Update checked in version of gsutil to version 4.6

gslib/boto_translation.py

+# -*- coding: utf-8 -*-
+# Copyright 2013 Google Inc. All Rights Reserved.
+#
+# 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.
+"""XML/boto gsutil Cloud API implementation for GCS and Amazon S3."""
+
+from __future__ import absolute_import
+
+import base64
+import binascii
+import datetime
+import errno
+import httplib
+import json
+import multiprocessing
+import os
+import pickle
+import random
+import re
+import socket
+import tempfile
+import textwrap
+import time
+import xml
+from xml.dom.minidom import parseString as XmlParseString
+from xml.sax import _exceptions as SaxExceptions
+
+import boto
+from boto import handler
+from boto.exception import ResumableDownloadException as BotoResumableDownloadException
+from boto.exception import ResumableTransferDisposition
+from boto.gs.cors import Cors
+from boto.gs.lifecycle import LifecycleConfig
+from boto.s3.deletemarker import DeleteMarker
+from boto.s3.prefix import Prefix
+
+from gslib.boto_resumable_upload import BotoResumableUpload
+from gslib.cloud_api import AccessDeniedException
+from gslib.cloud_api import ArgumentException
+from gslib.cloud_api import BadRequestException
+from gslib.cloud_api import CloudApi
+from gslib.cloud_api import NotEmptyException
+from gslib.cloud_api import NotFoundException
+from gslib.cloud_api import PreconditionException
+from gslib.cloud_api import ResumableDownloadException
+from gslib.cloud_api import ResumableUploadAbortException
+from gslib.cloud_api import ResumableUploadException
+from gslib.cloud_api import ServiceException
+from gslib.cloud_api_helper import ValidateDstObjectMetadata
+from gslib.exception import CommandException
+from gslib.exception import InvalidUrlError
+from gslib.project_id import GOOG_PROJ_ID_HDR
+from gslib.project_id import PopulateProjectId
+from gslib.storage_url import StorageUrlFromString
+from gslib.third_party.storage_apitools import storage_v1_messages as apitools_messages
+from gslib.translation_helper import AclTranslation
+from gslib.translation_helper import AddS3MarkerAclToObjectMetadata
+from gslib.translation_helper import CorsTranslation
+from gslib.translation_helper import CreateBucketNotFoundException
+from gslib.translation_helper import CreateObjectNotFoundException
+from gslib.translation_helper import DEFAULT_CONTENT_TYPE
+from gslib.translation_helper import EncodeStringAsLong
+from gslib.translation_helper import GenerationFromUrlAndString
+from gslib.translation_helper import HeadersFromObjectMetadata
+from gslib.translation_helper import LifecycleTranslation
+from gslib.translation_helper import REMOVE_CORS_CONFIG
+from gslib.translation_helper import S3MarkerAclFromObjectMetadata
+from gslib.util import ConfigureNoOpAuthIfNeeded
+from gslib.util import DEFAULT_FILE_BUFFER_SIZE
+from gslib.util import GetFileSize
+from gslib.util import GetMaxRetryDelay
+from gslib.util import GetNumRetries
+from gslib.util import MultiprocessingIsAvailable
+from gslib.util import S3_DELETE_MARKER_GUID
+from gslib.util import TWO_MB
+from gslib.util import UnaryDictToXml
+from gslib.util import UTF8
+from gslib.util import XML_PROGRESS_CALLBACKS
+
+TRANSLATABLE_BOTO_EXCEPTIONS = (boto.exception.BotoServerError,
+                                boto.exception.InvalidUriError,
+                                boto.exception.ResumableDownloadException,
+                                boto.exception.ResumableUploadException,
+                                boto.exception.StorageCreateError,
+                                boto.exception.StorageResponseError)
+
+# If multiprocessing is available, this will be overridden to a (thread-safe)
+# multiprocessing.Value in a call to InitializeMultiprocessingVariables.
+boto_auth_initialized = False
+
+NON_EXISTENT_OBJECT_REGEX = re.compile(r'.*non-\s*existent\s*object',
+                                       flags=re.DOTALL)
+# Determines whether an etag is a valid MD5.
+MD5_REGEX = re.compile(r'^"*[a-fA-F0-9]{32}"*$')
+
+
+def InitializeMultiprocessingVariables():
+  """Perform necessary initialization for multiprocessing.
+
+    See gslib.command.InitializeMultiprocessingVariables for an explanation
+    of why this is necessary.
+  """
+  global boto_auth_initialized  # pylint: disable=global-variable-undefined
+  boto_auth_initialized = multiprocessing.Value('i', 0)
+
+
+class BotoTranslation(CloudApi):
+  """Boto-based XML translation implementation of gsutil Cloud API.
+
+  This class takes gsutil Cloud API objects, translates them to XML service
+  calls, and translates the results back into gsutil Cloud API objects for
+  use by the caller.
+  """
+
+  def __init__(self, bucket_storage_uri_class, logger, provider=None,
+               credentials=None, debug=0):
+    """Performs necessary setup for interacting with the cloud storage provider.
+
+    Args:
+      bucket_storage_uri_class: boto storage_uri class, used by APIs that
+                                provide boto translation or mocking.
+      logger: logging.logger for outputting log messages.
+      provider: Provider prefix describing cloud storage provider to connect to.
+                'gs' and 's3' are supported. Function implementations ignore
+                the provider argument and use this one instead.
+      credentials: Unused.
+      debug: Debug level for the API implementation (0..3).
+    """
+    super(BotoTranslation, self).__init__(bucket_storage_uri_class, logger,
+                                          provider=provider, debug=debug)
+    _ = credentials
+    global boto_auth_initialized  # pylint: disable=global-variable-undefined
+    if MultiprocessingIsAvailable()[0] and not boto_auth_initialized.value:
+      ConfigureNoOpAuthIfNeeded()
+      boto_auth_initialized.value = 1
+    elif not boto_auth_initialized:
+      ConfigureNoOpAuthIfNeeded()
+      boto_auth_initialized = True
+    self.api_version = boto.config.get_value(
+        'GSUtil', 'default_api_version', '1')
+
+  def GetBucket(self, bucket_name, provider=None, fields=None):
+    """See CloudApi class for function doc strings."""
+    _ = provider
+    bucket_uri = self._StorageUriForBucket(bucket_name)
+    headers = {}
+    self._AddApiVersionToHeaders(headers)
+    try:
+      return self._BotoBucketToBucket(bucket_uri.get_bucket(validate=True,
+                                                            headers=headers),
+                                      fields=fields)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, bucket_name=bucket_name)
+
+  def ListBuckets(self, project_id=None, provider=None, fields=None):
+    """See CloudApi class for function doc strings."""
+    _ = provider
+    get_fields = self._ListToGetFields(list_fields=fields)
+    headers = {}
+    self._AddApiVersionToHeaders(headers)
+    if self.provider == 'gs':
+      headers[GOOG_PROJ_ID_HDR] = PopulateProjectId(project_id)
+    try:
+      provider_uri = boto.storage_uri(
+          '%s://' % self.provider,
+          suppress_consec_slashes=False,
+          bucket_storage_uri_class=self.bucket_storage_uri_class,
+          debug=self.debug)
+
+      buckets_iter = provider_uri.get_all_buckets(headers=headers)
+      for bucket in buckets_iter:
+        if self.provider == 's3' and bucket.name.lower() != bucket.name:
+          # S3 listings can return buckets with upper-case names, but boto
+          # can't successfully call them.
+          continue
+        yield self._BotoBucketToBucket(bucket, fields=get_fields)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e)
+
+  def PatchBucket(self, bucket_name, metadata, preconditions=None,
+                  provider=None, fields=None):
+    """See CloudApi class for function doc strings."""
+    _ = provider
+    bucket_uri = self._StorageUriForBucket(bucket_name)
+    headers = {}
+    self._AddApiVersionToHeaders(headers)
+    try:
+      self._AddPreconditionsToHeaders(preconditions, headers)
+      if metadata.acl:
+        boto_acl = AclTranslation.BotoAclFromMessage(metadata.acl)
+        bucket_uri.set_xml_acl(boto_acl.to_xml(), headers=headers)
+      if metadata.cors:
+        if metadata.cors == REMOVE_CORS_CONFIG:
+          metadata.cors = []
+        boto_cors = CorsTranslation.BotoCorsFromMessage(metadata.cors)
+        bucket_uri.set_cors(boto_cors, False)
+      if metadata.defaultObjectAcl:
+        boto_acl = AclTranslation.BotoAclFromMessage(
+            metadata.defaultObjectAcl)
+        bucket_uri.set_def_xml_acl(boto_acl.to_xml(), headers=headers)
+      if metadata.lifecycle:
+        boto_lifecycle = LifecycleTranslation.BotoLifecycleFromMessage(
+            metadata.lifecycle)
+        bucket_uri.configure_lifecycle(boto_lifecycle, False)
+      if metadata.logging:
+        if self.provider == 'gs':
+          headers[GOOG_PROJ_ID_HDR] = PopulateProjectId(None)
+        if metadata.logging.logBucket and metadata.logging.logObjectPrefix:
+          bucket_uri.enable_logging(metadata.logging.logBucket,
+                                    metadata.logging.logObjectPrefix,
+                                    False, headers)
+        else:  # Logging field is present and empty.  Disable logging.
+          bucket_uri.disable_logging(False, headers)
+      if metadata.versioning:
+        bucket_uri.configure_versioning(metadata.versioning.enabled,
+                                        headers=headers)
+      if metadata.website:
+        main_page_suffix = metadata.website.mainPageSuffix
+        error_page = metadata.website.notFoundPage
+        bucket_uri.set_website_config(main_page_suffix, error_page)
+      return self.GetBucket(bucket_name, fields=fields)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, bucket_name=bucket_name)
+
+  def CreateBucket(self, bucket_name, project_id=None, metadata=None,
+                   provider=None, fields=None):
+    """See CloudApi class for function doc strings."""
+    _ = provider
+    bucket_uri = self._StorageUriForBucket(bucket_name)
+    location = ''
+    if metadata and metadata.location:
+      location = metadata.location
+    # Pass storage_class param only if this is a GCS bucket. (In S3 the
+    # storage class is specified on the key object.)
+    headers = {}
+    if bucket_uri.scheme == 'gs':
+      self._AddApiVersionToHeaders(headers)
+      headers[GOOG_PROJ_ID_HDR] = PopulateProjectId(project_id)
+      storage_class = ''
+      if metadata and metadata.storageClass:
+        storage_class = metadata.storageClass
+      try:
+        bucket_uri.create_bucket(headers=headers, location=location,
+                                 storage_class=storage_class)
+      except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+        self._TranslateExceptionAndRaise(e, bucket_name=bucket_name)
+    else:
+      try:
+        bucket_uri.create_bucket(headers=headers, location=location)
+      except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+        self._TranslateExceptionAndRaise(e, bucket_name=bucket_name)
+    return self.GetBucket(bucket_name, fields=fields)
+
+  def DeleteBucket(self, bucket_name, preconditions=None, provider=None):
+    """See CloudApi class for function doc strings."""
+    _ = provider, preconditions
+    bucket_uri = self._StorageUriForBucket(bucket_name)
+    headers = {}
+    self._AddApiVersionToHeaders(headers)
+    try:
+      bucket_uri.delete_bucket(headers=headers)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      translated_exception = self._TranslateBotoException(
+          e, bucket_name=bucket_name)
+      if (translated_exception and
+          'BucketNotEmpty' in translated_exception.reason):
+        try:
+          if bucket_uri.get_versioning_config():
+            if self.provider == 's3':
+              raise NotEmptyException(
+                  'VersionedBucketNotEmpty (%s). Currently, gsutil does not '
+                  'support listing or removing S3 DeleteMarkers, so you may '
+                  'need to delete these using another tool to successfully '
+                  'delete this bucket.' % bucket_name, status=e.status)
+            raise NotEmptyException(
+                'VersionedBucketNotEmpty (%s)' % bucket_name, status=e.status)
+          else:
+            raise NotEmptyException('BucketNotEmpty (%s)' % bucket_name,
+                                    status=e.status)
+        except TRANSLATABLE_BOTO_EXCEPTIONS, e2:
+          self._TranslateExceptionAndRaise(e2, bucket_name=bucket_name)
+      elif translated_exception and translated_exception.status == 404:
+        raise NotFoundException('Bucket %s does not exist.' % bucket_name)
+      else:
+        self._TranslateExceptionAndRaise(e, bucket_name=bucket_name)
+
+  def ListObjects(self, bucket_name, prefix=None, delimiter=None,
+                  all_versions=None, provider=None, fields=None):
+    """See CloudApi class for function doc strings."""
+    _ = provider
+    get_fields = self._ListToGetFields(list_fields=fields)
+    bucket_uri = self._StorageUriForBucket(bucket_name)
+    prefix_list = []
+    headers = {}
+    self._AddApiVersionToHeaders(headers)
+    try:
+      objects_iter = bucket_uri.list_bucket(prefix=prefix or '',
+                                            delimiter=delimiter or '',
+                                            all_versions=all_versions,
+                                            headers=headers)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, bucket_name=bucket_name)
+
+    try:
+      for key in objects_iter:
+        if isinstance(key, Prefix):
+          prefix_list.append(key.name)
+          yield CloudApi.CsObjectOrPrefix(key.name,
+                                          CloudApi.CsObjectOrPrefixType.PREFIX)
+        else:
+          key_to_convert = key
+
+          # Listed keys are populated with these fields during bucket listing.
+          key_http_fields = set(['bucket', 'etag', 'name', 'updated',
+                                 'generation', 'metageneration', 'size'])
+
+          # When fields == None, the caller is requesting all possible fields.
+          # If the caller requested any fields that are not populated by bucket
+          # listing, we'll need to make a separate HTTP call for each object to
+          # get its metadata and populate the remaining fields with the result.
+          if not get_fields or (get_fields and not
+                                get_fields.issubset(key_http_fields)):
+
+            generation = None
+            if getattr(key, 'generation', None):
+              generation = key.generation
+            if getattr(key, 'version_id', None):
+              generation = key.version_id
+            key_to_convert = self._GetBotoKey(bucket_name, key.name,
+                                              generation=generation)
+          return_object = self._BotoKeyToObject(key_to_convert,
+                                                fields=get_fields)
+
+          yield CloudApi.CsObjectOrPrefix(return_object,
+                                          CloudApi.CsObjectOrPrefixType.OBJECT)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, bucket_name=bucket_name)
+
+  def GetObjectMetadata(self, bucket_name, object_name, generation=None,
+                        provider=None, fields=None):
+    """See CloudApi class for function doc strings."""
+    _ = provider
+    try:
+      return self._BotoKeyToObject(self._GetBotoKey(bucket_name, object_name,
+                                                    generation=generation),
+                                   fields=fields)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, bucket_name=bucket_name,
+                                       object_name=object_name,
+                                       generation=generation)
+
+  def _CurryDigester(self, digester_object):
+    """Curries a digester object into a form consumable by boto.
+
+    Key instantiates its own digesters by calling hash_algs[alg]() [note there
+    are no arguments to this function].  So in order to pass in our caught-up
+    digesters during a resumable download, we need to pass the digester
+    object but don't get to look it up based on the algorithm name.  Here we
+    use a lambda to make lookup implicit.
+
+    Args:
+      digester_object: Input object to be returned by the created function.
+
+    Returns:
+      A function which when called will return the input object.
+    """
+    return lambda: digester_object
+
+  def GetObjectMedia(
+      self, bucket_name, object_name, download_stream, provider=None,
+      generation=None, object_size=None,
+      download_strategy=CloudApi.DownloadStrategy.ONE_SHOT,
+      start_byte=0, end_byte=None, progress_callback=None,
+      serialization_data=None, digesters=None):
+    """See CloudApi class for function doc strings."""
+    # This implementation will get the object metadata first if we don't pass it
+    # in via serialization_data.
+    headers = {}
+    self._AddApiVersionToHeaders(headers)
+    if 'accept-encoding' not in headers:
+      headers['accept-encoding'] = 'gzip'
+    if end_byte:
+      headers['range'] = 'bytes=%s-%s' % (start_byte, end_byte)
+    elif start_byte > 0:
+      headers['range'] = 'bytes=%s-' % (start_byte)
+    else:
+      headers['range'] = 'bytes=%s' % (start_byte)
+
+    # Since in most cases we already made a call to get the object metadata,
+    # here we avoid an extra HTTP call by unpickling the key.  This is coupled
+    # with the implementation in _BotoKeyToObject.
+    if serialization_data:
+      serialization_dict = json.loads(serialization_data)
+      key = pickle.loads(binascii.a2b_base64(serialization_dict['url']))
+    else:
+      key = self._GetBotoKey(bucket_name, object_name, generation=generation)
+
+    if digesters and self.provider == 'gs':
+      hash_algs = {}
+      for alg in digesters:
+        hash_algs[alg] = self._CurryDigester(digesters[alg])
+    else:
+      hash_algs = {}
+
+    total_size = object_size or 0
+    if serialization_data:
+      total_size = json.loads(serialization_data)['total_size']
+
+    if download_strategy is CloudApi.DownloadStrategy.RESUMABLE:
+      try:
+        if total_size:
+          num_progress_callbacks = max(int(total_size) / TWO_MB,
+                                       XML_PROGRESS_CALLBACKS)
+        else:
+          num_progress_callbacks = XML_PROGRESS_CALLBACKS
+        self._PerformResumableDownload(
+            download_stream, key, headers=headers, callback=progress_callback,
+            num_callbacks=num_progress_callbacks, hash_algs=hash_algs)
+      except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+        self._TranslateExceptionAndRaise(e, bucket_name=bucket_name,
+                                         object_name=object_name,
+                                         generation=generation)
+    elif download_strategy is CloudApi.DownloadStrategy.ONE_SHOT:
+      try:
+        self._PerformSimpleDownload(download_stream, key, headers=headers,
+                                    hash_algs=hash_algs)
+      except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+        self._TranslateExceptionAndRaise(e, bucket_name=bucket_name,
+                                         object_name=object_name,
+                                         generation=generation)
+    else:
+      raise ArgumentException('Unsupported DownloadStrategy: %s' %
+                              download_strategy)
+
+    if self.provider == 's3':
+      if digesters:
+
+        class HashToDigester(object):
+          """Wrapper class to expose hash digests.
+
+          boto creates its own digesters in s3's get_file, returning on-the-fly
+          hashes only by way of key.local_hashes.  To propagate the digest back
+          to the caller, this stub class implements the digest() function.
+          """
+
+          def __init__(self, hash_val):
+            self.hash_val = hash_val
+
+          def digest(self):  # pylint: disable=invalid-name
+            return self.hash_val
+
+        for alg_name in digesters:
+          if ((download_strategy == CloudApi.DownloadStrategy.RESUMABLE and
+               start_byte != 0) or
+              not ((getattr(key, 'local_hashes', None) and
+                    alg_name in key.local_hashes))):
+            # For resumable downloads, boto does not provide a mechanism to
+            # catch up the hash in the case of a partially complete download.
+            # In this case or in the case where no digest was successfully
+            # calculated, set the digester to None, which indicates that we'll
+            # need to manually calculate the hash from the local file once it
+            # is complete.
+            digesters[alg_name] = None
+          else:
+            # Use the on-the-fly hash.
+            digesters[alg_name] = HashToDigester(key.local_hashes[alg_name])
+
+  def _PerformSimpleDownload(self, download_stream, key, headers=None,
+                             hash_algs=None):
+    if not headers:
+      headers = {}
+      self._AddApiVersionToHeaders(headers)
+    try:
+      key.get_contents_to_file(download_stream, headers=headers,
+                               hash_algs=hash_algs)
+    except TypeError:  # s3 and mocks do not support hash_algs
+      key.get_contents_to_file(download_stream, headers=headers)
+
+  def _PerformResumableDownload(self, fp, key, headers=None, callback=None,
+                                num_callbacks=XML_PROGRESS_CALLBACKS,
+                                hash_algs=None):
+    """Downloads bytes from key to fp, resuming as needed.
+
+    Args:
+      fp: File pointer into which data should be downloaded
+      key: Key object from which data is to be downloaded
+      headers: Headers to send when retrieving the file
+      callback: (optional) a callback function that will be called to report
+           progress on the download.  The callback should accept two integer
+           parameters.  The first integer represents the number of
+           bytes that have been successfully transmitted from the service.  The
+           second represents the total number of bytes that need to be
+           transmitted.
+      num_callbacks: (optional) If a callback is specified with the callback
+           parameter, this determines the granularity of the callback
+           by defining the maximum number of times the callback will be
+           called during the file transfer.
+      hash_algs: Dict of hash algorithms to apply to downloaded bytes.
+
+    Raises:
+      ResumableDownloadException on error.
+    """
+    if not headers:
+      headers = {}
+      self._AddApiVersionToHeaders(headers)
+
+    retryable_exceptions = (httplib.HTTPException, IOError, socket.error,
+                            socket.gaierror)
+
+    debug = key.bucket.connection.debug
+
+    num_retries = GetNumRetries()
+    progress_less_iterations = 0
+
+    while True:  # Retry as long as we're making progress.
+      had_file_bytes_before_attempt = GetFileSize(fp)
+      try:
+        cur_file_size = GetFileSize(fp, position_to_eof=True)
+
+        def DownloadProxyCallback(total_bytes_downloaded, total_size):
+          """Translates a boto callback into a gsutil Cloud API callback.
+
+          Callbacks are originally made by boto.s3.Key.get_file(); here we take
+          into account that we're resuming a download.
+
+          Args:
+            total_bytes_downloaded: Actual bytes downloaded so far, not
+                                    including the point we resumed from.
+            total_size: Total size of the download.
+          """
+          if callback:
+            callback(cur_file_size + total_bytes_downloaded, total_size)
+
+        headers = headers.copy()
+        headers['Range'] = 'bytes=%d-%d' % (cur_file_size, key.size - 1)
+        cb = DownloadProxyCallback
+
+        # Disable AWSAuthConnection-level retry behavior, since that would
+        # cause downloads to restart from scratch.
+        try:
+          key.get_file(fp, headers, cb, num_callbacks, override_num_retries=0,
+                       hash_algs=hash_algs)
+        except TypeError:
+          key.get_file(fp, headers, cb, num_callbacks, override_num_retries=0)
+        fp.flush()
+        # Download succeeded.
+        return
+      except retryable_exceptions, e:
+        if debug >= 1:
+          self.logger.info('Caught exception (%s)', repr(e))
+        if isinstance(e, IOError) and e.errno == errno.EPIPE:
+          # Broken pipe error causes httplib to immediately
+          # close the socket (http://bugs.python.org/issue5542),
+          # so we need to close and reopen the key before resuming
+          # the download.
+          if self.provider == 's3':
+            key.get_file(fp, headers, cb, num_callbacks, override_num_retries=0)
+          else:  # self.provider == 'gs'
+            key.get_file(fp, headers, cb, num_callbacks,
+                         override_num_retries=0, hash_algs=hash_algs)
+      except BotoResumableDownloadException, e:
+        if (e.disposition ==
+            ResumableTransferDisposition.ABORT_CUR_PROCESS):
+          raise ResumableDownloadException(e.message)
+        else:
+          if debug >= 1:
+            self.logger.info('Caught ResumableDownloadException (%s) - will '
+                             'retry', e.message)
+
+      # At this point we had a re-tryable failure; see if made progress.
+      if GetFileSize(fp) > had_file_bytes_before_attempt:
+        progress_less_iterations = 0
+      else:
+        progress_less_iterations += 1
+
+      if progress_less_iterations > num_retries:
+        # Don't retry any longer in the current process.
+        raise ResumableDownloadException(
+            'Too many resumable download attempts failed without '
+            'progress. You might try this download again later')
+
+      # Close the key, in case a previous download died partway
+      # through and left data in the underlying key HTTP buffer.
+      # Do this within a try/except block in case the connection is
+      # closed (since key.close() attempts to do a final read, in which
+      # case this read attempt would get an IncompleteRead exception,
+      # which we can safely ignore).
+      try:
+        key.close()
+      except httplib.IncompleteRead:
+        pass
+
+      sleep_time_secs = min(random.random() * (2 ** progress_less_iterations),
+                            GetMaxRetryDelay())
+      if debug >= 1:
+        self.logger.info(
+            'Got retryable failure (%d progress-less in a row).\nSleeping %d '
+            'seconds before re-trying', progress_less_iterations,
+            sleep_time_secs)
+      time.sleep(sleep_time_secs)
+
+  def PatchObjectMetadata(self, bucket_name, object_name, metadata,
+                          generation=None, preconditions=None, provider=None,
+                          fields=None):
+    """See CloudApi class for function doc strings."""
+    _ = provider
+    object_uri = self._StorageUriForObject(bucket_name, object_name,
+                                           generation=generation)
+
+    headers = {}
+    self._AddApiVersionToHeaders(headers)
+    meta_headers = HeadersFromObjectMetadata(metadata, self.provider)
+
+    metadata_plus = {}
+    metadata_minus = set()
+    metadata_changed = False
+    for k, v in meta_headers.iteritems():
+      metadata_changed = True
+      if v is None:
+        metadata_minus.add(k)
+      else:
+        metadata_plus[k] = v
+
+    self._AddPreconditionsToHeaders(preconditions, headers)
+
+    if metadata_changed:
+      try:
+        object_uri.set_metadata(metadata_plus, metadata_minus, False,
+                                headers=headers)
+      except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+        self._TranslateExceptionAndRaise(e, bucket_name=bucket_name,
+                                         object_name=object_name,
+                                         generation=generation)
+
+    if metadata.acl:
+      boto_acl = AclTranslation.BotoAclFromMessage(metadata.acl)
+      try:
+        object_uri.set_xml_acl(boto_acl.to_xml(), key_name=object_name)
+      except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+        self._TranslateExceptionAndRaise(e, bucket_name=bucket_name,
+                                         object_name=object_name,
+                                         generation=generation)
+    return self.GetObjectMetadata(bucket_name, object_name,
+                                  generation=generation, fields=fields)
+
+  def _PerformSimpleUpload(self, dst_uri, upload_stream, md5=None,
+                           canned_acl=None, progress_callback=None,
+                           headers=None):
+    dst_uri.set_contents_from_file(upload_stream, md5=md5, policy=canned_acl,
+                                   cb=progress_callback, headers=headers)
+
+  def _PerformStreamingUpload(self, dst_uri, upload_stream, canned_acl=None,
+                              progress_callback=None, headers=None):
+    if dst_uri.get_provider().supports_chunked_transfer():
+      dst_uri.set_contents_from_stream(upload_stream, policy=canned_acl,
+                                       cb=progress_callback, headers=headers)
+    else:
+      # Provider doesn't support chunked transfer, so copy to a temporary
+      # file.
+      (temp_fh, temp_path) = tempfile.mkstemp()
+      try:
+        with open(temp_path, 'wb') as out_fp:
+          stream_bytes = upload_stream.read(DEFAULT_FILE_BUFFER_SIZE)
+          while stream_bytes:
+            out_fp.write(stream_bytes)
+            stream_bytes = upload_stream.read(DEFAULT_FILE_BUFFER_SIZE)
+        with open(temp_path, 'rb') as in_fp:
+          dst_uri.set_contents_from_file(in_fp, policy=canned_acl,
+                                         headers=headers)
+      finally:
+        os.close(temp_fh)
+        os.unlink(temp_path)
+
+  def _PerformResumableUpload(self, key, upload_stream, upload_size,
+                              tracker_callback, canned_acl=None,
+                              serialization_data=None, progress_callback=None,
+                              headers=None):
+    resumable_upload = BotoResumableUpload(
+        tracker_callback, self.logger, resume_url=serialization_data)
+    resumable_upload.SendFile(key, upload_stream, upload_size,
+                              canned_acl=canned_acl, cb=progress_callback,
+                              headers=headers)
+
+  def _UploadSetup(self, object_metadata, preconditions=None):
+    """Shared upload implementation.
+
+    Args:
+      object_metadata: Object metadata describing destination object.
+      preconditions: Optional gsutil Cloud API preconditions.
+
+    Returns:
+      Headers dictionary, StorageUri for upload (based on inputs)
+    """
+    ValidateDstObjectMetadata(object_metadata)
+
+    headers = HeadersFromObjectMetadata(object_metadata, self.provider)
+    self._AddApiVersionToHeaders(headers)
+
+    if object_metadata.crc32c:
+      if 'x-goog-hash' in headers:
+        headers['x-goog-hash'] += (
+            ',crc32c=%s' % object_metadata.crc32c.rstrip('\n'))
+      else:
+        headers['x-goog-hash'] = (
+            'crc32c=%s' % object_metadata.crc32c.rstrip('\n'))
+    if object_metadata.md5Hash:
+      if 'x-goog-hash' in headers:
+        headers['x-goog-hash'] += (
+            ',md5=%s' % object_metadata.md5Hash.rstrip('\n'))
+      else:
+        headers['x-goog-hash'] = (
+            'md5=%s' % object_metadata.md5Hash.rstrip('\n'))
+
+    if 'content-type' in headers and not headers['content-type']:
+      headers['content-type'] = 'application/octet-stream'
+
+    self._AddPreconditionsToHeaders(preconditions, headers)
+
+    dst_uri = self._StorageUriForObject(object_metadata.bucket,
+                                        object_metadata.name)
+    return headers, dst_uri
+
+  def _HandleSuccessfulUpload(self, dst_uri, object_metadata, fields=None):
+    """Set ACLs on an uploaded object and return its metadata.
+
+    Args:
+      dst_uri: Generation-specific StorageUri describing the object.
+      object_metadata: Metadata for the object, including an ACL if applicable.
+      fields: If present, return only these Object metadata fields.
+
+    Returns:
+      gsutil Cloud API Object metadata.
+
+    Raises:
+      CommandException if the object was overwritten / deleted concurrently.
+    """
+    try:
+      # The XML API does not support if-generation-match for GET requests.
+      # Therefore, if the object gets overwritten before the ACL and get_key
+      # operations, the best we can do is warn that it happened.
+      self._SetObjectAcl(object_metadata, dst_uri)
+      return self._BotoKeyToObject(dst_uri.get_key(), fields=fields)
+    except boto.exception.InvalidUriError as e:
+      check_for_str = 'Attempt to get key for "%s" failed.' % dst_uri.uri
+      if check_for_str in e.message:
+        raise CommandException('\n'.join(textwrap.wrap(
+            'Uploaded object (%s) was deleted or overwritten immediately '
+            'after it was uploaded. This can happen if you attempt to upload '
+            'to the same object multiple times concurrently.' % dst_uri.uri)))
+      else:
+        raise
+
+  def _SetObjectAcl(self, object_metadata, dst_uri):
+    """Sets the ACL (if present in object_metadata) on an uploaded object."""
+    if object_metadata.acl:
+      boto_acl = AclTranslation.BotoAclFromMessage(object_metadata.acl)
+      dst_uri.set_xml_acl(boto_acl.to_xml())
+    elif self.provider == 's3':
+      s3_acl = S3MarkerAclFromObjectMetadata(object_metadata)
+      if s3_acl:
+        dst_uri.set_xml_acl(s3_acl)
+
+  def UploadObjectResumable(
+      self, upload_stream, object_metadata, canned_acl=None, preconditions=None,
+      provider=None, fields=None, size=None, serialization_data=None,
+      tracker_callback=None, progress_callback=None):
+    """See CloudApi class for function doc strings."""
+    if self.provider == 's3':
+      # Resumable uploads are not supported for s3.
+      return self.UploadObject(
+          upload_stream, object_metadata, canned_acl=canned_acl,
+          preconditions=preconditions, fields=fields, size=size)
+    headers, dst_uri = self._UploadSetup(object_metadata,
+                                         preconditions=preconditions)
+    if not tracker_callback:
+      raise ArgumentException('No tracker callback function set for '
+                              'resumable upload of %s' % dst_uri)
+    try:
+      self._PerformResumableUpload(dst_uri.new_key(headers=headers),
+                                   upload_stream, size, tracker_callback,
+                                   canned_acl=canned_acl,
+                                   serialization_data=serialization_data,
+                                   progress_callback=progress_callback,
+                                   headers=headers)
+      return self._HandleSuccessfulUpload(dst_uri, object_metadata,
+                                          fields=fields)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, bucket_name=object_metadata.bucket,
+                                       object_name=object_metadata.name)
+
+  def UploadObjectStreaming(self, upload_stream, object_metadata,
+                            canned_acl=None, progress_callback=None,
+                            preconditions=None, provider=None, fields=None):
+    """See CloudApi class for function doc strings."""
+    headers, dst_uri = self._UploadSetup(object_metadata,
+                                         preconditions=preconditions)
+
+    try:
+      self._PerformStreamingUpload(
+          dst_uri, upload_stream, canned_acl=canned_acl,
+          progress_callback=progress_callback, headers=headers)
+      return self._HandleSuccessfulUpload(dst_uri, object_metadata,
+                                          fields=fields)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, bucket_name=object_metadata.bucket,
+                                       object_name=object_metadata.name)
+
+  def UploadObject(self, upload_stream, object_metadata, canned_acl=None,
+                   preconditions=None, size=None, progress_callback=None,
+                   provider=None, fields=None):
+    """See CloudApi class for function doc strings."""
+    headers, dst_uri = self._UploadSetup(object_metadata,
+                                         preconditions=preconditions)
+
+    try:
+      md5 = None
+      if object_metadata.md5Hash:
+        md5 = []
+        # boto expects hex at index 0, base64 at index 1
+        md5.append(binascii.hexlify(
+            base64.decodestring(object_metadata.md5Hash.strip('\n"\''))))
+        md5.append(object_metadata.md5Hash.strip('\n"\''))
+      self._PerformSimpleUpload(dst_uri, upload_stream, md5=md5,
+                                canned_acl=canned_acl,
+                                progress_callback=progress_callback,
+                                headers=headers)
+      return self._HandleSuccessfulUpload(dst_uri, object_metadata,
+                                          fields=fields)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, bucket_name=object_metadata.bucket,
+                                       object_name=object_metadata.name)
+
+  def DeleteObject(self, bucket_name, object_name, preconditions=None,
+                   generation=None, provider=None):
+    """See CloudApi class for function doc strings."""
+    _ = provider
+    headers = {}
+    self._AddApiVersionToHeaders(headers)
+    self._AddPreconditionsToHeaders(preconditions, headers)
+
+    uri = self._StorageUriForObject(bucket_name, object_name,
+                                    generation=generation)
+    try:
+      uri.delete_key(validate=False, headers=headers)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, bucket_name=bucket_name,
+                                       object_name=object_name,
+                                       generation=generation)
+
+  def CopyObject(self, src_bucket_name, src_obj_name, dst_obj_metadata,
+                 src_generation=None, canned_acl=None, preconditions=None,
+                 provider=None, fields=None):
+    """See CloudApi class for function doc strings."""
+    _ = provider
+    dst_uri = self._StorageUriForObject(dst_obj_metadata.bucket,
+                                        dst_obj_metadata.name)
+
+    # Usually it's okay to treat version_id and generation as
+    # the same, but in this case the underlying boto call determines the
+    # provider based on the presence of one or the other.
+    src_version_id = None
+    if self.provider == 's3':
+      src_version_id = src_generation
+      src_generation = None
+
+    headers = HeadersFromObjectMetadata(dst_obj_metadata, self.provider)
+    self._AddApiVersionToHeaders(headers)
+    self._AddPreconditionsToHeaders(preconditions, headers)
+
+    if canned_acl:
+      headers[dst_uri.get_provider().acl_header] = canned_acl
+
+    preserve_acl = True if dst_obj_metadata.acl else False
+    if self.provider == 's3':
+      s3_acl = S3MarkerAclFromObjectMetadata(dst_obj_metadata)
+      if s3_acl:
+        preserve_acl = True
+
+    try:
+      new_key = dst_uri.copy_key(
+          src_bucket_name, src_obj_name, preserve_acl=preserve_acl,
+          headers=headers, src_version_id=src_version_id,
+          src_generation=src_generation)
+
+      return self._BotoKeyToObject(new_key, fields=fields)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, dst_obj_metadata.bucket,
+                                       dst_obj_metadata.name)
+
+  def ComposeObject(self, src_objs_metadata, dst_obj_metadata,
+                    preconditions=None, provider=None, fields=None):
+    """See CloudApi class for function doc strings."""
+    _ = provider
+    ValidateDstObjectMetadata(dst_obj_metadata)
+
+    dst_obj_name = dst_obj_metadata.name
+    dst_obj_metadata.name = None
+    dst_bucket_name = dst_obj_metadata.bucket
+    dst_obj_metadata.bucket = None
+    headers = HeadersFromObjectMetadata(dst_obj_metadata, self.provider)
+    if not dst_obj_metadata.contentType:
+      dst_obj_metadata.contentType = DEFAULT_CONTENT_TYPE
+      headers['content-type'] = dst_obj_metadata.contentType
+    self._AddApiVersionToHeaders(headers)
+    self._AddPreconditionsToHeaders(preconditions, headers)
+
+    dst_uri = self._StorageUriForObject(dst_bucket_name, dst_obj_name)
+
+    src_components = []
+    for src_obj in src_objs_metadata:
+      src_uri = self._StorageUriForObject(dst_bucket_name, src_obj.name,
+                                          generation=src_obj.generation)
+      src_components.append(src_uri)
+
+    try:
+      dst_uri.compose(src_components, headers=headers)
+
+      return self.GetObjectMetadata(dst_bucket_name, dst_obj_name,
+                                    fields=fields)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, dst_obj_metadata.bucket,
+                                       dst_obj_metadata.name)
+
+  def _AddPreconditionsToHeaders(self, preconditions, headers):
+    """Adds preconditions (if any) to headers."""
+    if preconditions and self.provider == 'gs':
+      if preconditions.gen_match:
+        headers['x-goog-if-generation-match'] = preconditions.gen_match
+      if preconditions.meta_gen_match:
+        headers['x-goog-if-metageneration-match'] = preconditions.meta_gen_match
+
+  def _AddApiVersionToHeaders(self, headers):
+    if self.provider == 'gs':
+      headers['x-goog-api-version'] = self.api_version
+
+  def _GetMD5FromETag(self, src_etag):
+    """Returns an MD5 from the etag iff the etag is a valid MD5 hash.
+
+    Args:
+      src_etag: Object etag for which to return the MD5.
+
+    Returns:
+      MD5 in hex string format, or None.
+    """
+    if src_etag and MD5_REGEX.search(src_etag):
+      return src_etag.strip('"\'').lower()
+
+  def _StorageUriForBucket(self, bucket):
+    """Returns a boto storage_uri for the given bucket name.
+
+    Args:
+      bucket: Bucket name (string).
+
+    Returns:
+      Boto storage_uri for the bucket.
+    """
+    return boto.storage_uri(
+        '%s://%s' % (self.provider, bucket),
+        suppress_consec_slashes=False,
+        bucket_storage_uri_class=self.bucket_storage_uri_class,
+        debug=self.debug)
+
+  def _StorageUriForObject(self, bucket, object_name, generation=None):
+    """Returns a boto storage_uri for the given object.
+
+    Args:
+      bucket: Bucket name (string).
+      object_name: Object name (string).
+      generation: Generation or version_id of object.  If None, live version
+                  of the object is used.
+
+    Returns:
+      Boto storage_uri for the object.
+    """
+    uri_string = '%s://%s/%s' % (self.provider, bucket, object_name)
+    if generation:
+      uri_string += '#%s' % generation
+    return boto.storage_uri(
+        uri_string, suppress_consec_slashes=False,
+        bucket_storage_uri_class=self.bucket_storage_uri_class,
+        debug=self.debug)
+
+  def _GetBotoKey(self, bucket_name, object_name, generation=None):
+    """Gets the boto key for an object.
+
+    Args:
+      bucket_name: Bucket containing the object.
+      object_name: Object name.
+      generation: Generation or version of the object to retrieve.
+
+    Returns:
+      Boto key for the object.
+    """
+    object_uri = self._StorageUriForObject(bucket_name, object_name,
+                                           generation=generation)
+    try:
+      key = object_uri.get_key()
+      if not key:
+        raise CreateObjectNotFoundException('404', self.provider,
+                                            bucket_name, object_name,
+                                            generation=generation)
+      return key
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e, bucket_name=bucket_name,
+                                       object_name=object_name,
+                                       generation=generation)
+
+  def _ListToGetFields(self, list_fields=None):
+    """Removes 'items/' from the input fields and converts it to a set.
+
+    This way field sets requested for ListBucket/ListObject can be used in
+    _BotoBucketToBucket and _BotoKeyToObject calls.
+
+    Args:
+      list_fields: Iterable fields usable in ListBucket/ListObject calls.
+
+    Returns:
+      Set of fields usable in GetBucket/GetObject or
+      _BotoBucketToBucket/_BotoKeyToObject calls.
+    """
+    if list_fields:
+      get_fields = set()
+      for field in list_fields:
+        if field in ['kind', 'nextPageToken', 'prefixes']:
+          # These are not actually object / bucket metadata fields.
+          # They are fields specific to listing, so we don't consider them.
+          continue
+        get_fields.add(re.sub(r'items/', '', field))
+      return get_fields
+
+  # pylint: disable=too-many-statements
+  def _BotoBucketToBucket(self, bucket, fields=None):
+    """Constructs an apitools Bucket from a boto bucket.
+
+    Args:
+      bucket: Boto bucket.
+      fields: If present, construct the apitools Bucket with only this set of
+              metadata fields.
+
+    Returns:
+      apitools Bucket.
+    """
+    bucket_uri = self._StorageUriForBucket(bucket.name)
+
+    cloud_api_bucket = apitools_messages.Bucket(name=bucket.name,
+                                                id=bucket.name)
+    headers = {}
+    self._AddApiVersionToHeaders(headers)
+    if self.provider == 'gs':
+      if not fields or 'storageClass' in fields:
+        if hasattr(bucket, 'get_storage_class'):
+          cloud_api_bucket.storageClass = bucket.get_storage_class()
+      if not fields or 'acl' in fields:
+        for acl in AclTranslation.BotoBucketAclToMessage(
+            bucket.get_acl(headers=headers)):
+          try:
+            cloud_api_bucket.acl.append(acl)
+          except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+            translated_exception = self._TranslateBotoException(
+                e, bucket_name=bucket.name)
+            if (translated_exception and
+                isinstance(translated_exception,
+                           AccessDeniedException)):
+              # JSON API doesn't differentiate between a blank ACL list
+              # and an access denied, so this is intentionally left blank.
+              pass
+            else:
+              self._TranslateExceptionAndRaise(e, bucket_name=bucket.name)
+      if not fields or 'cors' in fields:
+        try:
+          boto_cors = bucket_uri.get_cors()
+          cloud_api_bucket.cors = CorsTranslation.BotoCorsToMessage(boto_cors)
+        except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+          self._TranslateExceptionAndRaise(e, bucket_name=bucket.name)
+      if not fields or 'defaultObjectAcl' in fields:
+        for acl in AclTranslation.BotoObjectAclToMessage(
+            bucket.get_def_acl(headers=headers)):
+          try:
+            cloud_api_bucket.defaultObjectAcl.append(acl)
+          except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+            translated_exception = self._TranslateBotoException(
+                e, bucket_name=bucket.name)
+            if (translated_exception and
+                isinstance(translated_exception,
+                           AccessDeniedException)):
+              # JSON API doesn't differentiate between a blank ACL list
+              # and an access denied, so this is intentionally left blank.
+              pass
+            else:
+              self._TranslateExceptionAndRaise(e, bucket_name=bucket.name)
+      if not fields or 'lifecycle' in fields:
+        try:
+          boto_lifecycle = bucket_uri.get_lifecycle_config()
+          cloud_api_bucket.lifecycle = (
+              LifecycleTranslation.BotoLifecycleToMessage(boto_lifecycle))
+        except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+          self._TranslateExceptionAndRaise(e, bucket_name=bucket.name)
+      if not fields or 'logging' in fields:
+        try:
+          boto_logging = bucket_uri.get_logging_config()
+          if boto_logging and 'Logging' in boto_logging:
+            logging_config = boto_logging['Logging']
+            cloud_api_bucket.logging = apitools_messages.Bucket.LoggingValue()
+            if 'LogObjectPrefix' in logging_config:
+              cloud_api_bucket.logging.logObjectPrefix = (
+                  logging_config['LogObjectPrefix'])
+            if 'LogBucket' in logging_config:
+              cloud_api_bucket.logging.logBucket = logging_config['LogBucket']
+        except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+          self._TranslateExceptionAndRaise(e, bucket_name=bucket.name)
+      if not fields or 'website' in fields:
+        try:
+          boto_website = bucket_uri.get_website_config()
+          if boto_website and 'WebsiteConfiguration' in boto_website:
+            website_config = boto_website['WebsiteConfiguration']
+            cloud_api_bucket.website = apitools_messages.Bucket.WebsiteValue()
+            if 'MainPageSuffix' in website_config:
+              cloud_api_bucket.website.mainPageSuffix = (
+                  website_config['MainPageSuffix'])
+            if 'NotFoundPage' in website_config:
+              cloud_api_bucket.website.notFoundPage = (
+                  website_config['NotFoundPage'])
+        except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+          self._TranslateExceptionAndRaise(e, bucket_name=bucket.name)
+    if not fields or 'versioning' in fields:
+      versioning = bucket_uri.get_versioning_config(headers=headers)
+      if versioning:
+        if (self.provider == 's3' and 'Versioning' in versioning and
+            versioning['Versioning'] == 'Enabled'):
+          cloud_api_bucket.versioning = (
+              apitools_messages.Bucket.VersioningValue(enabled=True))
+        elif self.provider == 'gs':
+          cloud_api_bucket.versioning = (
+              apitools_messages.Bucket.VersioningValue(enabled=True))
+
+    # For S3 long bucket listing we do not support CORS, lifecycle, website, and
+    # logging translation. The individual commands can be used to get
+    # the XML equivalents for S3.
+    return cloud_api_bucket
+
+  def _BotoKeyToObject(self, key, fields=None):
+    """Constructs an apitools Object from a boto key.
+
+    Args:
+      key: Boto key to construct Object from.
+      fields: If present, construct the apitools Object with only this set of
+              metadata fields.
+
+    Returns:
+      apitools Object corresponding to key.
+    """
+    custom_metadata = None
+    if not fields or 'metadata' in fields:
+      custom_metadata = self._TranslateBotoKeyCustomMetadata(key)
+    cache_control = None
+    if not fields or 'cacheControl' in fields:
+      cache_control = getattr(key, 'cache_control', None)
+    component_count = None
+    if not fields or 'componentCount' in fields:
+      component_count = getattr(key, 'component_count', None)
+    content_disposition = None
+    if not fields or 'contentDisposition' in fields:
+      content_disposition = getattr(key, 'content_disposition', None)
+    # Other fields like updated and ACL depend on the generation
+    # of the object, so populate that regardless of whether it was requested.
+    generation = self._TranslateBotoKeyGeneration(key)
+    metageneration = None
+    if not fields or 'metageneration' in fields:
+      metageneration = self._TranslateBotoKeyMetageneration(key)
+    updated = None
+    # Translation code to avoid a dependency on dateutil.
+    if not fields or 'updated' in fields:
+      updated = self._TranslateBotoKeyTimestamp(key)
+    etag = None
+    if not fields or 'etag' in fields:
+      etag = getattr(key, 'etag', None)
+      if etag:
+        etag = etag.strip('"\'')
+    crc32c = None
+    if not fields or 'crc32c' in fields:
+      if hasattr(key, 'cloud_hashes') and 'crc32c' in key.cloud_hashes:
+        crc32c = base64.encodestring(key.cloud_hashes['crc32c']).rstrip('\n')
+    md5_hash = None
+    if not fields or 'md5Hash' in fields:
+      if hasattr(key, 'cloud_hashes') and 'md5' in key.cloud_hashes:
+        md5_hash = base64.encodestring(key.cloud_hashes['md5']).rstrip('\n')
+      elif self._GetMD5FromETag(getattr(key, 'etag', None)):
+        md5_hash = base64.encodestring(
+            binascii.unhexlify(self._GetMD5FromETag(key.etag))).rstrip('\n')
+      elif self.provider == 's3':
+        # S3 etags are MD5s for non-multi-part objects, but multi-part objects
+        # (which include all objects >= 5GB) have a custom checksum
+        # implementation that is not currently supported by gsutil.
+        self.logger.warn(
+            'Non-MD5 etag (%s) present for key %s, data integrity checks are '
+            'not possible.', key.etag, key)
+
+    # Serialize the boto key in the media link if it is requested.  This
+    # way we can later access the key without adding an HTTP call.
+    media_link = None
+    if not fields or 'mediaLink' in fields:
+      media_link = binascii.b2a_base64(
+          pickle.dumps(key, pickle.HIGHEST_PROTOCOL))
+    size = None
+    if not fields or 'size' in fields:
+      size = key.size or 0
+
+    cloud_api_object = apitools_messages.Object(
+        bucket=key.bucket.name,
+        name=key.name,
+        size=size,
+        contentEncoding=key.content_encoding,
+        contentLanguage=key.content_language,
+        contentType=key.content_type,
+        cacheControl=cache_control,
+        contentDisposition=content_disposition,
+        etag=etag,
+        crc32c=crc32c,
+        md5Hash=md5_hash,
+        generation=generation,
+        metageneration=metageneration,
+        componentCount=component_count,
+        updated=updated,
+        metadata=custom_metadata,
+        mediaLink=media_link)
+
+    # Remaining functions amend cloud_api_object.
+    self._TranslateDeleteMarker(key, cloud_api_object)
+    if not fields or 'acl' in fields:
+      generation_str = GenerationFromUrlAndString(
+          StorageUrlFromString(self.provider), generation)
+      self._TranslateBotoKeyAcl(key, cloud_api_object,
+                                generation=generation_str)
+
+    return cloud_api_object
+
+  def _TranslateBotoKeyCustomMetadata(self, key):
+    """Populates an apitools message from custom metadata in the boto key."""
+    custom_metadata = None
+    if getattr(key, 'metadata', None):
+      custom_metadata = apitools_messages.Object.MetadataValue(
+          additionalProperties=[])
+      for k, v in key.metadata.iteritems():
+        if k.lower() == 'content-language':
+          # Work around content-language being inserted into custom metadata.
+          continue
+        custom_metadata.additionalProperties.append(
+            apitools_messages.Object.MetadataValue.AdditionalProperty(
+                key=k, value=v))
+    return custom_metadata
+
+  def _TranslateBotoKeyGeneration(self, key):
+    """Returns the generation/version_id number from the boto key if present."""
+    generation = None
+    if self.provider == 'gs':
+      if getattr(key, 'generation', None):
+        generation = long(key.generation)
+    elif self.provider == 's3':
+      if getattr(key, 'version_id', None):
+        generation = EncodeStringAsLong(key.version_id)
+    return generation
+
+  def _TranslateBotoKeyMetageneration(self, key):
+    """Returns the metageneration number from the boto key if present."""
+    metageneration = None
+    if self.provider == 'gs':
+      if getattr(key, 'metageneration', None):
+        metageneration = long(key.metageneration)
+    return metageneration
+
+  def _TranslateBotoKeyTimestamp(self, key):
+    """Parses the timestamp from the boto key into an datetime object.
+
+    This avoids a dependency on dateutil.
+
+    Args:
+      key: Boto key to get timestamp from.
+
+    Returns:
+      datetime object if string is parsed successfully, None otherwise.
+    """
+    if key.last_modified:
+      if '.' in key.last_modified:
+        key_us_timestamp = key.last_modified.rstrip('Z') + '000Z'
+      else:
+        key_us_timestamp = key.last_modified.rstrip('Z') + '.000000Z'
+      fmt = '%Y-%m-%dT%H:%M:%S.%fZ'
+      try:
+        return datetime.datetime.strptime(key_us_timestamp, fmt)
+      except ValueError:
+        try:
+          # Try alternate format
+          fmt = '%a, %d %b %Y %H:%M:%S %Z'
+          return datetime.datetime.strptime(key.last_modified, fmt)
+        except ValueError:
+          # Could not parse the time; leave updated as None.
+          return None
+
+  def _TranslateDeleteMarker(self, key, cloud_api_object):
+    """Marks deleted objects with a metadata value (for S3 compatibility)."""
+    if isinstance(key, DeleteMarker):
+      if not cloud_api_object.metadata:
+        cloud_api_object.metadata = apitools_messages.Object.MetadataValue()
+        cloud_api_object.metadata.additionalProperties = []
+      cloud_api_object.metadata.additionalProperties.append(
+          apitools_messages.Object.MetadataValue.AdditionalProperty(
+              key=S3_DELETE_MARKER_GUID, value=True))
+
+  def _TranslateBotoKeyAcl(self, key, cloud_api_object, generation=None):
+    """Updates cloud_api_object with the ACL from the boto key."""
+    storage_uri_for_key = self._StorageUriForObject(key.bucket.name, key.name,
+                                                    generation=generation)
+    headers = {}
+    self._AddApiVersionToHeaders(headers)
+    try:
+      if self.provider == 'gs':
+        key_acl = storage_uri_for_key.get_acl(headers=headers)
+        # key.get_acl() does not support versioning so we need to use
+        # storage_uri to ensure we're getting the versioned ACL.
+        for acl in AclTranslation.BotoObjectAclToMessage(key_acl):
+          cloud_api_object.acl.append(acl)
+      if self.provider == 's3':
+        key_acl = key.get_xml_acl(headers=headers)
+        # ACLs for s3 are different and we use special markers to represent
+        # them in the gsutil Cloud API.
+        AddS3MarkerAclToObjectMetadata(cloud_api_object, key_acl)
+    except boto.exception.GSResponseError, e:
+      if e.status == 403:
+        # Consume access denied exceptions to mimic JSON behavior of simply
+        # returning None if sufficient permission is not present.  The caller
+        # needs to handle the case where the ACL is not populated.
+        pass
+      else:
+        raise
+
+  def _TranslateExceptionAndRaise(self, e, bucket_name=None, object_name=None,
+                                  generation=None):
+    """Translates a Boto exception and raises the translated or original value.
+
+    Args:
+      e: Any Exception.
+      bucket_name: Optional bucket name in request that caused the exception.
+      object_name: Optional object name in request that caused the exception.
+      generation: Optional generation in request that caused the exception.
+
+    Raises:
+      Translated CloudApi exception, or the original exception if it was not
+      translatable.
+    """
+    translated_exception = self._TranslateBotoException(
+        e, bucket_name=bucket_name, object_name=object_name,
+        generation=generation)
+    if translated_exception:
+      raise translated_exception
+    else:
+      raise
+
+  def _TranslateBotoException(self, e, bucket_name=None, object_name=None,
+                              generation=None):
+    """Translates boto exceptions into their gsutil Cloud API equivalents.
+
+    Args:
+      e: Any exception in TRANSLATABLE_BOTO_EXCEPTIONS.
+      bucket_name: Optional bucket name in request that caused the exception.
+      object_name: Optional object name in request that caused the exception.
+      generation: Optional generation in request that caused the exception.
+
+    Returns:
+      CloudStorageApiServiceException for translatable exceptions, None
+      otherwise.
+
+    Because we're using isinstance, check for subtypes first.
+    """
+    if isinstance(e, boto.exception.StorageResponseError):
+      if e.status == 400:
+        return BadRequestException(e.code, status=e.status, body=e.body)
+      elif e.status == 401 or e.status == 403:
+        return AccessDeniedException(e.code, status=e.status, body=e.body)
+      elif e.status == 404:
+        if bucket_name:
+          if object_name:
+            return CreateObjectNotFoundException(e.status, self.provider,
+                                                 bucket_name, object_name,
+                                                 generation=generation)
+          return CreateBucketNotFoundException(e.status, self.provider,
+                                               bucket_name)
+        return NotFoundException(e.code, status=e.status, body=e.body)
+      elif e.status == 409 and e.code and 'BucketNotEmpty' in e.code:
+        return NotEmptyException('BucketNotEmpty (%s)' % bucket_name,
+                                 status=e.status, body=e.body)
+      elif e.status == 412:
+        return PreconditionException(e.code, status=e.status, body=e.body)
+    if isinstance(e, boto.exception.StorageCreateError):
+      return ServiceException('Bucket already exists.', status=e.status,
+                              body=e.body)
+
+    if isinstance(e, boto.exception.BotoServerError):
+      return ServiceException(e.message, status=e.status, body=e.body)
+
+    if isinstance(e, boto.exception.InvalidUriError):
+      # Work around textwrap when searching for this string.
+      if e.message and NON_EXISTENT_OBJECT_REGEX.match(e.message.encode(UTF8)):
+        return NotFoundException(e.message, status=404)
+      return InvalidUrlError(e.message)
+
+    if isinstance(e, boto.exception.ResumableUploadException):
+      if (e.disposition == boto.exception.ResumableTransferDisposition.ABORT or
+          (e.disposition ==
+           boto.exception.ResumableTransferDisposition.START_OVER)):
+        return ResumableUploadAbortException(e.message)
+      else:
+        return ResumableUploadException(e.message)
+
+    if isinstance(e, boto.exception.ResumableDownloadException):
+      return ResumableDownloadException(e.message)
+
+    return None
+
+  # For function docstrings, see CloudApiDelegator class.
+  def XmlPassThroughGetAcl(self, storage_url, def_obj_acl=False):
+    """See CloudApiDelegator class for function doc strings."""
+    try:
+      uri = boto.storage_uri(
+          storage_url.url_string, suppress_consec_slashes=False,
+          bucket_storage_uri_class=self.bucket_storage_uri_class,
+          debug=self.debug)
+      if def_obj_acl:
+        return uri.get_def_acl()
+      else:
+        return uri.get_acl()
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e)
+
+  def XmlPassThroughSetAcl(self, acl_text, storage_url, canned=True,
+                           def_obj_acl=False):
+    """See CloudApiDelegator class for function doc strings."""
+    try:
+      uri = boto.storage_uri(
+          storage_url.url_string, suppress_consec_slashes=False,
+          bucket_storage_uri_class=self.bucket_storage_uri_class,
+          debug=self.debug)
+      if canned:
+        if def_obj_acl:
+          canned_acls = uri.canned_acls()
+          if acl_text not in canned_acls:
+            raise CommandException('Invalid canned ACL "%s".' % acl_text)
+          uri.set_def_acl(acl_text, uri.object_name)
+        else:
+          canned_acls = uri.canned_acls()
+          if acl_text not in canned_acls:
+            raise CommandException('Invalid canned ACL "%s".' % acl_text)
+          uri.set_acl(acl_text, uri.object_name)
+      else:
+        if def_obj_acl:
+          uri.set_def_xml_acl(acl_text, uri.object_name)
+        else:
+          uri.set_xml_acl(acl_text, uri.object_name)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e)
+
+  def XmlPassThroughSetCors(self, cors_text, storage_url):
+    """See CloudApiDelegator class for function doc strings."""
+    # Parse XML document and convert into Cors object.
+    cors_obj = Cors()
+    h = handler.XmlHandler(cors_obj, None)
+    try:
+      xml.sax.parseString(cors_text, h)
+    except SaxExceptions.SAXParseException, e:
+      raise CommandException('Requested CORS is invalid: %s at line %s, '
+                             'column %s' % (e.getMessage(), e.getLineNumber(),
+                                            e.getColumnNumber()))
+
+    try:
+      uri = boto.storage_uri(
+          storage_url.url_string, suppress_consec_slashes=False,
+          bucket_storage_uri_class=self.bucket_storage_uri_class,
+          debug=self.debug)
+      uri.set_cors(cors_obj, False)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e)
+
+  def XmlPassThroughGetCors(self, storage_url):
+    """See CloudApiDelegator class for function doc strings."""
+    uri = boto.storage_uri(
+        storage_url.url_string, suppress_consec_slashes=False,
+        bucket_storage_uri_class=self.bucket_storage_uri_class,
+        debug=self.debug)
+    try:
+      cors = uri.get_cors(False)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e)
+
+    parsed_xml = xml.dom.minidom.parseString(cors.to_xml().encode(UTF8))
+    # Pretty-print the XML to make it more easily human editable.
+    return parsed_xml.toprettyxml(indent='    ')
+
+  def XmlPassThroughGetLifecycle(self, storage_url):
+    """See CloudApiDelegator class for function doc strings."""
+    try:
+      uri = boto.storage_uri(
+          storage_url.url_string, suppress_consec_slashes=False,
+          bucket_storage_uri_class=self.bucket_storage_uri_class,
+          debug=self.debug)
+      lifecycle = uri.get_lifecycle_config(False)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e)
+
+    parsed_xml = xml.dom.minidom.parseString(lifecycle.to_xml().encode(UTF8))
+    # Pretty-print the XML to make it more easily human editable.
+    return parsed_xml.toprettyxml(indent='    ')
+
+  def XmlPassThroughSetLifecycle(self, lifecycle_text, storage_url):
+    """See CloudApiDelegator class for function doc strings."""
+    # Parse XML document and convert into lifecycle object.
+    lifecycle_obj = LifecycleConfig()
+    h = handler.XmlHandler(lifecycle_obj, None)
+    try:
+      xml.sax.parseString(lifecycle_text, h)
+    except SaxExceptions.SAXParseException, e:
+      raise CommandException(
+          'Requested lifecycle config is invalid: %s at line %s, column %s' %
+          (e.getMessage(), e.getLineNumber(), e.getColumnNumber()))
+
+    try:
+      uri = boto.storage_uri(
+          storage_url.url_string, suppress_consec_slashes=False,
+          bucket_storage_uri_class=self.bucket_storage_uri_class,
+          debug=self.debug)
+      uri.configure_lifecycle(lifecycle_obj, False)
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e)
+
+  def XmlPassThroughGetLogging(self, storage_url):
+    """See CloudApiDelegator class for function doc strings."""
+    try:
+      uri = boto.storage_uri(
+          storage_url.url_string, suppress_consec_slashes=False,
+          bucket_storage_uri_class=self.bucket_storage_uri_class,
+          debug=self.debug)
+      logging_config_xml = UnaryDictToXml(uri.get_logging_config())
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e)
+
+    return XmlParseString(logging_config_xml).toprettyxml()
+
+  def XmlPassThroughGetWebsite(self, storage_url):
+    """See CloudApiDelegator class for function doc strings."""
+    try:
+      uri = boto.storage_uri(
+          storage_url.url_string, suppress_consec_slashes=False,
+          bucket_storage_uri_class=self.bucket_storage_uri_class,
+          debug=self.debug)
+      web_config_xml = UnaryDictToXml(uri.get_website_config())
+    except TRANSLATABLE_BOTO_EXCEPTIONS, e:
+      self._TranslateExceptionAndRaise(e)
+
+    return XmlParseString(web_config_xml).toprettyxml()