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Diffstat (limited to 'urllib3/poolmanager.py')
-rw-r--r-- | urllib3/poolmanager.py | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/urllib3/poolmanager.py b/urllib3/poolmanager.py new file mode 100644 index 0000000..d42f35b --- /dev/null +++ b/urllib3/poolmanager.py @@ -0,0 +1,138 @@ +# urllib3/poolmanager.py +# Copyright 2008-2012 Andrey Petrov and contributors (see CONTRIBUTORS.txt) +# +# This module is part of urllib3 and is released under +# the MIT License: http://www.opensource.org/licenses/mit-license.php + +import logging + +from ._collections import RecentlyUsedContainer +from .connectionpool import HTTPConnectionPool, HTTPSConnectionPool +from .connectionpool import get_host, connection_from_url, port_by_scheme +from .exceptions import HostChangedError +from .request import RequestMethods + + +__all__ = ['PoolManager', 'ProxyManager', 'proxy_from_url'] + + +pool_classes_by_scheme = { + 'http': HTTPConnectionPool, + 'https': HTTPSConnectionPool, +} + +log = logging.getLogger(__name__) + + +class PoolManager(RequestMethods): + """ + Allows for arbitrary requests while transparently keeping track of + necessary connection pools for you. + + :param num_pools: + Number of connection pools to cache before discarding the least recently + used pool. + + :param \**connection_pool_kw: + Additional parameters are used to create fresh + :class:`urllib3.connectionpool.ConnectionPool` instances. + + Example: :: + + >>> manager = PoolManager() + >>> r = manager.urlopen("http://google.com/") + >>> r = manager.urlopen("http://google.com/mail") + >>> r = manager.urlopen("http://yahoo.com/") + >>> len(r.pools) + 2 + + """ + + # TODO: Make sure there are no memory leaks here. + + def __init__(self, num_pools=10, **connection_pool_kw): + self.connection_pool_kw = connection_pool_kw + self.pools = RecentlyUsedContainer(num_pools) + + def connection_from_host(self, host, port=80, scheme='http'): + """ + Get a :class:`ConnectionPool` based on the host, port, and scheme. + + Note that an appropriate ``port`` value is required here to normalize + connection pools in our container most effectively. + """ + pool_key = (scheme, host, port) + + # If the scheme, host, or port doesn't match existing open connections, + # open a new ConnectionPool. + pool = self.pools.get(pool_key) + if pool: + return pool + + # Make a fresh ConnectionPool of the desired type + pool_cls = pool_classes_by_scheme[scheme] + pool = pool_cls(host, port, **self.connection_pool_kw) + + self.pools[pool_key] = pool + + return pool + + def connection_from_url(self, url): + """ + Similar to :func:`urllib3.connectionpool.connection_from_url` but + doesn't pass any additional parameters to the + :class:`urllib3.connectionpool.ConnectionPool` constructor. + + Additional parameters are taken from the :class:`.PoolManager` + constructor. + """ + scheme, host, port = get_host(url) + + port = port or port_by_scheme.get(scheme, 80) + + return self.connection_from_host(host, port=port, scheme=scheme) + + def urlopen(self, method, url, **kw): + """ + Same as :meth:`urllib3.connectionpool.HTTPConnectionPool.urlopen`. + + ``url`` must be absolute, such that an appropriate + :class:`urllib3.connectionpool.ConnectionPool` can be chosen for it. + """ + conn = self.connection_from_url(url) + try: + return conn.urlopen(method, url, **kw) + + except HostChangedError as e: + kw['retries'] = e.retries # Persist retries countdown + return self.urlopen(method, e.url, **kw) + + +class ProxyManager(RequestMethods): + """ + Given a ConnectionPool to a proxy, the ProxyManager's ``urlopen`` method + will make requests to any url through the defined proxy. + """ + + def __init__(self, proxy_pool): + self.proxy_pool = proxy_pool + + def _set_proxy_headers(self, headers=None): + headers = headers or {} + + # Same headers are curl passes for --proxy1.0 + headers['Accept'] = '*/*' + headers['Proxy-Connection'] = 'Keep-Alive' + + return headers + + def urlopen(self, method, url, **kw): + "Same as HTTP(S)ConnectionPool.urlopen, ``url`` must be absolute." + kw['assert_same_host'] = False + kw['headers'] = self._set_proxy_headers(kw.get('headers')) + return self.proxy_pool.urlopen(method, url, **kw) + + +def proxy_from_url(url, **pool_kw): + proxy_pool = connection_from_url(url, **pool_kw) + return ProxyManager(proxy_pool) |