Add google-endpoints to third_party/.

third_party/google-endpoints/apitools/base/py/transfer.py

+#!/usr/bin/env python
+#
+# Copyright 2015 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Upload and download support for apitools."""
+from __future__ import print_function
+
+import email.generator as email_generator
+import email.mime.multipart as mime_multipart
+import email.mime.nonmultipart as mime_nonmultipart
+import io
+import json
+import mimetypes
+import os
+import threading
+
+import six
+from six.moves import http_client
+
+from apitools.base.py import buffered_stream
+from apitools.base.py import exceptions
+from apitools.base.py import http_wrapper
+from apitools.base.py import stream_slice
+from apitools.base.py import util
+
+__all__ = [
+    'Download',
+    'Upload',
+    'RESUMABLE_UPLOAD',
+    'SIMPLE_UPLOAD',
+    'DownloadProgressPrinter',
+    'DownloadCompletePrinter',
+    'UploadProgressPrinter',
+    'UploadCompletePrinter',
+]
+
+_RESUMABLE_UPLOAD_THRESHOLD = 5 << 20
+SIMPLE_UPLOAD = 'simple'
+RESUMABLE_UPLOAD = 'resumable'
+
+
+def DownloadProgressPrinter(response, unused_download):
+    """Print download progress based on response."""
+    if 'content-range' in response.info:
+        print('Received %s' % response.info['content-range'])
+    else:
+        print('Received %d bytes' % response.length)
+
+
+def DownloadCompletePrinter(unused_response, unused_download):
+    """Print information about a completed download."""
+    print('Download complete')
+
+
+def UploadProgressPrinter(response, unused_upload):
+    """Print upload progress based on response."""
+    print('Sent %s' % response.info['range'])
+
+
+def UploadCompletePrinter(unused_response, unused_upload):
+    """Print information about a completed upload."""
+    print('Upload complete')
+
+
+class _Transfer(object):
+
+    """Generic bits common to Uploads and Downloads."""
+
+    def __init__(self, stream, close_stream=False, chunksize=None,
+                 auto_transfer=True, http=None, num_retries=5):
+        self.__bytes_http = None
+        self.__close_stream = close_stream
+        self.__http = http
+        self.__stream = stream
+        self.__url = None
+
+        self.__num_retries = 5
+        # Let the @property do validation
+        self.num_retries = num_retries
+
+        self.retry_func = (
+            http_wrapper.HandleExceptionsAndRebuildHttpConnections)
+        self.auto_transfer = auto_transfer
+        self.chunksize = chunksize or 1048576
+
+    def __repr__(self):
+        return str(self)
+
+    @property
+    def close_stream(self):
+        return self.__close_stream
+
+    @property
+    def http(self):
+        return self.__http
+
+    @property
+    def bytes_http(self):
+        return self.__bytes_http or self.http
+
+    @bytes_http.setter
+    def bytes_http(self, value):
+        self.__bytes_http = value
+
+    @property
+    def num_retries(self):
+        return self.__num_retries
+
+    @num_retries.setter
+    def num_retries(self, value):
+        util.Typecheck(value, six.integer_types)
+        if value < 0:
+            raise exceptions.InvalidDataError(
+                'Cannot have negative value for num_retries')
+        self.__num_retries = value
+
+    @property
+    def stream(self):
+        return self.__stream
+
+    @property
+    def url(self):
+        return self.__url
+
+    def _Initialize(self, http, url):
+        """Initialize this download by setting self.http and self.url.
+
+        We want the user to be able to override self.http by having set
+        the value in the constructor; in that case, we ignore the provided
+        http.
+
+        Args:
+          http: An httplib2.Http instance or None.
+          url: The url for this transfer.
+
+        Returns:
+          None. Initializes self.
+        """
+        self.EnsureUninitialized()
+        if self.http is None:
+            self.__http = http or http_wrapper.GetHttp()
+        self.__url = url
+
+    @property
+    def initialized(self):
+        return self.url is not None and self.http is not None
+
+    @property
+    def _type_name(self):
+        return type(self).__name__
+
+    def EnsureInitialized(self):
+        if not self.initialized:
+            raise exceptions.TransferInvalidError(
+                'Cannot use uninitialized %s', self._type_name)
+
+    def EnsureUninitialized(self):
+        if self.initialized:
+            raise exceptions.TransferInvalidError(
+                'Cannot re-initialize %s', self._type_name)
+
+    def __del__(self):
+        if self.__close_stream:
+            self.__stream.close()
+
+    def _ExecuteCallback(self, callback, response):
+        # TODO(craigcitro): Push these into a queue.
+        if callback is not None:
+            threading.Thread(target=callback, args=(response, self)).start()
+
+
+class Download(_Transfer):
+
+    """Data for a single download.
+
+    Public attributes:
+      chunksize: default chunksize to use for transfers.
+    """
+    _ACCEPTABLE_STATUSES = set((
+        http_client.OK,
+        http_client.NO_CONTENT,
+        http_client.PARTIAL_CONTENT,
+        http_client.REQUESTED_RANGE_NOT_SATISFIABLE,
+    ))
+    _REQUIRED_SERIALIZATION_KEYS = set((
+        'auto_transfer', 'progress', 'total_size', 'url'))
+
+    def __init__(self, stream, progress_callback=None, finish_callback=None,
+                 **kwds):
+        total_size = kwds.pop('total_size', None)
+        super(Download, self).__init__(stream, **kwds)
+        self.__initial_response = None
+        self.__progress = 0
+        self.__total_size = total_size
+        self.__encoding = None
+
+        self.progress_callback = progress_callback
+        self.finish_callback = finish_callback
+
+    @property
+    def progress(self):
+        return self.__progress
+
+    @property
+    def encoding(self):
+        return self.__encoding
+
+    @classmethod
+    def FromFile(cls, filename, overwrite=False, auto_transfer=True, **kwds):
+        """Create a new download object from a filename."""
+        path = os.path.expanduser(filename)
+        if os.path.exists(path) and not overwrite:
+            raise exceptions.InvalidUserInputError(
+                'File %s exists and overwrite not specified' % path)
+        return cls(open(path, 'wb'), close_stream=True,
+                   auto_transfer=auto_transfer, **kwds)
+
+    @classmethod
+    def FromStream(cls, stream, auto_transfer=True, total_size=None, **kwds):
+        """Create a new Download object from a stream."""
+        return cls(stream, auto_transfer=auto_transfer, total_size=total_size,
+                   **kwds)
+
+    @classmethod
+    def FromData(cls, stream, json_data, http=None, auto_transfer=None,
+                 **kwds):
+        """Create a new Download object from a stream and serialized data."""
+        info = json.loads(json_data)
+        missing_keys = cls._REQUIRED_SERIALIZATION_KEYS - set(info.keys())
+        if missing_keys:
+            raise exceptions.InvalidDataError(
+                'Invalid serialization data, missing keys: %s' % (
+                    ', '.join(missing_keys)))
+        download = cls.FromStream(stream, **kwds)
+        if auto_transfer is not None:
+            download.auto_transfer = auto_transfer
+        else:
+            download.auto_transfer = info['auto_transfer']
+        setattr(download, '_Download__progress', info['progress'])
+        setattr(download, '_Download__total_size', info['total_size'])
+        download._Initialize(  # pylint: disable=protected-access
+            http, info['url'])
+        return download
+
+    @property
+    def serialization_data(self):
+        self.EnsureInitialized()
+        return {
+            'auto_transfer': self.auto_transfer,
+            'progress': self.progress,
+            'total_size': self.total_size,
+            'url': self.url,
+        }
+
+    @property
+    def total_size(self):
+        return self.__total_size
+
+    def __str__(self):
+        if not self.initialized:
+            return 'Download (uninitialized)'
+        else:
+            return 'Download with %d/%s bytes transferred from url %s' % (
+                self.progress, self.total_size, self.url)
+
+    def ConfigureRequest(self, http_request, url_builder):
+        url_builder.query_params['alt'] = 'media'
+        # TODO(craigcitro): We need to send range requests because by
+        # default httplib2 stores entire reponses in memory. Override
+        # httplib2's download method (as gsutil does) so that this is not
+        # necessary.
+        http_request.headers['Range'] = 'bytes=0-%d' % (self.chunksize - 1,)
+
+    def __SetTotal(self, info):
+        if 'content-range' in info:
+            _, _, total = info['content-range'].rpartition('/')
+            if total != '*':
+                self.__total_size = int(total)
+        # Note "total_size is None" means we don't know it; if no size
+        # info was returned on our initial range request, that means we
+        # have a 0-byte file. (That last statement has been verified
+        # empirically, but is not clearly documented anywhere.)
+        if self.total_size is None:
+            self.__total_size = 0
+
+    def InitializeDownload(self, http_request, http=None, client=None):
+        """Initialize this download by making a request.
+
+        Args:
+          http_request: The HttpRequest to use to initialize this download.
+          http: The httplib2.Http instance for this request.
+          client: If provided, let this client process the final URL before
+              sending any additional requests. If client is provided and
+              http is not, client.http will be used instead.
+        """
+        self.EnsureUninitialized()
+        if http is None and client is None:
+            raise exceptions.UserError('Must provide client or http.')
+        http = http or client.http
+        if client is not None:
+            http_request.url = client.FinalizeTransferUrl(http_request.url)
+        url = http_request.url
+        if self.auto_transfer:
+            end_byte = self.__ComputeEndByte(0)
+            self.__SetRangeHeader(http_request, 0, end_byte)
+            response = http_wrapper.MakeRequest(
+                self.bytes_http or http, http_request)
+            if response.status_code not in self._ACCEPTABLE_STATUSES:
+                raise exceptions.HttpError.FromResponse(response)
+            self.__initial_response = response
+            self.__SetTotal(response.info)
+            url = response.info.get('content-location', response.request_url)
+        if client is not None:
+            url = client.FinalizeTransferUrl(url)
+        self._Initialize(http, url)
+        # Unless the user has requested otherwise, we want to just
+        # go ahead and pump the bytes now.
+        if self.auto_transfer:
+            self.StreamInChunks()
+
+    def __NormalizeStartEnd(self, start, end=None):
+        if end is not None:
+            if start < 0:
+                raise exceptions.TransferInvalidError(
+                    'Cannot have end index with negative start index')
+            elif start >= self.total_size:
+                raise exceptions.TransferInvalidError(
+                    'Cannot have start index greater than total size')
+            end = min(end, self.total_size - 1)
+            if end < start:
+                raise exceptions.TransferInvalidError(
+                    'Range requested with end[%s] < start[%s]' % (end, start))
+            return start, end
+        else:
+            if start < 0:
+                start = max(0, start + self.total_size)
+            return start, self.total_size - 1
+
+    def __SetRangeHeader(self, request, start, end=None):
+        if start < 0:
+            request.headers['range'] = 'bytes=%d' % start
+        elif end is None:
+            request.headers['range'] = 'bytes=%d-' % start
+        else:
+            request.headers['range'] = 'bytes=%d-%d' % (start, end)
+
+    def __ComputeEndByte(self, start, end=None, use_chunks=True):
+        """Compute the last byte to fetch for this request.
+
+        This is all based on the HTTP spec for Range and
+        Content-Range.
+
+        Note that this is potentially confusing in several ways:
+          * the value for the last byte is 0-based, eg "fetch 10 bytes
+            from the beginning" would return 9 here.
+          * if we have no information about size, and don't want to
+            use the chunksize, we'll return None.
+        See the tests for more examples.
+
+        Args:
+          start: byte to start at.
+          end: (int or None, default: None) Suggested last byte.
+          use_chunks: (bool, default: True) If False, ignore self.chunksize.
+
+        Returns:
+          Last byte to use in a Range header, or None.
+
+        """
+        end_byte = end
+
+        if start < 0 and not self.total_size:
+            return end_byte
+
+        if use_chunks:
+            alternate = start + self.chunksize - 1
+            if end_byte is not None:
+                end_byte = min(end_byte, alternate)
+            else:
+                end_byte = alternate
+
+        if self.total_size:
+            alternate = self.total_size - 1
+            if end_byte is not None:
+                end_byte = min(end_byte, alternate)
+            else:
+                end_byte = alternate
+
+        return end_byte
+
+    def __GetChunk(self, start, end, additional_headers=None):
+        """Retrieve a chunk, and return the full response."""
+        self.EnsureInitialized()
+        request = http_wrapper.Request(url=self.url)
+        self.__SetRangeHeader(request, start, end=end)
+        if additional_headers is not None:
+            request.headers.update(additional_headers)
+        return http_wrapper.MakeRequest(
+            self.bytes_http, request, retry_func=self.retry_func,
+            retries=self.num_retries)
+
+    def __ProcessResponse(self, response):
+        """Process response (by updating self and writing to self.stream)."""
+        if response.status_code not in self._ACCEPTABLE_STATUSES:
+            # We distinguish errors that mean we made a mistake in setting
+            # up the transfer versus something we should attempt again.
+            if response.status_code in (http_client.FORBIDDEN,
+                                        http_client.NOT_FOUND):
+                raise exceptions.HttpError.FromResponse(response)
+            else:
+                raise exceptions.TransferRetryError(response.content)
+        if response.status_code in (http_client.OK,
+                                    http_client.PARTIAL_CONTENT):
+            self.stream.write(response.content)
+            self.__progress += response.length
+            if response.info and 'content-encoding' in response.info:
+                # TODO(craigcitro): Handle the case where this changes over a
+                # download.
+                self.__encoding = response.info['content-encoding']
+        elif response.status_code == http_client.NO_CONTENT:
+            # It's important to write something to the stream for the case
+            # of a 0-byte download to a file, as otherwise python won't
+            # create the file.
+            self.stream.write('')
+        return response
+
+    def GetRange(self, start, end=None, additional_headers=None,
+                 use_chunks=True):
+        """Retrieve a given byte range from this download, inclusive.
+
+        Range must be of one of these three forms:
+        * 0 <= start, end = None: Fetch from start to the end of the file.
+        * 0 <= start <= end: Fetch the bytes from start to end.
+        * start < 0, end = None: Fetch the last -start bytes of the file.
+
+        (These variations correspond to those described in the HTTP 1.1
+        protocol for range headers in RFC 2616, sec. 14.35.1.)
+
+        Args:
+          start: (int) Where to start fetching bytes. (See above.)
+          end: (int, optional) Where to stop fetching bytes. (See above.)
+          additional_headers: (bool, optional) Any additional headers to
+              pass with the request.
+          use_chunks: (bool, default: True) If False, ignore self.chunksize
+              and fetch this range in a single request.
+
+        Returns:
+          None. Streams bytes into self.stream.
+        """
+        self.EnsureInitialized()
+        progress_end_normalized = False
+        if self.total_size is not None:
+            progress, end_byte = self.__NormalizeStartEnd(start, end)
+            progress_end_normalized = True
+        else:
+            progress = start
+            end_byte = end
+        while (not progress_end_normalized or end_byte is None or
+               progress <= end_byte):
+            end_byte = self.__ComputeEndByte(progress, end=end_byte,
+                                             use_chunks=use_chunks)
+            response = self.__GetChunk(progress, end_byte,
+                                       additional_headers=additional_headers)
+            if not progress_end_normalized:
+                self.__SetTotal(response.info)
+                progress, end_byte = self.__NormalizeStartEnd(start, end)
+                progress_end_normalized = True
+            response = self.__ProcessResponse(response)
+            progress += response.length
+            if response.length == 0:
+                raise exceptions.TransferRetryError(
+                    'Zero bytes unexpectedly returned in download response')
+
+    def StreamInChunks(self, callback=None, finish_callback=None,
+                       additional_headers=None):
+        """Stream the entire download in chunks."""
+        self.StreamMedia(callback=callback, finish_callback=finish_callback,
+                         additional_headers=additional_headers,
+                         use_chunks=True)
+
+    def StreamMedia(self, callback=None, finish_callback=None,
+                    additional_headers=None, use_chunks=True):
+        """Stream the entire download.
+
+        Args:
+          callback: (default: None) Callback to call as each chunk is
+              completed.
+          finish_callback: (default: None) Callback to call when the
+              download is complete.
+          additional_headers: (default: None) Additional headers to
+              include in fetching bytes.
+          use_chunks: (bool, default: True) If False, ignore self.chunksize
+              and stream this download in a single request.
+
+        Returns:
+            None. Streams bytes into self.stream.
+        """
+        callback = callback or self.progress_callback
+        finish_callback = finish_callback or self.finish_callback
+
+        self.EnsureInitialized()
+        while True:
+            if self.__initial_response is not None:
+                response = self.__initial_response
+                self.__initial_response = None
+            else:
+                end_byte = self.__ComputeEndByte(self.progress,
+                                                 use_chunks=use_chunks)
+                response = self.__GetChunk(
+                    self.progress, end_byte,
+                    additional_headers=additional_headers)
+            if self.total_size is None:
+                self.__SetTotal(response.info)
+            response = self.__ProcessResponse(response)
+            self._ExecuteCallback(callback, response)
+            if (response.status_code == http_client.OK or
+                    self.progress >= self.total_size):
+                break
+        self._ExecuteCallback(finish_callback, response)
+
+
+class Upload(_Transfer):
+
+    """Data for a single Upload.
+
+    Fields:
+      stream: The stream to upload.
+      mime_type: MIME type of the upload.
+      total_size: (optional) Total upload size for the stream.
+      close_stream: (default: False) Whether or not we should close the
+          stream when finished with the upload.
+      auto_transfer: (default: True) If True, stream all bytes as soon as
+          the upload is created.
+    """
+    _REQUIRED_SERIALIZATION_KEYS = set((
+        'auto_transfer', 'mime_type', 'total_size', 'url'))
+
+    def __init__(self, stream, mime_type, total_size=None, http=None,
+                 close_stream=False, chunksize=None, auto_transfer=True,
+                 progress_callback=None, finish_callback=None,
+                 **kwds):
+        super(Upload, self).__init__(
+            stream, close_stream=close_stream, chunksize=chunksize,
+            auto_transfer=auto_transfer, http=http, **kwds)
+        self.__complete = False
+        self.__final_response = None
+        self.__mime_type = mime_type
+        self.__progress = 0
+        self.__server_chunk_granularity = None
+        self.__strategy = None
+        self.__total_size = None
+
+        self.progress_callback = progress_callback
+        self.finish_callback = finish_callback
+        self.total_size = total_size
+
+    @property
+    def progress(self):
+        return self.__progress
+
+    @classmethod
+    def FromFile(cls, filename, mime_type=None, auto_transfer=True, **kwds):
+        """Create a new Upload object from a filename."""
+        path = os.path.expanduser(filename)
+        if not os.path.exists(path):
+            raise exceptions.NotFoundError('Could not find file %s' % path)
+        if not mime_type:
+            mime_type, _ = mimetypes.guess_type(path)
+            if mime_type is None:
+                raise exceptions.InvalidUserInputError(
+                    'Could not guess mime type for %s' % path)
+        size = os.stat(path).st_size
+        return cls(open(path, 'rb'), mime_type, total_size=size,
+                   close_stream=True, auto_transfer=auto_transfer, **kwds)
+
+    @classmethod
+    def FromStream(cls, stream, mime_type, total_size=None, auto_transfer=True,
+                   **kwds):
+        """Create a new Upload object from a stream."""
+        if mime_type is None:
+            raise exceptions.InvalidUserInputError(
+                'No mime_type specified for stream')
+        return cls(stream, mime_type, total_size=total_size,
+                   close_stream=False, auto_transfer=auto_transfer, **kwds)
+
+    @classmethod
+    def FromData(cls, stream, json_data, http, auto_transfer=None, **kwds):
+        """Create a new Upload of stream from serialized json_data and http."""
+        info = json.loads(json_data)
+        missing_keys = cls._REQUIRED_SERIALIZATION_KEYS - set(info.keys())
+        if missing_keys:
+            raise exceptions.InvalidDataError(
+                'Invalid serialization data, missing keys: %s' % (
+                    ', '.join(missing_keys)))
+        if 'total_size' in kwds:
+            raise exceptions.InvalidUserInputError(
+                'Cannot override total_size on serialized Upload')
+        upload = cls.FromStream(stream, info['mime_type'],
+                                total_size=info.get('total_size'), **kwds)
+        if isinstance(stream, io.IOBase) and not stream.seekable():
+            raise exceptions.InvalidUserInputError(
+                'Cannot restart resumable upload on non-seekable stream')
+        if auto_transfer is not None:
+            upload.auto_transfer = auto_transfer
+        else:
+            upload.auto_transfer = info['auto_transfer']
+        upload.strategy = RESUMABLE_UPLOAD
+        upload._Initialize(  # pylint: disable=protected-access
+            http, info['url'])
+        upload.RefreshResumableUploadState()
+        upload.EnsureInitialized()
+        if upload.auto_transfer:
+            upload.StreamInChunks()
+        return upload
+
+    @property
+    def serialization_data(self):
+        self.EnsureInitialized()
+        if self.strategy != RESUMABLE_UPLOAD:
+            raise exceptions.InvalidDataError(
+                'Serialization only supported for resumable uploads')
+        return {
+            'auto_transfer': self.auto_transfer,
+            'mime_type': self.mime_type,
+            'total_size': self.total_size,
+            'url': self.url,
+        }
+
+    @property
+    def complete(self):
+        return self.__complete
+
+    @property
+    def mime_type(self):
+        return self.__mime_type
+
+    def __str__(self):
+        if not self.initialized:
+            return 'Upload (uninitialized)'
+        else:
+            return 'Upload with %d/%s bytes transferred for url %s' % (
+                self.progress, self.total_size or '???', self.url)
+
+    @property
+    def strategy(self):
+        return self.__strategy
+
+    @strategy.setter
+    def strategy(self, value):
+        if value not in (SIMPLE_UPLOAD, RESUMABLE_UPLOAD):
+            raise exceptions.UserError((
+                'Invalid value "%s" for upload strategy, must be one of '
+                '"simple" or "resumable".') % value)
+        self.__strategy = value
+
+    @property
+    def total_size(self):
+        return self.__total_size
+
+    @total_size.setter
+    def total_size(self, value):
+        self.EnsureUninitialized()
+        self.__total_size = value
+
+    def __SetDefaultUploadStrategy(self, upload_config, http_request):
+        """Determine and set the default upload strategy for this upload.
+
+        We generally prefer simple or multipart, unless we're forced to
+        use resumable. This happens when any of (1) the upload is too
+        large, (2) the simple endpoint doesn't support multipart requests
+        and we have metadata, or (3) there is no simple upload endpoint.
+
+        Args:
+          upload_config: Configuration for the upload endpoint.
+          http_request: The associated http request.
+
+        Returns:
+          None.
+        """
+        if upload_config.resumable_path is None:
+            self.strategy = SIMPLE_UPLOAD
+        if self.strategy is not None:
+            return
+        strategy = SIMPLE_UPLOAD
+        if (self.total_size is not None and
+                self.total_size > _RESUMABLE_UPLOAD_THRESHOLD):
+            strategy = RESUMABLE_UPLOAD
+        if http_request.body and not upload_config.simple_multipart:
+            strategy = RESUMABLE_UPLOAD
+        if not upload_config.simple_path:
+            strategy = RESUMABLE_UPLOAD
+        self.strategy = strategy
+
+    def ConfigureRequest(self, upload_config, http_request, url_builder):
+        """Configure the request and url for this upload."""
+        # Validate total_size vs. max_size
+        if (self.total_size and upload_config.max_size and
+                self.total_size > upload_config.max_size):
+            raise exceptions.InvalidUserInputError(
+                'Upload too big: %s larger than max size %s' % (
+                    self.total_size, upload_config.max_size))
+        # Validate mime type
+        if not util.AcceptableMimeType(upload_config.accept, self.mime_type):
+            raise exceptions.InvalidUserInputError(
+                'MIME type %s does not match any accepted MIME ranges %s' % (
+                    self.mime_type, upload_config.accept))
+
+        self.__SetDefaultUploadStrategy(upload_config, http_request)
+        if self.strategy == SIMPLE_UPLOAD:
+            url_builder.relative_path = upload_config.simple_path
+            if http_request.body:
+                url_builder.query_params['uploadType'] = 'multipart'
+                self.__ConfigureMultipartRequest(http_request)
+            else:
+                url_builder.query_params['uploadType'] = 'media'
+                self.__ConfigureMediaRequest(http_request)
+        else:
+            url_builder.relative_path = upload_config.resumable_path
+            url_builder.query_params['uploadType'] = 'resumable'
+            self.__ConfigureResumableRequest(http_request)
+
+    def __ConfigureMediaRequest(self, http_request):
+        """Configure http_request as a simple request for this upload."""
+        http_request.headers['content-type'] = self.mime_type
+        http_request.body = self.stream.read()
+        http_request.loggable_body = '<media body>'
+
+    def __ConfigureMultipartRequest(self, http_request):
+        """Configure http_request as a multipart request for this upload."""
+        # This is a multipart/related upload.
+        msg_root = mime_multipart.MIMEMultipart('related')
+        # msg_root should not write out its own headers
+        setattr(msg_root, '_write_headers', lambda self: None)
+
+        # attach the body as one part
+        msg = mime_nonmultipart.MIMENonMultipart(
+            *http_request.headers['content-type'].split('/'))
+        msg.set_payload(http_request.body)
+        msg_root.attach(msg)
+
+        # attach the media as the second part
+        msg = mime_nonmultipart.MIMENonMultipart(*self.mime_type.split('/'))
+        msg['Content-Transfer-Encoding'] = 'binary'
+        msg.set_payload(self.stream.read())
+        msg_root.attach(msg)
+
+        # NOTE: We encode the body, but can't use
+        #       `email.message.Message.as_string` because it prepends
+        #       `> ` to `From ` lines.
+        # NOTE: We must use six.StringIO() instead of io.StringIO() since the
+        #       `email` library uses cStringIO in Py2 and io.StringIO in Py3.
+        fp = six.StringIO()
+        g = email_generator.Generator(fp, mangle_from_=False)
+        g.flatten(msg_root, unixfrom=False)
+        http_request.body = fp.getvalue()
+
+        multipart_boundary = msg_root.get_boundary()
+        http_request.headers['content-type'] = (
+            'multipart/related; boundary=%r' % multipart_boundary)
+
+        body_components = http_request.body.split(multipart_boundary)
+        headers, _, _ = body_components[-2].partition('\n\n')
+        body_components[-2] = '\n\n'.join([headers, '<media body>\n\n--'])
+        http_request.loggable_body = multipart_boundary.join(body_components)
+
+    def __ConfigureResumableRequest(self, http_request):
+        http_request.headers['X-Upload-Content-Type'] = self.mime_type
+        if self.total_size is not None:
+            http_request.headers[
+                'X-Upload-Content-Length'] = str(self.total_size)
+
+    def RefreshResumableUploadState(self):
+        """Talk to the server and refresh the state of this resumable upload.
+
+        Returns:
+          Response if the upload is complete.
+        """
+        if self.strategy != RESUMABLE_UPLOAD:
+            return
+        self.EnsureInitialized()
+        refresh_request = http_wrapper.Request(
+            url=self.url, http_method='PUT',
+            headers={'Content-Range': 'bytes */*'})
+        refresh_response = http_wrapper.MakeRequest(
+            self.http, refresh_request, redirections=0,
+            retries=self.num_retries)
+        range_header = self._GetRangeHeaderFromResponse(refresh_response)
+        if refresh_response.status_code in (http_client.OK,
+                                            http_client.CREATED):
+            self.__complete = True
+            self.__progress = self.total_size
+            self.stream.seek(self.progress)
+            # If we're finished, the refresh response will contain the metadata
+            # originally requested. Cache it so it can be returned in
+            # StreamInChunks.
+            self.__final_response = refresh_response
+        elif refresh_response.status_code == http_wrapper.RESUME_INCOMPLETE:
+            if range_header is None:
+                self.__progress = 0
+            else:
+                self.__progress = self.__GetLastByte(range_header) + 1
+            self.stream.seek(self.progress)
+        else:
+            raise exceptions.HttpError.FromResponse(refresh_response)
+
+    def _GetRangeHeaderFromResponse(self, response):
+        return response.info.get('Range', response.info.get('range'))
+
+    def InitializeUpload(self, http_request, http=None, client=None):
+        """Initialize this upload from the given http_request."""
+        if self.strategy is None:
+            raise exceptions.UserError(
+                'No upload strategy set; did you call ConfigureRequest?')
+        if http is None and client is None:
+            raise exceptions.UserError('Must provide client or http.')
+        if self.strategy != RESUMABLE_UPLOAD:
+            return
+        http = http or client.http
+        if client is not None:
+            http_request.url = client.FinalizeTransferUrl(http_request.url)
+        self.EnsureUninitialized()
+        http_response = http_wrapper.MakeRequest(http, http_request,
+                                                 retries=self.num_retries)
+        if http_response.status_code != http_client.OK:
+            raise exceptions.HttpError.FromResponse(http_response)
+
+        self.__server_chunk_granularity = http_response.info.get(
+            'X-Goog-Upload-Chunk-Granularity')
+        url = http_response.info['location']
+        if client is not None:
+            url = client.FinalizeTransferUrl(url)
+        self._Initialize(http, url)
+
+        # Unless the user has requested otherwise, we want to just
+        # go ahead and pump the bytes now.
+        if self.auto_transfer:
+            return self.StreamInChunks()
+        else:
+            return http_response
+
+    def __GetLastByte(self, range_header):
+        _, _, end = range_header.partition('-')
+        # TODO(craigcitro): Validate start == 0?
+        return int(end)
+
+    def __ValidateChunksize(self, chunksize=None):
+        if self.__server_chunk_granularity is None:
+            return
+        chunksize = chunksize or self.chunksize
+        if chunksize % self.__server_chunk_granularity:
+            raise exceptions.ConfigurationValueError(
+                'Server requires chunksize to be a multiple of %d',
+                self.__server_chunk_granularity)
+
+    def __StreamMedia(self, callback=None, finish_callback=None,
+                      additional_headers=None, use_chunks=True):
+        """Helper function for StreamMedia / StreamInChunks."""
+        if self.strategy != RESUMABLE_UPLOAD:
+            raise exceptions.InvalidUserInputError(
+                'Cannot stream non-resumable upload')
+        callback = callback or self.progress_callback
+        finish_callback = finish_callback or self.finish_callback
+        # final_response is set if we resumed an already-completed upload.
+        response = self.__final_response
+        send_func = self.__SendChunk if use_chunks else self.__SendMediaBody
+        if use_chunks:
+            self.__ValidateChunksize(self.chunksize)
+        self.EnsureInitialized()
+        while not self.complete:
+            response = send_func(self.stream.tell(),
+                                 additional_headers=additional_headers)
+            if response.status_code in (http_client.OK, http_client.CREATED):
+                self.__complete = True
+                break
+            self.__progress = self.__GetLastByte(response.info['range'])
+            if self.progress + 1 != self.stream.tell():
+                # TODO(craigcitro): Add a better way to recover here.
+                raise exceptions.CommunicationError(
+                    'Failed to transfer all bytes in chunk, upload paused at '
+                    'byte %d' % self.progress)
+            self._ExecuteCallback(callback, response)
+        if self.__complete and hasattr(self.stream, 'seek'):
+            current_pos = self.stream.tell()
+            self.stream.seek(0, os.SEEK_END)
+            end_pos = self.stream.tell()
+            self.stream.seek(current_pos)
+            if current_pos != end_pos:
+                raise exceptions.TransferInvalidError(
+                    'Upload complete with %s additional bytes left in stream' %
+                    (int(end_pos) - int(current_pos)))
+        self._ExecuteCallback(finish_callback, response)
+        return response
+
+    def StreamMedia(self, callback=None, finish_callback=None,
+                    additional_headers=None):
+        """Send this resumable upload in a single request.
+
+        Args:
+          callback: Progress callback function with inputs
+              (http_wrapper.Response, transfer.Upload)
+          finish_callback: Final callback function with inputs
+              (http_wrapper.Response, transfer.Upload)
+          additional_headers: Dict of headers to include with the upload
+              http_wrapper.Request.
+
+        Returns:
+          http_wrapper.Response of final response.
+        """
+        return self.__StreamMedia(
+            callback=callback, finish_callback=finish_callback,
+            additional_headers=additional_headers, use_chunks=False)
+
+    def StreamInChunks(self, callback=None, finish_callback=None,
+                       additional_headers=None):
+        """Send this (resumable) upload in chunks."""
+        return self.__StreamMedia(
+            callback=callback, finish_callback=finish_callback,
+            additional_headers=additional_headers)
+
+    def __SendMediaRequest(self, request, end):
+        """Request helper function for SendMediaBody & SendChunk."""
+        response = http_wrapper.MakeRequest(
+            self.bytes_http, request, retry_func=self.retry_func,
+            retries=self.num_retries)
+        if response.status_code not in (http_client.OK, http_client.CREATED,
+                                        http_wrapper.RESUME_INCOMPLETE):
+            # We want to reset our state to wherever the server left us
+            # before this failed request, and then raise.
+            self.RefreshResumableUploadState()
+            raise exceptions.HttpError.FromResponse(response)
+        if response.status_code == http_wrapper.RESUME_INCOMPLETE:
+            last_byte = self.__GetLastByte(
+                self._GetRangeHeaderFromResponse(response))
+            if last_byte + 1 != end:
+                self.stream.seek(last_byte)
+        return response
+
+    def __SendMediaBody(self, start, additional_headers=None):
+        """Send the entire media stream in a single request."""
+        self.EnsureInitialized()
+        if self.total_size is None:
+            raise exceptions.TransferInvalidError(
+                'Total size must be known for SendMediaBody')
+        body_stream = stream_slice.StreamSlice(
+            self.stream, self.total_size - start)
+
+        request = http_wrapper.Request(url=self.url, http_method='PUT',
+                                       body=body_stream)
+        request.headers['Content-Type'] = self.mime_type
+        if start == self.total_size:
+            # End of an upload with 0 bytes left to send; just finalize.
+            range_string = 'bytes */%s' % self.total_size
+        else:
+            range_string = 'bytes %s-%s/%s' % (start, self.total_size - 1,
+                                               self.total_size)
+
+        request.headers['Content-Range'] = range_string
+        if additional_headers:
+            request.headers.update(additional_headers)
+
+        return self.__SendMediaRequest(request, self.total_size)
+
+    def __SendChunk(self, start, additional_headers=None):
+        """Send the specified chunk."""
+        self.EnsureInitialized()
+        no_log_body = self.total_size is None
+        if self.total_size is None:
+            # For the streaming resumable case, we need to detect when
+            # we're at the end of the stream.
+            body_stream = buffered_stream.BufferedStream(
+                self.stream, start, self.chunksize)
+            end = body_stream.stream_end_position
+            if body_stream.stream_exhausted:
+                self.__total_size = end
+            # TODO: Here, change body_stream from a stream to a string object,
+            # which means reading a chunk into memory.  This works around
+            # https://code.google.com/p/httplib2/issues/detail?id=176 which can
+            # cause httplib2 to skip bytes on 401's for file objects.
+            # Rework this solution to be more general.
+            # pylint: disable=redefined-variable-type
+            body_stream = body_stream.read(self.chunksize)
+        else:
+            end = min(start + self.chunksize, self.total_size)
+            body_stream = stream_slice.StreamSlice(self.stream, end - start)
+        # TODO(craigcitro): Think about clearer errors on "no data in
+        # stream".
+        request = http_wrapper.Request(url=self.url, http_method='PUT',
+                                       body=body_stream)
+        request.headers['Content-Type'] = self.mime_type
+        if no_log_body:
+            # Disable logging of streaming body.
+            # TODO: Remove no_log_body and rework as part of a larger logs
+            # refactor.
+            request.loggable_body = '<media body>'
+        if self.total_size is None:
+            # Streaming resumable upload case, unknown total size.
+            range_string = 'bytes %s-%s/*' % (start, end - 1)
+        elif end == start:
+            # End of an upload with 0 bytes left to send; just finalize.
+            range_string = 'bytes */%s' % self.total_size
+        else:
+            # Normal resumable upload case with known sizes.
+            range_string = 'bytes %s-%s/%s' % (start, end - 1, self.total_size)
+
+        request.headers['Content-Range'] = range_string
+        if additional_headers:
+            request.headers.update(additional_headers)
+
+        return self.__SendMediaRequest(request, end)