def start(self):
self._seen = set()
self._queue = Queue(loop=self._loop)
for url in self.config['urls']:
self._queue.put_nowait(Request(url))
workers = [asyncio.Task(self._work()) for _ in range(self.config['concurrency'])]
yield from self._queue.join()
for worker in workers:
worker.cancel()
class Spider(metaclass=abc.ABCMeta):
def __init__(self, middlewares=None, loop=None, **config):
self.config = config
self._context = {}
self._loop = loop or asyncio.get_event_loop()
self._connector = aiohttp.TCPConnector(loop=self._loop)
self._middlewares = CrawlerMiddlewareManager(self, middlewares)
def enqueue_request(self, **kwargs):
context = self._context[self.task]
max_depth = self.config.get('max_depth')
if max_depth and context['request'].depth > max_depth:
return
request = Request(referer=context['response'], **kwargs)
if request.url in self._seen:
return
if not self._url_allowed(request):
return
request.depth = context['response'].request.depth + 1
self._queue.put_nowait(request)
def _url_allowed(self, request):
return next(
(
True for domain in self.config['domains']
if request.furl.host.endswith(domain)
),
False,
)
@asyncio.coroutine
def start(self):
self._seen = set()
self._queue = Queue(loop=self._loop)
for url in self.config['urls']:
self._queue.put_nowait(Request(url))
workers = [asyncio.Task(self._work()) for _ in range(self.config['concurrency'])]
yield from self._queue.join()
for worker in workers:
worker.cancel()
@asyncio.coroutine
def _work(self):
while True:
request = yield from self._queue.get()
yield from self._fetch(request)
self._queue.task_done()
@asyncio.coroutine
def _fetch(self, request):
for callback in self._middlewares['before_request']:
request = callback(request)
resp = yield from aiohttp.request('GET', request.url, loop=self._loop)
body = yield from resp.read_and_close()
response = Response(request, resp, body)
for callback in self._middlewares['after_response']:
response = callback(response)
with self._request_context(self._loop, request, response):
self.parse(response)
@property
def _task(self):
return asyncio.get_current_task(loop=self._loop)
@contextlib.contextmanager
def _request_context(self, request, response):
self._context[self.task] = {'request': request, 'response': response}
try:
yield
finally:
del self._context[self.task]
@abc.abstractmethod
def parse(self, response):
pass
class Spider(metaclass=abc.ABCMeta):
def __init__(self, import_name, middlewares=None, loop=None, session=None):
self.import_name = import_name
self.root_path = get_root_path(import_name)
self.config = Config(self.root_path, default_config)
self._context = {}
self._loop = loop or asyncio.get_event_loop()
self._middlewares = SpiderMiddlewareManager(self, middlewares)
self._session = session or aiohttp.ClientSession(loop=self._loop)
def enqueue_request(self, **kwargs):
context = self._context[self._task]
max_depth = self.config.get('MAX_DEPTH')
if max_depth and context['request'].depth > max_depth:
return
request = Request(referer=context['response'], **kwargs)
if request.url in self._seen:
return
if not self._url_allowed(request):
return
request.depth = context['response'].request.depth + 1
self._queue.put_nowait(request)
def run(self):
self._loop.run_until_complete(self.start())
@asyncio.coroutine
def start(self):
self._seen = set()
self._queue = Queue(loop=self._loop)
for url in self.config['URLS']:
self._queue.put_nowait(Request(url))
workers = [asyncio.Task(self._work()) for _ in range(self.config['CONCURRENCY'])]
yield from self._queue.join()
for worker in workers:
worker.cancel()
@asyncio.coroutine
def _work(self):
while True:
request = yield from self._queue.get()
yield from self._fetch(request)
self._queue.task_done()
@asyncio.coroutine
def _fetch(self, request):
for callback in self._middlewares['before_request']:
request = callback(self, request)
resp = yield from self._session.request('get', **request.params)
body = yield from resp.read_and_close()
response = Response(request, resp, body)
for callback in self._middlewares['after_response']:
response = callback(self, response)
with self._request_context(request, response):
self.parse(response)
@property
def _task(self):
return asyncio.Task.current_task(loop=self._loop)
@contextlib.contextmanager
def _request_context(self, request, response):
self._context[self._task] = {'request': request, 'response': response}
try:
yield
finally:
del self._context[self._task]
def _url_allowed(self, request):
return next(
(
True for domain in self.config['DOMAINS']
if request.furl.host.endswith(domain)
),
False,
)
@abc.abstractmethod
def parse(self, response):
pass
