| // Copyright 2016 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.exec; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableList; |
| import com.google.devtools.build.lib.actions.ActionContext; |
| import com.google.devtools.build.lib.actions.ActionInputPrefetcher; |
| import com.google.devtools.build.lib.actions.Executor; |
| import com.google.devtools.build.lib.util.RegexFilter; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * Builder class to create an {@link Executor} instance. This class is part of the module API, |
| * which allows modules to affect how the executor is initialized. |
| */ |
| public class ExecutorBuilder { |
| private final List<ActionContextProvider> actionContextProviders = new ArrayList<>(); |
| private final SpawnActionContextMaps.Builder spawnActionContextMapsBuilder = |
| new SpawnActionContextMaps.Builder(); |
| private ActionInputPrefetcher prefetcher; |
| |
| // These methods shouldn't be public, but they have to be right now as ExecutionTool is in another |
| // package. |
| public ImmutableList<ActionContextProvider> getActionContextProviders() { |
| return ImmutableList.copyOf(actionContextProviders); |
| } |
| |
| public SpawnActionContextMaps.Builder getSpawnActionContextMapsBuilder() { |
| return spawnActionContextMapsBuilder; |
| } |
| |
| public ActionInputPrefetcher getActionInputPrefetcher() { |
| return prefetcher == null ? ActionInputPrefetcher.NONE : prefetcher; |
| } |
| |
| /** |
| * Adds the specified action context providers to the executor. |
| */ |
| public ExecutorBuilder addActionContextProvider(ActionContextProvider provider) { |
| this.actionContextProviders.add(provider); |
| return this; |
| } |
| |
| /** |
| * Adds the specified action context to the executor, by wrapping it in a simple action context |
| * provider implementation. |
| */ |
| public ExecutorBuilder addActionContext(ActionContext context) { |
| return addActionContextProvider(new SimpleActionContextProvider(context)); |
| } |
| |
| /** |
| * Sets the strategy name for a given action mnemonic. |
| * |
| * <p>The calling module can either decide for itself which implementation is needed and make the |
| * value associated with this key a constant or defer that decision to the user, for example, by |
| * providing a command line option and setting the value in the map based on that. |
| * |
| * <p>Setting the strategy to the empty string "" redirects it to the value for the empty |
| * mnemonic. |
| * |
| * <p>Example: a module requires {@code SpawnActionContext} to do its job, and it creates actions |
| * with the mnemonic <code>C++</code>. The the module can call |
| * <code>addStrategyByMnemonic("C++", strategy)</code>. |
| */ |
| public ExecutorBuilder addStrategyByMnemonic(String mnemonic, String strategy) { |
| spawnActionContextMapsBuilder.strategyByMnemonicMap().put(mnemonic, strategy); |
| return this; |
| } |
| |
| /** |
| * Adds an implementation with a specific strategy name. |
| * |
| * <p>Modules are free to provide different implementations of {@code ActionContext}. This can be |
| * used, for example, to implement sandboxed or distributed execution of {@code SpawnAction}s in |
| * different ways, while giving the user control over how exactly they are executed. |
| * |
| * <p>Example: a module requires {@code MyCustomActionContext} to be available, but doesn't |
| * associate it with any strategy. Call |
| * <code>addStrategyByContext(MyCustomActionContext.class, "")</code>. |
| * |
| * <p>Example: a module requires {@code MyLocalCustomActionContext} to be available, and wants |
| * it to always use the "local" strategy. Call |
| * <code>addStrategyByContext(MyCustomActionContext.class, "local")</code>. |
| */ |
| public ExecutorBuilder addStrategyByContext( |
| Class<? extends ActionContext> actionContext, String strategy) { |
| spawnActionContextMapsBuilder.strategyByContextMap().put(actionContext, strategy); |
| return this; |
| } |
| |
| /** |
| * Similar to {@link #addStrategyByMnemonic}, but allows specifying a regex for the set of |
| * matching mnemonics, instead of an exact string. |
| */ |
| public ExecutorBuilder addStrategyByRegexp(RegexFilter regexFilter, String strategy) { |
| spawnActionContextMapsBuilder.addStrategyByRegexp(regexFilter, strategy); |
| return this; |
| } |
| |
| /** |
| * Sets the action input prefetcher. Only one module may set the prefetcher. If multiple modules |
| * set it, this method will throw an {@link IllegalStateException}. |
| */ |
| public ExecutorBuilder setActionInputPrefetcher(ActionInputPrefetcher prefetcher) { |
| Preconditions.checkState(this.prefetcher == null); |
| this.prefetcher = Preconditions.checkNotNull(prefetcher); |
| return this; |
| } |
| } |