diff --git a/scrapy/crawler.py b/scrapy/crawler.py index 5658e264b..4531c3aac 100644 --- a/scrapy/crawler.py +++ b/scrapy/crawler.py @@ -305,7 +305,7 @@ class CrawlerProcess(CrawlerRunner): d.addBoth(self._stop_reactor) resolver_class = load_object(self.settings["DNS_RESOLVER"]) - resolver_class.install(reactor, self.settings) + resolver_class.install_on_reactor(reactor, crawler=self) tp = reactor.getThreadPool() tp.adjustPoolsize(maxthreads=self.settings.getint('REACTOR_THREADPOOL_MAXSIZE')) reactor.addSystemEventTrigger('before', 'shutdown', self.stop) diff --git a/scrapy/resolver.py b/scrapy/resolver.py index 2bef9f1b8..792563e79 100644 --- a/scrapy/resolver.py +++ b/scrapy/resolver.py @@ -4,6 +4,7 @@ from twisted.internet.interfaces import IHostnameResolver, IResolutionReceiver, from zope.interface.declarations import implementer, provider from scrapy.utils.datatypes import LocalCache +from scrapy.utils.misc import create_instance # TODO: cache misses @@ -13,23 +14,27 @@ dnscache = LocalCache(10000) @implementer(IResolverSimple) class CachingThreadedResolver(ThreadedResolver): """ - Default caching resolver. IPv4 only, supports setting a timeout value for DNS requests + Default caching resolver. IPv4 only, supports setting a timeout value for DNS requests. """ - @classmethod - def install(cls, reactor, settings): - if settings.getbool('DNSCACHE_ENABLED'): - cache_size = settings.getint('DNSCACHE_SIZE') - else: - cache_size = 0 - resolver = cls(reactor, cache_size, settings.getfloat('DNS_TIMEOUT')) - reactor.installResolver(resolver) - def __init__(self, reactor, cache_size, timeout): super(CachingThreadedResolver, self).__init__(reactor) dnscache.limit = cache_size self.timeout = timeout + @classmethod + def from_crawler(cls, crawler, reactor): + if crawler.settings.getbool('DNSCACHE_ENABLED'): + cache_size = crawler.settings.getint('DNSCACHE_SIZE') + else: + cache_size = 0 + return cls(reactor, cache_size, crawler.settings.getfloat('DNS_TIMEOUT')) + + @classmethod + def install_on_reactor(cls, reactor, crawler): + resolver = create_instance(cls, None, crawler, reactor=reactor) + reactor.installResolver(resolver) + def getHostByName(self, name, timeout=None): if name in dnscache: return defer.succeed(dnscache[name]) @@ -51,21 +56,26 @@ class CachingThreadedResolver(ThreadedResolver): @implementer(IHostnameResolver) class CachingHostnameResolver: """ - Experimental caching resolver, supporting IPv4 and IPv6 + Experimental caching resolver. Resolves IPv4 and IPv6 addresses, + does not support setting a timeout value for DNS requests. """ + def __init__(self, reactor, cache_size): + self.resolver = reactor.nameResolver + dnscache.limit = cache_size + @classmethod - def install(cls, reactor, settings): - if settings.getbool('DNSCACHE_ENABLED'): - cache_size = settings.getint('DNSCACHE_SIZE') + def from_crawler(cls, crawler, reactor): + if crawler.settings.getbool('DNSCACHE_ENABLED'): + cache_size = crawler.settings.getint('DNSCACHE_SIZE') else: cache_size = 0 - resolver = cls(reactor.nameResolver, cache_size) - reactor.installNameResolver(resolver) + return cls(reactor, cache_size) - def __init__(self, resolver, cache_size): - self.resolver = resolver - dnscache.limit = cache_size + @classmethod + def install_on_reactor(cls, reactor, crawler): + resolver = create_instance(cls, None, crawler, reactor=reactor) + reactor.installNameResolver(resolver) def resolveHostName(self, resolutionReceiver, hostName, portNumber=0, addressTypes=None, transportSemantics='TCP'):