Add usage message with available page_sets and benchmarks.

tools/telemetry/telemetry/core/discover.py

Index: tools/telemetry/telemetry/core/discover.py
diff --git a/tools/telemetry/telemetry/core/discover.py b/tools/telemetry/telemetry/core/discover.py
index 9e8118a731fd59e29f834043096b5438750eb694..9ef13cf8bd366e904ac37cce3a374dc558643b01 100644
--- a/tools/telemetry/telemetry/core/discover.py
+++ b/tools/telemetry/telemetry/core/discover.py
@@ -6,11 +6,16 @@ import fnmatch
 import inspect
 import os
 import re
+import sys
 
 from telemetry import decorators
 from telemetry.core import camel_case
+from telemetry.core import environment
 from telemetry.core import util
 from telemetry.page import page_set
+from telemetry.page import profile_creator
+
+config = environment.Environment([util.GetBaseDir()])

[nednguyen, 2014/09/04 03:31:37]

Why do we need a global?

 
 
 @decorators.Cache
@@ -133,3 +138,67 @@ def IsPageSetFile(file_path):
     return False
   module = util.GetPythonPageSetModule(file_path)
   return bool(DiscoverClassesInModule(module, page_set.PageSet))
+
+
+@decorators.Cache
+def GetValidSubclassesOfClasses(base_classes, base_dir=None):

[nednguyen, 2014/09/04 03:31:37]

Please add docstring for this function and the ones below.

+  classes = []
+  for base_class in base_classes:
+    paths = config.base_paths if base_dir is None else [base_dir]
+    for base_dir in paths:
+      classes += DiscoverClasses(base_dir, base_dir, base_class,
+                                 index_by_class_name=True).values()
+  return [cls for cls in classes
+          if not issubclass(cls, profile_creator.ProfileCreator)]
+
+
+def MatchName(base_classes, input_name, exact_matches=True, base_dir=None):
+  def _Matches(input_string, search_string):
+    if search_string.startswith(input_string):
+      return True
+    for part in search_string.split('.'):
+      if part.startswith(input_string):
+        return True
+    return False
+
+  # Exact matching.
+  if exact_matches:
+    # Don't add aliases to search dict, only allow exact matching for them.
+    if input_name in config.test_aliases:
+      exact_match = config.test_aliases[input_name]
+    else:
+      exact_match = input_name
+
+    for test_class in GetValidSubclassesOfClasses(base_classes, base_dir):
+      if exact_match == test_class.Name():
+        return [test_class]
+
+  # Fuzzy matching.
+  return [test_class for test_class in GetValidSubclassesOfClasses(base_classes,
+                                                                   base_dir)
+          if _Matches(input_name, test_class.Name())]
+
+
+def PrintAvailableClasses(base_classes, class_list=None,
+                          output_stream=sys.stdout):

[nednguyen, 2014/09/04 03:31:37]

Can we split this function to two functions: one that prints class in
classes_list in sorted order, and one that finds subclasses of base_classes?

And do we really have the use cases on the call sites that need the 2nd
function?

+  if class_list is None:
+    class_list = GetValidSubclassesOfClasses(base_classes)
+
+  if not class_list:
+    sys.stderr.write('No tests found!\n')
+    return
+
+  # Align the class names to the longest one.
+  format_string = '  %%-%ds %%s' % max(len(cls.Name()) for cls in class_list)
+
+  output = []
+  for base_class in base_classes:
+    classes = [cls for cls in class_list if issubclass(cls, base_class)]
+    if classes:
+      output.append('Available %ss are:' % base_class.Name())
+      sorted_classes = sorted(classes, key=lambda c: c.Name())
+      formatted_classes = map(
+          lambda c: format_string % (c.Name(), c.Description()), sorted_classes)
+      output.extend(formatted_classes)
+    output.append('')
+  output_stream.write('\n'.join(output))