Scripts to download files from google storage based on sha1 sums

third_party/gsutil/gslib/storage_uri_builder.py

+# Copyright 2012 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.
+
+"""
+Class that holds state (bucket_storage_uri_class and debug) needed for
+instantiating StorageUri objects. The StorageUri func defined in this class
+uses that state plus gsutil default flag values to instantiate this frequently
+constructed object with just one param for most cases.
+"""
+
+import boto
+import re
+from gslib.exception import CommandException
+
+GENERATION_RE = ('(?P<uri_str>.+)#'
+                 '(?P<generation>[0-9]+)(\.(?P<meta_generation>[0-9]+))?')
+VERSION_RE = '(?P<uri_str>.+)#(?P<version_id>.+)'
+
+
+class StorageUriBuilder(object):
+
+  def __init__(self, debug, bucket_storage_uri_class):
+    """
+    Args:
+      debug: Debug level to pass in to boto connection (range 0..3).
+      bucket_storage_uri_class: Class to instantiate for cloud StorageUris.
+                                Settable for testing/mocking.
+    """
+    self.bucket_storage_uri_class = bucket_storage_uri_class
+    self.debug = debug
+
+  def StorageUri(self, uri_str, parse_version=False):
+    """
+    Instantiates StorageUri using class state and gsutil default flag values.
+
+    Args:
+      uri_str: StorageUri naming bucket + optional object.
+      parse_version: boolean indicating whether to parse out version/generation
+          information from uri_str.
+
+    Returns:
+      boto.StorageUri for given uri_str.
+
+    Raises:
+      InvalidUriError: if uri_str not valid.
+    """
+    version_id = None
+    generation = None
+    meta_generation = None
+
+    uri_str_only = uri_str
+    if parse_version:
+      if uri_str.startswith('gs'):
+        match = re.search(GENERATION_RE, uri_str)
+        if not match:
+          raise CommandException(
+              'Generation number expected in uri %s' % uri_str)
+        md = match.groupdict()
+        uri_str_only = md['uri_str']
+        generation = int(md['generation'])
+        if md['meta_generation']:
+          meta_generation = int(md['meta_generation'])
+
+      elif uri_str.startswith('s3'):
+        match = re.search(VERSION_RE, uri_str)
+        if not match:
+          raise CommandException('Version ID expected in uri %s' % uri_str)
+        md = match.groupdict()
+        uri_str_only = md['uri_str']
+        version_id = md['version_id']
+
+      else:
+        raise CommandException('Unrecognized provider scheme in uri %s' %
+                               uri_str)
+
+    suri = boto.storage_uri(
+        uri_str_only, 'file', debug=self.debug, validate=False,
+        bucket_storage_uri_class=self.bucket_storage_uri_class,
+        suppress_consec_slashes=False)
+
+    suri.version_id = version_id
+    suri.generation = generation
+    suri.meta_generation = meta_generation
+
+    return suri