Limnoria/plugins/RSS.py
2004-04-13 18:25:49 +00:00

340 lines
14 KiB
Python

#!/usr/bin/env python
###
# Copyright (c) 2002, Jeremiah Fincher
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions, and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions, and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# * Neither the name of the author of this software nor the name of
# contributors to this software may be used to endorse or promote products
# derived from this software without specific prior written consent.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
###
"""
Provides basic functionality for handling RSS/RDF feeds.
"""
__revision__ = "$Id$"
import plugins
import sets
import time
import sgmllib
import threading
from itertools import imap
import rssparser
import conf
import utils
import world
import ircmsgs
import ircutils
import privmsgs
import registry
import callbacks
def configure(advanced):
from questions import output, expect, anything, something, yn
conf.registerPlugin('RSS', True)
prompt = 'Would you like to add an RSS feed?'
while yn(prompt):
prompt = 'Would you like to add another RSS feed?'
name = something('What\'s the name of the website?')
url = something('What\'s the URL of the RSS feed?')
registerFeed(name, url)
conf.registerPlugin('RSS')
conf.registerChannelValue(conf.supybot.plugins.RSS, 'bold', registry.Boolean(
True, """Determines whether the bot will bold the title of the feed when it
announces new news."""))
conf.registerChannelValue(conf.supybot.plugins.RSS, 'headlineSeparator',
registry.StringSurroundedBySpaces(' || ', """Determines what string is used
to separate headlines in new feeds."""))
conf.registerChannelValue(conf.supybot.plugins.RSS, 'announcementPrefix',
registry.StringWithSpaceOnRight('New news from ', """Determines what prefix
is prepended (if any) to the new news item announcements made in the
channel."""))
conf.registerChannelValue(conf.supybot.plugins.RSS, 'announce',
registry.SpaceSeparatedListOfStrings([], """Determines which RSS feeds
should be announced in the channel; valid input is a list of strings
(either registered RSS feeds or RSS feed URLs) separated by spaces."""))
conf.registerGlobalValue(conf.supybot.plugins.RSS, 'waitPeriod',
registry.PositiveInteger(1800, """Indicates how many seconds the bot will
wait between retrieving RSS feeds; requests made within this period will
return cached results."""))
conf.registerGroup(conf.supybot.plugins.RSS, 'feeds')
conf.supybot.plugins.RSS.feeds.help = utils.normalizeWhitespace("""These are
the registered feeds for the RSS plugin.""")
def registerFeed(name, url):
conf.supybot.plugins.RSS.feeds.register(name, registry.String(url, ''))
class RSS(callbacks.Privmsg):
threaded = True
def __init__(self):
callbacks.Privmsg.__init__(self)
self.feedNames = sets.Set()
self.locks = {}
self.lastRequest = {}
self.cachedFeeds = {}
self.gettingLockLock = threading.Lock()
for (name, url) in registry._cache.iteritems():
name = name.lower()
if name.startswith('supybot.plugins.rss.feeds.'):
name = rsplit(name, '.', 1)[-1]
v = registry.String('', 'help is not needed here')
v.set(url)
url = v()
self.makeFeedCommand(name, url)
def __call__(self, irc, msg):
callbacks.Privmsg.__call__(self, irc, msg)
irc = callbacks.IrcObjectProxyRegexp(irc, msg)
L = conf.supybot.plugins.RSS.announce.getValues(fullNames=False)
newFeeds = {}
for (channel, v) in L:
feeds = v()
for name in feeds:
if self.isCommand(callbacks.canonicalName(name)):
url = self.getCommand(name).url
else:
url = name
if self.willGetNewFeed(url):
newFeeds.setdefault((url, name), []).append(channel)
for ((url, name), channels) in newFeeds.iteritems():
# We check if we can acquire the lock right here because if we
# don't, we'll possibly end up spawning a lot of threads to get
# the feed, because this thread may run for a number of bytecodes
# before it switches to a thread that'll get the lock in
# _newHeadlines.
if self.acquireLock(url, blocking=False):
try:
t = threading.Thread(target=self._newHeadlines,
name='Fetching <%s>' % url,
args=(irc, channels, name, url))
self.log.info('Spawning thread to fetch <%s>', url)
world.threadsSpawned += 1
t.setDaemon(True)
t.start()
finally:
self.releaseLock(url)
time.sleep(0.1) # So other threads can run.
def _newHeadlines(self, irc, channels, name, url):
try:
# We acquire the lock here so there's only one announcement thread
# in this code at any given time. Otherwise, several announcement
# threads will getFeed (all blocking, in turn); then they'll all
# want to sent their news messages to the appropriate channels.
# Note that we're allowed to acquire this lock twice within the
# same thread because it's an RLock and not just a normal Lock.
self.acquireLock(url)
try:
oldresults = self.cachedFeeds[url]
oldheadlines = self.getHeadlines(oldresults)
except KeyError:
oldheadlines = []
newresults = self.getFeed(url)
newheadlines = self.getHeadlines(newresults)
for headline in oldheadlines:
try:
newheadlines.remove(headline)
except ValueError:
pass
if newheadlines:
for channel in channels:
bold = self.registryValue('bold', channel)
sep = self.registryValue('headlineSeparator', channel)
prefix = self.registryValue('announcementPrefix', channel)
pre = '%s%s: ' % (prefix, name)
if bold:
pre = ircutils.bold(pre)
irc.replies(newheadlines, prefixer=pre, joiner=sep,
to=channel, prefixName=False, private=True)
finally:
self.releaseLock(url)
def willGetNewFeed(self, url):
now = time.time()
wait = self.registryValue('waitPeriod')
if url not in self.lastRequest or now - self.lastRequest[url] > wait:
return True
else:
return False
def acquireLock(self, url, blocking=True):
try:
self.gettingLockLock.acquire()
try:
lock = self.locks[url]
except KeyError:
lock = threading.RLock()
self.locks[url] = lock
return lock.acquire(blocking=blocking)
finally:
self.gettingLockLock.release()
def releaseLock(self, url):
self.locks[url].release()
def getFeed(self, url):
try:
# This is the most obvious place to acquire the lock, because a
# malicious user could conceivably flood the bot with rss commands
# and DoS the website in question.
self.acquireLock(url)
if self.willGetNewFeed(url):
try:
self.log.info('Downloading new feed from <%s>', url)
results = rssparser.parse(url)
except sgmllib.SGMLParseError:
self.log.exception('Uncaught exception from rssparser:')
raise callbacks.Error, 'Invalid (unparseable) RSS feed.'
self.cachedFeeds[url] = results
self.lastRequest[url] = time.time()
try:
return self.cachedFeeds[url]
except KeyError:
self.lastRequest[url] = 0
return {'items': [{'title': 'Unable to download feed.'}]}
finally:
self.releaseLock(url)
def getHeadlines(self, feed):
return [utils.htmlToText(d['title'].strip()) for d in feed['items']]
def makeFeedCommand(self, name, url):
docstring = """takes no arguments
Reports the titles for %s at the RSS feed <%s>. RSS feeds are only
looked up every supybot.plugins.RSS.waitPeriod seconds, which defaults
to 1800 (30 minutes) since that's what most websites prefer.
""" % (name, url)
name = callbacks.canonicalName(name)
if url not in self.locks:
self.locks[url] = threading.RLock()
if hasattr(self, name):
s = 'I already have a command in this plugin named %s' % name
raise callbacks.Error, s
def f(self, irc, msg, args):
args.insert(0, url)
self.rss(irc, msg, args)
f = utils.changeFunctionName(f, name, docstring)
f.url = url # Used by __call__.
self.feedNames.add(name)
setattr(self.__class__, name, f)
registerFeed(name, url)
def add(self, irc, msg, args):
"""<name> <url>
Adds a command to this plugin that will look up the RSS feed at the
given URL.
"""
(name, url) = privmsgs.getArgs(args, required=2)
self.makeFeedCommand(name, url)
irc.replySuccess()
def remove(self, irc, msg, args):
"""<name>
Removes the command for looking up RSS feeds at <name> from
this plugin.
"""
name = privmsgs.getArgs(args)
name = callbacks.canonicalName(name)
if name not in self.feedNames:
irc.error('That\'s not a valid RSS feed command name.')
return
delattr(self.__class__, name)
irc.replySuccess()
def announce(self, irc, msg, args, channel):
"""[<channel>] [<name|url> ...]
Sets the current list of announced feeds in the channel to the feeds
given. Valid feeds include the names of registered feeds as well as
URLs for a RSS feeds. <channel> is only necessary if the message isn't
sent in the channel itself.
"""
conf.supybot.plugins.RSS.announce.get(channel).setValue(args)
if not args:
irc.replySuccess('All previous announced feeds removed.')
else:
irc.replySuccess()
announce = privmsgs.checkChannelCapability(announce, 'op')
def rss(self, irc, msg, args):
"""<url>
Gets the title components of the given RSS feed.
"""
url = privmsgs.getArgs(args)
self.log.debug('Fetching %s', url)
feed = self.getFeed(url)
if ircutils.isChannel(msg.args[0]):
channel = msg.args[0]
else:
channel = None
headlines = self.getHeadlines(feed)
if not headlines:
irc.error('Couldn\'t get RSS feed')
return
headlines = imap(utils.htmlToText, headlines)
sep = self.registryValue('headlineSeparator', channel)
irc.reply(sep.join(headlines))
def info(self, irc, msg, args):
"""<url>
Returns information from the given RSS feed, namely the title,
URL, description, and last update date, if available.
"""
url = privmsgs.getArgs(args)
feed = self.getFeed(url)
info = feed['channel']
if not info:
irc.error('I couldn\'t retrieve that RSS feed.')
return
# check the 'modified' key, if it's there, convert it here first
if 'modified' in feed:
seconds = time.mktime(feed['modified'])
now = time.mktime(time.gmtime())
when = utils.timeElapsed(now - seconds) + ' ago'
else:
when = "time unavailable"
# The rest of the entries are all available in the channel key
response = 'Title: %s; URL: <%s>; ' \
'Description: %s; Last updated %s.' % (
info.get('title', 'unavailable').strip(),
info.get('link', 'unavailable').strip(),
info.get('description', 'unavailable').strip(),
when)
irc.reply(' '.join(response.split()))
Class = RSS
# vim:set shiftwidth=4 tabstop=4 expandtab textwidth=78: