// Copyright 2014 The Bazel Authors. All rights reserved. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package com.google.devtools.build.lib.actions; import com.google.common.eventbus.EventBus; import com.google.devtools.build.lib.clock.Clock; import com.google.devtools.build.lib.events.EventHandler; import com.google.devtools.build.lib.vfs.FileSystem; import com.google.devtools.build.lib.vfs.Path; import com.google.devtools.common.options.OptionsClassProvider; /** * The Executor provides the context for the execution of actions. It is only valid during the * execution phase, and references should not be cached. * *
This class provides the actual logic to execute actions. The platonic ideal of this system * is that {@link Action}s are immutable objects that tell Blaze what to do and * ActionContexts tell Blaze how to do it (however, we do have an "execute" * method on actions now). * *
In theory, most of the methods below would not exist and they would be methods on action * contexts, but in practice, that would require some refactoring work so we are stuck with these * for the time being. * *
In theory, we could also merge {@link Executor} with {@link ActionExecutionContext}, since
* they both provide services to actions being executed and are passed to almost the same places.
*/
public interface Executor {
/** Returns the file system of blaze. */
FileSystem getFileSystem();
/**
* Returns the execution root. This is the directory underneath which Blaze builds its entire
* output working tree, including the source symlink forest. All build actions are executed
* relative to this directory.
*/
Path getExecRoot();
/**
* Returns a clock. This is not hermetic, and should only be used for build info actions or
* performance measurements / reporting.
*/
Clock getClock();
/**
* The EventBus for the current build.
*/
EventBus getEventBus();
/**
* Returns whether failures should have verbose error messages.
*/
boolean getVerboseFailures();
/**
* Returns the command line options of the Blaze command being executed.
*/
OptionsClassProvider getOptions();
/**
* Whether this Executor reports subcommands. If not, reportSubcommand has no effect.
* This is provided so the caller of reportSubcommand can avoid wastefully constructing the
* subcommand string.
*/
boolean reportsSubcommands();
/**
* An event listener to report messages to. Errors that signal a action failure should
* use ActionExecutionException.
*/
EventHandler getEventHandler();
/**
* Looks up and returns an action context implementation of the given interface type.
*/