| // 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.analysis.actions; |
| |
| import com.google.common.collect.ImmutableSet; |
| import com.google.common.collect.Iterables; |
| import com.google.common.util.concurrent.ListenableFuture; |
| import com.google.devtools.build.lib.actions.AbstractAction; |
| import com.google.devtools.build.lib.actions.ActionContext; |
| import com.google.devtools.build.lib.actions.ActionContinuationOrResult; |
| import com.google.devtools.build.lib.actions.ActionExecutionContext; |
| import com.google.devtools.build.lib.actions.ActionExecutionException; |
| import com.google.devtools.build.lib.actions.ActionOwner; |
| import com.google.devtools.build.lib.actions.ActionResult; |
| import com.google.devtools.build.lib.actions.Artifact; |
| import com.google.devtools.build.lib.actions.EnvironmentalExecException; |
| import com.google.devtools.build.lib.actions.ExecException; |
| import com.google.devtools.build.lib.actions.SpawnContinuation; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.collect.nestedset.NestedSet; |
| import com.google.protobuf.ByteString; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import javax.annotation.Nullable; |
| |
| /** |
| * Abstract Action to write to a file. |
| */ |
| public abstract class AbstractFileWriteAction extends AbstractAction { |
| |
| protected final boolean makeExecutable; |
| |
| /** |
| * Creates a new AbstractFileWriteAction instance. |
| * |
| * @param owner the action owner. |
| * @param inputs the Artifacts that this Action depends on |
| * @param output the Artifact that will be created by executing this Action. |
| * @param makeExecutable iff true will change the output file to be executable. |
| */ |
| public AbstractFileWriteAction( |
| ActionOwner owner, NestedSet<Artifact> inputs, Artifact output, boolean makeExecutable) { |
| // There is only one output, and it is primary. |
| super(owner, inputs, ImmutableSet.of(output)); |
| this.makeExecutable = makeExecutable; |
| } |
| |
| public boolean makeExecutable() { |
| return makeExecutable; |
| } |
| |
| @Override |
| public final ActionContinuationOrResult beginExecution( |
| ActionExecutionContext actionExecutionContext) |
| throws ActionExecutionException, InterruptedException { |
| try { |
| DeterministicWriter deterministicWriter; |
| try { |
| deterministicWriter = newDeterministicWriter(actionExecutionContext); |
| } catch (IOException e) { |
| // Message is a bit misleading but is good enough for the end user. |
| throw new EnvironmentalExecException( |
| "Failed to write '" + getPrimaryOutput().prettyPrint() + "'", e); |
| } |
| |
| FileWriteActionContext context = getStrategy(actionExecutionContext); |
| SpawnContinuation first = |
| context.beginWriteOutputToFile( |
| AbstractFileWriteAction.this, |
| actionExecutionContext, |
| deterministicWriter, |
| makeExecutable, |
| isRemotable()); |
| return new ActionContinuationOrResult() { |
| private SpawnContinuation spawnContinuation = first; |
| |
| @Nullable |
| @Override |
| public ListenableFuture<?> getFuture() { |
| return spawnContinuation.getFuture(); |
| } |
| |
| @Override |
| public ActionContinuationOrResult execute() |
| throws ActionExecutionException, InterruptedException { |
| SpawnContinuation nextContinuation; |
| try { |
| nextContinuation = spawnContinuation.execute(); |
| if (!nextContinuation.isDone()) { |
| spawnContinuation = nextContinuation; |
| return this; |
| } |
| } catch (ExecException e) { |
| throw e.toActionExecutionException( |
| "Writing file for rule '" + Label.print(getOwner().getLabel()) + "'", |
| actionExecutionContext.getVerboseFailures(), |
| AbstractFileWriteAction.this); |
| } |
| afterWrite(actionExecutionContext); |
| return ActionContinuationOrResult.of(ActionResult.create(nextContinuation.get())); |
| } |
| }; |
| } catch (ExecException e) { |
| throw e.toActionExecutionException( |
| "Writing file for rule '" + Label.print(getOwner().getLabel()) + "'", |
| actionExecutionContext.getVerboseFailures(), |
| this); |
| } |
| } |
| |
| /** |
| * Produce a DeterministicWriter that can write the file to an OutputStream deterministically. |
| * |
| * @param ctx context for use with creating the writer. |
| */ |
| public abstract DeterministicWriter newDeterministicWriter(ActionExecutionContext ctx) |
| throws IOException, InterruptedException, ExecException; |
| |
| /** |
| * This hook is called after the File has been successfully written to disk. |
| * |
| * @param actionExecutionContext the execution context |
| */ |
| protected void afterWrite(ActionExecutionContext actionExecutionContext) { |
| } |
| |
| @Override |
| public String getMnemonic() { |
| return "FileWrite"; |
| } |
| |
| @Override |
| protected String getRawProgressMessage() { |
| return "Writing " + (makeExecutable ? "script " : "file ") |
| + Iterables.getOnlyElement(getOutputs()).prettyPrint(); |
| } |
| |
| /** |
| * Whether the file write can be generated remotely. If the file is consumed in Blaze |
| * unconditionally, it doesn't make sense to run remotely. |
| */ |
| public boolean isRemotable() { |
| return true; |
| } |
| |
| private FileWriteActionContext getStrategy( |
| ActionContext.ActionContextRegistry actionContextRegistry) { |
| return actionContextRegistry.getContext(FileWriteActionContext.class); |
| } |
| |
| /** |
| * A deterministic writer writes bytes to an output stream. The same byte stream is written |
| * on every invocation of writeOutputFile(). |
| */ |
| public interface DeterministicWriter { |
| void writeOutputFile(OutputStream out) throws IOException; |
| |
| /** |
| * Returns the contents that would be written, as a {@link ByteString}. Used when the caller |
| * wants a {@link ByteString} in the end, to avoid making unnecessary copies. |
| */ |
| default ByteString getBytes() throws IOException { |
| ByteString.Output out = ByteString.newOutput(); |
| writeOutputFile(out); |
| return out.toByteString(); |
| } |
| } |
| } |