| /* |
| * Copyright 2012-present Facebook, Inc. |
| * |
| * 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.facebook.buck.util; |
| |
| import com.google.common.base.Charsets; |
| import com.google.common.base.Preconditions; |
| |
| import java.io.PrintStream; |
| |
| import javax.annotation.Nullable; |
| |
| /** |
| * Executes a {@link Process} and blocks until it is finished. |
| */ |
| public class ProcessExecutor { |
| |
| private final PrintStream stdOutStream; |
| private final PrintStream stdErrStream; |
| private final Ansi ansi; |
| |
| /** |
| * Creates a new {@link ProcessExecutor} with the specified parameters used for writing the output |
| * of the process. |
| */ |
| public ProcessExecutor(Console console) { |
| Preconditions.checkNotNull(console); |
| this.stdOutStream = console.getStdOut(); |
| this.stdErrStream = console.getStdErr(); |
| this.ansi = console.getAnsi(); |
| } |
| |
| /** |
| * Convenience method for {@link #execute(Process, boolean, boolean, boolean)} with boolean values |
| * set to {@code false}. |
| */ |
| public Result execute(Process process) { |
| return execute(process, |
| /* shouldPrintStdOut */ false, |
| /* shouldPrintStdErr */ false, |
| /* isSilent */ false); |
| } |
| |
| /** |
| * Executes the specified process. |
| * @param process The {@code Process} to execute. |
| * @param shouldPrintStdOut If {@code true}, then the stdout of the process will be written |
| * directly to the stdout passed to the constructor of this executor. If {@code false}, then |
| * the stdout of the process will be made available via {@link Result#getStdout()}. |
| * @param shouldPrintStdErr If {@code true}, then the stderr of the process will be written |
| * directly to the stderr passed to the constructor of this executor. If {@code false}, then |
| * the stderr of the process will be made available via {@link Result#getStderr()}. |
| */ |
| public Result execute( |
| Process process, |
| boolean shouldPrintStdOut, |
| boolean shouldPrintStdErr, |
| boolean isSilent) { |
| // Read stdout/stderr asynchronously while running a Process. |
| // See http://stackoverflow.com/questions/882772/capturing-stdout-when-calling-runtime-exec |
| @SuppressWarnings("resource") |
| PrintStream stdOutToWriteTo = shouldPrintStdOut ? |
| stdOutStream : new CapturingPrintStream(); |
| InputStreamConsumer stdOut = new InputStreamConsumer( |
| process.getInputStream(), |
| stdOutToWriteTo, |
| ansi); |
| |
| @SuppressWarnings("resource") |
| PrintStream stdErrToWriteTo = shouldPrintStdErr ? |
| stdErrStream : new CapturingPrintStream(); |
| InputStreamConsumer stdErr = new InputStreamConsumer( |
| process.getErrorStream(), |
| stdErrToWriteTo, |
| ansi); |
| |
| // Consume the streams so they do not deadlock. |
| Thread stdOutConsumer = Threads.namedThread("ProcessExecutor (stdOut)", stdOut); |
| stdOutConsumer.start(); |
| Thread stdErrConsumer = Threads.namedThread("ProcessExecutor (stdErr)", stdErr); |
| stdErrConsumer.start(); |
| |
| // Block until the Process completes. |
| try { |
| process.waitFor(); |
| stdOutConsumer.join(); |
| stdErrConsumer.join(); |
| } catch (InterruptedException e) { |
| // Buck was killed while waiting for the consumers to finish. This means either the user |
| // killed the process or a step failed causing us to kill all other running steps. Neither of |
| // these is an exceptional situation. |
| return new Result(1, /* stdout */ null, /* stderr */ null); |
| } |
| |
| String stdoutText = getDataIfNotPrinted(stdOutToWriteTo, shouldPrintStdOut); |
| String stderrText = getDataIfNotPrinted(stdErrToWriteTo, shouldPrintStdErr); |
| |
| // Report the exit code of the Process. |
| int exitCode = process.exitValue(); |
| |
| // If the command has failed and we're not being explicitly quiet, ensure everything gets |
| // printed. |
| if (exitCode != 0 && !isSilent) { |
| if (!shouldPrintStdOut) { |
| stdOutStream.print(stdoutText); |
| } |
| if (!shouldPrintStdErr) { |
| stdErrStream.print(stderrText); |
| } |
| } |
| |
| return new Result(exitCode, stdoutText, stderrText); |
| } |
| |
| @Nullable |
| private static String getDataIfNotPrinted(PrintStream printStream, boolean shouldPrint) { |
| if (!shouldPrint) { |
| CapturingPrintStream capturingPrintStream = (CapturingPrintStream)printStream; |
| return capturingPrintStream.getContentsAsString(Charsets.US_ASCII); |
| } else { |
| return null; |
| } |
| } |
| |
| /** |
| * Values from the result of {@link ProcessExecutor#execute(Process, boolean, boolean, boolean)}. |
| */ |
| public static class Result { |
| private final int exitCode; |
| @Nullable private final String stdout; |
| @Nullable private final String stderr; |
| |
| public Result(int exitCode, @Nullable String stdOut, @Nullable String stderr) { |
| this.exitCode = exitCode; |
| this.stdout = stdOut; |
| this.stderr = stderr; |
| } |
| |
| public int getExitCode() { |
| return exitCode; |
| } |
| |
| @Nullable |
| public String getStdout() { |
| return stdout; |
| } |
| |
| @Nullable |
| public String getStderr() { |
| return stderr; |
| } |
| } |
| } |