[Android] Add a configurable environment for devil/.

build/android/devil/devil_env.py

Index: build/android/devil/devil_env.py
diff --git a/build/android/devil/devil_env.py b/build/android/devil/devil_env.py
new file mode 100644
index 0000000000000000000000000000000000000000..1fc022011a8e109d08c196710301d06e03bc4a10
--- /dev/null
+++ b/build/android/devil/devil_env.py
@@ -0,0 +1,159 @@
+# 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.
+
+import json
+import logging
+import os
+import sys
+import tempfile
+import threading
+
+# TODO(jbudorick): Update this once dependency_manager moves to catapult.
+_TELEMETRY_PATH = os.path.abspath(os.path.join(
+    os.path.dirname(__file__), os.pardir, os.pardir, os.pardir,
+    'tools', 'telemetry'))
+sys.path.append(_TELEMETRY_PATH)
+from catapult_base import dependency_manager # pylint: disable=import-error
+
+
+_DEFAULT_CONFIG_FILES = [
+  os.path.abspath(os.path.join(
+      os.path.dirname(__file__), os.pardir, 'devil_config.json')),
+]
+
+
+class _Environment(object):
+
+  def __init__(self):
+    self._config = None
+    self._config_init_lock = threading.Lock()
+
+  def Initialize(self, configs=None, config_files=None):
+    """Initialize devil's environment.
+
+    This uses all configurations provided via |configs| and |config_files|
+    to determine the locations of devil's dependencies. Configurations should
+    all take the form described by catapult_base.dependency_manager.BaseConfig.
+    If no configurations are provided, a default one will be used if available.
+
+    Args:
+      configs: An optional list of dict configurations.
+      config_files: An optional list of files to load
+    """
+
+    # Make sure we only initialize self._config once.
+    with self._config_init_lock:
+      if self._config is not None:
+        return
+      self._config = {}
+
+    self._InitializeRecursive(configs=configs, config_files=config_files)
+
+  def _InitializeRecursive(self, configs=None, config_files=None):
+    # This recurses through configs to create temporary files for each and
+    # take advantage of context managers to appropriately close those files.
+    # TODO(jbudorick): Remove this recursion if/when dependency_manager
+    # supports loading configurations directly from a dict.
+    if configs:
+      with tempfile.NamedTemporaryFile() as next_config_file:
+        next_config_file.write(json.dumps(configs[0]))
+        next_config_file.flush()
+        self._InitializeRecursive(
+            configs=configs[1:],
+            config_files=[next_config_file.name] + (config_files or []))
+    else:
+      self._InitializeImpl(config_files)
+
+  def _InitializeImpl(self, config_files):
+    if not config_files:
+      config_files = _DEFAULT_CONFIG_FILES
+
+    dm = dependency_manager.DependencyManager(
+        [dependency_manager.BaseConfig(c) for c in config_files])
+    platform = 'linux_android'
+
+    android_sdk_path = dm.FetchPath('android_sdk', platform)
+
+    if os.path.exists(android_sdk_path):
+      self._config['android_sdk_path'] = android_sdk_path
+
+      # Chromium's hooks always download the SDK extras even if they aren't
+      # downloading the SDK, so we have to check for the existence of the
+      # particular components we care about.
+
+      try:
+        adb_path = dm.FetchPath('adb_path', platform)
+      except dependency_manager.NoPathFoundError:
+        adb_path = os.path.join(
+            self.android_sdk_path, 'platform-tools', 'adb')
+      if os.path.exists(adb_path):
+        self._config['adb_path'] = adb_path
+
+      build_tools_path = os.path.join(self.android_sdk_path, 'build-tools')
+      if os.path.exists(build_tools_path):
+        build_tools_contents = os.listdir(build_tools_path)
+        if build_tools_contents:
+          if len(build_tools_contents) > 1:
+            build_tools_contents.sort()
+            logging.warning(
+                'More than one set of build-tools provided by the Android SDK:'
+                ' %s', ','.join(build_tools_contents))
+            logging.warning('Defaulting to %s', build_tools_contents[-1])
+          self._config['android_sdk_build_tools_path'] = os.path.join(
+              self.android_sdk_path, 'build-tools', build_tools_contents[-1])
+
+    try:
+      self._config['forwarder_host_path'] = dm.FetchPath(
+          'forwarder_host', platform)
+      self._config['forwarder_device_path'] = dm.FetchPath(
+          'forwarder_device', platform)
+    except dependency_manager.NoPathFoundError as e:
+      logging.warning(str(e))
+
+    try:
+      self._config['md5sum_host_path'] = dm.FetchPath('md5sum_host', platform)
+      self._config['md5sum_device_path'] = dm.FetchPath(
+          'md5sum_device', platform)
+    except dependency_manager.NoPathFoundError as e:
+      logging.warning(str(e))
+
+    try:
+      self._config['pymock_path'] = dm.FetchPath('pymock', platform)
+    except dependency_manager.NoPathFoundError as e:
+      logging.warning(str(e))
+
+  def __getattr__(self, name):
+    if self._config is None:
+      self.Initialize()
+
+    if name not in self._config:
+      raise AttributeError('devil environment has no %r attribute' % name)
+
+    return self._config[name]
+
+
+config = _Environment()
+
+
+def GenerateDynamicConfig(deps):
+  """Generate a configuration dict from the provided deps dict.
+
+  Args:
+    deps: A dict mapping dependency names to lists of local files.
+  Returns:
+    A BaseConfig-compatible dict.
+  """
+  return {
+    'config_type': 'BaseConfig',
+    'dependencies': {
+      k: {
+        'file_info': {
+          'linux_android': {
+            'local_paths': v
+          }
+        }
+      } for k, v in deps.iteritems()
+    }
+  }
+