Mercurial > hg4j
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> |
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date | Wed, 15 May 2013 20:10:09 +0200 |
parents | |
children | 7c0d2ce340b8 |
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616:5e0313485eef | 617:65c01508f002 |
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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 } |