New hybrid method

resources/lib/libraries/requests/packages/urllib3/util/connection.py

@@ -0,0 +1,101 @@
+from __future__ import absolute_import
+import socket
+try:
+    from select import poll, POLLIN
+except ImportError:  # `poll` doesn't exist on OSX and other platforms
+    poll = False
+    try:
+        from select import select
+    except ImportError:  # `select` doesn't exist on AppEngine.
+        select = False
+
+
+def is_connection_dropped(conn):  # Platform-specific
+    """
+    Returns True if the connection is dropped and should be closed.
+
+    :param conn:
+        :class:`httplib.HTTPConnection` object.
+
+    Note: For platforms like AppEngine, this will always return ``False`` to
+    let the platform handle connection recycling transparently for us.
+    """
+    sock = getattr(conn, 'sock', False)
+    if sock is False:  # Platform-specific: AppEngine
+        return False
+    if sock is None:  # Connection already closed (such as by httplib).
+        return True
+
+    if not poll:
+        if not select:  # Platform-specific: AppEngine
+            return False
+
+        try:
+            return select([sock], [], [], 0.0)[0]
+        except socket.error:
+            return True
+
+    # This version is better on platforms that support it.
+    p = poll()
+    p.register(sock, POLLIN)
+    for (fno, ev) in p.poll(0.0):
+        if fno == sock.fileno():
+            # Either data is buffered (bad), or the connection is dropped.
+            return True
+
+
+# This function is copied from socket.py in the Python 2.7 standard
+# library test suite. Added to its signature is only `socket_options`.
+def create_connection(address, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
+                      source_address=None, socket_options=None):
+    """Connect to *address* and return the socket object.
+
+    Convenience function.  Connect to *address* (a 2-tuple ``(host,
+    port)``) and return the socket object.  Passing the optional
+    *timeout* parameter will set the timeout on the socket instance
+    before attempting to connect.  If no *timeout* is supplied, the
+    global default timeout setting returned by :func:`getdefaulttimeout`
+    is used.  If *source_address* is set it must be a tuple of (host, port)
+    for the socket to bind as a source address before making the connection.
+    An host of '' or port 0 tells the OS to use the default.
+    """
+
+    host, port = address
+    if host.startswith('['):
+        host = host.strip('[]')
+    err = None
+    for res in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM):
+        af, socktype, proto, canonname, sa = res
+        sock = None
+        try:
+            sock = socket.socket(af, socktype, proto)
+
+            # If provided, set socket level options before connecting.
+            # This is the only addition urllib3 makes to this function.
+            _set_socket_options(sock, socket_options)
+
+            if timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:
+                sock.settimeout(timeout)
+            if source_address:
+                sock.bind(source_address)
+            sock.connect(sa)
+            return sock
+
+        except socket.error as e:
+            err = e
+            if sock is not None:
+                sock.close()
+                sock = None
+
+    if err is not None:
+        raise err
+
+    raise socket.error("getaddrinfo returns an empty list")
+
+
+def _set_socket_options(sock, options):
+    if options is None:
+        return
+
+    for opt in options:
+        sock.setsockopt(*opt)