Mercurial > jhg
comparison src/org/tmatesoft/hg/internal/FileUtils.java @ 617:65c01508f002
Rollback support for commands that modify repository. Strategy to keep complete copy of a file being changed
| author | Artem Tikhomirov <tikhomirov.artem@gmail.com> |
|---|---|
| date | Wed, 15 May 2013 20:10:09 +0200 |
| parents | |
| children | 7c0d2ce340b8 |
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| 616:5e0313485eef | 617:65c01508f002 |
|---|---|
| 1 /* | |
| 2 * Copyright (c) 2013 TMate Software Ltd | |
| 3 * | |
| 4 * This program is free software; you can redistribute it and/or modify | |
| 5 * it under the terms of the GNU General Public License as published by | |
| 6 * the Free Software Foundation; version 2 of the License. | |
| 7 * | |
| 8 * This program is distributed in the hope that it will be useful, | |
| 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 11 * GNU General Public License for more details. | |
| 12 * | |
| 13 * For information on how to redistribute this software under | |
| 14 * the terms of a license other than GNU General Public License | |
| 15 * contact TMate Software at support@hg4j.com | |
| 16 */ | |
| 17 package org.tmatesoft.hg.internal; | |
| 18 | |
| 19 import static org.tmatesoft.hg.util.LogFacility.Severity.Debug; | |
| 20 | |
| 21 import java.io.Closeable; | |
| 22 import java.io.File; | |
| 23 import java.io.FileInputStream; | |
| 24 import java.io.FileOutputStream; | |
| 25 import java.io.IOException; | |
| 26 import java.nio.channels.FileChannel; | |
| 27 | |
| 28 import org.tmatesoft.hg.core.HgIOException; | |
| 29 import org.tmatesoft.hg.util.LogFacility; | |
| 30 import org.tmatesoft.hg.util.LogFacility.Severity; | |
| 31 | |
| 32 /** | |
| 33 * | |
| 34 * @author Artem Tikhomirov | |
| 35 * @author TMate Software Ltd. | |
| 36 */ | |
| 37 final class FileUtils { | |
| 38 | |
| 39 private final LogFacility log; | |
| 40 | |
| 41 public static void copyFile(File from, File to) throws HgIOException { | |
| 42 new FileUtils(new StreamLogFacility(Debug, true, System.err)).copy(from, to); | |
| 43 } | |
| 44 | |
| 45 public FileUtils(LogFacility logFacility) { | |
| 46 log = logFacility; | |
| 47 } | |
| 48 | |
| 49 public void copy(File from, File to) throws HgIOException { | |
| 50 FileInputStream fis = null; | |
| 51 FileOutputStream fos = null; | |
| 52 try { | |
| 53 fis = new FileInputStream(from); | |
| 54 fos = new FileOutputStream(to); | |
| 55 FileChannel input = fis.getChannel(); | |
| 56 FileChannel output = fos.getChannel(); | |
| 57 long count = input.size(); | |
| 58 long pos = 0; | |
| 59 int zeroCopied = 0; // flag to prevent hang-up | |
| 60 do { | |
| 61 long c = input.transferTo(pos, count, output); | |
| 62 pos += c; | |
| 63 count -= c; | |
| 64 if (c == 0) { | |
| 65 if (++zeroCopied == 3) { | |
| 66 String m = String.format("Can't copy %s to %s, transferTo copies 0 bytes. Position: %d, bytes left:%d", from.getName(), to.getName(), pos, count); | |
| 67 throw new IOException(m); | |
| 68 } | |
| 69 } else { | |
| 70 // reset | |
| 71 zeroCopied = 0; | |
| 72 } | |
| 73 } while (count > 0); | |
| 74 fos.close(); | |
| 75 fos = null; | |
| 76 fis.close(); | |
| 77 fis = null; | |
| 78 } catch (IOException ex) { | |
| 79 // not in finally because I don't want to loose exception from fos.close() | |
| 80 closeQuietly(fis); | |
| 81 closeQuietly(fos); | |
| 82 String m = String.format("Failed to copy %s to %s", from.getName(), to.getName()); | |
| 83 throw new HgIOException(m, ex, from); | |
| 84 } | |
| 85 } | |
| 86 | |
| 87 public void closeQuietly(Closeable stream) { | |
| 88 if (stream != null) { | |
| 89 try { | |
| 90 stream.close(); | |
| 91 } catch (IOException ex) { | |
| 92 // ignore | |
| 93 log.dump(getClass(), Severity.Warn, ex, "Exception while closing stream quietly"); | |
| 94 } | |
| 95 } | |
| 96 } | |
| 97 | |
| 98 } |
