tikhomirov@413: /*
tikhomirov@413:  * Copyright (c) 2012 TMate Software Ltd
tikhomirov@413:  *  
tikhomirov@413:  * This program is free software; you can redistribute it and/or modify
tikhomirov@413:  * it under the terms of the GNU General Public License as published by
tikhomirov@413:  * the Free Software Foundation; version 2 of the License.
tikhomirov@413:  *
tikhomirov@413:  * This program is distributed in the hope that it will be useful,
tikhomirov@413:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
tikhomirov@413:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
tikhomirov@413:  * GNU General Public License for more details.
tikhomirov@413:  *
tikhomirov@413:  * For information on how to redistribute this software under
tikhomirov@413:  * the terms of a license other than GNU General Public License
tikhomirov@413:  * contact TMate Software at support@hg4j.com
tikhomirov@413:  */
tikhomirov@413: package org.tmatesoft.hg.internal;
tikhomirov@413: 
tikhomirov@413: import java.io.File;
tikhomirov@413: import java.io.IOException;
tikhomirov@413: import java.io.InputStreamReader;
tikhomirov@413: import java.nio.CharBuffer;
tikhomirov@413: import java.util.Arrays;
tikhomirov@413: import java.util.LinkedList;
tikhomirov@413: import java.util.List;
tikhomirov@413: 
tikhomirov@413: /**
tikhomirov@413:  * Utility to run shell commands. Not thread-safe.
tikhomirov@413:  * Beware of memory overcommitment issue on Linux - suprocess get allocated virtual memory of parent process size
tikhomirov@413:  * @see http://developers.sun.com/solaris/articles/subprocess/subprocess.html
tikhomirov@413:  * 
tikhomirov@413:  * @author Artem Tikhomirov
tikhomirov@423:  * @author TMate Software Ltd.
tikhomirov@413:  */
tikhomirov@413: public class ProcessExecHelper {
tikhomirov@413: 	private File dir;
tikhomirov@413: 	private int exitValue;
tikhomirov@413: 	private ProcessBuilder pb;
tikhomirov@413: 	
tikhomirov@413: 	public ProcessExecHelper() {
tikhomirov@413: 	}
tikhomirov@413: 	
tikhomirov@413: 	protected List<String> prepareCommand(List<String> cmd) {
tikhomirov@413: 		return cmd;
tikhomirov@413: 	}
tikhomirov@413: 	
tikhomirov@413: 	public CharSequence exec(String... command) throws IOException, InterruptedException {
tikhomirov@413: 		return exec(Arrays.asList(command));
tikhomirov@413: 	}
tikhomirov@413: 
tikhomirov@413: 	public CharSequence exec(List<String> command) throws IOException, InterruptedException {
tikhomirov@413: 		List<String> cmd = prepareCommand(command);
tikhomirov@413: 		if (pb == null) {
tikhomirov@413: 			pb = new ProcessBuilder(cmd).directory(dir).redirectErrorStream(true);
tikhomirov@413: 		} else {
tikhomirov@413: 			pb.command(cmd); // dir and redirect are set
tikhomirov@413: 		}
tikhomirov@413: 		Process p = pb.start();
tikhomirov@413: 		InputStreamReader stdOut = new InputStreamReader(p.getInputStream());
tikhomirov@413: 		LinkedList<CharBuffer> l = new LinkedList<CharBuffer>();
tikhomirov@413: 		int r = -1;
tikhomirov@413: 		CharBuffer b = null;
tikhomirov@413: 		do {
tikhomirov@413: 			if (b == null || b.remaining() < b.capacity() / 3) {
tikhomirov@413: 				b = CharBuffer.allocate(512);
tikhomirov@413: 				l.add(b);
tikhomirov@413: 			}
tikhomirov@413: 			r = stdOut.read(b);
tikhomirov@413: 		} while (r != -1);
tikhomirov@413: 		int total = 0;
tikhomirov@413: 		for (CharBuffer cb : l) {
tikhomirov@413: 			total += cb.position();
tikhomirov@413: 			cb.flip();
tikhomirov@413: 		}
tikhomirov@413: 		CharBuffer res = CharBuffer.allocate(total);
tikhomirov@413: 		for (CharBuffer cb : l) {
tikhomirov@413: 			res.put(cb);
tikhomirov@413: 		}
tikhomirov@413: 		res.flip();
tikhomirov@413: 		p.waitFor();
tikhomirov@413: 		exitValue = p.exitValue();
tikhomirov@413: 		return res;
tikhomirov@413: 	}
tikhomirov@413: 	
tikhomirov@413: 	public int exitValue() {
tikhomirov@413: 		return exitValue;
tikhomirov@413: 	}
tikhomirov@413: 
tikhomirov@413: 	public ProcessExecHelper cwd(File wd) {
tikhomirov@413: 		dir = wd;
tikhomirov@413: 		if (pb != null) {
tikhomirov@413: 			pb.directory(dir);
tikhomirov@413: 		}
tikhomirov@413: 		return this;
tikhomirov@413: 	}
tikhomirov@413: }