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..d8341d0b333975c7770e5bec488200ea2ff840b6
--- /dev/null
+++ b/tracing/tracing/metrics/compare_samples.py
@@ -0,0 +1,32 @@
+# 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
+
+
+def CompareSamples(sample_a, sample_b, metric, data_format='chartjson'):
+  method = 'compareCharts' if data_format == 'chartjson' else 'compareValuesets'
+  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:

[RobertoCN, 2016/09/01 19:28:23]

loop ned in about the potential exceptions risen from vinn.runjsstring

[RobertoCN, 2016/09/02 21:19:31]

Adding him as reviewer.

+    res = vinn.RunJsString(
+        cmd, source_paths=list(project.source_paths),
+        stdout=temp_out)
+  except:

[benjhayden, 2016/08/10 17:40:21]

What types of exceptions can be caught here?

+    temp_out.seek(0)
+    print temp_out.read()  # Stack trace gets dumped here.
+    raise

[benjhayden, 2016/08/10 17:40:21]

Can you raise a specific type of exception?

+  temp_out.seek(0)
+  return res.returncode, temp_out.read()
+
+