Add the basics of geographic data distribution and get the tests to work.

storage/distributedstorage.py

@@ -0,0 +1,41 @@
+import random
+import logging
+
+from functools import wraps
+
+from storage.basestorage import StoragePaths, BaseStorage
+
+
+logger = logging.getLogger(__name__)
+
+
+def _location_aware(unbound_func):
+  @wraps(unbound_func)
+  def wrapper(self, locations, *args, **kwargs):
+    storage = None
+    for preferred in self.preferred_locations:
+      if preferred in locations:
+        storage = self._storages[preferred]
+
+    if not storage:
+      storage = self._storages[random.sample(locations, 1)[0]]
+
+    storage_func = getattr(storage, unbound_func.__name__)
+    return storage_func(*args, **kwargs)
+  return wrapper
+
+
+class DistributedStorage(StoragePaths):
+  def __init__(self, storages, preferred_locations=[]):
+    self._storages = dict(storages)
+    self.preferred_locations = list(preferred_locations)
+
+  get_direct_download_url = _location_aware(BaseStorage.get_direct_download_url)
+  get_content = _location_aware(BaseStorage.get_content)
+  put_content = _location_aware(BaseStorage.put_content)
+  stream_read = _location_aware(BaseStorage.stream_read)
+  stream_read_file = _location_aware(BaseStorage.stream_read_file)
+  stream_write = _location_aware(BaseStorage.stream_write)
+  list_directory = _location_aware(BaseStorage.list_directory)
+  exists = _location_aware(BaseStorage.exists)
+  remove = _location_aware(BaseStorage.remove)