Entry point for bisect sample comparison.

tracing/tracing/metrics/compare_samples.py

Index: tracing/tracing/metrics/compare_samples.py
diff --git a/tracing/tracing/metrics/compare_samples.py b/tracing/tracing/metrics/compare_samples.py
new file mode 100644
index 0000000000000000000000000000000000000000..0f7f76ce78d680144c932960f7d70765e9c26bc1
--- /dev/null
+++ b/tracing/tracing/metrics/compare_samples.py
@@ -0,0 +1,37 @@
+# Copyright 2016 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.
+
+import tempfile
+
+import tracing_project
+import vinn
+
+FORMAT_TO_METHOD = {
+    'chartjson': 'compareCharts',
+    'valueset': 'compareValuesets',
+    'buildbot': 'compareBuildbotOutputs'
+}
+
+def CompareSamples(sample_a, sample_b, metric, data_format='chartjson'):

[dtu, 2016/09/15 21:31:56]

Please docstring :)

[RobertoCN, 2016/09/19 20:07:43]

Done.

+  method = FORMAT_TO_METHOD[data_format]
+  project = tracing_project.TracingProject()
+  temp_out = tempfile.TemporaryFile()
+
+  cmd = """
+  HTMLImportsLoader.loadHTML('/tracing/metrics/compare_samples.html');
+  var results = tr.metrics.BisectComparison.%s('%s', '%s', '%s');
+  console.log(JSON.stringify(results));
+  """ % (method, sample_a, sample_b, metric)
+  try:
+    res = vinn.RunJsString(
+        cmd, source_paths=list(project.source_paths),
+        stdout=temp_out)

[dtu, 2016/09/15 21:31:56]

I think the default behavior is to stick the stdout into res.stdout (or in the
case of RuntimeError, to put it in the exception string). Do you need a
TemporaryFile here?

[RobertoCN, 2016/09/19 20:07:43]

Done.

+  except:
+    temp_out.seek(0)
+    print temp_out.read()  # Stack trace gets dumped here.
+    raise
+  temp_out.seek(0)
+  return res.returncode, temp_out.read()

[dtu, 2016/09/15 21:31:56]

If someone is using this as a library, this return value doesn't make sense.

[RobertoCN, 2016/09/19 20:07:43]

Done.

+
+