From 4a8438d7f2b7b16941240b91f39a9402c431ffc2 Mon Sep 17 00:00:00 2001 From: François Schmidts Date: Tue, 2 Feb 2016 23:30:57 +0100 Subject: writing a bit of doc, moving crawler together --- src/web/lib/crawler.py | 251 ------------------------------------------------- src/web/utils.py | 4 +- 2 files changed, 2 insertions(+), 253 deletions(-) delete mode 100644 src/web/lib/crawler.py (limited to 'src/web') diff --git a/src/web/lib/crawler.py b/src/web/lib/crawler.py deleted file mode 100644 index f480fe96..00000000 --- a/src/web/lib/crawler.py +++ /dev/null @@ -1,251 +0,0 @@ -""" -Here's a sum up on how it works : - -CrawlerScheduler.run - will retreive a list of feeds to be refreshed and pass result to -CrawlerScheduler.callback - which will retreive each feed and treat result with -FeedCrawler.callback - which will interprete the result (status_code, etag) collect ids - and match them agaisnt pyagg which will cause -PyAggUpdater.callback - to create the missing entries -""" - -import time -import conf -import json -import logging -import feedparser -from datetime import datetime, timedelta -from time import strftime, gmtime -from concurrent.futures import ThreadPoolExecutor -from requests_futures.sessions import FuturesSession -from web.lib.utils import default_handler, to_hash -from web.lib.feed_utils import construct_feed_from -from web.lib.article_utils import extract_id, construct_article - -logger = logging.getLogger(__name__) -logging.captureWarnings(True) -API_ROOT = "api/v2.0/" - - -class AbstractCrawler: - - def __init__(self, auth, pool=None, session=None): - self.auth = auth - self.pool = pool or ThreadPoolExecutor(max_workers=conf.NB_WORKER) - self.session = session or FuturesSession(executor=self.pool) - self.session.verify = False - self.url = conf.PLATFORM_URL - - def query_pyagg(self, method, urn, data=None): - """A wrapper for internal call, method should be ones you can find - on requests (header, post, get, options, ...), urn the distant - resources you want to access on pyagg, and data, the data you wanna - transmit.""" - if data is None: - data = {} - method = getattr(self.session, method) - return method("%s%s%s" % (self.url, API_ROOT, urn), - auth=self.auth, data=json.dumps(data, - default=default_handler), - headers={'Content-Type': 'application/json', - 'User-Agent': conf.USER_AGENT}) - - def wait(self, max_wait=300, checks=5, wait_for=2): - checked, second_waited = 0, 0 - while True: - time.sleep(wait_for) - second_waited += wait_for - if second_waited > max_wait: - logger.warn('Exiting after %d seconds', second_waited) - break - if self.pool._work_queue.qsize(): - checked = 0 - continue - checked += 1 - if checked == checks: - break - - -class PyAggUpdater(AbstractCrawler): - - def __init__(self, feed, entries, headers, parsed_feed, - auth, pool=None, session=None): - self.feed = feed - self.entries = entries - self.headers = headers - self.parsed_feed = parsed_feed - super().__init__(auth, pool, session) - - def callback(self, response): - """Will process the result from the challenge, creating missing article - and updating the feed""" - article_created = False - if response.result().status_code != 204: - results = response.result().json() - logger.debug('%r %r - %d entries were not matched ' - 'and will be created', - self.feed['id'], self.feed['title'], len(results)) - for id_to_create in results: - article_created = True - entry = construct_article( - self.entries[tuple(sorted(id_to_create.items()))], - self.feed) - logger.info('%r %r - creating %r for %r - %r', self.feed['id'], - self.feed['title'], entry['title'], - entry['user_id'], id_to_create) - self.query_pyagg('post', 'article', entry) - - logger.debug('%r %r - updating feed etag %r last_mod %r', - self.feed['id'], self.feed['title'], - self.headers.get('etag', ''), - self.headers.get('last-modified', '')) - - up_feed = {'error_count': 0, 'last_error': None, - 'etag': self.headers.get('etag', ''), - 'last_modified': self.headers.get('last-modified', - strftime('%a, %d %b %Y %X %Z', gmtime()))} - fresh_feed = construct_feed_from(url=self.feed['link'], - fp_parsed=self.parsed_feed) - for key in ('description', 'site_link', 'icon_url'): - if fresh_feed.get(key) and fresh_feed[key] != self.feed.get(key): - up_feed[key] = fresh_feed[key] - if not self.feed.get('title'): - up_feed['title'] = fresh_feed.get('title', '') - up_feed['user_id'] = self.feed['user_id'] - # re-getting that feed earlier since new entries appeared - if article_created: - up_feed['last_retrieved'] \ - = (datetime.now() - timedelta(minutes=45)).isoformat() - - diff_keys = {key for key in up_feed - if up_feed[key] != self.feed.get(key)} - if not diff_keys: - return # no change in the feed, no update - if not article_created and diff_keys == {'last_modified', 'etag'}: - return # meaningless if no new article has been published - logger.info('%r %r - pushing feed attrs %r', - self.feed['id'], self.feed['title'], - {key: "%s -> %s" % (up_feed[key], self.feed.get(key)) - for key in up_feed if up_feed[key] != self.feed.get(key)}) - - self.query_pyagg('put', 'feed/%d' % self.feed['id'], up_feed) - - -class FeedCrawler(AbstractCrawler): - - def __init__(self, feed, auth, pool=None, session=None): - self.feed = feed - super().__init__(auth, pool, session) - - def clean_feed(self): - """Will reset the errors counters on a feed that have known errors""" - if self.feed.get('error_count') or self.feed.get('last_error'): - self.query_pyagg('put', 'feed/%d' % self.feed['id'], - {'error_count': 0, 'last_error': ''}) - - def callback(self, response): - """will fetch the feed and interprete results (304, etag) or will - challenge pyagg to compare gotten entries with existing ones""" - try: - response = response.result() - response.raise_for_status() - except Exception as error: - error_count = self.feed['error_count'] + 1 - logger.exception('%r %r - an error occured while fetching ' - 'feed; bumping error count to %r', - self.feed['id'], self.feed['title'], error_count) - future = self.query_pyagg('put', 'feed/%d' % self.feed['id'], - {'error_count': error_count, - 'last_error': str(error), - 'user_id': self.feed['user_id']}) - return - - if response.status_code == 304: - logger.info("%r %r - feed responded with 304", - self.feed['id'], self.feed['title']) - self.clean_feed() - return - if 'etag' not in response.headers: - logger.debug('%r %r - manually generating etag', - self.feed['id'], self.feed['title']) - response.headers['etag'] = 'pyagg/"%s"' % to_hash(response.text) - if response.headers['etag'] and self.feed['etag'] \ - and response.headers['etag'] == self.feed['etag']: - if 'pyagg' in self.feed['etag']: - logger.info("%r %r - calculated hash matches (%d)", - self.feed['id'], self.feed['title'], - response.status_code) - else: - logger.info("%r %r - feed responded with same etag (%d)", - self.feed['id'], self.feed['title'], - response.status_code) - self.clean_feed() - return - else: - logger.debug('%r %r - etag mismatch %r != %r', - self.feed['id'], self.feed['title'], - response.headers['etag'], self.feed['etag']) - logger.info('%r %r - cache validation failed, challenging entries', - self.feed['id'], self.feed['title']) - - ids, entries = [], {} - parsed_response = feedparser.parse(response.content) - for entry in parsed_response['entries']: - entry_ids = extract_id(entry) - entry_ids['feed_id'] = self.feed['id'] - entry_ids['user_id'] = self.feed['user_id'] - entries[tuple(sorted(entry_ids.items()))] = entry - ids.append(entry_ids) - logger.debug('%r %r - found %d entries %r', - self.feed['id'], self.feed['title'], len(ids), ids) - future = self.query_pyagg('get', 'articles/challenge', {'ids': ids}) - updater = PyAggUpdater(self.feed, entries, response.headers, - parsed_response, - self.auth, self.pool, self.session) - future.add_done_callback(updater.callback) - - -class CrawlerScheduler(AbstractCrawler): - - def __init__(self, username, password, pool=None, session=None): - self.auth = (username, password) - super(CrawlerScheduler, self).__init__(self.auth, pool, session) - - def prepare_headers(self, feed): - """For a known feed, will construct some header dictionnary""" - headers = {'User-Agent': conf.USER_AGENT} - if feed.get('last_modified'): - headers['If-Modified-Since'] = feed['last_modified'] - if feed.get('etag') and 'pyagg' not in feed['etag']: - headers['If-None-Match'] = feed['etag'] - logger.debug('%r %r - calculated headers %r', - feed['id'], feed['title'], headers) - return headers - - def callback(self, response): - """processes feeds that need to be fetched""" - response = response.result() - response.raise_for_status() - if response.status_code == 204: - logger.debug("No feed to fetch") - return - feeds = response.json() - logger.debug('%d to fetch %r', len(feeds), feeds) - for feed in feeds: - logger.debug('%r %r - fetching resources', - feed['id'], feed['title']) - future = self.session.get(feed['link'], - headers=self.prepare_headers(feed)) - - feed_crwlr = FeedCrawler(feed, self.auth, self.pool, self.session) - future.add_done_callback(feed_crwlr.callback) - - def run(self, **kwargs): - """entry point, will retreive feeds to be fetch - and launch the whole thing""" - logger.debug('retreving fetchable feed') - future = self.query_pyagg('get', 'feeds/fetchable', kwargs) - future.add_done_callback(self.callback) diff --git a/src/web/utils.py b/src/web/utils.py index fcd791e8..1d4b30ab 100755 --- a/src/web/utils.py +++ b/src/web/utils.py @@ -109,8 +109,8 @@ def fetch(id, feed_id=None): Fetch the feeds in a new processus. The "asyncio" crawler is launched with the manager. """ - cmd = [sys.executable, conf.BASE_DIR+'/manager.py', 'fetch_asyncio', str(id), - str(feed_id)] + cmd = [sys.executable, conf.BASE_DIR + '/manager.py', 'fetch_asyncio', + str(id), str(feed_id)] return subprocess.Popen(cmd, stdout=subprocess.PIPE) def history(user_id, year=None, month=None): -- cgit