Add google-endpoints to third_party/.

third_party/google-endpoints/future/backports/http/client.py

Index: third_party/google-endpoints/future/backports/http/client.py
diff --git a/third_party/google-endpoints/future/backports/http/client.py b/third_party/google-endpoints/future/backports/http/client.py
new file mode 100644
index 0000000000000000000000000000000000000000..5dd983d80843f41474edf65e60467b2ca00937a4
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+++ b/third_party/google-endpoints/future/backports/http/client.py
@@ -0,0 +1,1332 @@
+"""HTTP/1.1 client library
+
+A backport of the Python 3.3 http/client.py module for python-future.
+
+<intro stuff goes here>
+<other stuff, too>
+
+HTTPConnection goes through a number of "states", which define when a client
+may legally make another request or fetch the response for a particular
+request. This diagram details these state transitions:
+
+    (null)
+      |
+      | HTTPConnection()
+      v
+    Idle
+      |
+      | putrequest()
+      v
+    Request-started
+      |
+      | ( putheader() )*  endheaders()
+      v
+    Request-sent
+      |
+      | response = getresponse()
+      v
+    Unread-response   [Response-headers-read]
+      |\____________________
+      |                     |
+      | response.read()     | putrequest()
+      v                     v
+    Idle                  Req-started-unread-response
+                     ______/|
+                   /        |
+   response.read() |        | ( putheader() )*  endheaders()
+                   v        v
+       Request-started    Req-sent-unread-response
+                            |
+                            | response.read()
+                            v
+                          Request-sent
+
+This diagram presents the following rules:
+  -- a second request may not be started until {response-headers-read}
+  -- a response [object] cannot be retrieved until {request-sent}
+  -- there is no differentiation between an unread response body and a
+     partially read response body
+
+Note: this enforcement is applied by the HTTPConnection class. The
+      HTTPResponse class does not enforce this state machine, which
+      implies sophisticated clients may accelerate the request/response
+      pipeline. Caution should be taken, though: accelerating the states
+      beyond the above pattern may imply knowledge of the server's
+      connection-close behavior for certain requests. For example, it
+      is impossible to tell whether the server will close the connection
+      UNTIL the response headers have been read; this means that further
+      requests cannot be placed into the pipeline until it is known that
+      the server will NOT be closing the connection.
+
+Logical State                  __state            __response
+-------------                  -------            ----------
+Idle                           _CS_IDLE           None
+Request-started                _CS_REQ_STARTED    None
+Request-sent                   _CS_REQ_SENT       None
+Unread-response                _CS_IDLE           <response_class>
+Req-started-unread-response    _CS_REQ_STARTED    <response_class>
+Req-sent-unread-response       _CS_REQ_SENT       <response_class>
+"""
+
+from __future__ import (absolute_import, division,
+                        print_function, unicode_literals)
+from future.builtins import bytes, int, str, super
+from future.utils import PY2
+
+from future.backports.email import parser as email_parser
+from future.backports.email import message as email_message
+from future.backports.misc import create_connection as socket_create_connection
+import io
+import os
+import socket
+import collections
+from future.backports.urllib.parse import urlsplit
+import warnings
+from array import array
+
+__all__ = ["HTTPResponse", "HTTPConnection",
+           "HTTPException", "NotConnected", "UnknownProtocol",
+           "UnknownTransferEncoding", "UnimplementedFileMode",
+           "IncompleteRead", "InvalidURL", "ImproperConnectionState",
+           "CannotSendRequest", "CannotSendHeader", "ResponseNotReady",
+           "BadStatusLine", "error", "responses"]
+
+HTTP_PORT = 80
+HTTPS_PORT = 443
+
+_UNKNOWN = 'UNKNOWN'
+
+# connection states
+_CS_IDLE = 'Idle'
+_CS_REQ_STARTED = 'Request-started'
+_CS_REQ_SENT = 'Request-sent'
+
+# status codes
+# informational
+CONTINUE = 100
+SWITCHING_PROTOCOLS = 101
+PROCESSING = 102
+
+# successful
+OK = 200
+CREATED = 201
+ACCEPTED = 202
+NON_AUTHORITATIVE_INFORMATION = 203
+NO_CONTENT = 204
+RESET_CONTENT = 205
+PARTIAL_CONTENT = 206
+MULTI_STATUS = 207
+IM_USED = 226
+
+# redirection
+MULTIPLE_CHOICES = 300
+MOVED_PERMANENTLY = 301
+FOUND = 302
+SEE_OTHER = 303
+NOT_MODIFIED = 304
+USE_PROXY = 305
+TEMPORARY_REDIRECT = 307
+
+# client error
+BAD_REQUEST = 400
+UNAUTHORIZED = 401
+PAYMENT_REQUIRED = 402
+FORBIDDEN = 403
+NOT_FOUND = 404
+METHOD_NOT_ALLOWED = 405
+NOT_ACCEPTABLE = 406
+PROXY_AUTHENTICATION_REQUIRED = 407
+REQUEST_TIMEOUT = 408
+CONFLICT = 409
+GONE = 410
+LENGTH_REQUIRED = 411
+PRECONDITION_FAILED = 412
+REQUEST_ENTITY_TOO_LARGE = 413
+REQUEST_URI_TOO_LONG = 414
+UNSUPPORTED_MEDIA_TYPE = 415
+REQUESTED_RANGE_NOT_SATISFIABLE = 416
+EXPECTATION_FAILED = 417
+UNPROCESSABLE_ENTITY = 422
+LOCKED = 423
+FAILED_DEPENDENCY = 424
+UPGRADE_REQUIRED = 426
+PRECONDITION_REQUIRED = 428
+TOO_MANY_REQUESTS = 429
+REQUEST_HEADER_FIELDS_TOO_LARGE = 431
+
+# server error
+INTERNAL_SERVER_ERROR = 500
+NOT_IMPLEMENTED = 501
+BAD_GATEWAY = 502
+SERVICE_UNAVAILABLE = 503
+GATEWAY_TIMEOUT = 504
+HTTP_VERSION_NOT_SUPPORTED = 505
+INSUFFICIENT_STORAGE = 507
+NOT_EXTENDED = 510
+NETWORK_AUTHENTICATION_REQUIRED = 511
+
+# Mapping status codes to official W3C names
+responses = {
+    100: 'Continue',
+    101: 'Switching Protocols',
+
+    200: 'OK',
+    201: 'Created',
+    202: 'Accepted',
+    203: 'Non-Authoritative Information',
+    204: 'No Content',
+    205: 'Reset Content',
+    206: 'Partial Content',
+
+    300: 'Multiple Choices',
+    301: 'Moved Permanently',
+    302: 'Found',
+    303: 'See Other',
+    304: 'Not Modified',
+    305: 'Use Proxy',
+    306: '(Unused)',
+    307: 'Temporary Redirect',
+
+    400: 'Bad Request',
+    401: 'Unauthorized',
+    402: 'Payment Required',
+    403: 'Forbidden',
+    404: 'Not Found',
+    405: 'Method Not Allowed',
+    406: 'Not Acceptable',
+    407: 'Proxy Authentication Required',
+    408: 'Request Timeout',
+    409: 'Conflict',
+    410: 'Gone',
+    411: 'Length Required',
+    412: 'Precondition Failed',
+    413: 'Request Entity Too Large',
+    414: 'Request-URI Too Long',
+    415: 'Unsupported Media Type',
+    416: 'Requested Range Not Satisfiable',
+    417: 'Expectation Failed',
+    428: 'Precondition Required',
+    429: 'Too Many Requests',
+    431: 'Request Header Fields Too Large',
+
+    500: 'Internal Server Error',
+    501: 'Not Implemented',
+    502: 'Bad Gateway',
+    503: 'Service Unavailable',
+    504: 'Gateway Timeout',
+    505: 'HTTP Version Not Supported',
+    511: 'Network Authentication Required',
+}
+
+# maximal amount of data to read at one time in _safe_read
+MAXAMOUNT = 1048576
+
+# maximal line length when calling readline().
+_MAXLINE = 65536
+_MAXHEADERS = 100
+
+
+class HTTPMessage(email_message.Message):
+    # XXX The only usage of this method is in
+    # http.server.CGIHTTPRequestHandler.  Maybe move the code there so
+    # that it doesn't need to be part of the public API.  The API has
+    # never been defined so this could cause backwards compatibility
+    # issues.
+
+    def getallmatchingheaders(self, name):
+        """Find all header lines matching a given header name.
+
+        Look through the list of headers and find all lines matching a given
+        header name (and their continuation lines).  A list of the lines is
+        returned, without interpretation.  If the header does not occur, an
+        empty list is returned.  If the header occurs multiple times, all
+        occurrences are returned.  Case is not important in the header name.
+
+        """
+        name = name.lower() + ':'
+        n = len(name)
+        lst = []
+        hit = 0
+        for line in self.keys():
+            if line[:n].lower() == name:
+                hit = 1
+            elif not line[:1].isspace():
+                hit = 0
+            if hit:
+                lst.append(line)
+        return lst
+
+def parse_headers(fp, _class=HTTPMessage):
+    """Parses only RFC2822 headers from a file pointer.
+
+    email Parser wants to see strings rather than bytes.
+    But a TextIOWrapper around self.rfile would buffer too many bytes
+    from the stream, bytes which we later need to read as bytes.
+    So we read the correct bytes here, as bytes, for email Parser
+    to parse.
+
+    """
+    headers = []
+    while True:
+        line = fp.readline(_MAXLINE + 1)
+        if len(line) > _MAXLINE:
+            raise LineTooLong("header line")
+        headers.append(line)
+        if len(headers) > _MAXHEADERS:
+            raise HTTPException("got more than %d headers" % _MAXHEADERS)
+        if line in (b'\r\n', b'\n', b''):
+            break
+    hstring = bytes(b'').join(headers).decode('iso-8859-1')
+    return email_parser.Parser(_class=_class).parsestr(hstring)
+
+
+_strict_sentinel = object()
+
+class HTTPResponse(io.RawIOBase):
+
+    # See RFC 2616 sec 19.6 and RFC 1945 sec 6 for details.
+
+    # The bytes from the socket object are iso-8859-1 strings.
+    # See RFC 2616 sec 2.2 which notes an exception for MIME-encoded
+    # text following RFC 2047.  The basic status line parsing only
+    # accepts iso-8859-1.
+
+    def __init__(self, sock, debuglevel=0, strict=_strict_sentinel, method=None, url=None):
+        # If the response includes a content-length header, we need to
+        # make sure that the client doesn't read more than the
+        # specified number of bytes.  If it does, it will block until
+        # the server times out and closes the connection.  This will
+        # happen if a self.fp.read() is done (without a size) whether
+        # self.fp is buffered or not.  So, no self.fp.read() by
+        # clients unless they know what they are doing.
+        self.fp = sock.makefile("rb")
+        self.debuglevel = debuglevel
+        if strict is not _strict_sentinel:
+            warnings.warn("the 'strict' argument isn't supported anymore; "
+                "http.client now always assumes HTTP/1.x compliant servers.",
+                DeprecationWarning, 2)
+        self._method = method
+
+        # The HTTPResponse object is returned via urllib.  The clients
+        # of http and urllib expect different attributes for the
+        # headers.  headers is used here and supports urllib.  msg is
+        # provided as a backwards compatibility layer for http
+        # clients.
+
+        self.headers = self.msg = None
+
+        # from the Status-Line of the response
+        self.version = _UNKNOWN # HTTP-Version
+        self.status = _UNKNOWN  # Status-Code
+        self.reason = _UNKNOWN  # Reason-Phrase
+
+        self.chunked = _UNKNOWN         # is "chunked" being used?
+        self.chunk_left = _UNKNOWN      # bytes left to read in current chunk
+        self.length = _UNKNOWN          # number of bytes left in response
+        self.will_close = _UNKNOWN      # conn will close at end of response
+
+    def _read_status(self):
+        line = str(self.fp.readline(_MAXLINE + 1), "iso-8859-1")
+        if len(line) > _MAXLINE:
+            raise LineTooLong("status line")
+        if self.debuglevel > 0:
+            print("reply:", repr(line))
+        if not line:
+            # Presumably, the server closed the connection before
+            # sending a valid response.
+            raise BadStatusLine(line)
+        try:
+            version, status, reason = line.split(None, 2)
+        except ValueError:
+            try:
+                version, status = line.split(None, 1)
+                reason = ""
+            except ValueError:
+                # empty version will cause next test to fail.
+                version = ""
+        if not version.startswith("HTTP/"):
+            self._close_conn()
+            raise BadStatusLine(line)
+
+        # The status code is a three-digit number
+        try:
+            status = int(status)
+            if status < 100 or status > 999:
+                raise BadStatusLine(line)
+        except ValueError:
+            raise BadStatusLine(line)
+        return version, status, reason
+
+    def begin(self):
+        if self.headers is not None:
+            # we've already started reading the response
+            return
+
+        # read until we get a non-100 response
+        while True:
+            version, status, reason = self._read_status()
+            if status != CONTINUE:
+                break
+            # skip the header from the 100 response
+            while True:
+                skip = self.fp.readline(_MAXLINE + 1)
+                if len(skip) > _MAXLINE:
+                    raise LineTooLong("header line")
+                skip = skip.strip()
+                if not skip:
+                    break
+                if self.debuglevel > 0:
+                    print("header:", skip)
+
+        self.code = self.status = status
+        self.reason = reason.strip()
+        if version in ("HTTP/1.0", "HTTP/0.9"):
+            # Some servers might still return "0.9", treat it as 1.0 anyway
+            self.version = 10
+        elif version.startswith("HTTP/1."):
+            self.version = 11   # use HTTP/1.1 code for HTTP/1.x where x>=1
+        else:
+            raise UnknownProtocol(version)
+
+        self.headers = self.msg = parse_headers(self.fp)
+
+        if self.debuglevel > 0:
+            for hdr in self.headers:
+                print("header:", hdr, end=" ")
+
+        # are we using the chunked-style of transfer encoding?
+        tr_enc = self.headers.get("transfer-encoding")
+        if tr_enc and tr_enc.lower() == "chunked":
+            self.chunked = True
+            self.chunk_left = None
+        else:
+            self.chunked = False
+
+        # will the connection close at the end of the response?
+        self.will_close = self._check_close()
+
+        # do we have a Content-Length?
+        # NOTE: RFC 2616, S4.4, #3 says we ignore this if tr_enc is "chunked"
+        self.length = None
+        length = self.headers.get("content-length")
+
+         # are we using the chunked-style of transfer encoding?
+        tr_enc = self.headers.get("transfer-encoding")
+        if length and not self.chunked:
+            try:
+                self.length = int(length)
+            except ValueError:
+                self.length = None
+            else:
+                if self.length < 0:  # ignore nonsensical negative lengths
+                    self.length = None
+        else:
+            self.length = None
+
+        # does the body have a fixed length? (of zero)
+        if (status == NO_CONTENT or status == NOT_MODIFIED or
+            100 <= status < 200 or      # 1xx codes
+            self._method == "HEAD"):
+            self.length = 0
+
+        # if the connection remains open, and we aren't using chunked, and
+        # a content-length was not provided, then assume that the connection
+        # WILL close.
+        if (not self.will_close and
+            not self.chunked and
+            self.length is None):
+            self.will_close = True
+
+    def _check_close(self):
+        conn = self.headers.get("connection")
+        if self.version == 11:
+            # An HTTP/1.1 proxy is assumed to stay open unless
+            # explicitly closed.
+            conn = self.headers.get("connection")
+            if conn and "close" in conn.lower():
+                return True
+            return False
+
+        # Some HTTP/1.0 implementations have support for persistent
+        # connections, using rules different than HTTP/1.1.
+
+        # For older HTTP, Keep-Alive indicates persistent connection.
+        if self.headers.get("keep-alive"):
+            return False
+
+        # At least Akamai returns a "Connection: Keep-Alive" header,
+        # which was supposed to be sent by the client.
+        if conn and "keep-alive" in conn.lower():
+            return False
+
+        # Proxy-Connection is a netscape hack.
+        pconn = self.headers.get("proxy-connection")
+        if pconn and "keep-alive" in pconn.lower():
+            return False
+
+        # otherwise, assume it will close
+        return True
+
+    def _close_conn(self):
+        fp = self.fp
+        self.fp = None
+        fp.close()
+
+    def close(self):
+        super().close() # set "closed" flag
+        if self.fp:
+            self._close_conn()
+
+    # These implementations are for the benefit of io.BufferedReader.
+
+    # XXX This class should probably be revised to act more like
+    # the "raw stream" that BufferedReader expects.
+
+    def flush(self):
+        super().flush()
+        if self.fp:
+            self.fp.flush()
+
+    def readable(self):
+        return True
+
+    # End of "raw stream" methods
+
+    def isclosed(self):
+        """True if the connection is closed."""
+        # NOTE: it is possible that we will not ever call self.close(). This
+        #       case occurs when will_close is TRUE, length is None, and we
+        #       read up to the last byte, but NOT past it.
+        #
+        # IMPLIES: if will_close is FALSE, then self.close() will ALWAYS be
+        #          called, meaning self.isclosed() is meaningful.
+        return self.fp is None
+
+    def read(self, amt=None):
+        if self.fp is None:
+            return bytes(b"")
+
+        if self._method == "HEAD":
+            self._close_conn()
+            return bytes(b"")
+
+        if amt is not None:
+            # Amount is given, so call base class version
+            # (which is implemented in terms of self.readinto)
+            return bytes(super(HTTPResponse, self).read(amt))
+        else:
+            # Amount is not given (unbounded read) so we must check self.length
+            # and self.chunked
+
+            if self.chunked:
+                return self._readall_chunked()
+
+            if self.length is None:
+                s = self.fp.read()
+            else:
+                try:
+                    s = self._safe_read(self.length)
+                except IncompleteRead:
+                    self._close_conn()
+                    raise
+                self.length = 0
+            self._close_conn()        # we read everything
+            return bytes(s)
+
+    def readinto(self, b):
+        if self.fp is None:
+            return 0
+
+        if self._method == "HEAD":
+            self._close_conn()
+            return 0
+
+        if self.chunked:
+            return self._readinto_chunked(b)
+
+        if self.length is not None:
+            if len(b) > self.length:
+                # clip the read to the "end of response"
+                b = memoryview(b)[0:self.length]
+
+        # we do not use _safe_read() here because this may be a .will_close
+        # connection, and the user is reading more bytes than will be provided
+        # (for example, reading in 1k chunks)
+
+        if PY2:
+            data = self.fp.read(len(b))
+            n = len(data)
+            b[:n] = data
+        else:
+            n = self.fp.readinto(b)
+
+        if not n and b:
+            # Ideally, we would raise IncompleteRead if the content-length
+            # wasn't satisfied, but it might break compatibility.
+            self._close_conn()
+        elif self.length is not None:
+            self.length -= n
+            if not self.length:
+                self._close_conn()
+        return n
+
+    def _read_next_chunk_size(self):
+        # Read the next chunk size from the file
+        line = self.fp.readline(_MAXLINE + 1)
+        if len(line) > _MAXLINE:
+            raise LineTooLong("chunk size")
+        i = line.find(b";")
+        if i >= 0:
+            line = line[:i] # strip chunk-extensions
+        try:
+            return int(line, 16)
+        except ValueError:
+            # close the connection as protocol synchronisation is
+            # probably lost
+            self._close_conn()
+            raise
+
+    def _read_and_discard_trailer(self):
+        # read and discard trailer up to the CRLF terminator
+        ### note: we shouldn't have any trailers!
+        while True:
+            line = self.fp.readline(_MAXLINE + 1)
+            if len(line) > _MAXLINE:
+                raise LineTooLong("trailer line")
+            if not line:
+                # a vanishingly small number of sites EOF without
+                # sending the trailer
+                break
+            if line in (b'\r\n', b'\n', b''):
+                break
+
+    def _readall_chunked(self):
+        assert self.chunked != _UNKNOWN
+        chunk_left = self.chunk_left
+        value = []
+        while True:
+            if chunk_left is None:
+                try:
+                    chunk_left = self._read_next_chunk_size()
+                    if chunk_left == 0:
+                        break
+                except ValueError:
+                    raise IncompleteRead(bytes(b'').join(value))
+            value.append(self._safe_read(chunk_left))
+
+            # we read the whole chunk, get another
+            self._safe_read(2)      # toss the CRLF at the end of the chunk
+            chunk_left = None
+
+        self._read_and_discard_trailer()
+
+        # we read everything; close the "file"
+        self._close_conn()
+
+        return bytes(b'').join(value)
+
+    def _readinto_chunked(self, b):
+        assert self.chunked != _UNKNOWN
+        chunk_left = self.chunk_left
+
+        total_bytes = 0
+        mvb = memoryview(b)
+        while True:
+            if chunk_left is None:
+                try:
+                    chunk_left = self._read_next_chunk_size()
+                    if chunk_left == 0:
+                        break
+                except ValueError:
+                    raise IncompleteRead(bytes(b[0:total_bytes]))
+
+            if len(mvb) < chunk_left:
+                n = self._safe_readinto(mvb)
+                self.chunk_left = chunk_left - n
+                return total_bytes + n
+            elif len(mvb) == chunk_left:
+                n = self._safe_readinto(mvb)
+                self._safe_read(2)  # toss the CRLF at the end of the chunk
+                self.chunk_left = None
+                return total_bytes + n
+            else:
+                temp_mvb = mvb[0:chunk_left]
+                n = self._safe_readinto(temp_mvb)
+                mvb = mvb[n:]
+                total_bytes += n
+
+            # we read the whole chunk, get another
+            self._safe_read(2)      # toss the CRLF at the end of the chunk
+            chunk_left = None
+
+        self._read_and_discard_trailer()
+
+        # we read everything; close the "file"
+        self._close_conn()
+
+        return total_bytes
+
+    def _safe_read(self, amt):
+        """Read the number of bytes requested, compensating for partial reads.
+
+        Normally, we have a blocking socket, but a read() can be interrupted
+        by a signal (resulting in a partial read).
+
+        Note that we cannot distinguish between EOF and an interrupt when zero
+        bytes have been read. IncompleteRead() will be raised in this
+        situation.
+
+        This function should be used when <amt> bytes "should" be present for
+        reading. If the bytes are truly not available (due to EOF), then the
+        IncompleteRead exception can be used to detect the problem.
+        """
+        s = []
+        while amt > 0:
+            chunk = self.fp.read(min(amt, MAXAMOUNT))
+            if not chunk:
+                raise IncompleteRead(bytes(b'').join(s), amt)
+            s.append(chunk)
+            amt -= len(chunk)
+        return bytes(b"").join(s)
+
+    def _safe_readinto(self, b):
+        """Same as _safe_read, but for reading into a buffer."""
+        total_bytes = 0
+        mvb = memoryview(b)
+        while total_bytes < len(b):
+            if MAXAMOUNT < len(mvb):
+                temp_mvb = mvb[0:MAXAMOUNT]
+                n = self.fp.readinto(temp_mvb)
+            else:
+                n = self.fp.readinto(mvb)
+            if not n:
+                raise IncompleteRead(bytes(mvb[0:total_bytes]), len(b))
+            mvb = mvb[n:]
+            total_bytes += n
+        return total_bytes
+
+    def fileno(self):
+        return self.fp.fileno()
+
+    def getheader(self, name, default=None):
+        if self.headers is None:
+            raise ResponseNotReady()
+        headers = self.headers.get_all(name) or default
+        if isinstance(headers, str) or not hasattr(headers, '__iter__'):
+            return headers
+        else:
+            return ', '.join(headers)
+
+    def getheaders(self):
+        """Return list of (header, value) tuples."""
+        if self.headers is None:
+            raise ResponseNotReady()
+        return list(self.headers.items())
+
+    # We override IOBase.__iter__ so that it doesn't check for closed-ness
+
+    def __iter__(self):
+        return self
+
+    # For compatibility with old-style urllib responses.
+
+    def info(self):
+        return self.headers
+
+    def geturl(self):
+        return self.url
+
+    def getcode(self):
+        return self.status
+
+class HTTPConnection(object):
+
+    _http_vsn = 11
+    _http_vsn_str = 'HTTP/1.1'
+
+    response_class = HTTPResponse
+    default_port = HTTP_PORT
+    auto_open = 1
+    debuglevel = 0
+
+    def __init__(self, host, port=None, strict=_strict_sentinel,
+                 timeout=socket._GLOBAL_DEFAULT_TIMEOUT, source_address=None):
+        if strict is not _strict_sentinel:
+            warnings.warn("the 'strict' argument isn't supported anymore; "
+                "http.client now always assumes HTTP/1.x compliant servers.",
+                DeprecationWarning, 2)
+        self.timeout = timeout
+        self.source_address = source_address
+        self.sock = None
+        self._buffer = []
+        self.__response = None
+        self.__state = _CS_IDLE
+        self._method = None
+        self._tunnel_host = None
+        self._tunnel_port = None
+        self._tunnel_headers = {}
+
+        self._set_hostport(host, port)
+
+    def set_tunnel(self, host, port=None, headers=None):
+        """ Sets up the host and the port for the HTTP CONNECT Tunnelling.
+
+        The headers argument should be a mapping of extra HTTP headers
+        to send with the CONNECT request.
+        """
+        self._tunnel_host = host
+        self._tunnel_port = port
+        if headers:
+            self._tunnel_headers = headers
+        else:
+            self._tunnel_headers.clear()
+
+    def _set_hostport(self, host, port):
+        if port is None:
+            i = host.rfind(':')
+            j = host.rfind(']')         # ipv6 addresses have [...]
+            if i > j:
+                try:
+                    port = int(host[i+1:])
+                except ValueError:
+                    if host[i+1:] == "": # http://foo.com:/ == http://foo.com/
+                        port = self.default_port
+                    else:
+                        raise InvalidURL("nonnumeric port: '%s'" % host[i+1:])
+                host = host[:i]
+            else:
+                port = self.default_port
+            if host and host[0] == '[' and host[-1] == ']':
+                host = host[1:-1]
+        self.host = host
+        self.port = port
+
+    def set_debuglevel(self, level):
+        self.debuglevel = level
+
+    def _tunnel(self):
+        self._set_hostport(self._tunnel_host, self._tunnel_port)
+        connect_str = "CONNECT %s:%d HTTP/1.0\r\n" % (self.host, self.port)
+        connect_bytes = connect_str.encode("ascii")
+        self.send(connect_bytes)
+        for header, value in self._tunnel_headers.items():
+            header_str = "%s: %s\r\n" % (header, value)
+            header_bytes = header_str.encode("latin-1")
+            self.send(header_bytes)
+        self.send(bytes(b'\r\n'))
+
+        response = self.response_class(self.sock, method=self._method)
+        (version, code, message) = response._read_status()
+
+        if code != 200:
+            self.close()
+            raise socket.error("Tunnel connection failed: %d %s" % (code,
+                                                                    message.strip()))
+        while True:
+            line = response.fp.readline(_MAXLINE + 1)
+            if len(line) > _MAXLINE:
+                raise LineTooLong("header line")
+            if not line:
+                # for sites which EOF without sending a trailer
+                break
+            if line in (b'\r\n', b'\n', b''):
+                break
+
+    def connect(self):
+        """Connect to the host and port specified in __init__."""
+        self.sock = socket_create_connection((self.host,self.port),
+                                             self.timeout, self.source_address)
+        if self._tunnel_host:
+            self._tunnel()
+
+    def close(self):
+        """Close the connection to the HTTP server."""
+        if self.sock:
+            self.sock.close()   # close it manually... there may be other refs
+            self.sock = None
+        if self.__response:
+            self.__response.close()
+            self.__response = None
+        self.__state = _CS_IDLE
+
+    def send(self, data):
+        """Send `data' to the server.
+        ``data`` can be a string object, a bytes object, an array object, a
+        file-like object that supports a .read() method, or an iterable object.
+        """
+
+        if self.sock is None:
+            if self.auto_open:
+                self.connect()
+            else:
+                raise NotConnected()
+
+        if self.debuglevel > 0:
+            print("send:", repr(data))
+        blocksize = 8192
+        # Python 2.7 array objects have a read method which is incompatible
+        # with the 2-arg calling syntax below.
+        if hasattr(data, "read") and not isinstance(data, array):
+            if self.debuglevel > 0:
+                print("sendIng a read()able")
+            encode = False
+            try:
+                mode = data.mode
+            except AttributeError:
+                # io.BytesIO and other file-like objects don't have a `mode`
+                # attribute.
+                pass
+            else:
+                if "b" not in mode:
+                    encode = True
+                    if self.debuglevel > 0:
+                        print("encoding file using iso-8859-1")
+            while 1:
+                datablock = data.read(blocksize)
+                if not datablock:
+                    break
+                if encode:
+                    datablock = datablock.encode("iso-8859-1")
+                self.sock.sendall(datablock)
+            return
+        try:
+            self.sock.sendall(data)
+        except TypeError:
+            if isinstance(data, collections.Iterable):
+                for d in data:
+                    self.sock.sendall(d)
+            else:
+                raise TypeError("data should be a bytes-like object "
+                                "or an iterable, got %r" % type(data))
+
+    def _output(self, s):
+        """Add a line of output to the current request buffer.
+
+        Assumes that the line does *not* end with \\r\\n.
+        """
+        self._buffer.append(s)
+
+    def _send_output(self, message_body=None):
+        """Send the currently buffered request and clear the buffer.
+
+        Appends an extra \\r\\n to the buffer.
+        A message_body may be specified, to be appended to the request.
+        """
+        self._buffer.extend((bytes(b""), bytes(b"")))
+        msg = bytes(b"\r\n").join(self._buffer)
+        del self._buffer[:]
+        # If msg and message_body are sent in a single send() call,
+        # it will avoid performance problems caused by the interaction
+        # between delayed ack and the Nagle algorithm.
+        if isinstance(message_body, bytes):
+            msg += message_body
+            message_body = None
+        self.send(msg)
+        if message_body is not None:
+            # message_body was not a string (i.e. it is a file), and
+            # we must run the risk of Nagle.
+            self.send(message_body)
+
+    def putrequest(self, method, url, skip_host=0, skip_accept_encoding=0):
+        """Send a request to the server.
+
+        `method' specifies an HTTP request method, e.g. 'GET'.
+        `url' specifies the object being requested, e.g. '/index.html'.
+        `skip_host' if True does not add automatically a 'Host:' header
+        `skip_accept_encoding' if True does not add automatically an
+           'Accept-Encoding:' header
+        """
+
+        # if a prior response has been completed, then forget about it.
+        if self.__response and self.__response.isclosed():
+            self.__response = None
+
+
+        # in certain cases, we cannot issue another request on this connection.
+        # this occurs when:
+        #   1) we are in the process of sending a request.   (_CS_REQ_STARTED)
+        #   2) a response to a previous request has signalled that it is going
+        #      to close the connection upon completion.
+        #   3) the headers for the previous response have not been read, thus
+        #      we cannot determine whether point (2) is true.   (_CS_REQ_SENT)
+        #
+        # if there is no prior response, then we can request at will.
+        #
+        # if point (2) is true, then we will have passed the socket to the
+        # response (effectively meaning, "there is no prior response"), and
+        # will open a new one when a new request is made.
+        #
+        # Note: if a prior response exists, then we *can* start a new request.
+        #       We are not allowed to begin fetching the response to this new
+        #       request, however, until that prior response is complete.
+        #
+        if self.__state == _CS_IDLE:
+            self.__state = _CS_REQ_STARTED
+        else:
+            raise CannotSendRequest(self.__state)
+
+        # Save the method we use, we need it later in the response phase
+        self._method = method
+        if not url:
+            url = '/'
+        request = '%s %s %s' % (method, url, self._http_vsn_str)
+
+        # Non-ASCII characters should have been eliminated earlier
+        self._output(request.encode('ascii'))
+
+        if self._http_vsn == 11:
+            # Issue some standard headers for better HTTP/1.1 compliance
+
+            if not skip_host:
+                # this header is issued *only* for HTTP/1.1
+                # connections. more specifically, this means it is
+                # only issued when the client uses the new
+                # HTTPConnection() class. backwards-compat clients
+                # will be using HTTP/1.0 and those clients may be
+                # issuing this header themselves. we should NOT issue
+                # it twice; some web servers (such as Apache) barf
+                # when they see two Host: headers
+
+                # If we need a non-standard port,include it in the
+                # header.  If the request is going through a proxy,
+                # but the host of the actual URL, not the host of the
+                # proxy.
+
+                netloc = ''
+                if url.startswith('http'):
+                    nil, netloc, nil, nil, nil = urlsplit(url)
+
+                if netloc:
+                    try:
+                        netloc_enc = netloc.encode("ascii")
+                    except UnicodeEncodeError:
+                        netloc_enc = netloc.encode("idna")
+                    self.putheader('Host', netloc_enc)
+                else:
+                    try:
+                        host_enc = self.host.encode("ascii")
+                    except UnicodeEncodeError:
+                        host_enc = self.host.encode("idna")
+
+                    # As per RFC 273, IPv6 address should be wrapped with []
+                    # when used as Host header
+
+                    if self.host.find(':') >= 0:
+                        host_enc = bytes(b'[' + host_enc + b']')
+
+                    if self.port == self.default_port:
+                        self.putheader('Host', host_enc)
+                    else:
+                        host_enc = host_enc.decode("ascii")
+                        self.putheader('Host', "%s:%s" % (host_enc, self.port))
+
+            # note: we are assuming that clients will not attempt to set these
+            #       headers since *this* library must deal with the
+            #       consequences. this also means that when the supporting
+            #       libraries are updated to recognize other forms, then this
+            #       code should be changed (removed or updated).
+
+            # we only want a Content-Encoding of "identity" since we don't
+            # support encodings such as x-gzip or x-deflate.
+            if not skip_accept_encoding:
+                self.putheader('Accept-Encoding', 'identity')
+
+            # we can accept "chunked" Transfer-Encodings, but no others
+            # NOTE: no TE header implies *only* "chunked"
+            #self.putheader('TE', 'chunked')
+
+            # if TE is supplied in the header, then it must appear in a
+            # Connection header.
+            #self.putheader('Connection', 'TE')
+
+        else:
+            # For HTTP/1.0, the server will assume "not chunked"
+            pass
+
+    def putheader(self, header, *values):
+        """Send a request header line to the server.
+
+        For example: h.putheader('Accept', 'text/html')
+        """
+        if self.__state != _CS_REQ_STARTED:
+            raise CannotSendHeader()
+
+        if hasattr(header, 'encode'):
+            header = header.encode('ascii')
+        values = list(values)
+        for i, one_value in enumerate(values):
+            if hasattr(one_value, 'encode'):
+                values[i] = one_value.encode('latin-1')
+            elif isinstance(one_value, int):
+                values[i] = str(one_value).encode('ascii')
+        value = bytes(b'\r\n\t').join(values)
+        header = header + bytes(b': ') + value
+        self._output(header)
+
+    def endheaders(self, message_body=None):
+        """Indicate that the last header line has been sent to the server.
+
+        This method sends the request to the server.  The optional message_body
+        argument can be used to pass a message body associated with the
+        request.  The message body will be sent in the same packet as the
+        message headers if it is a string, otherwise it is sent as a separate
+        packet.
+        """
+        if self.__state == _CS_REQ_STARTED:
+            self.__state = _CS_REQ_SENT
+        else:
+            raise CannotSendHeader()
+        self._send_output(message_body)
+
+    def request(self, method, url, body=None, headers={}):
+        """Send a complete request to the server."""
+        self._send_request(method, url, body, headers)
+
+    def _set_content_length(self, body):
+        # Set the content-length based on the body.
+        thelen = None
+        try:
+            thelen = str(len(body))
+        except TypeError as te:
+            # If this is a file-like object, try to
+            # fstat its file descriptor
+            try:
+                thelen = str(os.fstat(body.fileno()).st_size)
+            except (AttributeError, OSError):
+                # Don't send a length if this failed
+                if self.debuglevel > 0: print("Cannot stat!!")
+
+        if thelen is not None:
+            self.putheader('Content-Length', thelen)
+
+    def _send_request(self, method, url, body, headers):
+        # Honor explicitly requested Host: and Accept-Encoding: headers.
+        header_names = dict.fromkeys([k.lower() for k in headers])
+        skips = {}
+        if 'host' in header_names:
+            skips['skip_host'] = 1
+        if 'accept-encoding' in header_names:
+            skips['skip_accept_encoding'] = 1
+
+        self.putrequest(method, url, **skips)
+
+        if body is not None and ('content-length' not in header_names):
+            self._set_content_length(body)
+        for hdr, value in headers.items():
+            self.putheader(hdr, value)
+        if isinstance(body, str):
+            # RFC 2616 Section 3.7.1 says that text default has a
+            # default charset of iso-8859-1.
+            body = body.encode('iso-8859-1')
+        self.endheaders(body)
+
+    def getresponse(self):
+        """Get the response from the server.
+
+        If the HTTPConnection is in the correct state, returns an
+        instance of HTTPResponse or of whatever object is returned by
+        class the response_class variable.
+
+        If a request has not been sent or if a previous response has
+        not be handled, ResponseNotReady is raised.  If the HTTP
+        response indicates that the connection should be closed, then
+        it will be closed before the response is returned.  When the
+        connection is closed, the underlying socket is closed.
+        """
+
+        # if a prior response has been completed, then forget about it.
+        if self.__response and self.__response.isclosed():
+            self.__response = None
+
+        # if a prior response exists, then it must be completed (otherwise, we
+        # cannot read this response's header to determine the connection-close
+        # behavior)
+        #
+        # note: if a prior response existed, but was connection-close, then the
+        # socket and response were made independent of this HTTPConnection
+        # object since a new request requires that we open a whole new
+        # connection
+        #
+        # this means the prior response had one of two states:
+        #   1) will_close: this connection was reset and the prior socket and
+        #                  response operate independently
+        #   2) persistent: the response was retained and we await its
+        #                  isclosed() status to become true.
+        #
+        if self.__state != _CS_REQ_SENT or self.__response:
+            raise ResponseNotReady(self.__state)
+
+        if self.debuglevel > 0:
+            response = self.response_class(self.sock, self.debuglevel,
+                                           method=self._method)
+        else:
+            response = self.response_class(self.sock, method=self._method)
+
+        response.begin()
+        assert response.will_close != _UNKNOWN
+        self.__state = _CS_IDLE
+
+        if response.will_close:
+            # this effectively passes the connection to the response
+            self.close()
+        else:
+            # remember this, so we can tell when it is complete
+            self.__response = response
+
+        return response
+
+try:
+    import ssl
+    from ssl import SSLContext
+except ImportError:
+    pass
+else:
+    class HTTPSConnection(HTTPConnection):
+        "This class allows communication via SSL."
+
+        default_port = HTTPS_PORT
+
+        # XXX Should key_file and cert_file be deprecated in favour of context?
+
+        def __init__(self, host, port=None, key_file=None, cert_file=None,
+                     strict=_strict_sentinel, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
+                     source_address=None, **_3to2kwargs):
+            if 'check_hostname' in _3to2kwargs: check_hostname = _3to2kwargs['check_hostname']; del _3to2kwargs['check_hostname']
+            else: check_hostname = None
+            if 'context' in _3to2kwargs: context = _3to2kwargs['context']; del _3to2kwargs['context']
+            else: context = None
+            super(HTTPSConnection, self).__init__(host, port, strict, timeout,
+                                                  source_address)
+            self.key_file = key_file
+            self.cert_file = cert_file
+            if context is None:
+                # Some reasonable defaults
+                context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
+                context.options |= ssl.OP_NO_SSLv2
+            will_verify = context.verify_mode != ssl.CERT_NONE
+            if check_hostname is None:
+                check_hostname = will_verify
+            elif check_hostname and not will_verify:
+                raise ValueError("check_hostname needs a SSL context with "
+                                 "either CERT_OPTIONAL or CERT_REQUIRED")
+            if key_file or cert_file:
+                context.load_cert_chain(cert_file, key_file)
+            self._context = context
+            self._check_hostname = check_hostname
+
+        def connect(self):
+            "Connect to a host on a given (SSL) port."
+
+            sock = socket_create_connection((self.host, self.port),
+                                            self.timeout, self.source_address)
+
+            if self._tunnel_host:
+                self.sock = sock
+                self._tunnel()
+
+            server_hostname = self.host if ssl.HAS_SNI else None
+            self.sock = self._context.wrap_socket(sock,
+                                                  server_hostname=server_hostname)
+            try:
+                if self._check_hostname:
+                    ssl.match_hostname(self.sock.getpeercert(), self.host)
+            except Exception:
+                self.sock.shutdown(socket.SHUT_RDWR)
+                self.sock.close()
+                raise
+
+    __all__.append("HTTPSConnection")
+
+
+    # ######################################
+    # # We use the old HTTPSConnection class from Py2.7, because ssl.SSLContext
+    # # doesn't exist in the Py2.7 stdlib
+    # class HTTPSConnection(HTTPConnection):
+    #     "This class allows communication via SSL."
+
+    #     default_port = HTTPS_PORT
+
+    #     def __init__(self, host, port=None, key_file=None, cert_file=None,
+    #                  strict=None, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
+    #                  source_address=None):
+    #         HTTPConnection.__init__(self, host, port, strict, timeout,
+    #                                 source_address)
+    #         self.key_file = key_file
+    #         self.cert_file = cert_file
+
+    #     def connect(self):
+    #         "Connect to a host on a given (SSL) port."
+
+    #         sock = socket_create_connection((self.host, self.port),
+    #                                         self.timeout, self.source_address)
+    #         if self._tunnel_host:
+    #             self.sock = sock
+    #             self._tunnel()
+    #         self.sock = ssl.wrap_socket(sock, self.key_file, self.cert_file)
+
+    # __all__.append("HTTPSConnection")
+    # ######################################
+
+
+class HTTPException(Exception):
+    # Subclasses that define an __init__ must call Exception.__init__
+    # or define self.args.  Otherwise, str() will fail.
+    pass
+
+class NotConnected(HTTPException):
+    pass
+
+class InvalidURL(HTTPException):
+    pass
+
+class UnknownProtocol(HTTPException):
+    def __init__(self, version):
+        self.args = version,
+        self.version = version
+
+class UnknownTransferEncoding(HTTPException):
+    pass
+
+class UnimplementedFileMode(HTTPException):
+    pass
+
+class IncompleteRead(HTTPException):
+    def __init__(self, partial, expected=None):
+        self.args = partial,
+        self.partial = partial
+        self.expected = expected
+    def __repr__(self):
+        if self.expected is not None:
+            e = ', %i more expected' % self.expected
+        else:
+            e = ''
+        return 'IncompleteRead(%i bytes read%s)' % (len(self.partial), e)
+    def __str__(self):
+        return repr(self)
+
+class ImproperConnectionState(HTTPException):
+    pass
+
+class CannotSendRequest(ImproperConnectionState):
+    pass
+
+class CannotSendHeader(ImproperConnectionState):
+    pass
+
+class ResponseNotReady(ImproperConnectionState):
+    pass
+
+class BadStatusLine(HTTPException):
+    def __init__(self, line):
+        if not line:
+            line = repr(line)
+        self.args = line,
+        self.line = line
+
+class LineTooLong(HTTPException):
+    def __init__(self, line_type):
+        HTTPException.__init__(self, "got more than %d bytes when reading %s"
+                                     % (_MAXLINE, line_type))
+
+# for backwards compatibility
+error = HTTPException