Adding gather_stats (based on bisect-builds.py) to gather benchmarking

tools/bisect-builds.py

Index: tools/bisect-builds.py
diff --git a/tools/bisect-builds.py b/tools/bisect-builds.py
index 04b4689d4e42dd5935ff9fcb4b6b21bc11c7001f..3ccc2f03fec1de26a04da3d8fab6c820bb1ec859 100755
--- a/tools/bisect-builds.py
+++ b/tools/bisect-builds.py
@@ -182,7 +182,7 @@ class PathContext(object):
         except ValueError:
           pass
       return (revisions, next_marker)
-      
+
     # Fetch the first list of revisions.
     (revisions, next_marker) = _FetchAndParse(self.GetListingURL())
 
@@ -296,23 +296,31 @@ def FetchRevision(context, rev, filename, quit_event=None, progress_event=None):
     pass
 
 
-def RunRevision(context, revision, zipfile, profile, num_runs, args):
-  """Given a zipped revision, unzip it and run the test."""
+def RunRevision(context, revision, zipfile, num_runs, exec_args, outdir=None):
+  """Given a zipped revision, unzip it and run the test.
+  @param context A PathContext instance.
+  @param revision The Chromium revision number/tag to run.
+  @param zipfile Path to a zip file containing the Chromium revision.
+  @param num_runs Number of times to run the given Chromium revision.
+  @param exec_args Function which takes in the path of the unzipped Chromium
+                    revision and returns the full command to execute Chromium.
+  @param outdir Path to save output to. If specified, stdout will be saved at
+                    outdir/<revision>_<iteration>.out and stderr will be saved
+                    at outdir/<revision>_<iteration>.err. If left as None, the
+                    output is not saved.
+  """
   print "Trying revision %s..." % str(revision)
 
-  # Create a temp directory and unzip the revision into it.
-  cwd = os.getcwd()
   tempdir = tempfile.mkdtemp(prefix='bisect_tmp')
   UnzipFilenameToDir(zipfile, tempdir)
-  os.chdir(tempdir)
+  testargs = exec_args(os.path.join(tempdir, context.GetLaunchPath()))
 
-  # Run the build as many times as specified.
-  testargs = [context.GetLaunchPath(), '--user-data-dir=%s' % profile] + args
   # The sandbox must be run as root on Official Chrome, so bypass it.
   if context.is_official and (context.platform == 'linux' or
       context.platform == 'linux64'):
     testargs.append('--no-sandbox')
 
+  # Run the build as many times as specified.
   for i in range(0, num_runs):
     subproc = subprocess.Popen(testargs,
                                bufsize=-1,
@@ -320,7 +328,19 @@ def RunRevision(context, revision, zipfile, profile, num_runs, args):
                                stderr=subprocess.PIPE)
     (stdout, stderr) = subproc.communicate()
 
-  os.chdir(cwd)
+    if outdir is not None:
+      if not os.path.isdir(outdir):
+        os.mkdir(outdir)
+
+      fout = open(os.path.join(outdir, '%s_%s.out' % (str(revision), str(i))),
+                  'w')
+      fout.write(stdout)
+      fout.close()
+      ferr = open(os.path.join(outdir, '%s_%s.err' % (str(revision), str(i))),
+                  'w')
+      ferr.write(stderr)
+      ferr.close()
+
   try:
     shutil.rmtree(tempdir, True)
   except Exception, e:
@@ -471,6 +491,9 @@ def Bisect(platform,
                              _GetDownloadPath(up_rev))
       up_fetch.Start()
 
+    def execute_args(chrome_path):
+      return [chrome_path, '--user-data-dir=%s' % profile] + try_args
+
     # Run test on the pivot revision.
     status = None
     stdout = None
@@ -479,11 +502,11 @@ def Bisect(platform,
       (status, stdout, stderr) = RunRevision(context,
                                              rev,
                                              zipfile,
-                                             profile,
                                              num_runs,
-                                             try_args)
+                                             execute_args)
     except Exception, e:
       print >>sys.stderr, e
+
     os.unlink(zipfile)
     zipfile = None