Add a reporter for verbs to track number of storage streams are needed

endpoints/verbs/__init__.py

@@ -21,6 +21,7 @@ from util.http import exact_abort
 from util.registry.filelike import wrap_with_handler
 from util.registry.queuefile import QueueFile
 from util.registry.queueprocess import QueueProcess
+from util.registry.tarlayerformat import TarLayerFormatterReporter
 from util.registry.torrent import (
   make_torrent, per_user_torrent_filename, public_torrent_filename, PieceHasher)
 
@@ -32,7 +33,15 @@ license_validator.enforce_license_before_request(verbs)
 LAYER_MIMETYPE = 'binary/octet-stream'
 
 
-def _open_stream(formatter, repo_image, tag, derived_image_id, handlers):
+class VerbReporter(TarLayerFormatterReporter):
+  def __init__(self, kind):
+    self.kind = kind
+
+  def report_pass(self, pass_count):
+    metric_queue.verb_action_passes.Inc(labelvalues=[self.kind, pass_count])
+
+
+def _open_stream(formatter, repo_image, tag, derived_image_id, handlers, reporter):
   """
   This method generates a stream of data which will be replicated and read from the queue files.
   This method runs in a separate process.
@@ -47,14 +56,14 @@ def _open_stream(formatter, repo_image, tag, derived_image_id, handlers):
       yield current_image
 
   def image_stream_getter(store, current_image):
-    def func():
+    def get_stream_for_storage():
       current_image_path = model.get_blob_path(current_image.blob)
       current_image_stream = store.stream_read_file(current_image.blob.locations,
                                                     current_image_path)
 
       logger.debug('Returning image layer %s: %s', current_image.image_id, current_image_path)
       return current_image_stream
-    return func
+    return get_stream_for_storage
 
   def tar_stream_getter_iterator():
     # Re-Initialize the storage engine because some may not respond well to forking (e.g. S3)
@@ -63,7 +72,7 @@ def _open_stream(formatter, repo_image, tag, derived_image_id, handlers):
       yield image_stream_getter(store, current_image)
 
   stream = formatter.build_stream(repo_image, tag, derived_image_id, get_next_image,
-                                  tar_stream_getter_iterator)
+                                  tar_stream_getter_iterator, reporter=reporter)
 
   for handler_fn in handlers:
     stream = wrap_with_handler(stream, handler_fn)
@@ -286,7 +295,8 @@ def _repo_verb(namespace, repository, tag, verb, formatter, sign=False, checker=
   # Create a queue process to generate the data. The queue files will read from the process
   # and send the results to the client and storage.
   handlers = [hasher.update]
-  args = (formatter, repo_image, tag, derived_image_id, handlers)
+  reporter = VerbReporter(verb)
+  args = (formatter, repo_image, tag, derived_image_id, handlers, reporter)
   queue_process = QueueProcess(
     _open_stream,
     8 * 1024,