rebaseline_server: add pixel diffs, and sorting by diff metrics

gm/rebaseline_server/imagediffdb-test.py

+#!/usr/bin/python
+
+"""
+Copyright 2013 Google Inc.
+
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file.
+
+Test imagediffdb.py

[epoger, 2013/11/07 21:11:54]

Moved the self-test code into this new file.

[jcgregorio, 2013/11/08 02:02:29]

Please rename to imagediffdb_test.py. A file imagediffdb-test.py isn't
importable as a module, something we may want to do when we get more unit tests.
See below on using Python's unittest module.


On 2013/11/07 21:11:54, epoger wrote:

[epoger, 2013/11/08 16:11:28]

Done.

+"""
+
+# System-level imports
+import logging
+
+# Local imports
+import imagediffdb
+
+
+IMAGE_URL_BASE = 'http://chromium-skia-gm.commondatastorage.googleapis.com/gm/bitmap-64bitMD5/'
+
+def main():
+  logging.basicConfig(level=logging.INFO)
+
+  # params for each self-test:
+  # 0. expected image locator
+  # 1. expected image URL
+  # 2. actual image locator
+  # 3. actual image URL
+  # 4. expected percent_pixels_differing (as a string, to 4 decimal places)
+  # 5. expected weighted_diff_measure (as a string, to 4 decimal places)
+  selftests = [
+      ['16206093933823793653',
+       IMAGE_URL_BASE + 'arcofzorro/16206093933823793653.png',
+       '13786535001616823825',
+       IMAGE_URL_BASE + 'arcofzorro/13786535001616823825.png',
+       '0.0653', '0.0113'],
+  ]
+
+  # Add all image pairs to the database
+  db = imagediffdb.ImageDiffDB('/tmp/ImageDiffDB')
+  for selftest in selftests:
+    retval = db.add_image_pair(
+        expected_image_locator=selftest[0], expected_image_url=selftest[1],
+        actual_image_locator=selftest[2],   actual_image_url=selftest[3])
+
+  # Fetch each image pair from the database
+  for selftest in selftests:

[jcgregorio, 2013/11/08 02:02:29]

Either convert tests to use Python's unittest framework, or add a TODO to that
effect.

[epoger, 2013/11/08 16:11:28]

Added a TODO at the top of the renamed file.

+    record = db.get_diff_record(expected_image_locator=selftest[0],
+                                actual_image_locator=selftest[2])
+    assert (('%.4f' % record.get_percent_pixels_differing()) == selftest[4])
+    assert (('%.4f' % record.get_weighted_diff_measure()) == selftest[5])
+
+  logging.info("Self-test completed successfully!")
+
+
+if __name__ == '__main__':
+  main()