Add 'requests' library to third_party.

third_party/requests/packages/urllib3/poolmanager.py

Index: third_party/requests/packages/urllib3/poolmanager.py
diff --git a/third_party/requests/packages/urllib3/poolmanager.py b/third_party/requests/packages/urllib3/poolmanager.py
new file mode 100644
index 0000000000000000000000000000000000000000..ce0c248ea8df188ea8ed3b9afc29a6d36535212d
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+++ b/third_party/requests/packages/urllib3/poolmanager.py
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+# urllib3/poolmanager.py
+# Copyright 2008-2013 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 connection_from_url, port_by_scheme
+from .request import RequestMethods
+from .util import parse_url
+
+
+__all__ = ['PoolManager', 'ProxyManager', 'proxy_from_url']
+
+
+pool_classes_by_scheme = {
+    'http': HTTPConnectionPool,
+    'https': HTTPSConnectionPool,
+}
+
+log = logging.getLogger(__name__)
+
+SSL_KEYWORDS = ('key_file', 'cert_file', 'cert_reqs', 'ca_certs',
+                'ssl_version')
+
+
+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 headers:
+        Headers to include with all requests, unless other headers are given
+        explicitly.
+
+    :param \**connection_pool_kw:
+        Additional parameters are used to create fresh
+        :class:`urllib3.connectionpool.ConnectionPool` instances.
+
+    Example: ::
+
+        >>> manager = PoolManager(num_pools=2)
+        >>> r = manager.request('GET', 'http://google.com/')
+        >>> r = manager.request('GET', 'http://google.com/mail')
+        >>> r = manager.request('GET', 'http://yahoo.com/')
+        >>> len(manager.pools)
+        2
+
+    """
+
+    def __init__(self, num_pools=10, headers=None, **connection_pool_kw):
+        RequestMethods.__init__(self, headers)
+        self.connection_pool_kw = connection_pool_kw
+        self.pools = RecentlyUsedContainer(num_pools,
+                                           dispose_func=lambda p: p.close())
+
+    def _new_pool(self, scheme, host, port):
+        """
+        Create a new :class:`ConnectionPool` based on host, port and scheme.
+
+        This method is used to actually create the connection pools handed out
+        by :meth:`connection_from_url` and companion methods. It is intended
+        to be overridden for customization.
+        """
+        pool_cls = pool_classes_by_scheme[scheme]
+        kwargs = self.connection_pool_kw
+        if scheme == 'http':
+            kwargs = self.connection_pool_kw.copy()
+            for kw in SSL_KEYWORDS:
+                kwargs.pop(kw, None)
+
+        return pool_cls(host, port, **kwargs)
+
+    def clear(self):
+        """
+        Empty our store of pools and direct them all to close.
+
+        This will not affect in-flight connections, but they will not be
+        re-used after completion.
+        """
+        self.pools.clear()
+
+    def connection_from_host(self, host, port=None, scheme='http'):
+        """
+        Get a :class:`ConnectionPool` based on the host, port, and scheme.
+
+        If ``port`` isn't given, it will be derived from the ``scheme`` using
+        ``urllib3.connectionpool.port_by_scheme``.
+        """
+        scheme = scheme or 'http'
+        port = port or port_by_scheme.get(scheme, 80)
+
+        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 = self._new_pool(scheme, host, port)
+        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.
+        """
+        u = parse_url(url)
+        return self.connection_from_host(u.host, port=u.port, scheme=u.scheme)
+
+    def urlopen(self, method, url, redirect=True, **kw):
+        """
+        Same as :meth:`urllib3.connectionpool.HTTPConnectionPool.urlopen`
+        with custom cross-host redirect logic and only sends the request-uri
+        portion of the ``url``.
+
+        The given ``url`` parameter must be absolute, such that an appropriate
+        :class:`urllib3.connectionpool.ConnectionPool` can be chosen for it.
+        """
+        u = parse_url(url)
+        conn = self.connection_from_host(u.host, port=u.port, scheme=u.scheme)
+
+        kw['assert_same_host'] = False
+        kw['redirect'] = False
+        if 'headers' not in kw:
+            kw['headers'] = self.headers
+
+        response = conn.urlopen(method, u.request_uri, **kw)
+
+        redirect_location = redirect and response.get_redirect_location()
+        if not redirect_location:
+            return response
+
+        if response.status == 303:
+            method = 'GET'
+
+        log.info("Redirecting %s -> %s" % (url, redirect_location))
+        kw['retries'] = kw.get('retries', 3) - 1  # Persist retries countdown
+        kw['redirect'] = redirect
+        return self.urlopen(method, redirect_location, **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. The ProxyManager
+    class will automatically set the 'Host' header if it is not provided.
+    """
+
+    def __init__(self, proxy_pool):
+        self.proxy_pool = proxy_pool
+
+    def _set_proxy_headers(self, url, headers=None):
+        """
+        Sets headers needed by proxies: specifically, the Accept and Host
+        headers. Only sets headers not provided by the user.
+        """
+        headers_ = {'Accept': '*/*'}
+
+        host = parse_url(url).host
+        if host:
+            headers_['Host'] = host
+
+        if headers:
+            headers_.update(headers)
+
+        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(url, 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)