[catapult] - Copy Telemetry's gsutilz over to third_party.

third_party/gsutil/gslib/addlhelp/throttling.py

Index: third_party/gsutil/gslib/addlhelp/throttling.py
diff --git a/third_party/gsutil/gslib/addlhelp/throttling.py b/third_party/gsutil/gslib/addlhelp/throttling.py
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+++ b/third_party/gsutil/gslib/addlhelp/throttling.py
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+# -*- coding: utf-8 -*-
+# Copyright 2015 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.
+"""Additional help text for throttling gsutil."""
+
+from __future__ import absolute_import
+
+from gslib.help_provider import HelpProvider
+
+_DETAILED_HELP_TEXT = ("""
+<B>OVERVIEW</B>
+  Particularly when used with the -m (multi-threading) option, gsutil can
+  consume a significant amount of network bandwidth. In some cases this can
+  cause problems, for example if you start a large rsync operation over a
+  network connection used by a number of other important production tasks.
+
+  While gsutil has no built-in support for throttling requests, there are
+  various tools available on Linux and MacOS that can be used to throttle
+  gsutil requests.
+
+  One tool is `trickle<http://monkey.org/~marius/pages/?page=trickle>`_
+  (available via apt-get on Ubuntu systems), which will let you limit how much
+  bandwidth gsutil consumes. For example, the following command would limit
+  upload and download bandwidth consumed by gsutil rsync to 100 KBps:
+
+      trickle -d 100 -u 100 gsutil -m rsync -r ./dir gs://some bucket
+
+  Another tool is
+  `ionice<http://www.tutorialspoint.com/unix_commands/ionice.htm>`_ (built
+  in to many Linux systems), which will let you limit how much I/O capacity
+  gsutil consumes (e.g., to avoid letting it monopolize your local disk). For
+  example, the following command would reduce I/O priority of gsutil so it
+  doesn't monopolize your local disk:
+
+      ionice -c 2 -n 7 gsutil gsutil -m rsync -r ./dir gs://some bucket
+""")
+
+
+class CommandOptions(HelpProvider):
+  """Additional help text for throttling gsutil."""
+
+  # Help specification. See help_provider.py for documentation.
+  help_spec = HelpProvider.HelpSpec(
+      help_name='throttling',
+      help_name_aliases=['bandwidth', 'limit', 'nice'],
+      help_type='additional_help',
+      help_one_line_summary='Throttling gsutil',
+      help_text=_DETAILED_HELP_TEXT,
+      subcommand_help_text={},
+  )