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comparison src/org/tmatesoft/hg/util/PathPool.java @ 64:19e9e220bf68

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Convenient commands constitute hi-level API. org.tmatesoft namespace, GPL2 statement
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Fri, 21 Jan 2011 05:56:43 +0100
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63:a47530a2ea12 64:19e9e220bf68
1 /*
2 * Copyright (c) 2011 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@svnkit.com
16 */
17 package org.tmatesoft.hg.util;
18
19 import java.lang.ref.SoftReference;
20 import java.util.WeakHashMap;
21
22 import org.tmatesoft.hg.core.Path;
23
24 /**
25 *
26 * @author Artem Tikhomirov
27 * @author TMate Software Ltd.
28 */
29 public class PathPool {
30 private final WeakHashMap<String, SoftReference<Path>> cache;
31 private final PathRewrite pathRewrite;
32
33 public PathPool(PathRewrite rewrite) {
34 pathRewrite = rewrite;
35 cache = new WeakHashMap<String, SoftReference<Path>>();
36 }
37
38 public Path path(String p) {
39 p = pathRewrite.rewrite(p);
40 SoftReference<Path> sr = cache.get(p);
41 Path path = sr == null ? null : sr.get();
42 if (path == null) {
43 path = Path.create(p);
44 cache.put(p, new SoftReference<Path>(path));
45 }
46 return path;
47 }
48
49 // XXX what would be parent of an empty path?
50 // Path shall have similar functionality
51 public Path parent(Path path) {
52 if (path.length() == 0) {
53 throw new IllegalArgumentException();
54 }
55 for (int i = path.length() - 2 /*if path represents a dir, trailing char is slash, skip*/; i >= 0; i--) {
56 if (path.charAt(i) == '/') {
57 return get(path.subSequence(0, i+1).toString(), true);
58 }
59 }
60 return get("", true);
61 }
62
63 private Path get(String p, boolean create) {
64 SoftReference<Path> sr = cache.get(p);
65 Path path = sr == null ? null : sr.get();
66 if (path == null) {
67 if (create) {
68 path = Path.create(p);
69 cache.put(p, new SoftReference<Path>(path));
70 } else if (sr != null) {
71 // cached path no longer used, clear cache entry - do not wait for RefQueue to step in
72 cache.remove(p);
73 }
74 }
75 return path;
76 }
77 }