise SpiderError('Unknown result type: %s' % result)
@classmethod
def get_spider_name(cls):
if hasattr(cls, 'spider_name'):
return cls.spider_name
else:
return camel_case_to_underscore(cls.__name__)
@classmethod
def setup_spider_config(cls, config):
pass
def process_next_page(self,
grab,
task,
xpath,
resolve_base=False,
**kwargs):
"""
Generate task for next page.
:param grab: Grab instance
:param task: Task object which should be assigned to next page url
:param xpath: xpath expression which calculates list of URLS
:param **kwargs: extra settings for new task object
Example::
self.follow_links(grab, 'topic', '//div[@class="topic"]/a/@href')
"""
try:
# next_url = grab.xpath_text(xpath)
next_url = grab.doc.select(xpath).text()
except IndexError:
return False
else:
url = grab.make_url_absolute(next_url, resolve_base=resolve_base)
page = task.get('page', 1) + 1
grab2 = grab.clone()
grab2.setup(url=url)
task2 = task.clone(task_try_count=0,
grab=grab2,
page=page,
**kwargs)
self.add_task(task2)
return True
class Spider(SpiderMetaClassMixin, SpiderPattern, SpiderStat):
"""
Asynchronous scraping framework.
"""
# You can define here some urls and initial tasks
# with name "initial" will be created from these
# urls
# If the logic of generating initial tasks is complex
# then consider to use `task_generator` method instead of
# `initial_urls` attribute
initial_urls = None
# The base url which is used to resolve all relative urls
# The resolving takes place in `add_task` method
base_url = None
middlewares = []
middleware_points = {
'response': [],
}
class Meta:
# Meta.abstract means that this class will not be
# collected to spider registry by `grab crawl` CLI command.
# The Meta is inherited by descendant classes BUT
# Meta.abstract is reset to False in each descendant
abstract = True
def __init__(
self,
thread_number=3,
network_try_limit=10,
task_try_limit=10,
request_pause=NULL,
priority_mode='random',
meta=None,
only_cache=False,
config=None,
slave=False,
max_task_generator_chunk=None,
args=None,
# New options start here
waiting_shutdown_event=None,
taskq=None,
result_queue=None,
network_response_queue=None,
shutdown_event=None,
generator_done_event=None,
ng=False,
):
"""
Arguments:
* thread-number - Number of concurrent network streams
* network_try_limit - How many times try to send request
again if network error was occurred, use 0 to disable
* network_try_limit - Limit of tries to execute some task
this is not the same as network_try_limit
network try limit limits the number of tries which
are performed automatically in case of network timeout
of some other physical error
but task_try_limit limits the number of attempts which
are scheduled manually in the spider business logic
* priority_mode - could be "random" or "const"
* meta - arbitrary user data
* retry_rebuild_user_agent - generate new random user-agent for each
network request which is performed again due to network error
* args - command line arguments parsed with `setup_arg_parser` method
New options:
* waiting_shutdown_event=None,
* taskq=None,
* result_queue=None,
* newtork_response_queue=None,
* shutdown_event=None,
* generator_done_event=None):
"""
# New options starts
self.waiting_shutdown_event = waiting_shutdown_event
self.taskq = taskq
self.result_queue = result_queue
self.shutdown_event = shutdown_event
self.generator_done_event = generator_done_event
self.network_response_queue = network_response_queue
self.ng = ng
# New options ends
if args is None:
self.args = {}
else:
self.args = args
self.slave = slave
self.max_task_generator_chunk = max_task_generator_chunk
self.timers = {
'network-name-lookup': 0,
'network-connect': 0,
'network-total': 0,
}
self.time_points = {}
self.start_timer('total')
if config is not None:
self.config = config
else:
# Fix circular import error
from grab.util.config import Config
self.config = Config()
if meta:
self.meta = meta
else:
self.meta = {}
self.task_generator_enabled = False
self.only_cache = only_cache
self.thread_number = thread_number
self.counters = defaultdict(int)
self._grab_config = {}
self.items = {}
self.task_try_limit = task_try_limit
self.network_try_limit = network_try_limit
if priority_mode not in ['random', 'const']:
raise SpiderMisuseError('Value of priority_mode option should be '
'"random" or "const"')
else:
self.priority_mode = priority_mode
try:
signal.signal(signal.SIGUSR1, self.sigusr1_handler)
except (ValueError, AttributeError):
pass
try:
signal.signal(signal.SIGUSR2, self.sigusr2_handler)
except (ValueError, AttributeError):
pass
# Initial cache-subsystem values
self.cache_enabled = False
self.cache = None
self.work_allowed = True
if request_pause is not NULL:
logger.error('Option `request_pause` is deprecated and is not '
'supported anymore')
self.proxylist_enabled = None
self.proxylist = None
self.proxy = None
self.proxy_auto_change = False
# FIXIT: REMOVE
self.dump_spider_stats = None
self.controller = CommandController(self)
# snapshots contains information about spider's state
# for each 10 seconds interval
self.snapshots = {}
self.last_snapshot_values = {
'timestamp': 0,
'download-size': 0,
'upload-size': 0,
'download-size-with-cache': 0,
'request-count': 0,
}
self.snapshot_timestamps = []
self.snapshot_interval = self.config.get('GRAB_SNAPSHOT_CONFIG',
{}).get('interval', 10)
self.snapshot_file = self.config.get('GRAB_SNAPSHOT_CONFIG',
{}).get('file', None)
if self.snapshot_file:
open(self.snapshot_file, 'w').write('')
def get_grab_config(self):
logger.error('Using `grab_config` attribute is deprecated. Override '
'`create_grab_instance method instead.')
return self._grab_config
def set_grab_config(self, val):
logger.error('Using `grab_config` attribute is deprecated. Override '
'`create_grab_instance method instead.')
self._grab_config = val
grab_config = property(get_grab_config, set_grab_config)
def setup_middleware(self, middleware_list):
for item in middleware_list:
self.middlewares.append(item)
mod_path, cls_name = item.rsplit('.', 1)
mod = __import__(mod_path, None, None, ['foo'])
cls = getattr(mod, cls_name)
mid = cls()
if hasattr(mid, 'process_response'):
self.middleware_points['response'].append(mid)
def setup_cache(self,
backend='mongo',
database=None,
use_compression=True,
**kwargs):
if database is None:
raise SpiderMisuseError('setup_cache method requires database '
'option')
self.cache_enabled = True
mod = __import__('grab.spider.cache_backend.%s' % backend, globals(),
locals(), ['foo'])
self.cache = mod.CacheBackend(database=database,
use_compression=use_compression,
spider=self,
**kwargs)
def setup_queue(self, backend='memory', **kwargs):
logger.debug('Using %s backend for task queue' % backend)
mod = __import__('grab.spider.queue_backend.%s' % backend, globals(),
locals(), ['foo'])
self.taskq = mod.QueueBackend(spider_name=self.get_name(), **kwargs)
def prepare(self):
"""
You can do additional spider customization here
before it has started working. Simply redefine
this method in your Spider class.
"""
def sigusr1_handler(self, signal, frame):
"""
Catches SIGUSR1 signal and dumps current state
to temporary file
"""
with open('/tmp/spider.state', 'w') as out:
out.write(self.render_stats())
def sigusr2_handler(self, signal, frame):
"""
Catches SIGUSR1 signal and shutdowns spider.
"""
logger.error('Received SIGUSR2 signal. Doing shutdown')
self.stop()
def setup_grab(self, **kwargs):
logging.error('This method is deprecated. Instead override '
'`create_grab_instance` method in you spider sub-class')
self.grab_config.update(**kwargs)
def check_task_limits(self, task):
"""
Check that network/try counters are OK.
Returns:
* if success: (True, None)
* if error: (False, reason)
"""
if task.task_try_count > self.task_try_limit:
logger.debug('Task tries (%d) ended: %s / %s' %
(self.task_try_limit, task.name, task.url))
return False, 'task-try-count'
if task.network_try_count > self.network_try_limit:
logger.debug('Network tries (%d) ended: %s / %s' %
(self.network_try_limit, task.name, task.url))
return False, 'network-try-count'
return True, None
def generate_task_priority(self):
if self.priority_mode == 'const':
return DEFAULT_TASK_PRIORITY
else:
return randint(*RANDOM_TASK_PRIORITY_RANGE)
def add_task(self, task):
"""
Add task to the task queue.
"""
if self.taskq is None:
raise SpiderMisuseError('You should configure task queue before '
'adding tasks. Use `setup_queue` method.')
if task.priority is None or not task.priority_is_custom:
task.priority = self.generate_task_priority()
task.priority_is_custom = False
else:
task.priority_is_custom = True
if not isinstance(task, NullTask):
if not task.url.startswith(
('http://', 'https://', 'ftp://', 'file://', 'feed://')):
if self.base_url is None:
msg = 'Could not resolve relative URL because base_url ' \
'is not specified. Task: %s, URL: %s'\
% (task.name, task.url)
logger.error(msg)
self.add_item('task-with-invalid-url', task.url)
return False
else:
task.url = urljoin(self.base_url, task.url)
# If task has grab_config object then update it too
if task.grab_config:
task.grab_config['url'] = task.url
# TODO: keep original task priority if it was set explicitly
self.taskq.put(task, task.priority, schedule_time=task.schedule_time)
is_valid = True
return is_valid
def load_initial_urls(self):
"""
Create initial tasks from `self.initial_urls`.
Tasks are created with name "initial".
"""
if self.initial_urls:
for url in self.initial_urls:
self.add_task(Task('initial', url=url))
def setup_default_queue(self):
"""
If task queue is not configured explicitly
then create task queue with default parameters
This method is not the same as `self.setup_queue` because
`self.setup_queue` works by default with in-memory queue.
You can override `setup_default_queue` in your custom
Spider and use other storage engines for you
default task queue.
"""
# If queue is still not configured
# then configure it with default backend
if self.taskq is None:
self.setup_queue()
def process_task_generator(self):
"""
Load new tasks from `self.task_generator_object`
Create new tasks.
If task queue size is less than some value
then load new tasks from tasks file.
"""
if self.task_generator_enabled:
if hasattr(self.taskq, 'qsize'):
qsize = self.taskq.qsize()
else:
qsize = self.taskq.size()
if self.max_task_generator_chunk is not None:
min_limit = min(self.max_task_generator_chunk,
self.thread_number * 10)
else:
min_limit = self.thread_number * 10
if qsize < min_limit:
logger_verbose.debug('Task queue contains less tasks than '
'limit. Trying to add new tasks')
try:
for x in xrange(min_limit - qsize):
item = next(self.task_generator_object)
logger_verbose.debug('Got new item from generator. '
'Processing it.')
#self.add_task(item)
self.process_handler_result(item)
except StopIteration:
# If generator have no values to yield
# then disable it
logger_verbose.debug('Task generator has no more tasks. '
'Disabling it')
self.task_generator_enabled = False
def init_task_generator(self):
"""
Process `initial_urls` and `task_generator`.
Generate first portion of tasks.
TODO: task generator should work in separate OS process
"""
self.task_generator_object = self.task_generator()
self.task_generator_enabled = True
logger_verbose.debug('Processing initial urls')
self.load_initial_urls()
# Initial call to task generator
# before main cycle
self.process_task_generator()
def load_new_task(self):
start = time.time()
while True:
try:
with self.save_timer('task_queue'):
return self.taskq.get()
except queue.Empty:
if self.taskq.size():
logger_verbose.debug('Waiting for scheduled task')
return True
if not self.slave:
logger_verbose.debug('Task queue is empty.')
return None
else:
# Temporarily hack which force slave crawler
# to wait 5 seconds for new tasks, this solves
# the problem that sometimes slave crawler stop
# its work because it could not receive new
# tasks immediately
if not self.transport.active_task_number():
if time.time() - start < 5:
time.sleep(0.1)
logger.debug('Slave sleeping')
else:
break
else:
break
logger_verbose.debug('Task queue is empty.')
return None
def process_task_counters(self, task):
task.network_try_count += 1
if task.task_try_count == 0:
task.task_try_count = 1
def create_grab_instance(self, **kwargs):
# Back-ward compatibility for deprecated `grab_config` attribute
# Use _grab_config to not trigger warning messages
if self._grab_config and kwargs:
merged_config = deepcopy(self._grab_config)
merged_config.update(kwargs)
return Grab(**merged_config)
elif self._grab_config and not kwargs:
return Grab(**self._grab_config)
else:
return Grab(**kwargs)
def setup_grab_for_task(self, task):
grab = self.create_grab_instance()
if task.grab_config:
grab.load_config(task.grab_config)
else:
grab.setup(url=task.url)
# Generate new common headers
grab.config['common_headers'] = grab.common_headers()
return grab
def is_task_cacheable(self, task, grab):
if ( # cache is disabled for all tasks
not self.cache_enabled
# cache data should be refreshed
or task.get('refresh_cache', False)
# cache could not be used
or task.get('disable_cache', False)
# request type is not cacheable
or grab.detect_request_method() != 'GET'):
return False
else:
return True
def load_task_from_cache(self, transport, task, grab, grab_config_backup):
cache_item = self.cache.get_item(grab.config['url'],
timeout=task.cache_timeout)
if cache_item is None:
return None
else:
with self.save_timer('cache.read.prepare_request'):
grab.prepare_request()
with self.save_timer('cache.read.load_response'):
self.cache.load_response(grab, cache_item)
grab.log_request('CACHED')
self.inc_count('request')
self.inc_count('request-cache')
return {
'ok': True,
'grab': grab,
'grab_config_backup': grab_config_backup,
'task': task,
'emsg': None
}
def valid_response_code(self, code, task):
"""
Answer the question: if the response could be handled via
usual task handler or the task faield and should be processed as error.
"""
return (code < 400 or code == 404 or code in task.valid_status)
def process_handler_error(self, func_name, ex, task, error_tb=None):
self.inc_count('error-%s' % ex.__class__.__name__.lower())
if error_tb is not None:
logger.error('Error in %s function' % func_name)
logger.error(error_tb)
else:
logger.error('Error in %s function' % func_name, exc_info=ex)
# Looks strange but I really have some problems with
# serializing exception into string
try:
ex_str = unicode(ex)
except TypeError:
try:
ex_str = unicode(ex, 'utf-8', 'ignore')
except TypeError:
ex_str = str(ex)
task_url = task.url if task is not None else None
self.add_item(
'fatal', '%s|%s|%s|%s' %
(func_name, ex.__class__.__name__, ex_str, task_url))
if isinstance(ex, FatalError):
raise
def find_data_handler(self, data):
try:
return getattr(data, 'handler')
except AttributeError:
try:
handler = getattr(self, 'data_%s' % data.handler_key)
except AttributeError:
raise NoDataHandler('No handler defined for Data %s' %
data.handler_key)
else:
return handler
def execute_task_handler(self, res, handler):
"""
Apply `handler` function to the network result.
If network result is failed then submit task again
to the network task queue.
"""
try:
handler_name = handler.__name__
except AttributeError:
handler_name = 'NONE'
if (res['task'].get('raw') or (res['ok'] and self.valid_response_code(
res['grab'].response.code, res['task']))):
try:
with self.save_timer('response_handler'):
with self.save_timer('response_handler.%s' % handler_name):
result = handler(res['grab'], res['task'])
if result is None:
pass
else:
for item in result:
self.process_handler_result(item, res['task'])
except NoDataHandler as ex:
raise
except Exception as ex:
self.process_handler_error(handler_name, ex, res['task'])
else:
self.inc_count('task-%s-ok' % res['task'].name)
else:
# Log the error
if res['ok']:
msg = res['emsg'] = 'HTTP %s' % res['grab'].response.code
else:
msg = res['emsg']
# TODO: REMOVE
#if 'Operation timed out after' in msg:
#num = int(msg.split('Operation timed out after')[1].strip().split(' ')[0])
#if num > 20000:
#import pdb; pdb.set_trace()
self.inc_count('network-error-%s' % res['emsg'][:20])
logger.error(u'Network error: %s' % msg)
# Try to repeat the same network query
if self.network_try_limit > 0:
task = res['task']
task.refresh_cache = True
# Should use task.grab_config or backup of grab_config
task.setup_grab_config(res['grab_config_backup'])
self.add_task(task)
# TODO: allow to write error handlers
def find_task_handler(self, task):
callback = task.get('callback')
if callback:
return callback
else:
try:
handler = getattr(self, 'task_%s' % task.name)
except AttributeError:
raise NoTaskHandler('No handler or callback defined for '
'task %s' % task.name)
else:
return handler
def process_network_result(self, res, from_cache=False):
"""
Handle result received from network transport of
from the cache layer.
Find handler function for that task and call it.
"""
# Increase stat counters
self.inc_count('request-processed')
self.inc_count('task')
self.inc_count('task-%s' % res['task'].name)
if (res['task'].network_try_count == 1
and res['task'].task_try_count == 1):
self.inc_count('task-%s-initial' % res['task'].name)
# Update traffic statistics
if res['grab'] and res['grab'].response:
self.timers['network-name-lookup'] += res[
'grab'].response.name_lookup_time
self.timers['network-connect'] += res['grab'].response.connect_time
self.timers['network-total'] += res['grab'].response.total_time
if not from_cache:
self.inc_count('download-size',
res['grab'].response.download_size)
self.inc_count('upload-size', res['grab'].response.upload_size)
self.inc_count('download-size-with-cache',
res['grab'].response.download_size)
self.inc_count('upload-size-with-cache',
res['grab'].response.upload_size)
#self.inc_count('traffic-in
# NG
# FIX: Understand how it should work in NG spider
# TOFIX: start
stop = False
for mid in self.middleware_points['response']:
try:
mid_response = mid.process_response(self, res)
except StopTaskProcessing:
logger.debug('Got StopTaskProcessing exception')
stop = True
break
else:
if isinstance(mid_response, Task):
logger.debug('Got task from middleware')
self.add_task(mid_response)
stop = True
break
elif mid_response is None:
pass
else:
raise Exception('Unknown response from middleware %s' %
mid)
# TOFIX: end
if stop:
return
if self.ng:
logger_verbose.debug('Submitting result for task %s to response'
' queue' % res['task'])
self.network_response_queue.put(res)
else:
handler = self.find_task_handler(res['task'])
self.execute_task_handler(res, handler)
def change_proxy(self, task, grab):
"""
Assign new proxy from proxylist to the task.
"""
if task.use_proxylist and self.proxylist_enabled:
if self.proxy_auto_change:
self.proxy = self.proxylist.get_random()
if self.proxy:
proxy, proxy_userpwd, proxy_type = self.proxy
grab.setup(proxy=proxy,
proxy_userpwd=proxy_userpwd,
proxy_type=proxy_type)
def process_new_task(self, task):
"""
Handle new task.
1) Setup Grab object for that task
2) Try to load task from the cache
3) If no cached data then submit task to network transport
"""
grab = self.setup_grab_for_task(task)
grab_config_backup = grab.dump_config()
cache_result = None
if self.is_task_cacheable(task, grab):
with self.save_timer('cache'):
with self.save_timer('cache.read'):
cache_result = self.load_task_from_cache(
self.transport, task, grab, grab_config_backup)
if cache_result:
logger_verbose.debug('Task data is loaded from the cache. '
'Yielding task result.')
self.process_network_result(cache_result, from_cache=True)
self.inc_count('task-%s-cache' % task.name)
else:
if self.only_cache:
logger.debug('Skipping network request to %s' %
grab.config['url'])
else:
self.inc_count('request-network')
self.inc_count('task-%s-network' % task.name)
self.change_proxy(task, grab)
with self.save_timer('network_transport'):
logger_verbose.debug('Submitting task to the transport '
'layer')
try:
self.transport.process_task(task, grab,
grab_config_backup)
except GrabInvalidUrl as ex:
logger.debug('Task %s has invalid URL: %s' %
(task.name, task.url))
self.add_item('invalid-url', task.url)
else:
logger_verbose.debug('Asking transport layer to do '
'something')
def is_valid_for_cache(self, res):
"""
Check if network transport result could
be saved to cache layer.
res: {ok, grab, grab_config_backup, task, emsg}
"""
if res['ok']:
if self.cache_enabled:
if res['grab'].request_method == 'GET':
if not res['task'].get('disable_cache'):
if self.valid_response_code(res['grab'].response.code,
res['task']):
return True
return False
def stop(self):
"""
This method set internal flag which signal spider
to stop processing new task and shuts down.
"""
logger_verbose.debug('Method `stop` was called')
self.work_allowed = False
def run(self):
"""
Main method. All work is done here.
"""
self.start_timer('total')
self.transport = MulticurlTransport(self.thread_number)
try:
self.setup_default_queue()
self.prepare()
self.start_timer('task_generator')
if not self.slave:
if not self.ng:
self.init_task_generator()
self.stop_timer('task_generator')
while self.work_allowed:
now = int(time.time())
if now - self.last_snapshot_values[
'timestamp'] > self.snapshot_interval:
snapshot = {'timestamp': now}
for key in ('download-size', 'upload-size',
'download-size-with-cache'):
snapshot[key] = self.counters[
key] - self.last_snapshot_values[key]
self.last_snapshot_values[key] = self.counters[key]
snapshot['request-count'] = self.counters['request'] -\
self.last_snapshot_values['request-count']
self.last_snapshot_values['request-count'] = self.counters[
'request']
self.last_snapshot_values['timestamp'] = now
self.snapshots[now] = snapshot
self.snapshot_timestamps.append(now)
if self.snapshot_file:
with open(self.snapshot_file, 'a') as out:
out.write(json.dumps(snapshot) + '\n')
# FIXIT: REMOVE
# Run update task handler which
# updates database object which stores
# info about current scraping process
if self.dump_spider_stats:
self.dump_spider_stats(self)
if self.controller.enabled:
self.controller.process_commands()
if not self.ng:
# NG
self.start_timer('task_generator')
# star
if self.task_generator_enabled:
self.process_task_generator()
self.stop_timer('task_generator')
if self.transport.ready_for_task():
logger_verbose.debug('Transport has free resources. '
'Trying to add new task (if exists)')
# Try five times to get new task and proces task generator
# because slave parser could agressively consume
# tasks from task queue
for x in xrange(5):
task = self.load_new_task()
if task is None:
if not self.transport.active_task_number():
self.process_task_generator()
elif task is True:
# If only delayed tasks in queue
break
else:
# If got some task
break
if not task:
if not self.transport.active_task_number():
logger_verbose.debug('Network transport has no '
'active tasks')
# NG
if self.ng:
self.waiting_shutdown_event.set()
if self.shutdown_event.is_set():
logger_verbose.debug('Got shutdown signal')
self.stop()
else:
logger_verbose.debug('Shutdown event has'
' not been set yet')
else:
if not self.task_generator_enabled:
self.stop()
else:
logger_verbose.debug(
'Transport active tasks: %d' %
self.transport.active_task_number())
elif isinstance(task, NullTask):
logger_verbose.debug('Got NullTask')
if not self.transport.active_task_number():
if task.sleep:
logger.debug('Got NullTask with sleep '
'instruction. Sleeping for'
' %.2f seconds' % task.sleep)
time.sleep(task.sleep)
elif isinstance(task, bool) and (task is True):
pass
else:
if self.ng:
if self.waiting_shutdown_event.is_set():
self.waiting_shutdown_event.clear()
logger_verbose.debug(
'Got new task from task queue: %s' % task)
self.process_task_counters(task)
is_valid, reason = self.check_task_limits(task)
if not is_valid:
logger_verbose.debug('Task %s is rejected due to '
'%s limit' %
(task.name, reason))
if reason == 'task-try-count':
self.add_item('task-count-rejected', task.url)
elif reason == 'network-try-count':
self.add_item('network-count-rejected',
task.url)
else:
raise Exception('Unknown response from '
'check_task_limits: %s' %
reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
# TODO: not do following line
# TODO: middleware: TaskFails
else:
self.process_new_task(task)
self.transport.process_handlers()
with self.save_timer('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Iterate over network trasport ready results
# Each result could be valid or failed
# Result format: {ok, grab, grab_config_backup, task, emsg}
#print '[transport iterate results - start]'
for result in self.transport.iterate_results():
if self.is_valid_for_cache(result):
with self.save_timer('cache'):
with self.save_timer('cache.write'):
self.cache.save_response(
result['task'].url, result['grab'])
#print '[process network results]'
self.process_network_result(result)
#print '[done]'
self.inc_count('request')
#print '[transport iterate results - end]'
logger_verbose.debug('Work done')
except KeyboardInterrupt:
print('\nGot ^C signal. Stopping.')
raise
finally:
# This code is executed when main cycles is breaked
self.stop_timer('total')
self.shutdown()
def load_proxylist(self,
source,
source_type,
proxy_type='http',
auto_init=True,
auto_change=True,
**kwargs):
self.proxylist = ProxyList(source,
source_type,
proxy_type=proxy_type,
**kwargs)
self.proxylist_enabled = True
self.proxy = None
if not auto_change and auto_init:
self.proxy = self.proxylist.get_random()
self.proxy_auto_change = auto_change
def get_name(self):
if hasattr(self, 'spider_name'):
return self.spider_name
else:
return camel_case_to_underscore(self.__class__.__name__)
# ****************
# Abstract methods
# ****************
def shutdown(self):
"""
You can override this method to do some final actions
after parsing has been done.
"""
logger.debug('Job done!')
def task_generator(self):
"""
You can override this method to load new tasks smoothly.
It will be used each time as number of tasks
in task queue is less then number of threads multiplied on 2
This allows you to not overload all free memory if total number of
tasks is big.
"""
if False:
# Some magic to make this function empty generator
yield ':-)'
return
def process_handler_result(self, result, task=None):
"""
Process result received from the task handler.
Result could be:
* None
* Task instance
* Data instance.
"""
if isinstance(result, Task):
self.add_task(result)
elif isinstance(result, Data):
handler = self.find_data_handler(result)
try:
data_result = handler(**result.storage)
if data_result is None:
pass
else:
for something in data_result:
self.process_handler_result(something, task)
except Exception as ex:
self.process_handler_error('data_%s' % result.handler_key, ex,
task)
elif result is None:
pass
else:
raise SpiderError('Unknown result type: %s' % result)
@classmethod
def get_spider_name(cls):
if hasattr(cls, 'spider_name'):
return cls.spider_name
else:
return camel_case_to_underscore(cls.__name__)
@classmethod
def setup_spider_config(cls, config):
pass
# ***********
# NG Features
# ***********
def run_generator(self):
"""
Generate tasks and put them into Task Queue.
This is main method for Generator Process
"""
self.init_task_generator()
while True:
if not self.task_generator_enabled:
self.generator_done_event.set()
if self.shutdown_event.is_set():
logger.info('Got shutdown event')
break
time.sleep(1)
self.process_task_generator()
def run_parser(self):
"""
Process items received from Network Response Queue.
Network Response Queue are filled by Downloader Process.
This is main method for Parser Process.
"""
should_work = True
while should_work:
try:
response = self.network_response_queue.get(True, 0.1)
except queue.Empty:
logger_verbose.debug('Response queue is empty.')
response = None
if not response:
self.waiting_shutdown_event.set()
if self.shutdown_event.is_set():
logger_verbose.debug('Got shutdown signal')
should_work = False
else:
logger_verbose.debug('Shutdown event has not been set yet')
else:
if self.waiting_shutdown_event.is_set():
self.waiting_shutdown_event.clear()
logger_verbose.debug('Got new response from response '
'queue: %s' % response['task'].url)
handler = self.find_task_handler(response['task'])
self.execute_task_handler(response, handler)
logger_verbose.debug('Work done')
# TODO:
# Develop Manager Process which contains logic of accepting or rejecting
# task objects received from Parser Processes
# Maybe Manager Process also should controls the Data flow
# TODO2:
# Data handler process
#def run_manager(self):
#try:
#self.start_time = time.time()
#self.prepare()
#res_count = 0
#while True:
#try:
#res = self.result_queue.get(block=True, timeout=2)
#except Queue.Empty:
##pass
#res = None
#if res is None:
#logging.error('res is None: stopping')
#break
#if self.should_stop:
#break
#if self.task_generator_enabled:
#self.process_task_generator()
#for task, original_task in res['task_list']:
#logging.debug('Processing task items from result queue')
#self.process_handler_result(task)
##for data, original_task in res['data_list']:
##logging.debug('Processing data items from result queue')
##self.process_handler_result(data)
#except KeyboardInterrupt:
#print '\nGot ^C signal. Stopping.'
#print self.render_stats()
#raise
#finally:
## This code is executed when main cycles is breaked
#self.shutdown()
def command_get_stats(self, command):
return {'data': self.render_stats()}
@classmethod
def get_available_command_names(cls):
spider = cls()
clist = []
for key in dir(spider):
if key.startswith('command_'):
clist.append(key.split('command_', 1)[1])
return sorted(clist)
def run(self):
"""
Main method. All work is done here.
"""
if self.mp_mode:
from multiprocessing import Process, Event, Queue
else:
from multiprocessing.dummy import Process, Event, Queue
self.timer.start('total')
self.transport = MulticurlTransport(self.thread_number)
if self.http_api_port:
http_api_proc = self.start_api_thread()
else:
http_api_proc = None
self.parser_pipeline = ParserPipeline(
bot=self,
mp_mode=self.mp_mode,
pool_size=self.parser_pool_size,
shutdown_event=self.shutdown_event,
network_result_queue=self.network_result_queue,
requests_per_process=self.parser_requests_per_process,
)
network_result_queue_limit = max(10, self.thread_number * 2)
try:
# Run custom things defined by this specific spider
# By defaut it does nothing
self.prepare()
# Setup task queue if it has not been configured yet
if self.task_queue is None:
self.setup_queue()
# Initiate task generator. Only in main process!
with self.timer.log_time('task_generator'):
self.start_task_generator()
while self.work_allowed:
with self.timer.log_time('task_generator'):
if self.task_generator_enabled:
self.process_task_generator()
result_from_cache = None
free_threads = self.transport.get_free_threads_number()
# Load new task only if self.network_result_queue is not full
if (self.transport.get_free_threads_number()
and (self.network_result_queue.qsize() <
network_result_queue_limit)):
logger_verbose.debug(
'Transport and parser have free resources. '
'Trying to load new task from task queue.')
task = self.get_task_from_queue()
# If no task received from task queue
# try to query task generator
# and then check if spider could be shuted down
if task is None:
if not self.transport.get_active_threads_number():
self.process_task_generator()
if task is None:
# If no task received from task queue
# check if spider could be shut down
if self.is_ready_to_shutdown():
self.shutdown_event.set()
self.stop()
break # Break `if self.work_allowed` cycle
elif isinstance(task, bool) and (task is True):
# Take some sleep to not load CPU
if not self.transport.get_active_threads_number():
time.sleep(0.1)
else:
logger_verbose.debug(
'Got new task from task queue: %s' % task)
task.network_try_count += 1
is_valid, reason = self.check_task_limits(task)
if is_valid:
grab = self.setup_grab_for_task(task)
grab_config_backup = grab.dump_config()
result_from_cache = None
if self.is_task_cacheable(task, grab):
result_from_cache = self.load_task_from_cache(
task, grab, grab_config_backup)
if result_from_cache:
logger_verbose.debug(
'Task data is loaded from the cache. ')
else:
if self.only_cache:
logger.debug('Skipping network request to '
'%s' % grab.config['url'])
else:
self.process_grab_proxy(task, grab)
self.submit_task_to_transport(
task, grab, grab_config_backup)
else:
self.log_rejected_task(task, reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
with self.timer.log_time('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Collect completed network results
# Each result could be valid or failed
# Result is dict {ok, grab, grab_config_backup, task, emsg}
results = [(x, False)
for x in self.transport.iterate_results()]
if result_from_cache:
results.append((result_from_cache, True))
# Some sleep to avoid thousands of iterations per second.
# If no results from network transport
if not results:
# If task queue is empty (or if there are only
# delayed tasks)
if task is None or bool(task) == True:
# If no network activity
if not self.transport.get_active_threads_number():
# If parser result queue is empty
if not self.parser_pipeline.has_results():
# Just sleep some time, do not kill CPU
time.sleep(0.1)
for result, from_cache in results:
if not from_cache:
if self.is_valid_for_cache(result):
with self.timer.log_time('cache'):
with self.timer.log_time('cache.write'):
self.cache.save_response(
result['task'].url, result['grab'])
self.log_network_result_stats(result,
from_cache=from_cache)
if self.is_valid_network_result(result):
#handler = self.find_task_handler(result['task'])
#self.process_network_result_with_handler(
# result, handler)
# MP:
# ***
self.network_result_queue.put(result)
else:
self.log_failed_network_result(result)
# Try to do network request one more time
if self.network_try_limit > 0:
result['task'].refresh_cache = True
result['task'].setup_grab_config(
result['grab_config_backup'])
self.add_task(result['task'])
if from_cache:
self.stat.inc('spider:task-%s-cache' % task.name)
self.stat.inc('spider:request')
# MP:
# ***
while True:
try:
p_res, p_task = self.parser_pipeline.get_result()
except queue.Empty:
break
else:
self.stat.inc('spider:parser-result')
self.process_handler_result(p_res, p_task)
if not self.shutdown_event.is_set():
self.parser_pipeline.check_pool_health()
logger_verbose.debug('Work done')
except KeyboardInterrupt:
logger.info('\nGot ^C signal in process %d. Stopping.' %
os.getpid())
self.interrupted = True
raise
finally:
# This code is executed when main cycles is breaked
self.timer.stop('total')
self.stat.print_progress_line()
self.shutdown()
# Stop HTTP API process
if http_api_proc:
http_api_proc.server.shutdown()
http_api_proc.join()
self.task_queue.clear()
# Stop parser processes
self.shutdown_event.set()
self.parser_pipeline.shutdown()
logger.debug('Main process [pid=%s]: work done' % os.getpid())
def run(self):
"""
Main method. All work is done here.
"""
self.start_timer('total')
self.transport = MulticurlTransport(self.thread_number)
try:
self.setup_default_queue()
self.prepare()
self.start_timer('task_generator')
if not self.slave:
if not self.ng:
self.init_task_generator()
self.stop_timer('task_generator')
while self.work_allowed:
now = int(time.time())
if now - self.last_snapshot_values[
'timestamp'] > self.snapshot_interval:
snapshot = {'timestamp': now}
for key in ('download-size', 'upload-size',
'download-size-with-cache'):
snapshot[key] = self.counters[
key] - self.last_snapshot_values[key]
self.last_snapshot_values[key] = self.counters[key]
snapshot['request-count'] = self.counters['request'] -\
self.last_snapshot_values['request-count']
self.last_snapshot_values['request-count'] = self.counters[
'request']
self.last_snapshot_values['timestamp'] = now
self.snapshots[now] = snapshot
self.snapshot_timestamps.append(now)
if self.snapshot_file:
with open(self.snapshot_file, 'a') as out:
out.write(json.dumps(snapshot) + '\n')
# FIXIT: REMOVE
# Run update task handler which
# updates database object which stores
# info about current scraping process
if self.dump_spider_stats:
self.dump_spider_stats(self)
if self.controller.enabled:
self.controller.process_commands()
if not self.ng:
# NG
self.start_timer('task_generator')
# star
if self.task_generator_enabled:
self.process_task_generator()
self.stop_timer('task_generator')
if self.transport.ready_for_task():
logger_verbose.debug('Transport has free resources. '
'Trying to add new task (if exists)')
# Try five times to get new task and proces task generator
# because slave parser could agressively consume
# tasks from task queue
for x in xrange(5):
task = self.load_new_task()
if task is None:
if not self.transport.active_task_number():
self.process_task_generator()
elif task is True:
# If only delayed tasks in queue
break
else:
# If got some task
break
if not task:
if not self.transport.active_task_number():
logger_verbose.debug('Network transport has no '
'active tasks')
# NG
if self.ng:
self.waiting_shutdown_event.set()
if self.shutdown_event.is_set():
logger_verbose.debug('Got shutdown signal')
self.stop()
else:
logger_verbose.debug('Shutdown event has'
' not been set yet')
else:
if not self.task_generator_enabled:
self.stop()
else:
logger_verbose.debug(
'Transport active tasks: %d' %
self.transport.active_task_number())
elif isinstance(task, NullTask):
logger_verbose.debug('Got NullTask')
if not self.transport.active_task_number():
if task.sleep:
logger.debug('Got NullTask with sleep '
'instruction. Sleeping for'
' %.2f seconds' % task.sleep)
time.sleep(task.sleep)
elif isinstance(task, bool) and (task is True):
pass
else:
if self.ng:
if self.waiting_shutdown_event.is_set():
self.waiting_shutdown_event.clear()
logger_verbose.debug(
'Got new task from task queue: %s' % task)
self.process_task_counters(task)
is_valid, reason = self.check_task_limits(task)
if not is_valid:
logger_verbose.debug('Task %s is rejected due to '
'%s limit' %
(task.name, reason))
if reason == 'task-try-count':
self.add_item('task-count-rejected', task.url)
elif reason == 'network-try-count':
self.add_item('network-count-rejected',
task.url)
else:
raise Exception('Unknown response from '
'check_task_limits: %s' %
reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
# TODO: not do following line
# TODO: middleware: TaskFails
else:
self.process_new_task(task)
self.transport.process_handlers()
with self.save_timer('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Iterate over network trasport ready results
# Each result could be valid or failed
# Result format: {ok, grab, grab_config_backup, task, emsg}
#print '[transport iterate results - start]'
for result in self.transport.iterate_results():
if self.is_valid_for_cache(result):
with self.save_timer('cache'):
with self.save_timer('cache.write'):
self.cache.save_response(
result['task'].url, result['grab'])
#print '[process network results]'
self.process_network_result(result)
#print '[done]'
self.inc_count('request')
#print '[transport iterate results - end]'
logger_verbose.debug('Work done')
except KeyboardInterrupt:
print('\nGot ^C signal. Stopping.')
raise
finally:
# This code is executed when main cycles is breaked
self.stop_timer('total')
self.shutdown()
def run(self):
"""
Main method. All work is done here.
"""
if self.mp_mode:
from multiprocessing import Process, Event, Queue
else:
from multiprocessing.dummy import Process, Event, Queue
self.timer.start('total')
self.transport = MulticurlTransport(self.thread_number)
if self.http_api_port:
http_api_proc = self.start_api_thread()
else:
http_api_proc = None
self.parser_result_queue = Queue()
self.parser_pipeline = ParserPipeline(
bot=self,
mp_mode=self.mp_mode,
pool_size=self.parser_pool_size,
shutdown_event=self.shutdown_event,
network_result_queue=self.network_result_queue,
parser_result_queue=self.parser_result_queue,
requests_per_process=self.parser_requests_per_process,
)
network_result_queue_limit = max(10, self.thread_number * 2)
try:
# Run custom things defined by this specific spider
# By defaut it does nothing
self.prepare()
# Setup task queue if it has not been configured yet
if self.task_queue is None:
self.setup_queue()
# Initiate task generator. Only in main process!
with self.timer.log_time('task_generator'):
self.start_task_generators()
# Work in infinite cycle untill
# `self.work_allowed` flag is True
#shutdown_countdown = 0 # !!!
pending_tasks = deque()
while self.work_allowed:
free_threads = self.transport.get_free_threads_number()
# Load new task only if:
# 1) network transport has free threads
# 2) network result queue is not full
# 3) cache is disabled OR cache has free resources
if (self.transport.get_free_threads_number()
and (self.network_result_queue.qsize()
< network_result_queue_limit)
and (self.cache_pipeline is None
or self.cache_pipeline.has_free_resources())):
if pending_tasks:
task = pending_tasks.popleft()
else:
task = self.get_task_from_queue()
if task is None:
# If received task is None then
# check if spider is ready to be shut down
if not pending_tasks and self.is_ready_to_shutdown():
#shutdown_countdown -= 1
#time.sleep(0.02)
#if shutdown_countdown <= 0:
self.shutdown_event.set()
#print('STOP!!!!!!!!!')
self.stop()
break # Break from `while self.work_allowed` cycle
elif isinstance(task, bool) and (task is True):
# If received task is True
# and there is no active network threads then
# take some sleep
if not self.transport.get_active_threads_number():
time.sleep(0.01)
else:
logger_verbose.debug('Got new task from task queue: %s'
% task)
task.network_try_count += 1
is_valid, reason = self.check_task_limits(task)
if is_valid:
task_grab = self.setup_grab_for_task(task)
if self.cache_pipeline:
self.cache_pipeline.input_queue.put(
('load', (task, task_grab)),
)
else:
self.submit_task_to_transport(task, task_grab)
else:
self.log_rejected_task(task, reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
with self.timer.log_time('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Collect completed network results
# Each result could be valid or failed
# Result is dict {ok, grab, grab_config_backup, task, emsg}
results = [(x, False) for x in
self.transport.iterate_results()]
if self.cache_pipeline:
while True:
try:
action, result = self.cache_pipeline\
.result_queue.get(False)
except queue.Empty:
break
else:
assert action in ('network_result', 'task')
if action == 'network_result':
results.append((result, True))
elif action == 'task':
task = result
task_grab = self.setup_grab_for_task(task)
if (self.transport.get_free_threads_number()
and (self.network_result_queue.qsize()
< network_result_queue_limit)):
self.submit_task_to_transport(task, task_grab)
else:
pending_tasks.append(task)
# Take sleep to avoid millions of iterations per second.
# 1) If no results from network transport
# 2) If task queue is empty (or if there are only delayed tasks)
# 3) If no network activity
# 4) If parser result queue is empty
if (not results
and (task is None or bool(task) == True)
and not self.transport.get_active_threads_number()
and not self.parser_result_queue.qsize()
and (self.cache_pipeline is None
or (self.cache_pipeline.input_queue.qsize() == 0
and self.cache_pipeline.is_idle()
and self.cache_pipeline.result_queue.qsize() == 0))
):
time.sleep(0.001)
for result, from_cache in results:
if self.cache_pipeline and not from_cache:
if result['ok']:
self.cache_pipeline.input_queue.put(
('save', (result['task'], result['grab']))
)
self.log_network_result_stats(
result, from_cache=from_cache)
if self.is_valid_network_result(result):
#print('!! PUT NETWORK RESULT INTO QUEUE (base.py)')
self.network_result_queue.put(result)
else:
self.log_failed_network_result(result)
# Try to do network request one more time
if self.network_try_limit > 0:
result['task'].refresh_cache = True
result['task'].setup_grab_config(
result['grab_config_backup'])
self.add_task(result['task'])
if from_cache:
self.stat.inc('spider:task-%s-cache' % result['task'].name)
self.stat.inc('spider:request')
while True:
try:
p_res, p_task = self.parser_result_queue.get(block=False)
except queue.Empty:
break
else:
self.stat.inc('spider:parser-result')
self.process_handler_result(p_res, p_task)
if not self.shutdown_event.is_set():
self.parser_pipeline.check_pool_health()
logger_verbose.debug('Work done')
except KeyboardInterrupt:
logger.info('\nGot ^C signal in process %d. Stopping.'
% os.getpid())
self.interrupted = True
raise
finally:
# This code is executed when main cycles is breaked
self.timer.stop('total')
self.stat.print_progress_line()
self.shutdown()
# Stop HTTP API process
if http_api_proc:
http_api_proc.server.shutdown()
http_api_proc.join()
if self.task_queue:
self.task_queue.clear()
# Stop parser processes
self.shutdown_event.set()
self.parser_pipeline.shutdown()
logger.debug('Main process [pid=%s]: work done' % os.getpid())
class Spider(DeprecatedThingsSpiderMixin):
"""
Asynchronous scraping framework.
"""
# You can define here some urls and initial tasks
# with name "initial" will be created from these
# urls
# If the logic of generating initial tasks is complex
# then consider to use `task_generator` method instead of
# `initial_urls` attribute
initial_urls = None
class Meta:
# Meta.abstract means that this class will not be
# collected to spider registry by `grab crawl` CLI command.
# The Meta is inherited by descendant classes BUT
# Meta.abstract is reset to False in each descendant
abstract = True
# *************
# Class Methods
# *************
@classmethod
def update_spider_config(cls, config):
pass
@classmethod
def get_spider_name(cls):
if hasattr(cls, 'spider_name'):
return cls.spider_name
else:
return camel_case_to_underscore(cls.__name__)
# **************
# Public Methods
# **************
def __init__(self, thread_number=None,
network_try_limit=None, task_try_limit=None,
request_pause=NULL,
priority_mode='random',
meta=None,
only_cache=False,
config=None,
slave=None,
args=None,
# New options start here
taskq=None,
# MP:
network_result_queue=None,
parser_result_queue=None,
is_parser_idle=None,
shutdown_event=None,
mp_mode=False,
parser_pool_size=None,
parser_mode=False,
parser_requests_per_process=10000,
# http api
http_api_port=None,
):
"""
Arguments:
* thread-number - Number of concurrent network streams
* network_try_limit - How many times try to send request
again if network error was occurred, use 0 to disable
* network_try_limit - Limit of tries to execute some task
this is not the same as network_try_limit
network try limit limits the number of tries which
are performed automatically in case of network timeout
of some other physical error
but task_try_limit limits the number of attempts which
are scheduled manually in the spider business logic
* priority_mode - could be "random" or "const"
* meta - arbitrary user data
* retry_rebuild_user_agent - generate new random user-agent for each
network request which is performed again due to network error
* args - command line arguments parsed with `setup_arg_parser` method
New options:
* taskq=None,
* newtork_response_queue=None,
"""
if slave is not None:
raise SpiderConfigurtionError(
'Slave mode is not supported anymore. '
'Use `mp_mode=True` option to run multiple HTML'
' parser processes.')
# API:
self.http_api_port = http_api_port
# MP:
self.mp_mode = mp_mode
if self.mp_mode:
from multiprocessing import Process, Event, Queue
else:
from multiprocessing.dummy import Process, Event, Queue
if network_result_queue is not None:
self.network_result_queue = network_result_queue
else:
self.network_result_queue = Queue()
self.parser_result_queue = parser_result_queue
self.is_parser_idle = is_parser_idle
if shutdown_event is not None:
self.shutdown_event = shutdown_event
else:
self.shutdown_event = Event()
if not self.mp_mode and parser_pool_size and parser_pool_size > 1:
raise SpiderConfigurationError(
'Parser pool size could be only 1 in '
'non-multiprocess mode')
self.parser_pool_size = parser_pool_size
self.parser_mode = parser_mode
self.parser_requests_per_process = parser_requests_per_process
self.stat = Stat()
self.timer = Timer()
self.task_queue = taskq
if args is None:
self.args = {}
else:
self.args = args
if config is not None:
self.config = config
else:
self.config = {}
if meta:
self.meta = meta
else:
self.meta = {}
self.thread_number = (
thread_number or
int(self.config.get('thread_number',
DEFAULT_NETWORK_STREAM_NUMBER)))
self.task_try_limit = (
task_try_limit or
int(self.config.get('task_try_limit', DEFAULT_TASK_TRY_LIMIT)))
self.network_try_limit = (
network_try_limit or
int(self.config.get('network_try_limit',
DEFAULT_NETWORK_TRY_LIMIT)))
self._grab_config = {}
if priority_mode not in ['random', 'const']:
raise SpiderMisuseError('Value of priority_mode option should be '
'"random" or "const"')
else:
self.priority_mode = priority_mode
self.only_cache = only_cache
self.cache_pipeline = None
self.work_allowed = True
if request_pause is not NULL:
warn('Option `request_pause` is deprecated and is not '
'supported anymore')
self.proxylist_enabled = None
self.proxylist = None
self.proxy = None
self.proxy_auto_change = False
self.interrupted = False
def setup_cache(self, backend='mongo', database=None, use_compression=True,
**kwargs):
if database is None:
raise SpiderMisuseError('setup_cache method requires database '
'option')
self.cache_enabled = True
mod = __import__('grab.spider.cache_backend.%s' % backend,
globals(), locals(), ['foo'])
cache = mod.CacheBackend(database=database,
use_compression=use_compression,
spider=self, **kwargs)
self.cache_pipeline = CachePipeline(self, cache)
def setup_queue(self, backend='memory', **kwargs):
logger.debug('Using %s backend for task queue' % backend)
mod = __import__('grab.spider.queue_backend.%s' % backend,
globals(), locals(), ['foo'])
self.task_queue = mod.QueueBackend(spider_name=self.get_spider_name(),
**kwargs)
def add_task(self, task, raise_error=False):
"""
Add task to the task queue.
"""
# MP:
# ***
if self.parser_mode:
self.parser_result_queue.put((task, None))
return
if self.task_queue is None:
raise SpiderMisuseError('You should configure task queue before '
'adding tasks. Use `setup_queue` method.')
if task.priority is None or not task.priority_is_custom:
task.priority = self.generate_task_priority()
task.priority_is_custom = False
else:
task.priority_is_custom = True
try:
if not task.url.startswith(('http://', 'https://', 'ftp://',
'file://', 'feed://')):
if self.base_url is None:
msg = 'Could not resolve relative URL because base_url ' \
'is not specified. Task: %s, URL: %s'\
% (task.name, task.url)
raise SpiderError(msg)
else:
warn('Class attribute `Spider::base_url` is deprecated. '
'Use Task objects with absolute URLs')
task.url = urljoin(self.base_url, task.url)
# If task has grab_config object then update it too
if task.grab_config:
task.grab_config['url'] = task.url
except Exception as ex:
self.stat.collect('task-with-invalid-url', task.url)
if raise_error:
raise
else:
logger.error('', exc_info=ex)
return False
# TODO: keep original task priority if it was set explicitly
self.task_queue.put(task, task.priority, schedule_time=task.schedule_time)
return True
def stop(self):
"""
This method set internal flag which signal spider
to stop processing new task and shuts down.
"""
logger_verbose.debug('Method `stop` was called')
self.work_allowed = False
def load_proxylist(self, source, source_type=None, proxy_type='http',
auto_init=True, auto_change=True,
**kwargs):
self.proxylist = ProxyList()
if isinstance(source, BaseProxySource):
self.proxylist.set_source(source)
elif isinstance(source, six.string_types):
if source_type == 'text_file':
self.proxylist.load_file(source, proxy_type=proxy_type)
elif source_type == 'url':
self.proxylist.load_url(source, proxy_type=proxy_type)
else:
raise SpiderMisuseError('Method `load_proxylist` received '
'invalid `source_type` argument: %s'
% source_type)
else:
raise SpiderMisuseError('Method `load_proxylist` received '
'invalid `source` argument: %s'
% source)
self.proxylist_enabled = True
self.proxy = None
if not auto_change and auto_init:
self.proxy = self.proxylist.get_random_proxy()
self.proxy_auto_change = auto_change
def process_next_page(self, grab, task, xpath,
resolve_base=False, **kwargs):
"""
Generate task for next page.
:param grab: Grab instance
:param task: Task object which should be assigned to next page url
:param xpath: xpath expression which calculates list of URLS
:param **kwargs: extra settings for new task object
Example::
self.follow_links(grab, 'topic', '//div[@class="topic"]/a/@href')
"""
try:
# next_url = grab.xpath_text(xpath)
next_url = grab.doc.select(xpath).text()
except IndexError:
return False
else:
url = grab.make_url_absolute(next_url, resolve_base=resolve_base)
page = task.get('page', 1) + 1
grab2 = grab.clone()
grab2.setup(url=url)
task2 = task.clone(task_try_count=1, grab=grab2,
page=page, **kwargs)
self.add_task(task2)
return True
def render_stats(self, timing=True):
out = ['------------ Stats: ------------']
out.append('Counters:')
# Process counters
items = sorted(self.stat.counters.items(),
key=lambda x: x[0], reverse=True)
for item in items:
out.append(' %s: %s' % item)
out.append('')
out.append('Lists:')
# Process collections sorted by size desc
col_sizes = [(x, len(y)) for x, y in self.stat.collections.items()]
col_sizes = sorted(col_sizes, key=lambda x: x[1], reverse=True)
for col_size in col_sizes:
out.append(' %s: %d' % col_size)
out.append('')
# Process extra metrics
if 'download-size' in self.stat.counters:
out.append('Network download: %s' %
metric.format_traffic_value(
self.stat.counters['download-size']))
out.append('Queue size: %d' % self.task_queue.size()
if self.task_queue else 'NA')
out.append('Network streams: %d' % self.thread_number)
elapsed = self.timer.timers['total']
hours, seconds = divmod(elapsed, 3600)
minutes, seconds = divmod(seconds, 60)
out.append('Time elapsed: %d:%d:%d (H:M:S)' % (
hours, minutes, seconds))
out.append('End time: %s' %
datetime.utcnow().strftime('%d %b %Y, %H:%M:%S UTC'))
if timing:
out.append('')
out.append(self.render_timing())
return '\n'.join(out) + '\n'
def render_timing(self):
out = ['Timers:']
out.append(' DOM: %.3f' % GLOBAL_STATE['dom_build_time'])
time_items = [(x, y) for x, y in self.timer.timers.items()]
time_items = sorted(time_items, key=lambda x: x[1])
for time_item in time_items:
out.append(' %s: %.03f' % time_item)
return '\n'.join(out) + '\n'
# ********************************
# Methods for spider customization
# ********************************
def prepare(self):
"""
You can do additional spider customization here
before it has started working. Simply redefine
this method in your Spider class.
"""
def prepare_parser(self):
"""
You can do additional spider customization here
before it has started working. Simply redefine
this method in your Spider class.
This method is called only from Spider working in parser mode
that, in turn, is spawned automatically by main spider proces
working in multiprocess mode.
"""
def shutdown(self):
"""
You can override this method to do some final actions
after parsing has been done.
"""
pass
def update_grab_instance(self, grab):
"""
Use this method to automatically update config of any
`Grab` instance created by the spider.
"""
pass
def create_grab_instance(self, **kwargs):
# Back-ward compatibility for deprecated `grab_config` attribute
# Here I use `_grab_config` to not trigger warning messages
if self._grab_config and kwargs:
merged_config = deepcopy(self._grab_config)
merged_config.update(kwargs)
grab = Grab(**merged_config)
elif self._grab_config and not kwargs:
grab = Grab(**self._grab_config)
else:
grab = Grab(**kwargs)
return grab
def task_generator(self):
"""
You can override this method to load new tasks smoothly.
It will be used each time as number of tasks
in task queue is less then number of threads multiplied on 2
This allows you to not overload all free memory if total number of
tasks is big.
"""
if False:
# Some magic to make this function empty generator
yield ':-)'
return
# ***************
# Private Methods
# ***************
def check_task_limits(self, task):
"""
Check that task's network & try counters do not exceed limits.
Returns:
* if success: (True, None)
* if error: (False, reason)
"""
if task.task_try_count > self.task_try_limit:
return False, 'task-try-count'
if task.network_try_count > self.network_try_limit:
return False, 'network-try-count'
return True, None
def generate_task_priority(self):
if self.priority_mode == 'const':
return DEFAULT_TASK_PRIORITY
else:
return randint(*RANDOM_TASK_PRIORITY_RANGE)
def task_generator_thread_wrapper(self, task_generator):
"""
Load new tasks from `self.task_generator_object`
Create new tasks.
If task queue size is less than some value
then load new tasks from tasks file.
"""
while True:
with self.timer.log_time('task_generator'):
queue_size = self.task_queue.size()
min_limit = self.thread_number * 10
if queue_size < min_limit:
with self.timer.log_time('task_generator'):
logger_verbose.debug(
'Task queue contains less tasks (%d) than '
'allowed limit (%d). Trying to add '
'new tasks.' % (queue_size, min_limit))
try:
for x in six.moves.range(min_limit - queue_size):
item = next(task_generator)
logger_verbose.debug('Got new item from generator. '
'Processing it.')
self.process_handler_result(item)
except StopIteration:
# If generator have no values to yield
# then disable it
logger_verbose.debug('Task generator has no more tasks. '
'Disabling it')
break
else:
time.sleep(0.1)
def start_task_generators(self):
"""
Process `self.initial_urls` list and `self.task_generator`
method.
"""
logger_verbose.debug('Processing initial urls')
if self.initial_urls:
for url in self.initial_urls:
self.add_task(Task('initial', url=url))
self._task_generator_list = []
th = Thread(target=self.task_generator_thread_wrapper,
args=[self.task_generator()])
th.daemon = True
th.start()
self._task_generator_list.append(th)
def get_task_from_queue(self):
start = time.time()
try:
with self.timer.log_time('task_queue'):
return self.task_queue.get()
except queue.Empty:
size = self.task_queue.size()
if size:
logger_verbose.debug(
'No ready-to-go tasks, Waiting for '
'scheduled tasks (%d)' % size)
return True
else:
logger_verbose.debug('Task queue is empty.')
return None
def setup_grab_for_task(self, task):
grab = self.create_grab_instance()
if task.grab_config:
grab.load_config(task.grab_config)
else:
grab.setup(url=task.url)
# Generate new common headers
grab.config['common_headers'] = grab.common_headers()
self.update_grab_instance(grab)
return grab
def is_valid_network_response_code(self, code, task):
"""
Answer the question: if the response could be handled via
usual task handler or the task faield and should be processed as error.
"""
return (code < 400 or code == 404 or
code in task.valid_status)
def process_handler_error(self, func_name, ex, task):
self.stat.inc('spider:error-%s' % ex.__class__.__name__.lower())
if hasattr(ex, 'tb'):
logger.error('Error in %s function' % func_name)
logger.error(ex.tb)
else:
logger.error('Error in %s function' % func_name, exc_info=ex)
# Looks strange but I really have some problems with
# serializing exception into string
try:
ex_str = six.text_type(ex)
except TypeError:
try:
ex_str = ex.decode('utf-8', 'ignore')
except TypeError:
ex_str = str(ex)
task_url = task.url if task is not None else None
self.stat.collect('fatal', '%s|%s|%s|%s' % (
func_name, ex.__class__.__name__, ex_str, task_url))
if isinstance(ex, FatalError):
#raise FatalError()
#six.reraise(FatalError, ex)
#logger.error(ex.tb)
raise ex
def find_data_handler(self, data):
try:
return getattr(data, 'handler')
except AttributeError:
try:
handler = getattr(self, 'data_%s' % data.handler_key)
except AttributeError:
raise NoDataHandler('No handler defined for Data %s'
% data.handler_key)
else:
return handler
def is_valid_network_result(self, res):
if res['task'].get('raw'):
return True
if res['ok']:
res_code = res['grab'].response.code
if self.is_valid_network_response_code(res_code, res['task']):
return True
return False
def run_parser(self):
"""
Main work cycle of spider process working in parser-mode.
"""
self.is_parser_idle.clear()
# Use Stat instance that does not print any logging messages
if self.parser_mode:
self.stat = Stat(logging_period=None)
self.prepare_parser()
process_request_count = 0
try:
recent_task_time = time.time()
while True:
try:
result = self.network_result_queue.get(block=False)
except queue.Empty:
self.is_parser_idle.set()
time.sleep(0.1)
self.is_parser_idle.clear()
logger_verbose.debug('Network result queue is empty')
# Set `waiting_shutdown_event` only after 1 seconds
# of waiting for tasks to avoid
# race-condition issues
#if time.time() - recent_task_time > 1:
# self.waiting_shutdown_event.set()
if self.shutdown_event.is_set():
logger_verbose.debug('Got shutdown event')
return
else:
process_request_count += 1
recent_task_time = time.time()
if self.parser_mode:
self.stat.reset()
#if self.waiting_shutdown_event.is_set():
# self.waiting_shutdown_event.clear()
try:
handler = self.find_task_handler(result['task'])
except NoTaskHandler as ex:
ex.tb = format_exc()
self.parser_result_queue.put((ex, result['task']))
self.stat.inc('parser:handler-not-found')
else:
self.process_network_result_with_handler(
result, handler)
self.stat.inc('parser:handler-processed')
finally:
if self.parser_mode:
data = {
'type': 'stat',
'counters': self.stat.counters,
'collections': self.stat.collections,
}
self.parser_result_queue.put((data,
result['task']))
if self.parser_mode:
if self.parser_requests_per_process:
if (process_request_count >=
self.parser_requests_per_process):
break
except Exception as ex:
logging.error('', exc_info=ex)
raise
#finally:
# self.waiting_shutdown_event.set()
def process_network_result_with_handler(self, result, handler):
handler_name = getattr(handler, '__name__', 'NONE')
try:
with self.timer.log_time('response_handler'):
with self.timer.log_time('response_handler.%s' % handler_name):
handler_result = handler(result['grab'], result['task'])
if handler_result is None:
pass
else:
for something in handler_result:
self.parser_result_queue.put((something,
result['task']))
except NoDataHandler as ex:
ex.tb = format_exc()
self.parser_result_queue.put((ex, result['task']))
except Exception as ex:
ex.tb = format_exc()
self.parser_result_queue.put((ex, result['task']))
def find_task_handler(self, task):
if task.origin_task_generator is not None:
return self.handler_for_inline_task
callback = task.get('callback')
if callback:
return callback
else:
try:
handler = getattr(self, 'task_%s' % task.name)
except AttributeError:
raise NoTaskHandler('No handler or callback defined for '
'task %s' % task.name)
else:
return handler
def handler_for_inline_task(self, grab, task):
# It can be subroutine for the first call,
# So we should check it
if isinstance(task, types.GeneratorType):
coroutines_stack = []
sendval = None
origin_task_generator = task
target = origin_task_generator
else:
coroutines_stack = task.coroutines_stack
sendval = grab
origin_task_generator = task.origin_task_generator
target = origin_task_generator
while True:
try:
result = target.send(sendval)
# If it is subroutine we have to initialize it and
# save coroutine in the coroutines stack
if isinstance(result, types.GeneratorType):
coroutines_stack.append(target)
sendval = None
target = result
origin_task_generator = target
else:
new_task = result
new_task.origin_task_generator = origin_task_generator
new_task.coroutines_stack = coroutines_stack
self.add_task(new_task)
return
except StopIteration:
# If coroutine is over we should check coroutines stack,
# may be it is subroutine
if coroutines_stack:
target = coroutines_stack.pop()
origin_task_generator = target
else:
return
def log_network_result_stats(self, res, from_cache=False):
# Increase stat counters
self.stat.inc('spider:request-processed')
self.stat.inc('spider:task')
self.stat.inc('spider:task-%s' % res['task'].name)
if (res['task'].network_try_count == 1 and
res['task'].task_try_count == 1):
self.stat.inc('spider:task-%s-initial' % res['task'].name)
# Update traffic statistics
if res['grab'] and res['grab'].response:
resp = res['grab'].response
self.timer.inc_timer('network-name-lookup', resp.name_lookup_time)
self.timer.inc_timer('network-connect', resp.connect_time)
self.timer.inc_timer('network-total', resp.total_time)
if from_cache:
self.stat.inc('spider:download-size-with-cache',
resp.download_size)
self.stat.inc('spider:upload-size-with-cache',
resp.upload_size)
else:
self.stat.inc('spider:download-size', resp.download_size)
self.stat.inc('spider:upload-size', resp.upload_size)
def process_grab_proxy(self, task, grab):
"Assign new proxy from proxylist to the task"
if task.use_proxylist:
if self.proxylist_enabled:
# Need this to work around
# pycurl feature/bug:
# pycurl instance uses previously connected proxy server
# even if `proxy` options is set with another proxy server
grab.setup(connection_reuse=False)
if self.proxy_auto_change:
self.proxy = self.change_proxy(task, grab)
def change_proxy(self, task, grab):
proxy = self.proxylist.get_random_proxy()
grab.setup(proxy=proxy.get_address(),
proxy_userpwd=proxy.get_userpwd(),
proxy_type=proxy.proxy_type)
return proxy
def submit_task_to_transport(self, task, grab):
if self.only_cache:
self.stat.inc('spider:request-network-disabled-only-cache')
else:
grab_config_backup = grab.dump_config()
self.process_grab_proxy(task, grab)
self.stat.inc('spider:request-network')
self.stat.inc('spider:task-%s-network' % task.name)
with self.timer.log_time('network_transport'):
logger_verbose.debug('Submitting task to the transport '
'layer')
try:
self.transport.start_task_processing(
task, grab, grab_config_backup)
except GrabInvalidUrl:
logger.debug('Task %s has invalid URL: %s' % (
task.name, task.url))
self.stat.collect('invalid-url', task.url)
def start_api_thread(self):
from grab.spider.http_api import HttpApiThread
proc = HttpApiThread(self)
proc.start()
return proc
def is_ready_to_shutdown(self):
# Things should be true to shutdown spider
# 1) No active task handlers (task_* functions)
# 2) All task generators has completed work
# 3) No active network threads
# 4) Task queue is empty
# 5) Network result queue is empty
# 6) Cache is disabled or is in idle mode
return (
not self.parser_result_queue.qsize()
and all(x['is_parser_idle'].is_set()
for x in self.parser_pipeline.parser_pool)
and not any(x.isAlive() for x in self._task_generator_list) # (2)
and not self.transport.get_active_threads_number() # (3)
and not self.task_queue.size() # (4)
and not self.network_result_queue.qsize() # (5)
and (self.cache_pipeline is None
or (self.cache_pipeline.is_idle()
and self.cache_pipeline.input_queue.qsize() == 0
and self.cache_pipeline.result_queue.qsize() == 0))
)
def run(self):
"""
Main method. All work is done here.
"""
if self.mp_mode:
from multiprocessing import Process, Event, Queue
else:
from multiprocessing.dummy import Process, Event, Queue
self.timer.start('total')
self.transport = MulticurlTransport(self.thread_number)
if self.http_api_port:
http_api_proc = self.start_api_thread()
else:
http_api_proc = None
self.parser_result_queue = Queue()
self.parser_pipeline = ParserPipeline(
bot=self,
mp_mode=self.mp_mode,
pool_size=self.parser_pool_size,
shutdown_event=self.shutdown_event,
network_result_queue=self.network_result_queue,
parser_result_queue=self.parser_result_queue,
requests_per_process=self.parser_requests_per_process,
)
network_result_queue_limit = max(10, self.thread_number * 2)
try:
# Run custom things defined by this specific spider
# By defaut it does nothing
self.prepare()
# Setup task queue if it has not been configured yet
if self.task_queue is None:
self.setup_queue()
# Initiate task generator. Only in main process!
with self.timer.log_time('task_generator'):
self.start_task_generators()
# Work in infinite cycle untill
# `self.work_allowed` flag is True
#shutdown_countdown = 0 # !!!
pending_tasks = deque()
while self.work_allowed:
free_threads = self.transport.get_free_threads_number()
# Load new task only if:
# 1) network transport has free threads
# 2) network result queue is not full
# 3) cache is disabled OR cache has free resources
if (self.transport.get_free_threads_number()
and (self.network_result_queue.qsize()
< network_result_queue_limit)
and (self.cache_pipeline is None
or self.cache_pipeline.has_free_resources())):
if pending_tasks:
task = pending_tasks.popleft()
else:
task = self.get_task_from_queue()
if task is None:
# If received task is None then
# check if spider is ready to be shut down
if not pending_tasks and self.is_ready_to_shutdown():
#shutdown_countdown -= 1
#time.sleep(0.02)
#if shutdown_countdown <= 0:
self.shutdown_event.set()
#print('STOP!!!!!!!!!')
self.stop()
break # Break from `while self.work_allowed` cycle
elif isinstance(task, bool) and (task is True):
# If received task is True
# and there is no active network threads then
# take some sleep
if not self.transport.get_active_threads_number():
time.sleep(0.01)
else:
logger_verbose.debug('Got new task from task queue: %s'
% task)
task.network_try_count += 1
is_valid, reason = self.check_task_limits(task)
if is_valid:
task_grab = self.setup_grab_for_task(task)
if self.cache_pipeline:
self.cache_pipeline.input_queue.put(
('load', (task, task_grab)),
)
else:
self.submit_task_to_transport(task, task_grab)
else:
self.log_rejected_task(task, reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
with self.timer.log_time('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Collect completed network results
# Each result could be valid or failed
# Result is dict {ok, grab, grab_config_backup, task, emsg}
results = [(x, False) for x in
self.transport.iterate_results()]
if self.cache_pipeline:
while True:
try:
action, result = self.cache_pipeline\
.result_queue.get(False)
except queue.Empty:
break
else:
assert action in ('network_result', 'task')
if action == 'network_result':
results.append((result, True))
elif action == 'task':
task = result
task_grab = self.setup_grab_for_task(task)
if (self.transport.get_free_threads_number()
and (self.network_result_queue.qsize()
< network_result_queue_limit)):
self.submit_task_to_transport(task, task_grab)
else:
pending_tasks.append(task)
# Take sleep to avoid millions of iterations per second.
# 1) If no results from network transport
# 2) If task queue is empty (or if there are only delayed tasks)
# 3) If no network activity
# 4) If parser result queue is empty
if (not results
and (task is None or bool(task) == True)
and not self.transport.get_active_threads_number()
and not self.parser_result_queue.qsize()
and (self.cache_pipeline is None
or (self.cache_pipeline.input_queue.qsize() == 0
and self.cache_pipeline.is_idle()
and self.cache_pipeline.result_queue.qsize() == 0))
):
time.sleep(0.001)
for result, from_cache in results:
if self.cache_pipeline and not from_cache:
if result['ok']:
self.cache_pipeline.input_queue.put(
('save', (result['task'], result['grab']))
)
self.log_network_result_stats(
result, from_cache=from_cache)
if self.is_valid_network_result(result):
#print('!! PUT NETWORK RESULT INTO QUEUE (base.py)')
self.network_result_queue.put(result)
else:
self.log_failed_network_result(result)
# Try to do network request one more time
if self.network_try_limit > 0:
result['task'].refresh_cache = True
result['task'].setup_grab_config(
result['grab_config_backup'])
self.add_task(result['task'])
if from_cache:
self.stat.inc('spider:task-%s-cache' % result['task'].name)
self.stat.inc('spider:request')
while True:
try:
p_res, p_task = self.parser_result_queue.get(block=False)
except queue.Empty:
break
else:
self.stat.inc('spider:parser-result')
self.process_handler_result(p_res, p_task)
if not self.shutdown_event.is_set():
self.parser_pipeline.check_pool_health()
logger_verbose.debug('Work done')
except KeyboardInterrupt:
logger.info('\nGot ^C signal in process %d. Stopping.'
% os.getpid())
self.interrupted = True
raise
finally:
# This code is executed when main cycles is breaked
self.timer.stop('total')
self.stat.print_progress_line()
self.shutdown()
# Stop HTTP API process
if http_api_proc:
http_api_proc.server.shutdown()
http_api_proc.join()
if self.task_queue:
self.task_queue.clear()
# Stop parser processes
self.shutdown_event.set()
self.parser_pipeline.shutdown()
logger.debug('Main process [pid=%s]: work done' % os.getpid())
def log_failed_network_result(self, res):
# Log the error
if res['ok']:
msg = 'http-%s' % res['grab'].response.code
else:
msg = res['error_abbr']
self.stat.inc('error:%s' % msg)
#logger.error(u'Network error: %s' % msg)#%
#make_unicode(msg, errors='ignore'))
def log_rejected_task(self, task, reason):
logger_verbose.debug('Task %s is rejected due to '
'%s limit'
% (task.name, reason))
if reason == 'task-try-count':
self.stat.collect('task-count-rejected',
task.url)
elif reason == 'network-try-count':
self.stat.collect('network-count-rejected',
task.url)
else:
raise SpiderError('Unknown response from '
'check_task_limits: %s'
% reason)
def process_handler_result(self, result, task=None):
"""
Process result received from the task handler.
Result could be:
* None
* Task instance
* Data instance.
"""
if isinstance(result, Task):
self.add_task(result)
elif isinstance(result, Data):
handler = self.find_data_handler(result)
try:
data_result = handler(**result.storage)
if data_result is None:
pass
else:
for something in data_result:
self.process_handler_result(something, task)
except Exception as ex:
self.process_handler_error('data_%s' % result.handler_key, ex,
task)
elif result is None:
pass
elif isinstance(result, Exception):
handler = self.find_task_handler(task)
handler_name = getattr(handler, '__name__', 'NONE')
self.process_handler_error(handler_name, result, task)
elif isinstance(result, dict):
if result.get('type') == 'stat':
for name, count in result['counters'].items():
self.stat.inc(name, count)
for name, items in result['collections'].items():
for item in items:
self.stat.collect(name, item)
else:
raise SpiderError('Unknown result type: %s' % result)
else:
raise SpiderError('Unknown result type: %s' % result)
class Spider(object):
"""
Asynchronous scraping framework.
"""
# You can define here some urls and initial tasks
# with name "initial" will be created from these
# urls
# If the logic of generating initial tasks is complex
# then consider to use `task_generator` method instead of
# `initial_urls` attribute
initial_urls = None
# The base url which is used to resolve all relative urls
# The resolving takes place in `add_task` method
base_url = None
class Meta:
# Meta.abstract means that this class will not be
# collected to spider registry by `grab crawl` CLI command.
# The Meta is inherited by descendant classes BUT
# Meta.abstract is reset to False in each descendant
abstract = True
def __init__(self, thread_number=None,
network_try_limit=None, task_try_limit=None,
request_pause=NULL,
priority_mode='random',
meta=None,
only_cache=False,
config=None,
slave=False,
max_task_generator_chunk=None,
args=None,
# New options start here
taskq=None,
):
"""
Arguments:
* thread-number - Number of concurrent network streams
* network_try_limit - How many times try to send request
again if network error was occurred, use 0 to disable
* network_try_limit - Limit of tries to execute some task
this is not the same as network_try_limit
network try limit limits the number of tries which
are performed automatically in case of network timeout
of some other physical error
but task_try_limit limits the number of attempts which
are scheduled manually in the spider business logic
* priority_mode - could be "random" or "const"
* meta - arbitrary user data
* retry_rebuild_user_agent - generate new random user-agent for each
network request which is performed again due to network error
* args - command line arguments parsed with `setup_arg_parser` method
New options:
* taskq=None,
* newtork_response_queue=None,
"""
self.stat = Stat()
self.taskq = taskq
if args is None:
self.args = {}
else:
self.args = args
self.slave = slave
self.max_task_generator_chunk = max_task_generator_chunk
self.stat.start_timer('total')
if config is not None:
self.config = config
else:
self.config = {}
if meta:
self.meta = meta
else:
self.meta = {}
self.task_generator_enabled = False
self.only_cache = only_cache
self.thread_number = (
thread_number or
int(self.config.get('thread_number',
DEFAULT_NETWORK_STREAM_NUMBER)))
self.task_try_limit = (
task_try_limit or
int(self.config.get('task_try_limit', DEFAULT_TASK_TRY_LIMIT)))
self.network_try_limit = (
network_try_limit or
int(self.config.get('network_try_limit',
DEFAULT_NETWORK_TRY_LIMIT)))
self._grab_config = {}
self.items = {}
if priority_mode not in ['random', 'const']:
raise SpiderMisuseError('Value of priority_mode option should be '
'"random" or "const"')
else:
self.priority_mode = priority_mode
# Initial cache-subsystem values
self.cache_enabled = False
self.cache = None
self.work_allowed = True
if request_pause is not NULL:
logger.error('Option `request_pause` is deprecated and is not '
'supported anymore')
self.proxylist_enabled = None
self.proxylist = None
self.proxy = None
self.proxy_auto_change = False
self.interrupted = False
def get_grab_config(self):
logger.error('Using `grab_config` attribute is deprecated. Override '
'`create_grab_instance method instead.')
return self._grab_config
def set_grab_config(self, val):
logger.error('Using `grab_config` attribute is deprecated. Override '
'`create_grab_instance method instead.')
self._grab_config = val
grab_config = property(get_grab_config, set_grab_config)
def setup_cache(self, backend='mongo', database=None, use_compression=True,
**kwargs):
if database is None:
raise SpiderMisuseError('setup_cache method requires database '
'option')
self.cache_enabled = True
mod = __import__('grab.spider.cache_backend.%s' % backend,
globals(), locals(), ['foo'])
self.cache = mod.CacheBackend(database=database,
use_compression=use_compression,
spider=self, **kwargs)
def setup_queue(self, backend='memory', **kwargs):
logger.debug('Using %s backend for task queue' % backend)
mod = __import__('grab.spider.queue_backend.%s' % backend,
globals(), locals(), ['foo'])
self.taskq = mod.QueueBackend(spider_name=self.get_spider_name(),
**kwargs)
def prepare(self):
"""
You can do additional spider customization here
before it has started working. Simply redefine
this method in your Spider class.
"""
def setup_grab(self, **kwargs):
logging.error('This method is deprecated. Instead override '
'`create_grab_instance` method in you spider sub-class')
self.grab_config.update(**kwargs)
def check_task_limits(self, task):
"""
Check that network/try counters are OK.
Returns:
* if success: (True, None)
* if error: (False, reason)
"""
if task.task_try_count > self.task_try_limit:
logger.debug('Task tries (%d) ended: %s / %s' % (
self.task_try_limit, task.name, task.url))
return False, 'task-try-count'
if task.network_try_count > self.network_try_limit:
logger.debug('Network tries (%d) ended: %s / %s' % (
self.network_try_limit, task.name, task.url))
return False, 'network-try-count'
return True, None
def generate_task_priority(self):
if self.priority_mode == 'const':
return DEFAULT_TASK_PRIORITY
else:
return randint(*RANDOM_TASK_PRIORITY_RANGE)
def add_task(self, task, raise_error=False):
"""
Add task to the task queue.
"""
if self.taskq is None:
raise SpiderMisuseError('You should configure task queue before '
'adding tasks. Use `setup_queue` method.')
if task.priority is None or not task.priority_is_custom:
task.priority = self.generate_task_priority()
task.priority_is_custom = False
else:
task.priority_is_custom = True
if not isinstance(task, NullTask):
try:
if not task.url.startswith(('http://', 'https://', 'ftp://',
'file://', 'feed://')):
if self.base_url is None:
msg = 'Could not resolve relative URL because base_url ' \
'is not specified. Task: %s, URL: %s'\
% (task.name, task.url)
raise SpiderError(msg)
else:
task.url = urljoin(self.base_url, task.url)
# If task has grab_config object then update it too
if task.grab_config:
task.grab_config['url'] = task.url
except Exception as ex:
self.stat.append('task-with-invalid-url', task.url)
if raise_error:
raise
else:
logger.error('', exc_info=ex)
return False
# TODO: keep original task priority if it was set explicitly
self.taskq.put(task, task.priority, schedule_time=task.schedule_time)
return True
def load_initial_urls(self):
"""
Create initial tasks from `self.initial_urls`.
Tasks are created with name "initial".
"""
if self.initial_urls:
for url in self.initial_urls:
self.add_task(Task('initial', url=url))
def setup_default_queue(self):
"""
If task queue is not configured explicitly
then create task queue with default parameters
This method is not the same as `self.setup_queue` because
`self.setup_queue` works by default with in-memory queue.
You can override `setup_default_queue` in your custom
Spider and use other storage engines for you
default task queue.
"""
# If queue is still not configured
# then configure it with default backend
if self.taskq is None:
self.setup_queue()
def process_task_generator(self):
"""
Load new tasks from `self.task_generator_object`
Create new tasks.
If task queue size is less than some value
then load new tasks from tasks file.
"""
if self.task_generator_enabled:
if hasattr(self.taskq, 'qsize'):
qsize = self.taskq.qsize()
else:
qsize = self.taskq.size()
if self.max_task_generator_chunk is not None:
min_limit = min(self.max_task_generator_chunk,
self.thread_number * 10)
else:
min_limit = self.thread_number * 10
if qsize < min_limit:
logger_verbose.debug(
'Task queue contains less tasks (%d) than '
'allowed limit (%d). Trying to add '
'new tasks.' % (qsize, min_limit))
try:
for x in six.moves.range(min_limit - qsize):
item = next(self.task_generator_object)
logger_verbose.debug('Got new item from generator. '
'Processing it.')
# self.add_task(item)
self.process_handler_result(item)
except StopIteration:
# If generator have no values to yield
# then disable it
logger_verbose.debug('Task generator has no more tasks. '
'Disabling it')
self.task_generator_enabled = False
def init_task_generator(self):
"""
Process `initial_urls` and `task_generator`.
Generate first portion of tasks.
TODO: task generator should work in separate OS process
"""
self.task_generator_object = self.task_generator()
self.task_generator_enabled = True
logger_verbose.debug('Processing initial urls')
self.load_initial_urls()
# Initial call to task generator
# before main cycle
self.process_task_generator()
def load_new_task(self):
start = time.time()
while True:
try:
with self.stat.log_time('task_queue'):
return self.taskq.get()
except queue.Empty:
qsize = self.taskq.size()
if qsize:
logger_verbose.debug(
'No ready-to-go tasks, Waiting for '
'scheduled tasks (%d)' % qsize)
return True
if not self.slave:
logger_verbose.debug('Task queue is empty.')
return None
else:
# Temporarily hack which force slave crawler
# to wait 5 seconds for new tasks, this solves
# the problem that sometimes slave crawler stop
# its work because it could not receive new
# tasks immediately
if not self.transport.active_task_number():
if time.time() - start < 5:
time.sleep(0.1)
logger.debug('Slave sleeping')
else:
break
else:
break
logger_verbose.debug('Task queue is empty.')
return None
def process_task_counters(self, task):
task.network_try_count += 1
if task.task_try_count == 0:
task.task_try_count = 1
def create_grab_instance(self, **kwargs):
# Back-ward compatibility for deprecated `grab_config` attribute
# Here I use `_grab_config` to not trigger warning messages
if self._grab_config and kwargs:
merged_config = deepcopy(self._grab_config)
merged_config.update(kwargs)
grab = Grab(**merged_config)
elif self._grab_config and not kwargs:
grab = Grab(**self._grab_config)
else:
grab = Grab(**kwargs)
return grab
def update_grab_instance(self, grab):
"""
Use this method to automatically update config of any
`Grab` instance created by the spider.
"""
pass
def setup_grab_for_task(self, task):
grab = self.create_grab_instance()
if task.grab_config:
grab.load_config(task.grab_config)
else:
grab.setup(url=task.url)
# Generate new common headers
grab.config['common_headers'] = grab.common_headers()
self.update_grab_instance(grab)
return grab
def is_task_cacheable(self, task, grab):
if ( # cache is disabled for all tasks
not self.cache_enabled
# cache data should be refreshed
or task.get('refresh_cache', False)
# cache could not be used
or task.get('disable_cache', False)
# request type is not cacheable
or grab.detect_request_method() != 'GET'):
return False
else:
return True
def load_task_from_cache(self, transport, task, grab, grab_config_backup):
cache_item = self.cache.get_item(grab.config['url'],
timeout=task.cache_timeout)
if cache_item is None:
return None
else:
with self.stat.log_time('cache.read.prepare_request'):
grab.prepare_request()
with self.stat.log_time('cache.read.load_response'):
self.cache.load_response(grab, cache_item)
grab.log_request('CACHED')
self.stat.inc('spider:request')
self.stat.inc('spider:request-cache')
return {'ok': True, 'grab': grab,
'grab_config_backup': grab_config_backup,
'task': task, 'emsg': None}
def valid_response_code(self, code, task):
"""
Answer the question: if the response could be handled via
usual task handler or the task faield and should be processed as error.
"""
return (code < 400 or code == 404 or
code in task.valid_status)
def process_handler_error(self, func_name, ex, task):
self.stat.inc('spider:error-%s' % ex.__class__.__name__.lower())
logger.error('Error in %s function' % func_name, exc_info=ex)
# Looks strange but I really have some problems with
# serializing exception into string
try:
ex_str = six.text_type(ex)
except TypeError:
try:
ex_str = ex.decode('utf-8', 'ignore')
except TypeError:
ex_str = str(ex)
task_url = task.url if task is not None else None
self.stat.append('fatal', '%s|%s|%s|%s' % (
func_name, ex.__class__.__name__, ex_str, task_url))
if isinstance(ex, FatalError):
raise
def find_data_handler(self, data):
try:
return getattr(data, 'handler')
except AttributeError:
try:
handler = getattr(self, 'data_%s' % data.handler_key)
except AttributeError:
raise NoDataHandler('No handler defined for Data %s'
% data.handler_key)
else:
return handler
def execute_task_handler(self, res, handler):
"""
Apply `handler` function to the network result.
If network result is failed then submit task again
to the network task queue.
"""
try:
handler_name = handler.__name__
except AttributeError:
handler_name = 'NONE'
if (res['task'].get('raw') or (
res['ok'] and self.valid_response_code(res['grab'].response.code,
res['task']))):
try:
with self.stat.log_time('response_handler'):
with self.stat.log_time('response_handler.%s' % handler_name):
result = handler(res['grab'], res['task'])
if result is None:
pass
else:
for item in result:
self.process_handler_result(item, res['task'])
except NoDataHandler as ex:
raise
except Exception as ex:
self.process_handler_error(handler_name, ex, res['task'])
else:
self.stat.inc('spider:task-%s-ok' % res['task'].name)
else:
# Log the error
if res['ok']:
msg = res['emsg'] = 'HTTP %s' % res['grab'].response.code
else:
msg = res['emsg']
self.stat.inc('spider:network-error-%s' %
make_str(res['emsg'][:20], errors='ignore'))
logger.error(u'Network error: %s' %
make_unicode(msg, errors='ignore'))
# Try to repeat the same network query
if self.network_try_limit > 0:
task = res['task']
task.refresh_cache = True
# Should use task.grab_config or backup of grab_config
task.setup_grab_config(res['grab_config_backup'])
self.add_task(task)
# TODO: allow to write error handlers
def find_task_handler(self, task):
if task.origin_task_generator is not None:
return self.handler_for_inline_task
callback = task.get('callback')
if callback:
return callback
else:
try:
handler = getattr(self, 'task_%s' % task.name)
except AttributeError:
raise NoTaskHandler('No handler or callback defined for '
'task %s' % task.name)
else:
return handler
def handler_for_inline_task(self, grab, task):
# It can be subroutine for the first call,
# So we should check it
if isinstance(task, types.GeneratorType):
coroutines_stack = []
sendval = None
origin_task_generator = task
target = origin_task_generator
else:
coroutines_stack = task.coroutines_stack
sendval = grab
origin_task_generator = task.origin_task_generator
target = origin_task_generator
while True:
try:
result = target.send(sendval)
# If it is subroutine we have to initialize it and
# save coroutine in the coroutines stack
if isinstance(result, types.GeneratorType):
coroutines_stack.append(target)
sendval = None
target = result
origin_task_generator = target
else:
new_task = result
new_task.origin_task_generator = origin_task_generator
new_task.coroutines_stack = coroutines_stack
self.add_task(new_task)
return
except StopIteration:
# If coroutine is over we should check coroutines stack,
# may be it is subroutine
if coroutines_stack:
target = coroutines_stack.pop()
origin_task_generator = target
else:
return
def process_network_result(self, res, from_cache=False):
"""
Handle result received from network transport of
from the cache layer.
Find handler function for that task and call it.
"""
# Increase stat counters
self.stat.inc('spider:request-processed')
self.stat.inc('spider:task')
self.stat.inc('spider:task-%s' % res['task'].name)
if (res['task'].network_try_count == 1 and
res['task'].task_try_count == 1):
self.stat.inc('spider:task-%s-initial' % res['task'].name)
# Update traffic statistics
if res['grab'] and res['grab'].response:
self.stat.timers['network-name-lookup'] +=\
res['grab'].response.name_lookup_time
self.stat.timers['network-connect'] +=\
res['grab'].response .connect_time
self.stat.timers['network-total'] +=\
res['grab'].response .total_time
if from_cache:
self.stat.inc('spider:download-size-with-cache',
res['grab'].response.download_size)
self.stat.inc('spider:upload-size-with-cache',
res['grab'].response.upload_size)
else:
self.stat.inc('spider:download-size',
res['grab'].response.download_size)
self.stat.inc('spider:upload-size',
res['grab'].response.upload_size)
handler = self.find_task_handler(res['task'])
self.execute_task_handler(res, handler)
def process_grab_proxy(self, task, grab):
"Assign new proxy from proxylist to the task"
if task.use_proxylist:
if self.proxylist_enabled:
if self.proxy_auto_change:
self.proxy = self.change_proxy(task, grab)
def change_proxy(self, task, grab):
proxy = self.proxylist.get_random_proxy()
grab.setup(proxy=proxy.get_address(),
proxy_userpwd=proxy.get_userpwd(),
proxy_type=proxy.proxy_type)
return proxy
def process_new_task(self, task):
"""
Handle new task.
1) Setup Grab object for that task
2) Try to load task from the cache
3) If no cached data then submit task to network transport
"""
grab = self.setup_grab_for_task(task)
grab_config_backup = grab.dump_config()
cache_result = None
if self.is_task_cacheable(task, grab):
with self.stat.log_time('cache'):
with self.stat.log_time('cache.read'):
cache_result = self.load_task_from_cache(
self.transport, task, grab, grab_config_backup)
if cache_result:
logger_verbose.debug('Task data is loaded from the cache. '
'Yielding task result.')
self.process_network_result(cache_result, from_cache=True)
self.stat.inc('spider:task-%s-cache' % task.name)
else:
if self.only_cache:
logger.debug('Skipping network request to %s' %
grab.config['url'])
else:
self.stat.inc('spider:request-network')
self.stat.inc('spider:task-%s-network' % task.name)
self.process_grab_proxy(task, grab)
with self.stat.log_time('network_transport'):
logger_verbose.debug('Submitting task to the transport '
'layer')
try:
self.transport.process_task(task, grab,
grab_config_backup)
except GrabInvalidUrl:
logger.debug('Task %s has invalid URL: %s' % (
task.name, task.url))
self.stat.append('invalid-url', task.url)
else:
logger_verbose.debug('Asking transport layer to do '
'something')
def is_valid_for_cache(self, res):
"""
Check if network transport result could
be saved to cache layer.
res: {ok, grab, grab_config_backup, task, emsg}
"""
if res['ok']:
if self.cache_enabled:
if res['grab'].request_method == 'GET':
if not res['task'].get('disable_cache'):
if self.valid_response_code(res['grab'].response.code,
res['task']):
return True
return False
def stop(self):
"""
This method set internal flag which signal spider
to stop processing new task and shuts down.
"""
logger_verbose.debug('Method `stop` was called')
self.work_allowed = False
def run(self):
"""
Main method. All work is done here.
"""
self.stat.start_timer('total')
self.transport = MulticurlTransport(self.thread_number)
try:
self.setup_default_queue()
self.prepare()
self.stat.start_timer('task_generator')
if not self.slave:
self.init_task_generator()
self.stat.stop_timer('task_generator')
while self.work_allowed:
self.stat.start_timer('task_generator')
if self.task_generator_enabled:
self.process_task_generator()
self.stat.stop_timer('task_generator')
free_threads = self.transport.get_free_threads_number()
if free_threads:
logger_verbose.debug(
'Transport has free resources (%d). '
'Trying to add new task (if exists).' % free_threads)
# Try five times to get new task and proces task generator
# because slave parser could agressively consume
# tasks from task queue
for x in six.moves.range(5):
task = self.load_new_task()
if task is None:
if not self.transport.active_task_number():
self.process_task_generator()
elif task is True:
# If only delayed tasks in queue
break
else:
# If got some task
break
if not task:
if not self.transport.active_task_number():
logger_verbose.debug('Network transport has no '
'active tasks')
if not self.task_generator_enabled:
self.stop()
else:
logger_verbose.debug(
'Transport active tasks: %d' %
self.transport.active_task_number())
elif isinstance(task, NullTask):
logger_verbose.debug('Got NullTask')
if not self.transport.active_task_number():
if task.sleep:
logger.debug('Got NullTask with sleep '
'instruction. Sleeping for'
' %.2f seconds' % task.sleep)
time.sleep(task.sleep)
elif isinstance(task, bool) and (task is True):
# Take some sleep to not load CPU
if not self.transport.active_task_number():
time.sleep(0.1)
else:
logger_verbose.debug('Got new task from task queue: %s'
% task)
self.process_task_counters(task)
is_valid, reason = self.check_task_limits(task)
if not is_valid:
logger_verbose.debug('Task %s is rejected due to '
'%s limit'
% (task.name, reason))
if reason == 'task-try-count':
self.stat.append('task-count-rejected',
task.url)
elif reason == 'network-try-count':
self.stat.append('network-count-rejected',
task.url)
else:
raise SpiderError('Unknown response from '
'check_task_limits: %s'
% reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
else:
self.process_new_task(task)
self.transport.process_handlers()
with self.stat.log_time('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Iterate over network trasport ready results
# Each result could be valid or failed
# Result format: {ok, grab, grab_config_backup, task, emsg}
# print '[transport iterate results - start]'
for result in self.transport.iterate_results():
if self.is_valid_for_cache(result):
with self.stat.log_time('cache'):
with self.stat.log_time('cache.write'):
self.cache.save_response(result['task'].url,
result['grab'])
# print '[process network results]'
self.process_network_result(result)
# print '[done]'
self.stat.inc('spider:request')
# print '[transport iterate results - end]'
logger_verbose.debug('Work done')
except KeyboardInterrupt:
print('\nGot ^C signal in process %d. Stopping.' % os.getpid())
self.interrupted = True
raise
finally:
# This code is executed when main cycles is breaked
self.stat.stop_timer('total')
self.shutdown()
def load_proxylist(self, source, source_type=None, proxy_type='http',
auto_init=True, auto_change=True,
**kwargs):
self.proxylist = ProxyList()
if isinstance(source, BaseProxySource):
self.proxylist.set_source(source)
elif isinstance(source, six.string_types):
if source_type == 'text_file':
self.proxylist.load_file(source, proxy_type=proxy_type)
elif source_type == 'url':
self.proxylist.load_url(source, proxy_type=proxy_type)
else:
raise SpiderMisuseError('Method `load_proxylist` received '
'invalid `source_type` argument: %s'
% source_type)
else:
raise SpiderMisuseError('Method `load_proxylist` received '
'invalid `source` argument: %s'
% source)
self.proxylist_enabled = True
self.proxy = None
if not auto_change and auto_init:
self.proxy = self.proxylist.get_random_proxy()
self.proxy_auto_change = auto_change
def process_handler_result(self, result, task=None):
"""
Process result received from the task handler.
Result could be:
* None
* Task instance
* Data instance.
"""
if isinstance(result, Task):
self.add_task(result)
elif isinstance(result, Data):
handler = self.find_data_handler(result)
try:
data_result = handler(**result.storage)
if data_result is None:
pass
else:
for something in data_result:
self.process_handler_result(something, task)
except Exception as ex:
self.process_handler_error('data_%s' % result.handler_key, ex,
task)
elif result is None:
pass
elif isinstance(result, NullTask):
pass
else:
raise SpiderError('Unknown result type: %s' % result)
@classmethod
def get_spider_name(cls):
if hasattr(cls, 'spider_name'):
return cls.spider_name
else:
return camel_case_to_underscore(cls.__name__)
def process_next_page(self, grab, task, xpath,
resolve_base=False, **kwargs):
"""
Generate task for next page.
:param grab: Grab instance
:param task: Task object which should be assigned to next page url
:param xpath: xpath expression which calculates list of URLS
:param **kwargs: extra settings for new task object
Example::
self.follow_links(grab, 'topic', '//div[@class="topic"]/a/@href')
"""
try:
# next_url = grab.xpath_text(xpath)
next_url = grab.doc.select(xpath).text()
except IndexError:
return False
else:
url = grab.make_url_absolute(next_url, resolve_base=resolve_base)
page = task.get('page', 1) + 1
grab2 = grab.clone()
grab2.setup(url=url)
task2 = task.clone(task_try_count=0, grab=grab2,
page=page, **kwargs)
self.add_task(task2)
return True
def render_stats(self, timing=True):
out = ['------------ Stats: ------------']
out.append('Counters:')
# Process counters
items = sorted(self.stat.counters.items(),
key=lambda x: x[0], reverse=True)
for item in items:
out.append(' %s: %s' % item)
out.append('')
out.append('Lists:')
# Process collections sorted by size desc
col_sizes = [(x, len(y)) for x, y in self.stat.collections.items()]
col_sizes = sorted(col_sizes, key=lambda x: x[1], reverse=True)
for col_size in col_sizes:
out.append(' %s: %d' % col_size)
out.append('')
# Process extra metrics
if 'download-size' in self.stat.counters:
out.append('Network download: %s' %
metric.format_traffic_value(
self.stat.counters['download-size']))
out.append('Queue size: %d' % self.taskq.size()
if self.taskq else 'NA')
out.append('Network streams: %d' % self.thread_number)
if timing:
out.append('')
out.append(self.render_timing())
return '\n'.join(out) + '\n'
def render_timing(self):
out = ['Timers:']
out.append(' DOM: %.3f' % GLOBAL_STATE['dom_build_time'])
time_items = [(x, y) for x, y in self.stat.timers.items()]
time_items = sorted(time_items, key=lambda x: x[1])
for time_item in time_items:
out.append(' %s: %.03f' % time_item)
return '\n'.join(out) + '\n'
# ****************
# Abstract methods
# ****************
def shutdown(self):
"""
You can override this method to do some final actions
after parsing has been done.
"""
logger.debug('Job done!')
def task_generator(self):
"""
You can override this method to load new tasks smoothly.
It will be used each time as number of tasks
in task queue is less then number of threads multiplied on 2
This allows you to not overload all free memory if total number of
tasks is big.
"""
if False:
# Some magic to make this function empty generator
yield ':-)'
return
@classmethod
def setup_spider_config(cls, config):
pass
# ******************
# Deprecated Methods
# ******************
def add_item(self, list_name, item):
logger.debug('Method `Spider::add_item` is deprecated. '
'Use `Spider::stat.append` method instead.')
self.stat.append(list_name, item)
def inc_count(self, key, count=1):
logger.debug('Method `Spider::inc_count` is deprecated. '
'Use `Spider::stat.inc` method instead.')
self.stat.inc(key, count)
def start_timer(self, key):
logger.debug('Method `Spider::start_timer` is deprecated. '
'Use `Spider::stat.start_timer` method instead.')
self.stat.start_timer(key)
def stop_timer(self, key):
logger.debug('Method `Spider::stop_timer` is deprecated. '
'Use `Spider::stat.stop_timer` method instead.')
self.stat.stop_timer(key)
@contextmanager
def save_timer(self, key):
logger.debug('Method `Spider::save_timer` is deprecated. '
'Use `Spider::stat.log_time` method instead.')
self.stat.start_timer(key)
try:
yield
finally:
self.stat.stop_timer(key)
def run(self):
"""
Main method. All work is done here.
"""
self.stat.start_timer('total')
self.transport = MulticurlTransport(self.thread_number)
try:
self.setup_default_queue()
self.prepare()
self.stat.start_timer('task_generator')
if not self.slave:
self.init_task_generator()
self.stat.stop_timer('task_generator')
while self.work_allowed:
self.stat.start_timer('task_generator')
if self.task_generator_enabled:
self.process_task_generator()
self.stat.stop_timer('task_generator')
free_threads = self.transport.get_free_threads_number()
if free_threads:
logger_verbose.debug(
'Transport has free resources (%d). '
'Trying to add new task (if exists).' % free_threads)
# Try five times to get new task and proces task generator
# because slave parser could agressively consume
# tasks from task queue
for x in six.moves.range(5):
task = self.load_new_task()
if task is None:
if not self.transport.active_task_number():
self.process_task_generator()
elif task is True:
# If only delayed tasks in queue
break
else:
# If got some task
break
if not task:
if not self.transport.active_task_number():
logger_verbose.debug('Network transport has no '
'active tasks')
if not self.task_generator_enabled:
self.stop()
else:
logger_verbose.debug(
'Transport active tasks: %d' %
self.transport.active_task_number())
elif isinstance(task, NullTask):
logger_verbose.debug('Got NullTask')
if not self.transport.active_task_number():
if task.sleep:
logger.debug('Got NullTask with sleep '
'instruction. Sleeping for'
' %.2f seconds' % task.sleep)
time.sleep(task.sleep)
elif isinstance(task, bool) and (task is True):
# Take some sleep to not load CPU
if not self.transport.active_task_number():
time.sleep(0.1)
else:
logger_verbose.debug('Got new task from task queue: %s'
% task)
self.process_task_counters(task)
is_valid, reason = self.check_task_limits(task)
if not is_valid:
logger_verbose.debug('Task %s is rejected due to '
'%s limit'
% (task.name, reason))
if reason == 'task-try-count':
self.stat.append('task-count-rejected',
task.url)
elif reason == 'network-try-count':
self.stat.append('network-count-rejected',
task.url)
else:
raise SpiderError('Unknown response from '
'check_task_limits: %s'
% reason)
handler = task.get_fallback_handler(self)
if handler:
handler(task)
else:
self.process_new_task(task)
self.transport.process_handlers()
with self.stat.log_time('network_transport'):
logger_verbose.debug('Asking transport layer to do '
'something')
self.transport.process_handlers()
logger_verbose.debug('Processing network results (if any).')
# Iterate over network trasport ready results
# Each result could be valid or failed
# Result format: {ok, grab, grab_config_backup, task, emsg}
# print '[transport iterate results - start]'
for result in self.transport.iterate_results():
if self.is_valid_for_cache(result):
with self.stat.log_time('cache'):
with self.stat.log_time('cache.write'):
self.cache.save_response(result['task'].url,
result['grab'])
# print '[process network results]'
self.process_network_result(result)
# print '[done]'
self.stat.inc('spider:request')
# print '[transport iterate results - end]'
logger_verbose.debug('Work done')
except KeyboardInterrupt:
print('\nGot ^C signal in process %d. Stopping.' % os.getpid())
self.interrupted = True
raise
finally:
# This code is executed when main cycles is breaked
self.stat.stop_timer('total')
self.shutdown()