def test_config_constructor(self): config = Config() self.assertEqual(len(config.keys()), 0) config = Config({'foo': 'bar'}) self.assertEqual(len(config.keys()), 1) self.assertEqual(config['foo'], 'bar')
def test_update_with_path_allowed_keys(self): modname = setup_settings_file(SOME_DICT) config = Config() config.update_with_path(modname, allowed_keys=['VAR1']) self.assertEqual(config, {'VAR1': 'val1'})
def test_update_with_path_new_keys(self): modname = setup_settings_file(SOME_DICT) config = Config({'VAR1': 'ORIGINAL'}) config.update_with_path(modname, only_new_keys=True) self.assertEqual(config, {'VAR1': 'ORIGINAL', 'VAR2': 'val2'})
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 test_update_with_path(self): modname = setup_settings_file(SOME_DICT) config = Config() config.update_with_path(modname) self.assertEqual(config, {'VAR1': 'val1', 'VAR2': 'val2'})
def test_update_with_dict_new_keys(self): config = Config({'VAR1': 'ORIGINAL'}) config.update_with_object(SOME_DICT, only_new_keys=True) self.assertEqual(config, {'VAR1': 'ORIGINAL', 'VAR2': 'val2'})
def test_update_with_object_allowed_keys(self): config = Config({'VAR1': 'ORIGINAL'}) obj = SomeSettings() config.update_with_object(obj, allowed_keys=['VAR1']) self.assertEqual(config, {'VAR1': 'val1'})
def test_update_with_object(self): config = Config() obj = SomeSettings() config.update_with_object(obj) self.assertEqual(config, {'VAR1': 'val1', 'VAR2': 'val2'})
def test_update_with_object_new_keys(self): config = Config({'VAR1': 'ORIGINAL'}) obj = SomeSettings() config.update_with_object(obj, only_new_keys=True) self.assertEqual(config, {'VAR1': 'ORIGINAL', 'VAR2': 'val2'})
def test_clone(self): config = Config({'foo': 'bar'}) config2 = config.clone() self.assertEqual(config, config2) self.assertFalse(config is config2)
def test_update_with_dict(self): config = Config() config.update_with_object(SOME_DICT) self.assertEqual(config, {'VAR1': 'val1', 'VAR2': 'val2'})
def test_update_with_dict_allowed_keys(self): config = Config({'VAR1': 'ORIGINAL'}) config.update_with_object(SOME_DICT, allowed_keys=['VAR1']) self.assertEqual(config, {'VAR1': 'val1'})
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, # 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 occuried, 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 automaticall 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_rebuid_user_agent - generate new random user-agent for each network request which is performed again due to network error 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 self.slave = slave self.max_task_generator_chunk = max_task_generator_chunk self.timers = {} self.time_points = {} self.start_timer('total') if config is not None: self.config = config else: # Fix curcular 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
class Spider(SpiderMetaClassMixin, SpiderPattern, SpiderStat): """ Asynchronious 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 whil 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 desendant 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, # 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 occuried, 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 automaticall 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_rebuid_user_agent - generate new random user-agent for each network request which is performed again due to network error 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 self.slave = slave self.max_task_generator_chunk = max_task_generator_chunk self.timers = {} self.time_points = {} self.start_timer('total') if config is not None: self.config = config else: # Fix curcular 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 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 customizatin 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): self.grab_config.update(**kwargs) def check_task_limits(self, task): """ Check that network/try counters are OK. If one of counter is invalid then display error and try to call fallback handler. """ is_valid = True if not self.config.get('TASK_ENABLED', {}).get(task.name, True): logger.debug('Task %s disabled via config' % task.name) self.inc_count('task-disabled') is_valid = False elif task.task_try_count > self.task_try_limit: logger.debug('Task tries (%d) ended: %s / %s' % ( self.task_try_limit, task.name, task.url)) self.add_item('too-many-task-tries', task.url) is_valid = False elif task.network_try_count > self.network_try_limit: logger.debug('Network tries (%d) ended: %s / %s' % ( self.network_try_limit, task.name, task.url)) self.add_item('too-many-network-tries', task.url) is_valid = False return is_valid def process_task_fallback(self, task): try: fallback_handler = getattr(self, 'task_%s_fallback' % task.name) except AttributeError: pass else: logger.error('task_*_fallback methods are deprecated! Do not use this feature please. It will be replaced with middleware layer') fallback_handler(task) def check_task_limits_deprecated(self, task): is_valid = self.check_task_limits(task) if not is_valid: self.process_task_fallback(task) return is_valid 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. Abort the task which was restarted too many times. """ 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://') and not task.url.startswith('https://') and not task.url.startswith('ftp://')): if self.base_url is None: raise SpiderMisuseError('Could not resolve relative URL because base_url is not specified. Task: %s, URL: %s' % (task.name, task.url)) 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 if self.config.get('TASK_REFRESH_CACHE', {}).get(task.name, False): task.refresh_cache = True is_valid = False is_valid = self.check_task_limits_deprecated(task) if is_valid: # TODO: keep original task priority if it was set explicitly self.taskq.put(task, task.priority, schedule_time=task.schedule_time) else: self.add_item('task-could-not-be-added', task.url) 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. Tryring to add new tasks') try: for x in xrange(min_limit - qsize): item = next(self.task_generator_object) logger_verbose.debug('Found new task. Adding it') self.add_task(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: # Temporarly 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 immediatelly 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): return Grab(**self.grab_config) 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) 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' % res['emsg'][:20]) logger.error(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): """ 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) # 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) 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') self.transport.process_task(task, grab, grab_config_backup) logger_verbose.debug('Asking transport layer to do something') self.transport.process_handlers() 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. """ 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: # 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 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: 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 == 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) if not self.check_task_limits(task): logger_verbose.debug('Task %s is rejected due to limits' % task.name) self.process_task_fallback(task) else: self.process_new_task(task) with self.save_timer('network_transport'): logger_verbose.debug('Asking transport layer to do something') # Process active handlers self.transport.select(0.01) 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} 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']) self.process_network_result(result) self.inc_count('request') 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 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): """ 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 update_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')
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 __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('')