Added `cros_pin` CrOS pin-bump tool.

infra/libs/gitiles/gitiles.py

Index: infra/libs/gitiles/gitiles.py
diff --git a/infra/libs/gitiles/gitiles.py b/infra/libs/gitiles/gitiles.py
index 97d16db8e5f9ee8eb8fc7ac47512938cb4b97355..4bf984fd81e8cd84637b4171baf186356ddb0c46 100644
--- a/infra/libs/gitiles/gitiles.py
+++ b/infra/libs/gitiles/gitiles.py
@@ -8,6 +8,7 @@
 
 import base64
 import logging
+import httplib
 import httplib2
 import json
 import urlparse
@@ -18,11 +19,15 @@ import time
 LOGGER = logging.getLogger(__name__)
 
 
+# The default number of retries when a Gitiles error is encountered.
+DEFAULT_RETRIES = 10
+
+
 class GitilesError(Exception):
   pass
 
 
-def call_gitiles(url, response_format, netrc_path=None, max_attempts=10):
+def call_gitiles(url, response_format, netrc_path=None, max_attempts=None):
   """Invokes Gitiles API and parses the JSON result.
   
   Given a gitiles URL, makes a ?format=json or ?format=text call and interprets
@@ -38,12 +43,13 @@ def call_gitiles(url, response_format, netrc_path=None, max_attempts=10):
              not specified, no authentication is used.
 
   max_attempts is the number of attempts to call gitiles before giving up on
-              error.
+              error. If None/zero, DEFAULT_RETRIES will be used.
   """
   assert response_format in ('json', 'text'), (
       'response must be either json or text')
   assert '?' not in url, 'url must not have a query parameter (?)'
 
+  max_attempts = max_attempts or DEFAULT_RETRIES
   http = httplib2.Http()
   headers = {}
   if netrc_path:
@@ -59,8 +65,10 @@ def call_gitiles(url, response_format, netrc_path=None, max_attempts=10):
         'GET',
         headers=headers
     )
-    if response['status'] != '200':
-      LOGGER.warning('GET %s failed with HTTP code %s', url, response['status'])
+    if response.status != httplib.OK:
+      LOGGER.warning('GET %s failed with HTTP code %d', url, response.status)
+      if response.status < httplib.INTERNAL_SERVER_ERROR:
+        break
       if attempt != max_attempts:
         LOGGER.warning('Retrying...')
       continue  # pragma: no cover (actually reached, see https://goo.gl/QA8B2U)
@@ -85,3 +93,28 @@ def get_oauth_token_from_netrc(url, netrc_path):
         'netrc file %s is missing an entry for %s' % (
           netrc_path, parsed.hostname))
   return auth[2]
+
+
+class Repository(object):
+  def __init__(self, base_url, netrc_path=None, max_attempts=None):
+    self._base_url = self._trim_slashes(base_url)
+    self._netrc_path = netrc_path
+    self._max_attempts = max_attempts
+
+  @staticmethod
+  def _trim_slashes(v):
+    return v.strip('/')
+
+  def __call__(self, ref='master', subpath=None):
+    url = [self._base_url, '+', ref]
+    if subpath:
+      url.append(self._trim_slashes(subpath))
+    url = '/'.join(url)
+    return call_gitiles(
+        url,
+        'json',
+        netrc_path=self._netrc_path,
+        max_attempts=self._max_attempts)
+
+  def ref_info(self, ref):
+    return self(ref)