Split GenerateBenchGraphs into three build steps

slave/skia_slave_scripts/check_for_regressions.py

 #!/usr/bin/env python

[borenet, 2013/03/12 12:15:38]

SVN-copied from generate_bench_graphs.py.

 # Copyright (c) 2012 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.
 
-""" Generate performance graphs from bench output. """
+""" Check for regressions in bench data. """
 
 from build_step import BuildStep
-from utils import bench_common
 from utils import shell_utils
-from utils import sync_bucket_subdir
 
-import errno
 import os
-import posixpath
 import sys
 
 
-class GenerateBenchGraphs(BuildStep):
+class CheckForRegressions(BuildStep):
   def __init__(self, timeout=600, no_output_timeout=600, **kwargs):
-    super(GenerateBenchGraphs, self).__init__(
+    super(CheckForRegressions, self).__init__(
         timeout=timeout,
         no_output_timeout=no_output_timeout,
         **kwargs)
 
   def _RunInternal(self, representation):
-    try:
-      os.makedirs(self._perf_graphs_dir)
-    except OSError as e:
-      if e.errno == errno.EEXIST:
-        pass
-      else:
-        raise e
-    dest_gsbase = (self._args.get('dest_gsbase') or
-                   sync_bucket_subdir.DEFAULT_PERFDATA_GS_BASE)
-
     path_to_bench_graph_svg = os.path.join('bench', 'bench_graph_svg.py')
     path_to_bench_expectations = os.path.join('bench',
                                               'bench_expectations.txt')
     graph_title = 'Bench_Performance_for_%s' % self._builder_name
-    graph_filepath = bench_common.GraphFilePath(self._perf_graphs_dir,
-                                                self._builder_name,
-                                                representation)
-    sync_bucket_subdir.SyncBucketSubdir(directory=self._perf_data_dir,
-        dest_gsbase=dest_gsbase,
-        subdir=posixpath.join('perfdata', self._builder_name),
-        do_upload=False,
-        do_download=True,
-        min_download_revision=self._got_revision -
-            bench_common.BENCH_GRAPH_NUM_REVISIONS)
-
     cmd = ['python', path_to_bench_graph_svg,

[epoger, 2013/03/12 15:58:33]

Maybe add a comment like this?

Run bench_graph_svg in such a mode that it just looks for performance
regressions in the most recent revision.

            '-d', self._perf_data_dir,
            '-e', path_to_bench_expectations,
-           '-r', '-%d' % bench_common.BENCH_GRAPH_NUM_REVISIONS,
-           '-f', '-%d' % bench_common.BENCH_GRAPH_NUM_REVISIONS,
-           '-x', '%d' % bench_common.BENCH_GRAPH_X,
-           '-y', '%d' % bench_common.BENCH_GRAPH_Y,
+           '-r', '-1',
+           '-f', '-1',
            '-l', graph_title,
            '-m', representation,
-           '-o', graph_filepath,
            ]
     if self._builder_name.find('_Win') >= 0:
       cmd.extend(['-i', 'c'])  # Ignore cpu time for Windows.
 
     shell_utils.Bash(cmd)
 
   def _Run(self):
     if self._perf_data_dir:
       for rep in ['avg', 'min', 'med', '25th']:
         self._RunInternal(rep)
 
 
 if '__main__' == __name__:
-  sys.exit(BuildStep.RunBuildStep(GenerateBenchGraphs))
+  sys.exit(BuildStep.RunBuildStep(CheckForRegressions))