/*******************************************************************************
* Copyright (c) 2012-2017 Codenvy, S.A.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Codenvy, S.A. - initial API and implementation
*******************************************************************************/
package org.eclipse.che.api.core.util;
import com.google.common.base.Joiner;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import static java.lang.String.format;
/**
* Helpers to manage system processes.
*
* @author andrew00x
* @author Alexander Garagatyi
*/
public final class ProcessUtil {
private static final Logger LOG = LoggerFactory.getLogger(ProcessUtil.class);
private static final ProcessManager PROCESS_MANAGER = ProcessManager.newInstance();
/**
* Writes stdout and stderr of the process to consumers.<br>
* Supposes that stderr of the process is redirected to stdout.
*
* @param p
* process to read output from
* @param stdout
* a consumer where stdout will be redirected
* @param stderr
* a consumer where stderr will be redirected
* @throws IOException
*/
public static void process(Process p, LineConsumer stdout, LineConsumer stderr) throws IOException {
try (BufferedReader inputReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
BufferedReader errorReader = new BufferedReader(new InputStreamReader(p.getErrorStream()))) {
String line;
while ((line = inputReader.readLine()) != null) {
stdout.writeLine(line);
}
while ((line = errorReader.readLine()) != null) {
stderr.writeLine(line);
}
}
}
/**
* Writes stdout of the process to consumer.<br>
* Supposes that stderr of the process is redirected to stdout.
*
* @param p
* process to read output from
* @param stdout
* a consumer where stdout will be redirected
* @throws IOException
*/
public static void process(Process p, LineConsumer stdout) throws IOException {
try (BufferedReader inputReader = new BufferedReader(new InputStreamReader(p.getInputStream()))) {
String line;
while ((line = inputReader.readLine()) != null) {
stdout.writeLine(line);
}
}
}
/**
* Start the process, writing the stdout and stderr to {@code outputConsumer} and terminate process by {@code timeout}.<br>
*
* @param commandLine
* arguments of process command
* @param timeout
* timeout for process. If process duration > {@code timeout} than kill process and throw {@link TimeoutException}.
* @param timeUnit
* timeUnit of the {@code timeout}.
* @param outputConsumer
* a consumer where stdout and stderr will be redirected
* @return the started process
* @throws InterruptedException
* in case terminate process
* @throws IOException
* in case I/O error
* @throws TimeoutException
* if process gets more time then defined by {@code timeout}
*/
public static Process executeAndWait(String[] commandLine, int timeout, TimeUnit timeUnit, LineConsumer outputConsumer)
throws TimeoutException, IOException, InterruptedException {
ProcessBuilder pb = new ProcessBuilder(commandLine).redirectErrorStream(true);
Process process = pb.start();
CompletableFuture.runAsync(() -> {
try {
// consume logs until process ends
process(process, outputConsumer);
} catch (IOException e) {
LOG.error(format("Failed to complete reading of the process '%s' output due to occurred error",
Joiner.on(" ").join(commandLine)), e);
}
});
if (!process.waitFor(timeout, timeUnit)) {
try {
ProcessUtil.kill(process);
} catch (RuntimeException x) {
LOG.error("An error occurred while killing process '{}'", Joiner.on(" ").join(commandLine));
}
throw new TimeoutException(format("Process '%s' was terminated by timeout %s %s.",
Joiner.on(" ").join(commandLine), timeout, timeUnit.name().toLowerCase()));
}
return process;
}
/**
* Start the process, writing the stdout and stderr to consumer.
*
* @param pb
* process builder to start
* @param consumer
* a consumer where stdout and stderr will be redirected
* @return the started process
* @throws IOException
*/
public static Process execute(ProcessBuilder pb, LineConsumer consumer) throws IOException {
pb.redirectErrorStream(true);
Process process = pb.start();
process(process, consumer);
return process;
}
public static boolean isAlive(Process process) {
return PROCESS_MANAGER.isAlive(process);
}
public static void kill(Process process) {
PROCESS_MANAGER.kill(process);
}
public static int system(String command) {
return PROCESS_MANAGER.system(command);
}
private ProcessUtil() {
}
}