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Diffstat (limited to 'urllib3/response.py')
| -rw-r--r-- | urllib3/response.py | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/urllib3/response.py b/urllib3/response.py new file mode 100644 index 0000000..7e0d47f --- /dev/null +++ b/urllib3/response.py @@ -0,0 +1,320 @@ +import zlib +import io +from socket import timeout as SocketTimeout + +from ._collections import HTTPHeaderDict +from .exceptions import ProtocolError, DecodeError, ReadTimeoutError +from .packages.six import string_types as basestring, binary_type +from .connection import HTTPException, BaseSSLError +from .util.response import is_fp_closed + + + +class DeflateDecoder(object): + + def __init__(self): + self._first_try = True + self._data = binary_type() + self._obj = zlib.decompressobj() + + def __getattr__(self, name): + return getattr(self._obj, name) + + def decompress(self, data): + if not self._first_try: + return self._obj.decompress(data) + + self._data += data + try: + return self._obj.decompress(data) + except zlib.error: + self._first_try = False + self._obj = zlib.decompressobj(-zlib.MAX_WBITS) + try: + return self.decompress(self._data) + finally: + self._data = None + + +def _get_decoder(mode): + if mode == 'gzip': + return zlib.decompressobj(16 + zlib.MAX_WBITS) + + return DeflateDecoder() + + +class HTTPResponse(io.IOBase): + """ + HTTP Response container. + + Backwards-compatible to httplib's HTTPResponse but the response ``body`` is + loaded and decoded on-demand when the ``data`` property is accessed. + + Extra parameters for behaviour not present in httplib.HTTPResponse: + + :param preload_content: + If True, the response's body will be preloaded during construction. + + :param decode_content: + If True, attempts to decode specific content-encoding's based on headers + (like 'gzip' and 'deflate') will be skipped and raw data will be used + instead. + + :param original_response: + When this HTTPResponse wrapper is generated from an httplib.HTTPResponse + object, it's convenient to include the original for debug purposes. It's + otherwise unused. + """ + + CONTENT_DECODERS = ['gzip', 'deflate'] + REDIRECT_STATUSES = [301, 302, 303, 307, 308] + + def __init__(self, body='', headers=None, status=0, version=0, reason=None, + strict=0, preload_content=True, decode_content=True, + original_response=None, pool=None, connection=None): + + self.headers = HTTPHeaderDict() + if headers: + self.headers.update(headers) + self.status = status + self.version = version + self.reason = reason + self.strict = strict + self.decode_content = decode_content + + self._decoder = None + self._body = None + self._fp = None + self._original_response = original_response + self._fp_bytes_read = 0 + + if body and isinstance(body, (basestring, binary_type)): + self._body = body + + self._pool = pool + self._connection = connection + + if hasattr(body, 'read'): + self._fp = body + + if preload_content and not self._body: + self._body = self.read(decode_content=decode_content) + + def get_redirect_location(self): + """ + Should we redirect and where to? + + :returns: Truthy redirect location string if we got a redirect status + code and valid location. ``None`` if redirect status and no + location. ``False`` if not a redirect status code. + """ + if self.status in self.REDIRECT_STATUSES: + return self.headers.get('location') + + return False + + def release_conn(self): + if not self._pool or not self._connection: + return + + self._pool._put_conn(self._connection) + self._connection = None + + @property + def data(self): + # For backwords-compat with earlier urllib3 0.4 and earlier. + if self._body: + return self._body + + if self._fp: + return self.read(cache_content=True) + + def tell(self): + """ + Obtain the number of bytes pulled over the wire so far. May differ from + the amount of content returned by :meth:``HTTPResponse.read`` if bytes + are encoded on the wire (e.g, compressed). + """ + return self._fp_bytes_read + + def read(self, amt=None, decode_content=None, cache_content=False): + """ + Similar to :meth:`httplib.HTTPResponse.read`, but with two additional + parameters: ``decode_content`` and ``cache_content``. + + :param amt: + How much of the content to read. If specified, caching is skipped + because it doesn't make sense to cache partial content as the full + response. + + :param decode_content: + If True, will attempt to decode the body based on the + 'content-encoding' header. + + :param cache_content: + If True, will save the returned data such that the same result is + returned despite of the state of the underlying file object. This + is useful if you want the ``.data`` property to continue working + after having ``.read()`` the file object. (Overridden if ``amt`` is + set.) + """ + # Note: content-encoding value should be case-insensitive, per RFC 7230 + # Section 3.2 + content_encoding = self.headers.get('content-encoding', '').lower() + if self._decoder is None: + if content_encoding in self.CONTENT_DECODERS: + self._decoder = _get_decoder(content_encoding) + if decode_content is None: + decode_content = self.decode_content + + if self._fp is None: + return + + flush_decoder = False + + try: + try: + if amt is None: + # cStringIO doesn't like amt=None + data = self._fp.read() + flush_decoder = True + else: + cache_content = False + data = self._fp.read(amt) + if amt != 0 and not data: # Platform-specific: Buggy versions of Python. + # Close the connection when no data is returned + # + # This is redundant to what httplib/http.client _should_ + # already do. However, versions of python released before + # December 15, 2012 (http://bugs.python.org/issue16298) do + # not properly close the connection in all cases. There is + # no harm in redundantly calling close. + self._fp.close() + flush_decoder = True + + except SocketTimeout: + # FIXME: Ideally we'd like to include the url in the ReadTimeoutError but + # there is yet no clean way to get at it from this context. + raise ReadTimeoutError(self._pool, None, 'Read timed out.') + + except BaseSSLError as e: + # FIXME: Is there a better way to differentiate between SSLErrors? + if not 'read operation timed out' in str(e): # Defensive: + # This shouldn't happen but just in case we're missing an edge + # case, let's avoid swallowing SSL errors. + raise + + raise ReadTimeoutError(self._pool, None, 'Read timed out.') + + except HTTPException as e: + # This includes IncompleteRead. + raise ProtocolError('Connection broken: %r' % e, e) + + self._fp_bytes_read += len(data) + + try: + if decode_content and self._decoder: + data = self._decoder.decompress(data) + except (IOError, zlib.error) as e: + raise DecodeError( + "Received response with content-encoding: %s, but " + "failed to decode it." % content_encoding, e) + + if flush_decoder and decode_content and self._decoder: + buf = self._decoder.decompress(binary_type()) + data += buf + self._decoder.flush() + + if cache_content: + self._body = data + + return data + + finally: + if self._original_response and self._original_response.isclosed(): + self.release_conn() + + def stream(self, amt=2**16, decode_content=None): + """ + A generator wrapper for the read() method. A call will block until + ``amt`` bytes have been read from the connection or until the + connection is closed. + + :param amt: + How much of the content to read. The generator will return up to + much data per iteration, but may return less. This is particularly + likely when using compressed data. However, the empty string will + never be returned. + + :param decode_content: + If True, will attempt to decode the body based on the + 'content-encoding' header. + """ + while not is_fp_closed(self._fp): + data = self.read(amt=amt, decode_content=decode_content) + + if data: + yield data + + @classmethod + def from_httplib(ResponseCls, r, **response_kw): + """ + Given an :class:`httplib.HTTPResponse` instance ``r``, return a + corresponding :class:`urllib3.response.HTTPResponse` object. + + Remaining parameters are passed to the HTTPResponse constructor, along + with ``original_response=r``. + """ + + headers = HTTPHeaderDict() + for k, v in r.getheaders(): + headers.add(k, v) + + # HTTPResponse objects in Python 3 don't have a .strict attribute + strict = getattr(r, 'strict', 0) + return ResponseCls(body=r, + headers=headers, + status=r.status, + version=r.version, + reason=r.reason, + strict=strict, + original_response=r, + **response_kw) + + # Backwards-compatibility methods for httplib.HTTPResponse + def getheaders(self): + return self.headers + + def getheader(self, name, default=None): + return self.headers.get(name, default) + + # Overrides from io.IOBase + def close(self): + if not self.closed: + self._fp.close() + + @property + def closed(self): + if self._fp is None: + return True + elif hasattr(self._fp, 'closed'): + return self._fp.closed + elif hasattr(self._fp, 'isclosed'): # Python 2 + return self._fp.isclosed() + else: + return True + + def fileno(self): + if self._fp is None: + raise IOError("HTTPResponse has no file to get a fileno from") + elif hasattr(self._fp, "fileno"): + return self._fp.fileno() + else: + raise IOError("The file-like object this HTTPResponse is wrapped " + "around has no file descriptor") + + def flush(self): + if self._fp is not None and hasattr(self._fp, 'flush'): + return self._fp.flush() + + def readable(self): + return True |