[Android] memory_inspector: update PRESUBMIT.py to check prebuilts.

tools/memory_inspector/PRESUBMIT.py

Index: tools/memory_inspector/PRESUBMIT.py
diff --git a/tools/memory_inspector/PRESUBMIT.py b/tools/memory_inspector/PRESUBMIT.py
index 5d0e21e3d35ec130486171526ef8518fef52cd38..9e44d9e8d2e3abd16dcc95c2dbaa7c99c15328c8 100644
--- a/tools/memory_inspector/PRESUBMIT.py
+++ b/tools/memory_inspector/PRESUBMIT.py
@@ -9,7 +9,7 @@ details on the presubmit API built into gcl.
 """
 
 
-def CommonChecks(input_api, output_api):
+def _CommonChecks(input_api, output_api):
   output = []
   blacklist = [r'classification_rules.*']
   output.extend(input_api.canned_checks.RunPylint(
@@ -30,9 +30,46 @@ def CommonChecks(input_api, output_api):
   return output
 
 
+def _CheckPrebuiltsAreUploaded(input_api, output_api):
+  import sys
+  import urllib2
+  old_sys_path = sys.path[:]

[M-A Ruel, 2014/09/12 13:58:37]

Actually you want to do the reverse;

old_sys_path = sys.path
try:
  sys.path = [input_api.PresubmitLocalPath()] + sys.path
  ...
finally:
  sys.path = old_sys_path

[Primiano Tucci (use gerrit), 2014/09/12 15:30:41]

Uh? I'm fine both ways.
Can I ask just you what would be the difference between creating a copy before,
mangling the original path and reassigning the copy versus assigning the path to
a new mangled one and restoring the original?

[M-A Ruel, 2014/09/16 13:00:19]

Well, the original could be something else than a list. Technically, it could be
anything implementing a list-like behavior, this is python. :)

+  try:
+    sys.path.append(input_api.os_path.join(input_api.PresubmitLocalPath()))
+    from memory_inspector import constants
+  finally:
+    sys.path = old_sys_path
+  missing_files = []
+  for f in input_api.os_listdir(constants.PREBUILTS_PATH):
+    if not f.endswith('.sha1'):
+      continue
+    prebuilt_sha_path = input_api.os_path.join(constants.PREBUILTS_PATH, f)
+    with open(prebuilt_sha_path) as sha_file:
+      sha = sha_file.read().strip()
+    url = constants.PREBUILTS_BASE_URL + sha

[M-A Ruel, 2014/09/12 13:58:37]

Is it https?

[Primiano Tucci (use gerrit), 2014/09/12 15:30:42]

Yes, it is
PREBUILTS_BASE_URL = 'https://storage.googleapis.com/chromium-telemetry/'

+    request = urllib2.Request(url)
+    request.get_method = lambda : 'HEAD'
+    try:
+      urllib2.urlopen(request)

[M-A Ruel, 2014/09/12 13:58:37]

Use a timeout

[Primiano Tucci (use gerrit), 2014/09/12 15:30:41]

Done.

+    except Exception, e:

[M-A Ruel, 2014/09/12 13:58:37]

Exception as e:

[Primiano Tucci (use gerrit), 2014/09/12 15:30:42]

Done.

+      if isinstance(e, urllib2.HTTPError) and e.code == 404:
+        missing_files += [prebuilt_sha_path]
+      else:
+        return [output_api.PresubmitError('HTTP Error while checking %s' % url,
+                                          long_text=str(e))]
+  if missing_files:
+    return [output_api.PresubmitError(
+        'Some prebuilts have not been uploaded. Perhaps you forgot to '
+        'upload_to_google_storage.py?', missing_files)]
+  return []
+
+
 def CheckChangeOnUpload(input_api, output_api):
-  return CommonChecks(input_api, output_api)
+  results = []
+  results.extend(_CommonChecks(input_api, output_api))
+  results.extend(_CheckPrebuiltsAreUploaded(input_api, output_api))
+  return results
 
 
 def CheckChangeOnCommit(input_api, output_api):
-  return CommonChecks(input_api, output_api)
+  return _CommonChecks(input_api, output_api)