comparison src/org/tmatesoft/hg/util/RegularFileStats.java @ 413:7f27122011c3

Support and respect for symbolic links and executable flag, with /bin/ls backed implementation to discover these
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Wed, 21 Mar 2012 20:40:28 +0100
parents
children 9c9c442b5f2e
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406:d56ea1a2537a 413:7f27122011c3
1 /*
2 * Copyright (c) 2012 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.util;
18
19 import java.io.File;
20 import java.io.IOException;
21 import java.util.ArrayList;
22 import java.util.Arrays;
23 import java.util.Collections;
24 import java.util.HashMap;
25 import java.util.HashSet;
26 import java.util.List;
27 import java.util.Map;
28 import java.util.Set;
29 import java.util.TreeMap;
30 import java.util.regex.Matcher;
31 import java.util.regex.Pattern;
32
33 import org.tmatesoft.hg.internal.Internals;
34 import org.tmatesoft.hg.internal.ProcessExecHelper;
35
36 /**
37 * Utility to collect executable files and symbolic links in a directory.
38 *
39 *
40 * Not public as present approach (expect file but collect once per directory) may need to be made explicit
41 *
42 * TODO post-1.0 Add Linux-specific set of tests (similar to my test-flags repository, with symlink, executable and regular file,
43 * and few revisions where link and exec flags change. +testcase when link points to non-existing file (shall not report as missing,
44 * iow either FileInfo.exist() shall respect symlinks or WCSC account for )
45 *
46 * TODO post-1.0 Add extraction of link modification time, see RegularFileInfo#lastModified()
47 *
48 * @author Artem Tikhomirov
49 * @author Tmate Software Ltd.
50 */
51 /*package-local*/ class RegularFileStats {
52 private boolean isExec, isSymlink;
53 private String symlinkValue;
54 private final List<String> command;
55 private final ProcessExecHelper execHelper;
56 private final Matcher linkMatcher, execMatcher;
57
58
59 // directory name to (short link name -> link target)
60 private Map<String, Map<String, String>> dir2links = new TreeMap<String, Map<String, String>>();
61 // directory name to set of executable file short names
62 private Map<String, Set<String>> dir2execs = new TreeMap<String, Set<String>>();
63
64
65 RegularFileStats() {
66 if (Internals.runningOnWindows()) {
67 // XXX this implementation is not yet tested against any Windows repository,
68 // only against sample dir listings. As long as Mercurial doesn't handle Windows
69 // links, we don't really need this
70 command = Arrays.asList("cmd", "/c", "dir");
71 // Windows patterns need to work against full directory listing (I didn't find a way
72 // to list single file with its attributes like SYMLINK)
73 Pattern pLink = Pattern.compile("^\\S+.*\\s+<SYMLINK>\\s+(\\S.*)\\s+\\[(.+)\\]$", Pattern.MULTILINE);
74 Pattern pExec = Pattern.compile("^\\S+.*\\s+\\d+\\s+(\\S.*\\.exe)$", Pattern.MULTILINE);
75 linkMatcher = pLink.matcher("");
76 execMatcher = pExec.matcher("");
77 } else {
78 command = Arrays.asList("/bin/ls", "-l", "-Q"); // -Q is essential to get quoted name - the only way to
79 // tell exact file name (which may start or end with spaces.
80 Pattern pLink = Pattern.compile("^lrwxrwxrwx\\s.*\\s\"(.*)\"\\s+->\\s+\"(.*)\"$", Pattern.MULTILINE);
81 // pLink: group(1) is full name if single file listing (ls -l /usr/bin/java) and short name if directory listing (ls -l /usr/bin)
82 // group(2) is link target
83 Pattern pExec = Pattern.compile("^-..[sx]..[sx]..[sx]\\s.*\\s\"(.+)\"$", Pattern.MULTILINE);
84 // pExec: group(1) is name of executable file
85 linkMatcher = pLink.matcher("");
86 execMatcher = pExec.matcher("");
87 }
88 execHelper = new ProcessExecHelper();
89 }
90
91 public void init(File f) {
92 // can't check isFile because Java would say false for a symlink with non-existing target
93 if (f.isDirectory()) {
94 // perhaps, shall just collect stats for all files and set false to exec/link flags?
95 throw new IllegalArgumentException(); // FIXME EXCEPTIONS
96 }
97 final String dirName = f.getParentFile().getAbsolutePath();
98 final String fileName = f.getName();
99 Map<String, String> links = dir2links.get(dirName);
100 Set<String> execs = dir2execs.get(dirName);
101 if (links == null || execs == null) {
102 try {
103 ArrayList<String> cmd = new ArrayList<String>(command);
104 cmd.add(dirName);
105 CharSequence result = execHelper.exec(cmd);
106
107 if (execMatcher.reset(result).find()) {
108 execs = new HashSet<String>();
109 do {
110 execs.add(execMatcher.group(1));
111 } while (execMatcher.find());
112 } else {
113 execs = Collections.emptySet(); // indicate we tried and found nothing
114 }
115 if (linkMatcher.reset(result).find()) {
116 links = new HashMap<String, String>();
117 do {
118 links.put(linkMatcher.group(1), linkMatcher.group(2));
119 } while (linkMatcher.find());
120 } else {
121 links = Collections.emptyMap();
122 }
123 dir2links.put(dirName, links);
124 dir2execs.put(dirName, execs);
125 } catch (InterruptedException ex) {
126 // try again? ensure not too long? stop right away?
127 // FIXME EXCEPTIONS
128 throw new RuntimeException();
129 } catch (IOException ex) {
130 // FIXME EXCEPTIONS perhaps, fail silently indicating false for both x and l?
131 throw new RuntimeException();
132 }
133 }
134 isExec = execs.contains(fileName);
135 isSymlink = links.containsKey(fileName);
136 if (isSymlink) {
137 symlinkValue = links.get(fileName);
138 } else {
139 symlinkValue = null;
140 }
141 }
142
143 public boolean isExecutable() {
144 return isExec;
145 }
146
147 public boolean isSymlink() {
148 return isSymlink;
149 }
150
151 public String getSymlinkTarget() {
152 if (isSymlink) {
153 return symlinkValue;
154 }
155 throw new UnsupportedOperationException();
156 }
157 }