[Predator] Add ``Project`` class and ``ClassifySuspect`` method to project and component classifier

appengine/findit/handlers/crash/crash_config.py

 # 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.
 
 """Handles requests to the crash config page."""
 
 import json
 
 from google.appengine.api import users
 
 from common.base_handler import BaseHandler, Permission
 from model.crash.crash_config import CrashConfig as CrashConfigModel
 
 
+def _SortConfig(config):
+  """Sorts ``host_direcotries`` list in config dict.
+
+  N.B This method can only be called after validation function, namely the
+  config should be properly formatted.
+  """
+  project_config = config.get('project_classifier')
+  for project_pattern in project_config['project_path_function_hosts']:
+    # Validation assures that the host_directories in the 3rd index of
+    # project_pattern.
+    hosts = project_pattern[3]
+    for index, host in enumerate(hosts or []):
+      if not host.endswith('/'):
+        hosts[index] = host + '/'
+
+    if hosts:
+      hosts.sort(key=lambda host: -len(host.split('/')))
+
+
+def _ValidateComponentClassifierConfig(component_classifier_config):
+  """Checks that a component_classifier_config dict is properly formatted.
+
+  Args:
+    commponent_classifier_config (dict): A dictionary that provides component to
+      its function and path patterns, and some other settings.
+      For example:
+      {
+          'path_function_component': [
+              [
+                  'src/chrome/common/extensions/api/gcm.json',
+                  '',
+                  'Services>CloudMessaging'
+              ],
+              ...
+              [
+                  'src/chrome/browser/accessibility',
+                  '',
+                  'UI>Accessibility'
+              ],
+           ],
+          'top_n': 4
+      }
+
+  Returns:
+    True if ``component_classifier_config`` is properly formatted, False
+    otherwise.
+  """
+  if not isinstance(component_classifier_config, dict):
+    return False
+
+  path_function_component = component_classifier_config.get(
+      'path_function_component')
+  if not isinstance(path_function_component, list):
+    return False
+
+  top_n = component_classifier_config.get('top_n')
+  if not isinstance(top_n, int):
+    return False
+
+  return True
+
+
+def _ValidateProjectClassifierConfig(project_classifier_config):
+  """Checks that a project_classifier_config dict is properly formatted.
+
+  Args:
+    project_classifier_config (dict): A dictionary that provides mapping from
+      project to its function patterns, path patterns and its host_directories,
+      and some other settings.
+      For example:
+      {
+          'project_path_function_hosts': [
+              ['android_os', ['googleplex-android/'], ['android.'], None],
+              ['chromium', None, ['org.chromium'],
+               ['src/chrome/browser/resources/',
+                'src/chrome/test/data/layout_tests/',
+                'src/media/']]
+          ],
+          'non_chromium_project_rank_priority': {
+              'android_os': '-1',
+              'others': '-2',
+          },
+          'top_n': 4
+      }
+
+  Returns:
+    True if ``project_classifier_config`` is properly formatted, False
+    otherwise.
+  """
+  if not isinstance(project_classifier_config, dict):
+    return False
+
+  project_path_function_hosts = project_classifier_config.get(
+      'project_path_function_hosts')
+  if not isinstance(project_path_function_hosts, list):
+    return False
+
+  non_chromium_project_rank_priority = project_classifier_config.get(
+      'non_chromium_project_rank_priority')
+  if not isinstance(non_chromium_project_rank_priority, dict):
+    return False
+
+  top_n = project_classifier_config.get('top_n')
+  if not isinstance(top_n, int):
+    return False
+
+  return True
+
+
+# TODO(katesonia): Add validation function for ``cracas`` and ``fracas``.
+# Maps config properties to their validation functions.
+_CONFIG_VALIDATION_FUNCTIONS = {
+    'fracas': None,
+    'cracas': None,
+    'component_classifier': _ValidateComponentClassifierConfig,
+    'project_classifier': _ValidateProjectClassifierConfig
+}
+
+
+def _ConfigurationDictIsValid(configuration_dict):
+  """Checks that each configuration setting is properly formatted.
+
+  Args:
+      configuration_dict: A dictionary expected to map configuration properties
+      by name to their intended settings. For example,
+
+      configuration_dict = {
+          'some_config_property': (some dictionary),
+          'some_other_config_property': (some list),
+          'another_config_property': (some value),
+          ...
+      }
+
+  Returns:
+      True if all configuration properties are properly formatted, False
+      otherwise.
+  """
+  if not isinstance(configuration_dict, dict):
+    return False
+
+  for configurable_property, validation_function in (
+      _CONFIG_VALIDATION_FUNCTIONS.iteritems()):
+    if configurable_property not in configuration_dict:
+      return False
+
+    # No validation rules specified for this property.
+    if validation_function is None:
+      continue
+
+    configuration = configuration_dict[configurable_property]
+    if not validation_function(configuration):
+      return False
+
+  return True
+
+
 class CrashConfig(BaseHandler):
   PERMISSION_LEVEL = Permission.ADMIN
 
   def HandleGet(self):
     settings = CrashConfigModel.Get()
 
     data = {
         'fracas': settings.fracas,
         'cracas': settings.cracas,
         'component_classifier': settings.component_classifier,
         'project_classifier': settings.project_classifier,
     }
 
     return {'template': 'crash/crash_config.html', 'data': data}
 
   def HandlePost(self):
     data = self.request.params.get('data')
     new_config_dict = json.loads(data)
+    if not _ConfigurationDictIsValid(new_config_dict):
+      return self.CreateError(
+          'New configuration settings are not properly formatted.', 400)
+
+    # Sort config dict in place.
+    _SortConfig(new_config_dict)
 
     crash_config = CrashConfigModel.Get()
-
     crash_config.ClearCache()
     crash_config.Update(
         users.get_current_user(), users.IsCurrentUserAdmin(), **new_config_dict)
     return self.HandleGet()