Coverage for urllib3/response.py: 17%

# Coverage for urllib3/response.py : 17%

## 308 statements 53 run 255 missing 0 excluded

Hot-keys on this page

r m x p toggle line displays

j k next/prev highlighted chunk

0 (zero) top of page

1 (one) first highlighted chunk

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 | from __future__ import absolute_import from contextlib import contextmanager import zlib import io import logging from socket import timeout as SocketTimeout from socket import error as SocketError from ._collections import HTTPHeaderDict from .exceptions import ( BodyNotHttplibCompatible, ProtocolError, DecodeError, ReadTimeoutError, ResponseNotChunked, IncompleteRead, InvalidHeader ) from .packages.six import string_types as basestring, binary_type, PY3 from .packages.six.moves import http_client as httplib from .connection import HTTPException, BaseSSLError from .util.response import is_fp_closed, is_response_to_head log = logging.getLogger(__name__) 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 data: return data if not self._first_try: return self._obj.decompress(data) self._data += data try: decompressed = self._obj.decompress(data) if decompressed: self._first_try = False self._data = None return decompressed except zlib.error: self._first_try = False self._obj = zlib.decompressobj(-zlib.MAX_WBITS) try: return self.decompress(self._data) finally: self._data = None class GzipDecoder(object): def __init__(self): self._obj = zlib.decompressobj(16 + zlib.MAX_WBITS) def __getattr__(self, name): return getattr(self._obj, name) def decompress(self, data): if not data: return data return self._obj.decompress(data) def _get_decoder(mode): if mode == 'gzip': return GzipDecoder() 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. This class is also compatible with the Python standard library's :mod:`io` module, and can hence be treated as a readable object in the context of that framework. 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. :param retries: The retries contains the last :class:`~urllib3.util.retry.Retry` that was used during the request. :param enforce_content_length: Enforce content length checking. Body returned by server must match value of Content-Length header, if present. Otherwise, raise error. """ 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, retries=None, enforce_content_length=False, request_method=None): if isinstance(headers, HTTPHeaderDict): self.headers = headers else: self.headers = HTTPHeaderDict(headers) self.status = status self.version = version self.reason = reason self.strict = strict self.decode_content = decode_content self.retries = retries self.enforce_content_length = enforce_content_length 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 # Are we using the chunked-style of transfer encoding? self.chunked = False self.chunk_left = None tr_enc = self.headers.get('transfer-encoding', '').lower() # Don't incur the penalty of creating a list and then discarding it encodings = (enc.strip() for enc in tr_enc.split(",")) if "chunked" in encodings: self.chunked = True # Determine length of response self.length_remaining = self._init_length(request_method) # If requested, preload the 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) @property def connection(self): return self._connection 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 _init_length(self, request_method): """ Set initial length value for Response content if available. """ length = self.headers.get('content-length') if length is not None and self.chunked: # This Response will fail with an IncompleteRead if it can't be # received as chunked. This method falls back to attempt reading # the response before raising an exception. log.warning("Received response with both Content-Length and " "Transfer-Encoding set. This is expressly forbidden " "by RFC 7230 sec 3.3.2. Ignoring Content-Length and " "attempting to process response as Transfer-Encoding: " "chunked.") return None elif length is not None: try: # RFC 7230 section 3.3.2 specifies multiple content lengths can # be sent in a single Content-Length header # (e.g. Content-Length: 42, 42). This line ensures the values # are all valid ints and that as long as the `set` length is 1, # all values are the same. Otherwise, the header is invalid. lengths = set([int(val) for val in length.split(',')]) if len(lengths) > 1: raise InvalidHeader("Content-Length contained multiple " "unmatching values (%s)" % length) length = lengths.pop() except ValueError: length = None else: if length < 0: length = None # Convert status to int for comparison # In some cases, httplib returns a status of "_UNKNOWN" try: status = int(self.status) except ValueError: status = 0 # Check for responses that shouldn't include a body if status in (204, 304) or 100 <= status < 200 or request_method == 'HEAD': length = 0 return length def _init_decoder(self): """ Set-up the _decoder attribute if necessary. """ # 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 and content_encoding in self.CONTENT_DECODERS: self._decoder = _get_decoder(content_encoding) def _decode(self, data, decode_content, flush_decoder): """ Decode the data passed in and potentially flush the decoder. """ try: if decode_content and self._decoder: data = self._decoder.decompress(data) except (IOError, zlib.error) as e: content_encoding = self.headers.get('content-encoding', '').lower() raise DecodeError( "Received response with content-encoding: %s, but " "failed to decode it." % content_encoding, e) if flush_decoder and decode_content: data += self._flush_decoder() return data def _flush_decoder(self): """ Flushes the decoder. Should only be called if the decoder is actually being used. """ if self._decoder: buf = self._decoder.decompress(b'') return buf + self._decoder.flush() return b'' @contextmanager def _error_catcher(self): """ Catch low-level python exceptions, instead re-raising urllib3 variants, so that low-level exceptions are not leaked in the high-level api. On exit, release the connection back to the pool. """ clean_exit = False try: try: yield 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 'read operation timed out' not 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, SocketError) as e: # This includes IncompleteRead. raise ProtocolError('Connection broken: %r' % e, e) # If no exception is thrown, we should avoid cleaning up # unnecessarily. clean_exit = True finally: # If we didn't terminate cleanly, we need to throw away our # connection. if not clean_exit: # The response may not be closed but we're not going to use it # anymore so close it now to ensure that the connection is # released back to the pool. if self._original_response: self._original_response.close() # Closing the response may not actually be sufficient to close # everything, so if we have a hold of the connection close that # too. if self._connection: self._connection.close() # If we hold the original response but it's closed now, we should # return the connection back to the pool. if self._original_response and self._original_response.isclosed(): self.release_conn() 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.) """ self._init_decoder() if decode_content is None: decode_content = self.decode_content if self._fp is None: return flush_decoder = False data = None with self._error_catcher(): 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 if self.enforce_content_length and self.length_remaining not in (0, None): # This is an edge case that httplib failed to cover due # to concerns of backward compatibility. We're # addressing it here to make sure IncompleteRead is # raised during streaming, so all calls with incorrect # Content-Length are caught. raise IncompleteRead(self._fp_bytes_read, self.length_remaining) if data: self._fp_bytes_read += len(data) if self.length_remaining is not None: self.length_remaining -= len(data) data = self._decode(data, decode_content, flush_decoder) if cache_content: self._body = data return data 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. """ if self.chunked and self.supports_chunked_reads(): for line in self.read_chunked(amt, decode_content=decode_content): yield line else: 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 = r.msg if not isinstance(headers, HTTPHeaderDict): if PY3: # Python 3 headers = HTTPHeaderDict(headers.items()) else: # Python 2 headers = HTTPHeaderDict.from_httplib(headers) # HTTPResponse objects in Python 3 don't have a .strict attribute strict = getattr(r, 'strict', 0) resp = ResponseCls(body=r, headers=headers, status=r.status, version=r.version, reason=r.reason, strict=strict, original_response=r, **response_kw) return resp # Backwards-compatibility methods for httplib.HTTPResponse def getheaders(self): return self.headers def getheader(self, name, default=None): return self.headers.get(name, default) # Backwards compatibility for http.cookiejar def info(self): return self.headers # Overrides from io.IOBase def close(self): if not self.closed: self._fp.close() if self._connection: self._connection.close() @property def closed(self): if self._fp is None: return True elif hasattr(self._fp, 'isclosed'): return self._fp.isclosed() elif hasattr(self._fp, 'closed'): return self._fp.closed 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): # This method is required for `io` module compatibility. return True def readinto(self, b): # This method is required for `io` module compatibility. temp = self.read(len(b)) if len(temp) == 0: return 0 else: b[:len(temp)] = temp return len(temp) def supports_chunked_reads(self): """ Checks if the underlying file-like object looks like a httplib.HTTPResponse object. We do this by testing for the fp attribute. If it is present we assume it returns raw chunks as processed by read_chunked(). """ return hasattr(self._fp, 'fp') def _update_chunk_length(self): # First, we'll figure out length of a chunk and then # we'll try to read it from socket. if self.chunk_left is not None: return line = self._fp.fp.readline() line = line.split(b';', 1)[0] try: self.chunk_left = int(line, 16) except ValueError: # Invalid chunked protocol response, abort. self.close() raise httplib.IncompleteRead(line) def _handle_chunk(self, amt): returned_chunk = None if amt is None: chunk = self._fp._safe_read(self.chunk_left) returned_chunk = chunk self._fp._safe_read(2) # Toss the CRLF at the end of the chunk. self.chunk_left = None elif amt < self.chunk_left: value = self._fp._safe_read(amt) self.chunk_left = self.chunk_left - amt returned_chunk = value elif amt == self.chunk_left: value = self._fp._safe_read(amt) self._fp._safe_read(2) # Toss the CRLF at the end of the chunk. self.chunk_left = None returned_chunk = value else: # amt > self.chunk_left returned_chunk = self._fp._safe_read(self.chunk_left) self._fp._safe_read(2) # Toss the CRLF at the end of the chunk. self.chunk_left = None return returned_chunk def read_chunked(self, amt=None, decode_content=None): """ Similar to :meth:`HTTPResponse.read`, but with an additional parameter: ``decode_content``. :param decode_content: If True, will attempt to decode the body based on the 'content-encoding' header. """ self._init_decoder() # FIXME: Rewrite this method and make it a class with a better structured logic. if not self.chunked: raise ResponseNotChunked( "Response is not chunked. " "Header 'transfer-encoding: chunked' is missing.") if not self.supports_chunked_reads(): raise BodyNotHttplibCompatible( "Body should be httplib.HTTPResponse like. " "It should have have an fp attribute which returns raw chunks.") # Don't bother reading the body of a HEAD request. if self._original_response and is_response_to_head(self._original_response): self._original_response.close() return with self._error_catcher(): while True: self._update_chunk_length() if self.chunk_left == 0: break chunk = self._handle_chunk(amt) decoded = self._decode(chunk, decode_content=decode_content, flush_decoder=False) if decoded: yield decoded if decode_content: # On CPython and PyPy, we should never need to flush the # decoder. However, on Jython we *might* need to, so # lets defensively do it anyway. decoded = self._flush_decoder() if decoded: # Platform-specific: Jython. yield decoded # Chunk content ends with \r\n: discard it. while True: line = self._fp.fp.readline() if not line: # Some sites may not end with '\r\n'. break if line == b'\r\n': break # We read everything; close the "file". if self._original_response: self._original_response.close()