1# Copyright 2014 Google Inc. All Rights Reserved.
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#      http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14
15"""Classes to encapsulate a single HTTP request.
16
17The classes implement a command pattern, with every
18object supporting an execute() method that does the
19actuall HTTP request.
20"""
21from __future__ import absolute_import
22import six
23from six.moves import range
24
25__author__ = 'jcgregorio@google.com (Joe Gregorio)'
26
27from six import BytesIO, StringIO
28from six.moves.urllib.parse import urlparse, urlunparse, quote, unquote
29
30import base64
31import copy
32import gzip
33import httplib2
34import json
35import logging
36import mimetypes
37import os
38import random
39import sys
40import time
41import uuid
42
43from email.generator import Generator
44from email.mime.multipart import MIMEMultipart
45from email.mime.nonmultipart import MIMENonMultipart
46from email.parser import FeedParser
47
48from googleapiclient import mimeparse
49from googleapiclient.errors import BatchError
50from googleapiclient.errors import HttpError
51from googleapiclient.errors import InvalidChunkSizeError
52from googleapiclient.errors import ResumableUploadError
53from googleapiclient.errors import UnexpectedBodyError
54from googleapiclient.errors import UnexpectedMethodError
55from googleapiclient.model import JsonModel
56from oauth2client import util
57
58
59DEFAULT_CHUNK_SIZE = 512*1024
60
61MAX_URI_LENGTH = 2048
62
63
64class MediaUploadProgress(object):
65  """Status of a resumable upload."""
66
67  def __init__(self, resumable_progress, total_size):
68    """Constructor.
69
70    Args:
71      resumable_progress: int, bytes sent so far.
72      total_size: int, total bytes in complete upload, or None if the total
73        upload size isn't known ahead of time.
74    """
75    self.resumable_progress = resumable_progress
76    self.total_size = total_size
77
78  def progress(self):
79    """Percent of upload completed, as a float.
80
81    Returns:
82      the percentage complete as a float, returning 0.0 if the total size of
83      the upload is unknown.
84    """
85    if self.total_size is not None:
86      return float(self.resumable_progress) / float(self.total_size)
87    else:
88      return 0.0
89
90
91class MediaDownloadProgress(object):
92  """Status of a resumable download."""
93
94  def __init__(self, resumable_progress, total_size):
95    """Constructor.
96
97    Args:
98      resumable_progress: int, bytes received so far.
99      total_size: int, total bytes in complete download.
100    """
101    self.resumable_progress = resumable_progress
102    self.total_size = total_size
103
104  def progress(self):
105    """Percent of download completed, as a float.
106
107    Returns:
108      the percentage complete as a float, returning 0.0 if the total size of
109      the download is unknown.
110    """
111    if self.total_size is not None:
112      return float(self.resumable_progress) / float(self.total_size)
113    else:
114      return 0.0
115
116
117class MediaUpload(object):
118  """Describes a media object to upload.
119
120  Base class that defines the interface of MediaUpload subclasses.
121
122  Note that subclasses of MediaUpload may allow you to control the chunksize
123  when uploading a media object. It is important to keep the size of the chunk
124  as large as possible to keep the upload efficient. Other factors may influence
125  the size of the chunk you use, particularly if you are working in an
126  environment where individual HTTP requests may have a hardcoded time limit,
127  such as under certain classes of requests under Google App Engine.
128
129  Streams are io.Base compatible objects that support seek(). Some MediaUpload
130  subclasses support using streams directly to upload data. Support for
131  streaming may be indicated by a MediaUpload sub-class and if appropriate for a
132  platform that stream will be used for uploading the media object. The support
133  for streaming is indicated by has_stream() returning True. The stream() method
134  should return an io.Base object that supports seek(). On platforms where the
135  underlying httplib module supports streaming, for example Python 2.6 and
136  later, the stream will be passed into the http library which will result in
137  less memory being used and possibly faster uploads.
138
139  If you need to upload media that can't be uploaded using any of the existing
140  MediaUpload sub-class then you can sub-class MediaUpload for your particular
141  needs.
142  """
143
144  def chunksize(self):
145    """Chunk size for resumable uploads.
146
147    Returns:
148      Chunk size in bytes.
149    """
150    raise NotImplementedError()
151
152  def mimetype(self):
153    """Mime type of the body.
154
155    Returns:
156      Mime type.
157    """
158    return 'application/octet-stream'
159
160  def size(self):
161    """Size of upload.
162
163    Returns:
164      Size of the body, or None of the size is unknown.
165    """
166    return None
167
168  def resumable(self):
169    """Whether this upload is resumable.
170
171    Returns:
172      True if resumable upload or False.
173    """
174    return False
175
176  def getbytes(self, begin, end):
177    """Get bytes from the media.
178
179    Args:
180      begin: int, offset from beginning of file.
181      length: int, number of bytes to read, starting at begin.
182
183    Returns:
184      A string of bytes read. May be shorter than length if EOF was reached
185      first.
186    """
187    raise NotImplementedError()
188
189  def has_stream(self):
190    """Does the underlying upload support a streaming interface.
191
192    Streaming means it is an io.IOBase subclass that supports seek, i.e.
193    seekable() returns True.
194
195    Returns:
196      True if the call to stream() will return an instance of a seekable io.Base
197      subclass.
198    """
199    return False
200
201  def stream(self):
202    """A stream interface to the data being uploaded.
203
204    Returns:
205      The returned value is an io.IOBase subclass that supports seek, i.e.
206      seekable() returns True.
207    """
208    raise NotImplementedError()
209
210  @util.positional(1)
211  def _to_json(self, strip=None):
212    """Utility function for creating a JSON representation of a MediaUpload.
213
214    Args:
215      strip: array, An array of names of members to not include in the JSON.
216
217    Returns:
218       string, a JSON representation of this instance, suitable to pass to
219       from_json().
220    """
221    t = type(self)
222    d = copy.copy(self.__dict__)
223    if strip is not None:
224      for member in strip:
225        del d[member]
226    d['_class'] = t.__name__
227    d['_module'] = t.__module__
228    return json.dumps(d)
229
230  def to_json(self):
231    """Create a JSON representation of an instance of MediaUpload.
232
233    Returns:
234       string, a JSON representation of this instance, suitable to pass to
235       from_json().
236    """
237    return self._to_json()
238
239  @classmethod
240  def new_from_json(cls, s):
241    """Utility class method to instantiate a MediaUpload subclass from a JSON
242    representation produced by to_json().
243
244    Args:
245      s: string, JSON from to_json().
246
247    Returns:
248      An instance of the subclass of MediaUpload that was serialized with
249      to_json().
250    """
251    data = json.loads(s)
252    # Find and call the right classmethod from_json() to restore the object.
253    module = data['_module']
254    m = __import__(module, fromlist=module.split('.')[:-1])
255    kls = getattr(m, data['_class'])
256    from_json = getattr(kls, 'from_json')
257    return from_json(s)
258
259
260class MediaIoBaseUpload(MediaUpload):
261  """A MediaUpload for a io.Base objects.
262
263  Note that the Python file object is compatible with io.Base and can be used
264  with this class also.
265
266    fh = BytesIO('...Some data to upload...')
267    media = MediaIoBaseUpload(fh, mimetype='image/png',
268      chunksize=1024*1024, resumable=True)
269    farm.animals().insert(
270        id='cow',
271        name='cow.png',
272        media_body=media).execute()
273
274  Depending on the platform you are working on, you may pass -1 as the
275  chunksize, which indicates that the entire file should be uploaded in a single
276  request. If the underlying platform supports streams, such as Python 2.6 or
277  later, then this can be very efficient as it avoids multiple connections, and
278  also avoids loading the entire file into memory before sending it. Note that
279  Google App Engine has a 5MB limit on request size, so you should never set
280  your chunksize larger than 5MB, or to -1.
281  """
282
283  @util.positional(3)
284  def __init__(self, fd, mimetype, chunksize=DEFAULT_CHUNK_SIZE,
285      resumable=False):
286    """Constructor.
287
288    Args:
289      fd: io.Base or file object, The source of the bytes to upload. MUST be
290        opened in blocking mode, do not use streams opened in non-blocking mode.
291        The given stream must be seekable, that is, it must be able to call
292        seek() on fd.
293      mimetype: string, Mime-type of the file.
294      chunksize: int, File will be uploaded in chunks of this many bytes. Only
295        used if resumable=True. Pass in a value of -1 if the file is to be
296        uploaded as a single chunk. Note that Google App Engine has a 5MB limit
297        on request size, so you should never set your chunksize larger than 5MB,
298        or to -1.
299      resumable: bool, True if this is a resumable upload. False means upload
300        in a single request.
301    """
302    super(MediaIoBaseUpload, self).__init__()
303    self._fd = fd
304    self._mimetype = mimetype
305    if not (chunksize == -1 or chunksize > 0):
306      raise InvalidChunkSizeError()
307    self._chunksize = chunksize
308    self._resumable = resumable
309
310    self._fd.seek(0, os.SEEK_END)
311    self._size = self._fd.tell()
312
313  def chunksize(self):
314    """Chunk size for resumable uploads.
315
316    Returns:
317      Chunk size in bytes.
318    """
319    return self._chunksize
320
321  def mimetype(self):
322    """Mime type of the body.
323
324    Returns:
325      Mime type.
326    """
327    return self._mimetype
328
329  def size(self):
330    """Size of upload.
331
332    Returns:
333      Size of the body, or None of the size is unknown.
334    """
335    return self._size
336
337  def resumable(self):
338    """Whether this upload is resumable.
339
340    Returns:
341      True if resumable upload or False.
342    """
343    return self._resumable
344
345  def getbytes(self, begin, length):
346    """Get bytes from the media.
347
348    Args:
349      begin: int, offset from beginning of file.
350      length: int, number of bytes to read, starting at begin.
351
352    Returns:
353      A string of bytes read. May be shorted than length if EOF was reached
354      first.
355    """
356    self._fd.seek(begin)
357    return self._fd.read(length)
358
359  def has_stream(self):
360    """Does the underlying upload support a streaming interface.
361
362    Streaming means it is an io.IOBase subclass that supports seek, i.e.
363    seekable() returns True.
364
365    Returns:
366      True if the call to stream() will return an instance of a seekable io.Base
367      subclass.
368    """
369    return True
370
371  def stream(self):
372    """A stream interface to the data being uploaded.
373
374    Returns:
375      The returned value is an io.IOBase subclass that supports seek, i.e.
376      seekable() returns True.
377    """
378    return self._fd
379
380  def to_json(self):
381    """This upload type is not serializable."""
382    raise NotImplementedError('MediaIoBaseUpload is not serializable.')
383
384
385class MediaFileUpload(MediaIoBaseUpload):
386  """A MediaUpload for a file.
387
388  Construct a MediaFileUpload and pass as the media_body parameter of the
389  method. For example, if we had a service that allowed uploading images:
390
391
392    media = MediaFileUpload('cow.png', mimetype='image/png',
393      chunksize=1024*1024, resumable=True)
394    farm.animals().insert(
395        id='cow',
396        name='cow.png',
397        media_body=media).execute()
398
399  Depending on the platform you are working on, you may pass -1 as the
400  chunksize, which indicates that the entire file should be uploaded in a single
401  request. If the underlying platform supports streams, such as Python 2.6 or
402  later, then this can be very efficient as it avoids multiple connections, and
403  also avoids loading the entire file into memory before sending it. Note that
404  Google App Engine has a 5MB limit on request size, so you should never set
405  your chunksize larger than 5MB, or to -1.
406  """
407
408  @util.positional(2)
409  def __init__(self, filename, mimetype=None, chunksize=DEFAULT_CHUNK_SIZE,
410               resumable=False):
411    """Constructor.
412
413    Args:
414      filename: string, Name of the file.
415      mimetype: string, Mime-type of the file. If None then a mime-type will be
416        guessed from the file extension.
417      chunksize: int, File will be uploaded in chunks of this many bytes. Only
418        used if resumable=True. Pass in a value of -1 if the file is to be
419        uploaded in a single chunk. Note that Google App Engine has a 5MB limit
420        on request size, so you should never set your chunksize larger than 5MB,
421        or to -1.
422      resumable: bool, True if this is a resumable upload. False means upload
423        in a single request.
424    """
425    self._filename = filename
426    fd = open(self._filename, 'rb')
427    if mimetype is None:
428      (mimetype, encoding) = mimetypes.guess_type(filename)
429    super(MediaFileUpload, self).__init__(fd, mimetype, chunksize=chunksize,
430                                          resumable=resumable)
431
432  def to_json(self):
433    """Creating a JSON representation of an instance of MediaFileUpload.
434
435    Returns:
436       string, a JSON representation of this instance, suitable to pass to
437       from_json().
438    """
439    return self._to_json(strip=['_fd'])
440
441  @staticmethod
442  def from_json(s):
443    d = json.loads(s)
444    return MediaFileUpload(d['_filename'], mimetype=d['_mimetype'],
445                           chunksize=d['_chunksize'], resumable=d['_resumable'])
446
447
448class MediaInMemoryUpload(MediaIoBaseUpload):
449  """MediaUpload for a chunk of bytes.
450
451  DEPRECATED: Use MediaIoBaseUpload with either io.TextIOBase or StringIO for
452  the stream.
453  """
454
455  @util.positional(2)
456  def __init__(self, body, mimetype='application/octet-stream',
457               chunksize=DEFAULT_CHUNK_SIZE, resumable=False):
458    """Create a new MediaInMemoryUpload.
459
460  DEPRECATED: Use MediaIoBaseUpload with either io.TextIOBase or StringIO for
461  the stream.
462
463  Args:
464    body: string, Bytes of body content.
465    mimetype: string, Mime-type of the file or default of
466      'application/octet-stream'.
467    chunksize: int, File will be uploaded in chunks of this many bytes. Only
468      used if resumable=True.
469    resumable: bool, True if this is a resumable upload. False means upload
470      in a single request.
471    """
472    fd = BytesIO(body)
473    super(MediaInMemoryUpload, self).__init__(fd, mimetype, chunksize=chunksize,
474                                              resumable=resumable)
475
476
477class MediaIoBaseDownload(object):
478  """"Download media resources.
479
480  Note that the Python file object is compatible with io.Base and can be used
481  with this class also.
482
483
484  Example:
485    request = farms.animals().get_media(id='cow')
486    fh = io.FileIO('cow.png', mode='wb')
487    downloader = MediaIoBaseDownload(fh, request, chunksize=1024*1024)
488
489    done = False
490    while done is False:
491      status, done = downloader.next_chunk()
492      if status:
493        print "Download %d%%." % int(status.progress() * 100)
494    print "Download Complete!"
495  """
496
497  @util.positional(3)
498  def __init__(self, fd, request, chunksize=DEFAULT_CHUNK_SIZE):
499    """Constructor.
500
501    Args:
502      fd: io.Base or file object, The stream in which to write the downloaded
503        bytes.
504      request: googleapiclient.http.HttpRequest, the media request to perform in
505        chunks.
506      chunksize: int, File will be downloaded in chunks of this many bytes.
507    """
508    self._fd = fd
509    self._request = request
510    self._uri = request.uri
511    self._chunksize = chunksize
512    self._progress = 0
513    self._total_size = None
514    self._done = False
515
516    # Stubs for testing.
517    self._sleep = time.sleep
518    self._rand = random.random
519
520  @util.positional(1)
521  def next_chunk(self, num_retries=0):
522    """Get the next chunk of the download.
523
524    Args:
525      num_retries: Integer, number of times to retry 500's with randomized
526            exponential backoff. If all retries fail, the raised HttpError
527            represents the last request. If zero (default), we attempt the
528            request only once.
529
530    Returns:
531      (status, done): (MediaDownloadStatus, boolean)
532         The value of 'done' will be True when the media has been fully
533         downloaded.
534
535    Raises:
536      googleapiclient.errors.HttpError if the response was not a 2xx.
537      httplib2.HttpLib2Error if a transport error has occured.
538    """
539    headers = {
540        'range': 'bytes=%d-%d' % (
541            self._progress, self._progress + self._chunksize)
542        }
543    http = self._request.http
544
545    for retry_num in range(num_retries + 1):
546      if retry_num > 0:
547        self._sleep(self._rand() * 2**retry_num)
548        logging.warning(
549            'Retry #%d for media download: GET %s, following status: %d'
550            % (retry_num, self._uri, resp.status))
551
552      resp, content = http.request(self._uri, headers=headers)
553      if resp.status < 500:
554        break
555
556    if resp.status in [200, 206]:
557      if 'content-location' in resp and resp['content-location'] != self._uri:
558        self._uri = resp['content-location']
559      self._progress += len(content)
560      self._fd.write(content)
561
562      if 'content-range' in resp:
563        content_range = resp['content-range']
564        length = content_range.rsplit('/', 1)[1]
565        self._total_size = int(length)
566      elif 'content-length' in resp:
567        self._total_size = int(resp['content-length'])
568
569      if self._progress == self._total_size:
570        self._done = True
571      return MediaDownloadProgress(self._progress, self._total_size), self._done
572    else:
573      raise HttpError(resp, content, uri=self._uri)
574
575
576class _StreamSlice(object):
577  """Truncated stream.
578
579  Takes a stream and presents a stream that is a slice of the original stream.
580  This is used when uploading media in chunks. In later versions of Python a
581  stream can be passed to httplib in place of the string of data to send. The
582  problem is that httplib just blindly reads to the end of the stream. This
583  wrapper presents a virtual stream that only reads to the end of the chunk.
584  """
585
586  def __init__(self, stream, begin, chunksize):
587    """Constructor.
588
589    Args:
590      stream: (io.Base, file object), the stream to wrap.
591      begin: int, the seek position the chunk begins at.
592      chunksize: int, the size of the chunk.
593    """
594    self._stream = stream
595    self._begin = begin
596    self._chunksize = chunksize
597    self._stream.seek(begin)
598
599  def read(self, n=-1):
600    """Read n bytes.
601
602    Args:
603      n, int, the number of bytes to read.
604
605    Returns:
606      A string of length 'n', or less if EOF is reached.
607    """
608    # The data left available to read sits in [cur, end)
609    cur = self._stream.tell()
610    end = self._begin + self._chunksize
611    if n == -1 or cur + n > end:
612      n = end - cur
613    return self._stream.read(n)
614
615
616class HttpRequest(object):
617  """Encapsulates a single HTTP request."""
618
619  @util.positional(4)
620  def __init__(self, http, postproc, uri,
621               method='GET',
622               body=None,
623               headers=None,
624               methodId=None,
625               resumable=None):
626    """Constructor for an HttpRequest.
627
628    Args:
629      http: httplib2.Http, the transport object to use to make a request
630      postproc: callable, called on the HTTP response and content to transform
631                it into a data object before returning, or raising an exception
632                on an error.
633      uri: string, the absolute URI to send the request to
634      method: string, the HTTP method to use
635      body: string, the request body of the HTTP request,
636      headers: dict, the HTTP request headers
637      methodId: string, a unique identifier for the API method being called.
638      resumable: MediaUpload, None if this is not a resumbale request.
639    """
640    self.uri = uri
641    self.method = method
642    self.body = body
643    self.headers = headers or {}
644    self.methodId = methodId
645    self.http = http
646    self.postproc = postproc
647    self.resumable = resumable
648    self.response_callbacks = []
649    self._in_error_state = False
650
651    # Pull the multipart boundary out of the content-type header.
652    major, minor, params = mimeparse.parse_mime_type(
653        headers.get('content-type', 'application/json'))
654
655    # The size of the non-media part of the request.
656    self.body_size = len(self.body or '')
657
658    # The resumable URI to send chunks to.
659    self.resumable_uri = None
660
661    # The bytes that have been uploaded.
662    self.resumable_progress = 0
663
664    # Stubs for testing.
665    self._rand = random.random
666    self._sleep = time.sleep
667
668  @util.positional(1)
669  def execute(self, http=None, num_retries=0):
670    """Execute the request.
671
672    Args:
673      http: httplib2.Http, an http object to be used in place of the
674            one the HttpRequest request object was constructed with.
675      num_retries: Integer, number of times to retry 500's with randomized
676            exponential backoff. If all retries fail, the raised HttpError
677            represents the last request. If zero (default), we attempt the
678            request only once.
679
680    Returns:
681      A deserialized object model of the response body as determined
682      by the postproc.
683
684    Raises:
685      googleapiclient.errors.HttpError if the response was not a 2xx.
686      httplib2.HttpLib2Error if a transport error has occured.
687    """
688    if http is None:
689      http = self.http
690
691    if self.resumable:
692      body = None
693      while body is None:
694        _, body = self.next_chunk(http=http, num_retries=num_retries)
695      return body
696
697    # Non-resumable case.
698
699    if 'content-length' not in self.headers:
700      self.headers['content-length'] = str(self.body_size)
701    # If the request URI is too long then turn it into a POST request.
702    if len(self.uri) > MAX_URI_LENGTH and self.method == 'GET':
703      self.method = 'POST'
704      self.headers['x-http-method-override'] = 'GET'
705      self.headers['content-type'] = 'application/x-www-form-urlencoded'
706      parsed = urlparse(self.uri)
707      self.uri = urlunparse(
708          (parsed.scheme, parsed.netloc, parsed.path, parsed.params, None,
709           None)
710          )
711      self.body = parsed.query
712      self.headers['content-length'] = str(len(self.body))
713
714    # Handle retries for server-side errors.
715    for retry_num in range(num_retries + 1):
716      if retry_num > 0:
717        self._sleep(self._rand() * 2**retry_num)
718        logging.warning('Retry #%d for request: %s %s, following status: %d'
719                        % (retry_num, self.method, self.uri, resp.status))
720
721      resp, content = http.request(str(self.uri), method=str(self.method),
722                                   body=self.body, headers=self.headers)
723      if resp.status < 500:
724        break
725
726    for callback in self.response_callbacks:
727      callback(resp)
728    if resp.status >= 300:
729      raise HttpError(resp, content, uri=self.uri)
730    return self.postproc(resp, content)
731
732  @util.positional(2)
733  def add_response_callback(self, cb):
734    """add_response_headers_callback
735
736    Args:
737      cb: Callback to be called on receiving the response headers, of signature:
738
739      def cb(resp):
740        # Where resp is an instance of httplib2.Response
741    """
742    self.response_callbacks.append(cb)
743
744  @util.positional(1)
745  def next_chunk(self, http=None, num_retries=0):
746    """Execute the next step of a resumable upload.
747
748    Can only be used if the method being executed supports media uploads and
749    the MediaUpload object passed in was flagged as using resumable upload.
750
751    Example:
752
753      media = MediaFileUpload('cow.png', mimetype='image/png',
754                              chunksize=1000, resumable=True)
755      request = farm.animals().insert(
756          id='cow',
757          name='cow.png',
758          media_body=media)
759
760      response = None
761      while response is None:
762        status, response = request.next_chunk()
763        if status:
764          print "Upload %d%% complete." % int(status.progress() * 100)
765
766
767    Args:
768      http: httplib2.Http, an http object to be used in place of the
769            one the HttpRequest request object was constructed with.
770      num_retries: Integer, number of times to retry 500's with randomized
771            exponential backoff. If all retries fail, the raised HttpError
772            represents the last request. If zero (default), we attempt the
773            request only once.
774
775    Returns:
776      (status, body): (ResumableMediaStatus, object)
777         The body will be None until the resumable media is fully uploaded.
778
779    Raises:
780      googleapiclient.errors.HttpError if the response was not a 2xx.
781      httplib2.HttpLib2Error if a transport error has occured.
782    """
783    if http is None:
784      http = self.http
785
786    if self.resumable.size() is None:
787      size = '*'
788    else:
789      size = str(self.resumable.size())
790
791    if self.resumable_uri is None:
792      start_headers = copy.copy(self.headers)
793      start_headers['X-Upload-Content-Type'] = self.resumable.mimetype()
794      if size != '*':
795        start_headers['X-Upload-Content-Length'] = size
796      start_headers['content-length'] = str(self.body_size)
797
798      for retry_num in range(num_retries + 1):
799        if retry_num > 0:
800          self._sleep(self._rand() * 2**retry_num)
801          logging.warning(
802              'Retry #%d for resumable URI request: %s %s, following status: %d'
803              % (retry_num, self.method, self.uri, resp.status))
804
805        resp, content = http.request(self.uri, method=self.method,
806                                     body=self.body,
807                                     headers=start_headers)
808        if resp.status < 500:
809          break
810
811      if resp.status == 200 and 'location' in resp:
812        self.resumable_uri = resp['location']
813      else:
814        raise ResumableUploadError(resp, content)
815    elif self._in_error_state:
816      # If we are in an error state then query the server for current state of
817      # the upload by sending an empty PUT and reading the 'range' header in
818      # the response.
819      headers = {
820          'Content-Range': 'bytes */%s' % size,
821          'content-length': '0'
822          }
823      resp, content = http.request(self.resumable_uri, 'PUT',
824                                   headers=headers)
825      status, body = self._process_response(resp, content)
826      if body:
827        # The upload was complete.
828        return (status, body)
829
830    # The httplib.request method can take streams for the body parameter, but
831    # only in Python 2.6 or later. If a stream is available under those
832    # conditions then use it as the body argument.
833    if self.resumable.has_stream() and sys.version_info[1] >= 6:
834      data = self.resumable.stream()
835      if self.resumable.chunksize() == -1:
836        data.seek(self.resumable_progress)
837        chunk_end = self.resumable.size() - self.resumable_progress - 1
838      else:
839        # Doing chunking with a stream, so wrap a slice of the stream.
840        data = _StreamSlice(data, self.resumable_progress,
841                            self.resumable.chunksize())
842        chunk_end = min(
843            self.resumable_progress + self.resumable.chunksize() - 1,
844            self.resumable.size() - 1)
845    else:
846      data = self.resumable.getbytes(
847          self.resumable_progress, self.resumable.chunksize())
848
849      # A short read implies that we are at EOF, so finish the upload.
850      if len(data) < self.resumable.chunksize():
851        size = str(self.resumable_progress + len(data))
852
853      chunk_end = self.resumable_progress + len(data) - 1
854
855    headers = {
856        'Content-Range': 'bytes %d-%d/%s' % (
857            self.resumable_progress, chunk_end, size),
858        # Must set the content-length header here because httplib can't
859        # calculate the size when working with _StreamSlice.
860        'Content-Length': str(chunk_end - self.resumable_progress + 1)
861        }
862
863    for retry_num in range(num_retries + 1):
864      if retry_num > 0:
865        self._sleep(self._rand() * 2**retry_num)
866        logging.warning(
867            'Retry #%d for media upload: %s %s, following status: %d'
868            % (retry_num, self.method, self.uri, resp.status))
869
870      try:
871        resp, content = http.request(self.resumable_uri, method='PUT',
872                                     body=data,
873                                     headers=headers)
874      except:
875        self._in_error_state = True
876        raise
877      if resp.status < 500:
878        break
879
880    return self._process_response(resp, content)
881
882  def _process_response(self, resp, content):
883    """Process the response from a single chunk upload.
884
885    Args:
886      resp: httplib2.Response, the response object.
887      content: string, the content of the response.
888
889    Returns:
890      (status, body): (ResumableMediaStatus, object)
891         The body will be None until the resumable media is fully uploaded.
892
893    Raises:
894      googleapiclient.errors.HttpError if the response was not a 2xx or a 308.
895    """
896    if resp.status in [200, 201]:
897      self._in_error_state = False
898      return None, self.postproc(resp, content)
899    elif resp.status == 308:
900      self._in_error_state = False
901      # A "308 Resume Incomplete" indicates we are not done.
902      self.resumable_progress = int(resp['range'].split('-')[1]) + 1
903      if 'location' in resp:
904        self.resumable_uri = resp['location']
905    else:
906      self._in_error_state = True
907      raise HttpError(resp, content, uri=self.uri)
908
909    return (MediaUploadProgress(self.resumable_progress, self.resumable.size()),
910            None)
911
912  def to_json(self):
913    """Returns a JSON representation of the HttpRequest."""
914    d = copy.copy(self.__dict__)
915    if d['resumable'] is not None:
916      d['resumable'] = self.resumable.to_json()
917    del d['http']
918    del d['postproc']
919    del d['_sleep']
920    del d['_rand']
921
922    return json.dumps(d)
923
924  @staticmethod
925  def from_json(s, http, postproc):
926    """Returns an HttpRequest populated with info from a JSON object."""
927    d = json.loads(s)
928    if d['resumable'] is not None:
929      d['resumable'] = MediaUpload.new_from_json(d['resumable'])
930    return HttpRequest(
931        http,
932        postproc,
933        uri=d['uri'],
934        method=d['method'],
935        body=d['body'],
936        headers=d['headers'],
937        methodId=d['methodId'],
938        resumable=d['resumable'])
939
940
941class BatchHttpRequest(object):
942  """Batches multiple HttpRequest objects into a single HTTP request.
943
944  Example:
945    from googleapiclient.http import BatchHttpRequest
946
947    def list_animals(request_id, response, exception):
948      \"\"\"Do something with the animals list response.\"\"\"
949      if exception is not None:
950        # Do something with the exception.
951        pass
952      else:
953        # Do something with the response.
954        pass
955
956    def list_farmers(request_id, response, exception):
957      \"\"\"Do something with the farmers list response.\"\"\"
958      if exception is not None:
959        # Do something with the exception.
960        pass
961      else:
962        # Do something with the response.
963        pass
964
965    service = build('farm', 'v2')
966
967    batch = BatchHttpRequest()
968
969    batch.add(service.animals().list(), list_animals)
970    batch.add(service.farmers().list(), list_farmers)
971    batch.execute(http=http)
972  """
973
974  @util.positional(1)
975  def __init__(self, callback=None, batch_uri=None):
976    """Constructor for a BatchHttpRequest.
977
978    Args:
979      callback: callable, A callback to be called for each response, of the
980        form callback(id, response, exception). The first parameter is the
981        request id, and the second is the deserialized response object. The
982        third is an googleapiclient.errors.HttpError exception object if an HTTP error
983        occurred while processing the request, or None if no error occurred.
984      batch_uri: string, URI to send batch requests to.
985    """
986    if batch_uri is None:
987      batch_uri = 'https://www.googleapis.com/batch'
988    self._batch_uri = batch_uri
989
990    # Global callback to be called for each individual response in the batch.
991    self._callback = callback
992
993    # A map from id to request.
994    self._requests = {}
995
996    # A map from id to callback.
997    self._callbacks = {}
998
999    # List of request ids, in the order in which they were added.
1000    self._order = []
1001
1002    # The last auto generated id.
1003    self._last_auto_id = 0
1004
1005    # Unique ID on which to base the Content-ID headers.
1006    self._base_id = None
1007
1008    # A map from request id to (httplib2.Response, content) response pairs
1009    self._responses = {}
1010
1011    # A map of id(Credentials) that have been refreshed.
1012    self._refreshed_credentials = {}
1013
1014  def _refresh_and_apply_credentials(self, request, http):
1015    """Refresh the credentials and apply to the request.
1016
1017    Args:
1018      request: HttpRequest, the request.
1019      http: httplib2.Http, the global http object for the batch.
1020    """
1021    # For the credentials to refresh, but only once per refresh_token
1022    # If there is no http per the request then refresh the http passed in
1023    # via execute()
1024    creds = None
1025    if request.http is not None and hasattr(request.http.request,
1026        'credentials'):
1027      creds = request.http.request.credentials
1028    elif http is not None and hasattr(http.request, 'credentials'):
1029      creds = http.request.credentials
1030    if creds is not None:
1031      if id(creds) not in self._refreshed_credentials:
1032        creds.refresh(http)
1033        self._refreshed_credentials[id(creds)] = 1
1034
1035    # Only apply the credentials if we are using the http object passed in,
1036    # otherwise apply() will get called during _serialize_request().
1037    if request.http is None or not hasattr(request.http.request,
1038        'credentials'):
1039      creds.apply(request.headers)
1040
1041  def _id_to_header(self, id_):
1042    """Convert an id to a Content-ID header value.
1043
1044    Args:
1045      id_: string, identifier of individual request.
1046
1047    Returns:
1048      A Content-ID header with the id_ encoded into it. A UUID is prepended to
1049      the value because Content-ID headers are supposed to be universally
1050      unique.
1051    """
1052    if self._base_id is None:
1053      self._base_id = uuid.uuid4()
1054
1055    return '<%s+%s>' % (self._base_id, quote(id_))
1056
1057  def _header_to_id(self, header):
1058    """Convert a Content-ID header value to an id.
1059
1060    Presumes the Content-ID header conforms to the format that _id_to_header()
1061    returns.
1062
1063    Args:
1064      header: string, Content-ID header value.
1065
1066    Returns:
1067      The extracted id value.
1068
1069    Raises:
1070      BatchError if the header is not in the expected format.
1071    """
1072    if header[0] != '<' or header[-1] != '>':
1073      raise BatchError("Invalid value for Content-ID: %s" % header)
1074    if '+' not in header:
1075      raise BatchError("Invalid value for Content-ID: %s" % header)
1076    base, id_ = header[1:-1].rsplit('+', 1)
1077
1078    return unquote(id_)
1079
1080  def _serialize_request(self, request):
1081    """Convert an HttpRequest object into a string.
1082
1083    Args:
1084      request: HttpRequest, the request to serialize.
1085
1086    Returns:
1087      The request as a string in application/http format.
1088    """
1089    # Construct status line
1090    parsed = urlparse(request.uri)
1091    request_line = urlunparse(
1092        ('', '', parsed.path, parsed.params, parsed.query, '')
1093        )
1094    status_line = request.method + ' ' + request_line + ' HTTP/1.1\n'
1095    major, minor = request.headers.get('content-type', 'application/json').split('/')
1096    msg = MIMENonMultipart(major, minor)
1097    headers = request.headers.copy()
1098
1099    if request.http is not None and hasattr(request.http.request,
1100        'credentials'):
1101      request.http.request.credentials.apply(headers)
1102
1103    # MIMENonMultipart adds its own Content-Type header.
1104    if 'content-type' in headers:
1105      del headers['content-type']
1106
1107    for key, value in six.iteritems(headers):
1108      msg[key] = value
1109    msg['Host'] = parsed.netloc
1110    msg.set_unixfrom(None)
1111
1112    if request.body is not None:
1113      msg.set_payload(request.body)
1114      msg['content-length'] = str(len(request.body))
1115
1116    # Serialize the mime message.
1117    fp = StringIO()
1118    # maxheaderlen=0 means don't line wrap headers.
1119    g = Generator(fp, maxheaderlen=0)
1120    g.flatten(msg, unixfrom=False)
1121    body = fp.getvalue()
1122
1123    # Strip off the \n\n that the MIME lib tacks onto the end of the payload.
1124    if request.body is None:
1125      body = body[:-2]
1126
1127    return status_line + body
1128
1129  def _deserialize_response(self, payload):
1130    """Convert string into httplib2 response and content.
1131
1132    Args:
1133      payload: string, headers and body as a string.
1134
1135    Returns:
1136      A pair (resp, content), such as would be returned from httplib2.request.
1137    """
1138    # Strip off the status line
1139    status_line, payload = payload.split('\n', 1)
1140    protocol, status, reason = status_line.split(' ', 2)
1141
1142    # Parse the rest of the response
1143    parser = FeedParser()
1144    parser.feed(payload)
1145    msg = parser.close()
1146    msg['status'] = status
1147
1148    # Create httplib2.Response from the parsed headers.
1149    resp = httplib2.Response(msg)
1150    resp.reason = reason
1151    resp.version = int(protocol.split('/', 1)[1].replace('.', ''))
1152
1153    content = payload.split('\r\n\r\n', 1)[1]
1154
1155    return resp, content
1156
1157  def _new_id(self):
1158    """Create a new id.
1159
1160    Auto incrementing number that avoids conflicts with ids already used.
1161
1162    Returns:
1163       string, a new unique id.
1164    """
1165    self._last_auto_id += 1
1166    while str(self._last_auto_id) in self._requests:
1167      self._last_auto_id += 1
1168    return str(self._last_auto_id)
1169
1170  @util.positional(2)
1171  def add(self, request, callback=None, request_id=None):
1172    """Add a new request.
1173
1174    Every callback added will be paired with a unique id, the request_id. That
1175    unique id will be passed back to the callback when the response comes back
1176    from the server. The default behavior is to have the library generate it's
1177    own unique id. If the caller passes in a request_id then they must ensure
1178    uniqueness for each request_id, and if they are not an exception is
1179    raised. Callers should either supply all request_ids or nevery supply a
1180    request id, to avoid such an error.
1181
1182    Args:
1183      request: HttpRequest, Request to add to the batch.
1184      callback: callable, A callback to be called for this response, of the
1185        form callback(id, response, exception). The first parameter is the
1186        request id, and the second is the deserialized response object. The
1187        third is an googleapiclient.errors.HttpError exception object if an HTTP error
1188        occurred while processing the request, or None if no errors occurred.
1189      request_id: string, A unique id for the request. The id will be passed to
1190        the callback with the response.
1191
1192    Returns:
1193      None
1194
1195    Raises:
1196      BatchError if a media request is added to a batch.
1197      KeyError is the request_id is not unique.
1198    """
1199    if request_id is None:
1200      request_id = self._new_id()
1201    if request.resumable is not None:
1202      raise BatchError("Media requests cannot be used in a batch request.")
1203    if request_id in self._requests:
1204      raise KeyError("A request with this ID already exists: %s" % request_id)
1205    self._requests[request_id] = request
1206    self._callbacks[request_id] = callback
1207    self._order.append(request_id)
1208
1209  def _execute(self, http, order, requests):
1210    """Serialize batch request, send to server, process response.
1211
1212    Args:
1213      http: httplib2.Http, an http object to be used to make the request with.
1214      order: list, list of request ids in the order they were added to the
1215        batch.
1216      request: list, list of request objects to send.
1217
1218    Raises:
1219      httplib2.HttpLib2Error if a transport error has occured.
1220      googleapiclient.errors.BatchError if the response is the wrong format.
1221    """
1222    message = MIMEMultipart('mixed')
1223    # Message should not write out it's own headers.
1224    setattr(message, '_write_headers', lambda self: None)
1225
1226    # Add all the individual requests.
1227    for request_id in order:
1228      request = requests[request_id]
1229
1230      msg = MIMENonMultipart('application', 'http')
1231      msg['Content-Transfer-Encoding'] = 'binary'
1232      msg['Content-ID'] = self._id_to_header(request_id)
1233
1234      body = self._serialize_request(request)
1235      msg.set_payload(body)
1236      message.attach(msg)
1237
1238    # encode the body: note that we can't use `as_string`, because
1239    # it plays games with `From ` lines.
1240    fp = StringIO()
1241    g = Generator(fp, mangle_from_=False)
1242    g.flatten(message, unixfrom=False)
1243    body = fp.getvalue()
1244
1245    headers = {}
1246    headers['content-type'] = ('multipart/mixed; '
1247                               'boundary="%s"') % message.get_boundary()
1248
1249    resp, content = http.request(self._batch_uri, method='POST', body=body,
1250                                 headers=headers)
1251
1252    if resp.status >= 300:
1253      raise HttpError(resp, content, uri=self._batch_uri)
1254
1255    # Now break out the individual responses and store each one.
1256    boundary, _ = content.split(None, 1)
1257
1258    # Prepend with a content-type header so FeedParser can handle it.
1259    header = 'content-type: %s\r\n\r\n' % resp['content-type']
1260    for_parser = header + content
1261
1262    parser = FeedParser()
1263    parser.feed(for_parser)
1264    mime_response = parser.close()
1265
1266    if not mime_response.is_multipart():
1267      raise BatchError("Response not in multipart/mixed format.", resp=resp,
1268                       content=content)
1269
1270    for part in mime_response.get_payload():
1271      request_id = self._header_to_id(part['Content-ID'])
1272      response, content = self._deserialize_response(part.get_payload())
1273      self._responses[request_id] = (response, content)
1274
1275  @util.positional(1)
1276  def execute(self, http=None):
1277    """Execute all the requests as a single batched HTTP request.
1278
1279    Args:
1280      http: httplib2.Http, an http object to be used in place of the one the
1281        HttpRequest request object was constructed with. If one isn't supplied
1282        then use a http object from the requests in this batch.
1283
1284    Returns:
1285      None
1286
1287    Raises:
1288      httplib2.HttpLib2Error if a transport error has occured.
1289      googleapiclient.errors.BatchError if the response is the wrong format.
1290    """
1291
1292    # If http is not supplied use the first valid one given in the requests.
1293    if http is None:
1294      for request_id in self._order:
1295        request = self._requests[request_id]
1296        if request is not None:
1297          http = request.http
1298          break
1299
1300    if http is None:
1301      raise ValueError("Missing a valid http object.")
1302
1303    self._execute(http, self._order, self._requests)
1304
1305    # Loop over all the requests and check for 401s. For each 401 request the
1306    # credentials should be refreshed and then sent again in a separate batch.
1307    redo_requests = {}
1308    redo_order = []
1309
1310    for request_id in self._order:
1311      resp, content = self._responses[request_id]
1312      if resp['status'] == '401':
1313        redo_order.append(request_id)
1314        request = self._requests[request_id]
1315        self._refresh_and_apply_credentials(request, http)
1316        redo_requests[request_id] = request
1317
1318    if redo_requests:
1319      self._execute(http, redo_order, redo_requests)
1320
1321    # Now process all callbacks that are erroring, and raise an exception for
1322    # ones that return a non-2xx response? Or add extra parameter to callback
1323    # that contains an HttpError?
1324
1325    for request_id in self._order:
1326      resp, content = self._responses[request_id]
1327
1328      request = self._requests[request_id]
1329      callback = self._callbacks[request_id]
1330
1331      response = None
1332      exception = None
1333      try:
1334        if resp.status >= 300:
1335          raise HttpError(resp, content, uri=request.uri)
1336        response = request.postproc(resp, content)
1337      except HttpError as e:
1338        exception = e
1339
1340      if callback is not None:
1341        callback(request_id, response, exception)
1342      if self._callback is not None:
1343        self._callback(request_id, response, exception)
1344
1345
1346class HttpRequestMock(object):
1347  """Mock of HttpRequest.
1348
1349  Do not construct directly, instead use RequestMockBuilder.
1350  """
1351
1352  def __init__(self, resp, content, postproc):
1353    """Constructor for HttpRequestMock
1354
1355    Args:
1356      resp: httplib2.Response, the response to emulate coming from the request
1357      content: string, the response body
1358      postproc: callable, the post processing function usually supplied by
1359                the model class. See model.JsonModel.response() as an example.
1360    """
1361    self.resp = resp
1362    self.content = content
1363    self.postproc = postproc
1364    if resp is None:
1365      self.resp = httplib2.Response({'status': 200, 'reason': 'OK'})
1366    if 'reason' in self.resp:
1367      self.resp.reason = self.resp['reason']
1368
1369  def execute(self, http=None):
1370    """Execute the request.
1371
1372    Same behavior as HttpRequest.execute(), but the response is
1373    mocked and not really from an HTTP request/response.
1374    """
1375    return self.postproc(self.resp, self.content)
1376
1377
1378class RequestMockBuilder(object):
1379  """A simple mock of HttpRequest
1380
1381    Pass in a dictionary to the constructor that maps request methodIds to
1382    tuples of (httplib2.Response, content, opt_expected_body) that should be
1383    returned when that method is called. None may also be passed in for the
1384    httplib2.Response, in which case a 200 OK response will be generated.
1385    If an opt_expected_body (str or dict) is provided, it will be compared to
1386    the body and UnexpectedBodyError will be raised on inequality.
1387
1388    Example:
1389      response = '{"data": {"id": "tag:google.c...'
1390      requestBuilder = RequestMockBuilder(
1391        {
1392          'plus.activities.get': (None, response),
1393        }
1394      )
1395      googleapiclient.discovery.build("plus", "v1", requestBuilder=requestBuilder)
1396
1397    Methods that you do not supply a response for will return a
1398    200 OK with an empty string as the response content or raise an excpetion
1399    if check_unexpected is set to True. The methodId is taken from the rpcName
1400    in the discovery document.
1401
1402    For more details see the project wiki.
1403  """
1404
1405  def __init__(self, responses, check_unexpected=False):
1406    """Constructor for RequestMockBuilder
1407
1408    The constructed object should be a callable object
1409    that can replace the class HttpResponse.
1410
1411    responses - A dictionary that maps methodIds into tuples
1412                of (httplib2.Response, content). The methodId
1413                comes from the 'rpcName' field in the discovery
1414                document.
1415    check_unexpected - A boolean setting whether or not UnexpectedMethodError
1416                       should be raised on unsupplied method.
1417    """
1418    self.responses = responses
1419    self.check_unexpected = check_unexpected
1420
1421  def __call__(self, http, postproc, uri, method='GET', body=None,
1422               headers=None, methodId=None, resumable=None):
1423    """Implements the callable interface that discovery.build() expects
1424    of requestBuilder, which is to build an object compatible with
1425    HttpRequest.execute(). See that method for the description of the
1426    parameters and the expected response.
1427    """
1428    if methodId in self.responses:
1429      response = self.responses[methodId]
1430      resp, content = response[:2]
1431      if len(response) > 2:
1432        # Test the body against the supplied expected_body.
1433        expected_body = response[2]
1434        if bool(expected_body) != bool(body):
1435          # Not expecting a body and provided one
1436          # or expecting a body and not provided one.
1437          raise UnexpectedBodyError(expected_body, body)
1438        if isinstance(expected_body, str):
1439          expected_body = json.loads(expected_body)
1440        body = json.loads(body)
1441        if body != expected_body:
1442          raise UnexpectedBodyError(expected_body, body)
1443      return HttpRequestMock(resp, content, postproc)
1444    elif self.check_unexpected:
1445      raise UnexpectedMethodError(methodId=methodId)
1446    else:
1447      model = JsonModel(False)
1448      return HttpRequestMock(None, '{}', model.response)
1449
1450
1451class HttpMock(object):
1452  """Mock of httplib2.Http"""
1453
1454  def __init__(self, filename=None, headers=None):
1455    """
1456    Args:
1457      filename: string, absolute filename to read response from
1458      headers: dict, header to return with response
1459    """
1460    if headers is None:
1461      headers = {'status': '200 OK'}
1462    if filename:
1463      f = open(filename, 'r')
1464      self.data = f.read()
1465      f.close()
1466    else:
1467      self.data = None
1468    self.response_headers = headers
1469    self.headers = None
1470    self.uri = None
1471    self.method = None
1472    self.body = None
1473    self.headers = None
1474
1475
1476  def request(self, uri,
1477              method='GET',
1478              body=None,
1479              headers=None,
1480              redirections=1,
1481              connection_type=None):
1482    self.uri = uri
1483    self.method = method
1484    self.body = body
1485    self.headers = headers
1486    return httplib2.Response(self.response_headers), self.data
1487
1488
1489class HttpMockSequence(object):
1490  """Mock of httplib2.Http
1491
1492  Mocks a sequence of calls to request returning different responses for each
1493  call. Create an instance initialized with the desired response headers
1494  and content and then use as if an httplib2.Http instance.
1495
1496    http = HttpMockSequence([
1497      ({'status': '401'}, ''),
1498      ({'status': '200'}, '{"access_token":"1/3w","expires_in":3600}'),
1499      ({'status': '200'}, 'echo_request_headers'),
1500      ])
1501    resp, content = http.request("http://examples.com")
1502
1503  There are special values you can pass in for content to trigger
1504  behavours that are helpful in testing.
1505
1506  'echo_request_headers' means return the request headers in the response body
1507  'echo_request_headers_as_json' means return the request headers in
1508     the response body
1509  'echo_request_body' means return the request body in the response body
1510  'echo_request_uri' means return the request uri in the response body
1511  """
1512
1513  def __init__(self, iterable):
1514    """
1515    Args:
1516      iterable: iterable, a sequence of pairs of (headers, body)
1517    """
1518    self._iterable = iterable
1519    self.follow_redirects = True
1520
1521  def request(self, uri,
1522              method='GET',
1523              body=None,
1524              headers=None,
1525              redirections=1,
1526              connection_type=None):
1527    resp, content = self._iterable.pop(0)
1528    if content == 'echo_request_headers':
1529      content = headers
1530    elif content == 'echo_request_headers_as_json':
1531      content = json.dumps(headers)
1532    elif content == 'echo_request_body':
1533      if hasattr(body, 'read'):
1534        content = body.read()
1535      else:
1536        content = body
1537    elif content == 'echo_request_uri':
1538      content = uri
1539    return httplib2.Response(resp), content
1540
1541
1542def set_user_agent(http, user_agent):
1543  """Set the user-agent on every request.
1544
1545  Args:
1546     http - An instance of httplib2.Http
1547         or something that acts like it.
1548     user_agent: string, the value for the user-agent header.
1549
1550  Returns:
1551     A modified instance of http that was passed in.
1552
1553  Example:
1554
1555    h = httplib2.Http()
1556    h = set_user_agent(h, "my-app-name/6.0")
1557
1558  Most of the time the user-agent will be set doing auth, this is for the rare
1559  cases where you are accessing an unauthenticated endpoint.
1560  """
1561  request_orig = http.request
1562
1563  # The closure that will replace 'httplib2.Http.request'.
1564  def new_request(uri, method='GET', body=None, headers=None,
1565                  redirections=httplib2.DEFAULT_MAX_REDIRECTS,
1566                  connection_type=None):
1567    """Modify the request headers to add the user-agent."""
1568    if headers is None:
1569      headers = {}
1570    if 'user-agent' in headers:
1571      headers['user-agent'] = user_agent + ' ' + headers['user-agent']
1572    else:
1573      headers['user-agent'] = user_agent
1574    resp, content = request_orig(uri, method, body, headers,
1575                        redirections, connection_type)
1576    return resp, content
1577
1578  http.request = new_request
1579  return http
1580
1581
1582def tunnel_patch(http):
1583  """Tunnel PATCH requests over POST.
1584  Args:
1585     http - An instance of httplib2.Http
1586         or something that acts like it.
1587
1588  Returns:
1589     A modified instance of http that was passed in.
1590
1591  Example:
1592
1593    h = httplib2.Http()
1594    h = tunnel_patch(h, "my-app-name/6.0")
1595
1596  Useful if you are running on a platform that doesn't support PATCH.
1597  Apply this last if you are using OAuth 1.0, as changing the method
1598  will result in a different signature.
1599  """
1600  request_orig = http.request
1601
1602  # The closure that will replace 'httplib2.Http.request'.
1603  def new_request(uri, method='GET', body=None, headers=None,
1604                  redirections=httplib2.DEFAULT_MAX_REDIRECTS,
1605                  connection_type=None):
1606    """Modify the request headers to add the user-agent."""
1607    if headers is None:
1608      headers = {}
1609    if method == 'PATCH':
1610      if 'oauth_token' in headers.get('authorization', ''):
1611        logging.warning(
1612            'OAuth 1.0 request made with Credentials after tunnel_patch.')
1613      headers['x-http-method-override'] = "PATCH"
1614      method = 'POST'
1615    resp, content = request_orig(uri, method, body, headers,
1616                        redirections, connection_type)
1617    return resp, content
1618
1619  http.request = new_request
1620  return http
1621