Add script to verify that image files exist for every actual_result checksum

tools/verify_images_for_gm_results.py

Index: tools/verify_images_for_gm_results.py
===================================================================
--- tools/verify_images_for_gm_results.py	(revision 0)
+++ tools/verify_images_for_gm_results.py	(revision 0)
@@ -0,0 +1,147 @@
+#!/usr/bin/python

[epoger, 2013/07/11 14:14:25]

Some high-level, long-term thoughts:

A. This script could be the basis for a tool to "groom" the images stored in
Google Storage (deleting any that aren't referred to anymore, so that it does
not grow without bound).


B. In the long term (not necessary right away), I think this script could
operate more efficiently by being implemented this way:

1. Iterate over all the actual-results.json (and maybe expected-results.json)
files, building up a checksums_needed dictionary like this:

{
  'aaclip': set(['111111', '2222222']),
  'imageblur': set('333333', '444444']),
  ...
}

2. Do a "gsutil ls" of each test directory in Google Storage ('aaclip', then
'imageblur', etc.; this is more efficient than doing a "gsutil ls" of each file)
to build up a checksums_available dictionary like this:

{
  'aaclip': set(['2222222']),
  'imageblur': set('333333', '444444', '555555']),
  ...
}

3. Diff the two dictionaries:

missing_checksums = checksums_needed - checksums_available
checksums_we_can_delete = checksums_available - checksums_needed

+
+# Copyright (c) 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+
+""" Look through skia-autogen, searching for all checksums which should have
+corresponding files in Google Storage, and verify that those files exist. """
+
+
+import json
+import posixpath
+import re
+import subprocess
+import sys
+
+
+AUTOGEN_URL = 'http://skia-autogen.googlecode.com/svn/gm-actual'
+GS_URL = 'gs://chromium-skia-gm/gm'
+TEST_NAME_PATTERN = re.compile('(\S+)_(\S+).png')
+
+
+def FileNameToGSURL(filename, hash_type, hash_value):
+  """ Convert a file name given in a checksum file to the URL of the
+  corresponding image file in Google Storage.
+
+  filename: string; the file name to convert. Takes the form specified by
+      TEST_NAME_PATTERN.
+  hash_type: string; the type of the checksum.
+  hash_value: string; the checksum itself.
+  """
+  test_name = TEST_NAME_PATTERN.match(filename).group(1)
+  if not test_name:
+    raise Exception('Invalid test name for file: %s' % filename)
+  return '%s/%s/%s/%s.png' % (GS_URL, hash_type, test_name, hash_value)
+
+
+def FindURLSInJSON(json_file, gs_urls):
+  """ Extract Google Storage URLs from a JSON file in svn, adding them to the
+  gs_urls dictionary.
+
+  json_file: string; URL of the JSON file.
+  gs_urls: dict; stores Google Storage URLs as keys and lists of the JSON files

[epoger, 2013/07/11 14:14:25]

optional: I find that a small example of a valid dictionary is very helpful in
these cases

+      which reference them.
+  """
+  output = subprocess.check_output(['svn', 'cat', json_file])
+  json_content = json.loads(output)
+  for dict_type in ['actual-results']:
+    for result_type in json_content[dict_type]:
+      if json_content[dict_type][result_type]:
+        for result in json_content[dict_type][result_type].keys():
+          hash_type, hash_value = json_content[dict_type][result_type][result]
+          gs_url = FileNameToGSURL(result, hash_type, str(hash_value))
+          if gs_urls.get(gs_url):
+            gs_urls[gs_url].append(json_file)
+          else:
+            gs_urls[gs_url] = [json_file]
+
+
+def _FindJSONFiles(url, json_files):
+  """ Helper function for FindJsonFiles. Recursively explore the repository,
+  adding JSON files to a list.
+
+  url: string; URL of the repository (or subdirectory thereof) to explore.
+  json_files: list to which JSON file urls will be added.
+  """
+  proc = subprocess.Popen(['svn', 'ls', url], stdout=subprocess.PIPE,
+                          stderr=subprocess.STDOUT)
+  if proc.wait() != 0:
+    raise Exception('Failed to list svn directory.')
+  output = proc.communicate()[0].splitlines()
+  subdirs = []
+  for item in output:
+    if item.endswith(posixpath.sep):
+      subdirs.append(item)
+    elif item.endswith('.json'):
+      json_files.append(posixpath.join(url, item))
+    else:
+      print 'Warning: ignoring %s' % posixpath.join(url, item)
+  for subdir in subdirs:
+    _FindJSONFiles(posixpath.join(url, subdir), json_files)
+
+
+def FindJSONFiles(url):
+  """ Recursively explore the given repository and return a list of the JSON
+  files it contains.
+
+  url: string; URL of the repository to explore.
+  """
+  print 'Searching for JSON files in %s' % url
+  json_files = []
+  _FindJSONFiles(url, json_files)
+  return json_files
+
+
+def FindURLs(url):
+  """ Find Google Storage URLs inside of JSON files in the given repository.
+  Returns a dictionary whose keys are Google Storage URLs and values are lists
+  of the JSON files which reference them.
+
+  url: string; URL of the repository to explore.
+  """
+  gs_urls = {}
+  for json_file in FindJSONFiles(url):
+    print 'Looking for checksums in %s' % json_file
+    FindURLSInJSON(json_file, gs_urls)
+  return gs_urls
+
+
+def VerifyURL(url):
+  """ Verify that the given URL exists.
+
+  url: string; the Google Storage URL of the image file in question.
+  """
+  proc = subprocess.Popen(['gsutil', 'ls', url], stdout=subprocess.PIPE,
+                          stderr=subprocess.STDOUT)
+  if proc.wait() != 0:
+    return False
+  return True
+
+
+def VerifyURLs(urls):
+  """ Verify that each of the given URLs exists. Return a list of which URLs do
+  not exist.
+  
+  urls: dictionary; URLs of the image files in question.
+  """
+  print 'Verifying that images exist for URLs...'
+  missing = []
+  for url in urls.iterkeys():
+    if not VerifyURL(url):
+      print 'Missing: %s, referenced by: \n  %s' % (url, '\n  '.join(urls[url]))
+      missing.append(url)
+  return missing
+
+
+def Main():
+  urls = FindURLs(AUTOGEN_URL)
+  missing = VerifyURLs(urls)
+  if missing:
+    print 'Found %d Missing files.' % len(missing)
+    return 1
+
+
+if __name__ == '__main__':
+  sys.exit(Main())