Create DependencyManager API.

tools/telemetry/catapult_base/dependency_manager.py

+# Copyright 2015 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.
+
+
+class UnsupportedConfigFormatError(ValueError):
+  def __init__(self, config_type, config_file):
+    if not config_type:
+      message = ('The json file at %s is unsupported by the dependency_manager '
+                 'due to no specified config type' % config_file)
+    else:
+      message = ('The json file at %s has config type %s, which is unsupported '
+                 'by the dependency manager.' % (config_file, config_type))
+    super(UnsupportedConfigFormatError, self).__init__(message)
+
+
+class EmptyConfigError(ValueError):
+  def __init__(self, file_path):
+    super(EmptyConfigError, self).__init__('Empty config at %s.' % file_path)
+
+
+class ConfigConflictError(Exception):
+  def __init__(self, config_files, conflict):
+    super(ConfigConflictError, self).__init__(
+        'Multiple definitions of %s found in given config files: %s .'
+        'Only overrides of local_path are allowed.' % (config_files, conflict))
+
+
+class FileNotFoundError(Exception):
+  def __init__(self, file_path):
+    super(FileNotFoundError, self).__init__('No file found at %s' % file_path)
+
+
+class NoPathFoundError(FileNotFoundError):
+  def __init__(self, dependency, platform, arch):
+    super(NoPathFoundError, self).__init__(
+        'No file could be found locally, and no file to download from cloud '
+        'storage for %s on platform %s and arch %s' % (dependency, platform,
+                                                       arch))
+
+
+class DependencyManager(object):
+  def __init__(self, config_files):
+    pass
+
+  def FetchPath(self, dependency, platform, arch):
+    """Find the given dependency in the locations given in configs.
+
+    Return a path to the appropriate executable for <dependency>,

[nednguyen, 2015/08/06 21:26:38]

|dependency|

+    downloading from cloud storage if needed, or None if it cannot be found.
+    """
+    raise NotImplementedError
+
+  def LocalPath(self, dependency, platform, arch):
+    """Get a local version of the dependency from locations given in configs.
+
+    Return a local path to the given dependency name, or None if an
+    executable cannot be found. Will not download the executable.
+    """
+    raise NotImplementedError
+
+  def UpdateCloudStorageDependency(
+      self, dependency, platform, arch, version=None):
+    """Update the cloud storage hash and the version for the given dependency.
+    """
+    raise NotImplementedError
+
+  def GetVersion(self, dependency, platform, arch):
+    """Return the Version information for the given dependency.
+    """
+    raise NotImplementedError
+
+  def _UpdateDependencies(self, config_file):
+    raise NotImplementedError
+
+  def _GetDependencyInfo(self, dependency, platform, arch):
+    raise NotImplementedError
+
+  @staticmethod
+  def _LocalPath(dependency_info):
+    raise NotImplementedError
+
+  @staticmethod
+  def _CloudStoragePath(dependency_info):
+    raise NotImplementedError
+