| // 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 static java.nio.charset.StandardCharsets.UTF_8; |
| |
| import com.google.devtools.build.lib.actions.ActionExecutionContext; |
| import com.google.devtools.build.lib.actions.ActionOwner; |
| import com.google.devtools.build.lib.actions.Artifact; |
| import com.google.devtools.build.lib.analysis.RuleContext; |
| import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable; |
| import com.google.devtools.build.lib.util.Fingerprint; |
| import com.google.devtools.build.lib.util.LazyString; |
| |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.util.Collection; |
| |
| /** |
| * Action to write to a file. |
| * <p>TODO(bazel-team): Choose a better name to distinguish this class from |
| * {@link BinaryFileWriteAction}. |
| */ |
| @Immutable // if fileContents is immutable |
| public final class FileWriteAction extends AbstractFileWriteAction { |
| |
| private static final String GUID = "332877c7-ca9f-4731-b387-54f620408522"; |
| |
| /** |
| * We keep it as a CharSequence for memory-efficiency reasons. The toString() |
| * method of the object represents the content of the file. |
| * |
| * <p>For example, this allows us to keep a {@code List<Artifact>} wrapped |
| * in a {@code LazyString} instead of the string representation of the concatenation. |
| * This saves memory because the Artifacts are shared objects but the |
| * resulting String is not. |
| */ |
| private final CharSequence fileContents; |
| |
| /** |
| * Creates a new FileWriteAction instance without inputs using UTF8 encoding. |
| * |
| * @param owner the action owner. |
| * @param output the Artifact that will be created by executing this Action. |
| * @param fileContents the contents to be written to the file. |
| * @param makeExecutable iff true will change the output file to be |
| * executable. |
| */ |
| public FileWriteAction(ActionOwner owner, Artifact output, CharSequence fileContents, |
| boolean makeExecutable) { |
| this(owner, Artifact.NO_ARTIFACTS, output, fileContents, makeExecutable); |
| } |
| |
| /** |
| * Creates a new FileWriteAction instance using UTF8 encoding. |
| * |
| * @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 fileContents the contents to be written to the file. |
| * @param makeExecutable iff true will change the output file to be |
| * executable. |
| */ |
| public FileWriteAction(ActionOwner owner, Collection<Artifact> inputs, |
| Artifact output, CharSequence fileContents, boolean makeExecutable) { |
| super(owner, inputs, output, makeExecutable); |
| if (fileContents instanceof String && fileContents.length() > 256) { |
| fileContents = new StoredAsUTF8((String) fileContents); |
| } |
| this.fileContents = fileContents; |
| } |
| |
| private static final class StoredAsUTF8 extends LazyString { |
| final byte[] bytes; |
| |
| StoredAsUTF8(String chars) { |
| this.bytes = chars.getBytes(UTF_8); |
| } |
| |
| @Override |
| public String toString() { |
| return new String(bytes, UTF_8); |
| } |
| } |
| |
| /** |
| * Creates a new FileWriteAction instance using UTF8 encoding. |
| * |
| * @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. |
| */ |
| protected FileWriteAction(ActionOwner owner, Collection<Artifact> inputs, |
| Artifact output, boolean makeExecutable) { |
| this(owner, inputs, output, "", makeExecutable); |
| } |
| |
| public String getFileContents() { |
| return fileContents.toString(); |
| } |
| |
| /** |
| * Create a DeterministicWriter for the content of the output file as provided by |
| * {@link #getFileContents()}. |
| */ |
| @Override |
| public DeterministicWriter newDeterministicWriter(ActionExecutionContext ctx) { |
| return new DeterministicWriter() { |
| @Override |
| public void writeOutputFile(OutputStream out) throws IOException { |
| out.write(getFileContents().getBytes(UTF_8)); |
| } |
| }; |
| } |
| |
| /** |
| * Computes the Action key for this action by computing the fingerprint for |
| * the file contents. |
| */ |
| @Override |
| protected String computeKey() { |
| Fingerprint f = new Fingerprint(); |
| f.addString(GUID); |
| f.addString(String.valueOf(makeExecutable)); |
| f.addString(getFileContents()); |
| return f.hexDigestAndReset(); |
| } |
| |
| /** |
| * Creates a FileWriteAction to write contents to the resulting artifact |
| * fileName in the genfiles root underneath the package path. |
| * |
| * @param ruleContext the ruleContext that will own the action of creating this file. |
| * @param fileName name of the file to create. |
| * @param contents data to write to file. |
| * @param executable flags that file should be marked executable. |
| * @return Artifact describing the file to create. |
| */ |
| public static Artifact createFile(RuleContext ruleContext, |
| String fileName, CharSequence contents, boolean executable) { |
| Artifact scriptFileArtifact = ruleContext.getPackageRelativeArtifact( |
| fileName, ruleContext.getConfiguration().getGenfilesDirectory( |
| ruleContext.getRule().getRepository())); |
| ruleContext.registerAction(new FileWriteAction( |
| ruleContext.getActionOwner(), scriptFileArtifact, contents, executable)); |
| return scriptFileArtifact; |
| } |
| } |