Refactor serving_dirs.

tools/telemetry/telemetry/util/cloud_storage.py

Index: tools/telemetry/telemetry/util/cloud_storage.py
diff --git a/tools/telemetry/telemetry/util/cloud_storage.py b/tools/telemetry/telemetry/util/cloud_storage.py
index ed97ccbb4837bcbab573b4fab844fc0898e9c1f1..1e9fc4f9831455c249b8a9b3588d5a632b71843d 100644
--- a/tools/telemetry/telemetry/util/cloud_storage.py
+++ b/tools/telemetry/telemetry/util/cloud_storage.py
@@ -15,6 +15,7 @@ import sys
 import tarfile
 import urllib2
 
+from telemetry import decorators
 from telemetry.core import util
 from telemetry.util import path
 
@@ -220,10 +221,8 @@ def Insert(bucket, remote_path, local_path, publicly_readable=False):
 
 
 def GetIfChanged(file_path, bucket):
-  """Gets the file at file_path if it has a hash file that doesn't match.
-
-  If the file is not in Cloud Storage, log a warning instead of raising an
-  exception. We assume that the user just hasn't uploaded the file yet.
+  """Gets the file at file_path if it has a hash file that doesn't match or
+  if there is no local copy of file_path, but there is a hash file for it.
 
   Returns:
     True if the binary was changed.
@@ -244,6 +243,25 @@ def GetIfChanged(file_path, bucket):
   Get(bucket, expected_hash, file_path)
   return True
 
+# TODO(aiolos): remove @decorators.Cache for http://crbug.com/459787
+@decorators.Cache
+def GetFilesInDirectoryIfChanged(directory, bucket):
+  """ Scan the directory for .sha1 files, and download them from the given
+  bucket in cloud storage if the local and remote hash don't match or
+  there is no local copy.
+  """
+  if not os.path.isdir(directory):
+    raise ValueError('Must provide a valid directory.')
+  # Don't allow the root directory to be a serving_dir.
+  if directory == os.path.abspath(os.sep):
+    raise ValueError('Trying to serve root directory from HTTP server.')
+  for dirpath, _, filenames in os.walk(directory):
+    for filename in filenames:
+      path_name, extension = os.path.splitext(
+          os.path.join(dirpath, filename))
+      if extension != '.sha1':
+        continue
+      GetIfChanged(path_name, bucket)
 
 def CalculateHash(file_path):
   """Calculates and returns the hash of the file at file_path."""