Mercurial > hg4j

comparison src/org/tmatesoft/hg/internal/NewlineFilter.java @ 113:67ae317408c9

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Filter implementation for newline translation
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Wed, 02 Feb 2011 21:19:02 +0100
parents
children 46291ec605a0
comparison
equal deleted inserted replaced
112:d488c7638b87 113:67ae317408c9
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.internal;
18
19 import static org.tmatesoft.hg.internal.Filter.Direction.FromRepo;
20 import static org.tmatesoft.hg.internal.Filter.Direction.ToRepo;
21 import static org.tmatesoft.hg.internal.KeywordFilter.copySlice;
22
23 import java.io.File;
24 import java.io.FileInputStream;
25 import java.io.FileOutputStream;
26 import java.nio.ByteBuffer;
27
28 import org.tmatesoft.hg.core.Path;
29 import org.tmatesoft.hg.repo.HgRepository;
30
31 /**
32 *
33 * @author Artem Tikhomirov
34 * @author TMate Software Ltd.
35 */
36 public class NewlineFilter implements Filter {
37
38 // if allowInconsistent is true, filter simply pass incorrect newline characters (single \r or \r\n on *nix and single \n on Windows) as is,
39 // i.e. doesn't try to convert them into appropriate newline characters. XXX revisit if Keyword extension behaves differently
40 private final boolean allowInconsistent;
41 private final boolean winToNix;
42
43 private NewlineFilter(boolean failIfInconsistent, int transform) {
44 winToNix = transform == 0;
45 allowInconsistent = !failIfInconsistent;
46 }
47
48 public ByteBuffer filter(ByteBuffer src) {
49 if (winToNix) {
50 return win2nix(src);
51 } else {
52 return nix2win(src);
53 }
54 }
55
56 private ByteBuffer win2nix(ByteBuffer src) {
57 int x = src.position(); // source index
58 int lookupStart = x;
59 ByteBuffer dst = null;
60 while (x < src.limit()) {
61 // x, lookupStart, ir and in are absolute positions within src buffer, which is never read with modifying operations
62 int ir = indexOf('\r', src, lookupStart);
63 int in = indexOf('\n', src, lookupStart);
64 if (ir == -1) {
65 if (in == -1 || allowInconsistent) {
66 if (dst != null) {
67 copySlice(src, x, src.limit(), dst);
68 x = src.limit(); // consumed all
69 }
70 break;
71 } else {
72 fail(src, in);
73 }
74 }
75 // in == -1 while ir != -1 may be valid case if ir is the last char of the buffer, we check below for that
76 if (in != -1 && in != ir+1 && !allowInconsistent) {
77 fail(src, in);
78 }
79 if (dst == null) {
80 dst = ByteBuffer.allocate(src.remaining());
81 }
82 copySlice(src, x, ir, dst);
83 if (ir+1 == src.limit()) {
84 // last char of the buffer -
85 // consume src till that char and let next iteration work on it
86 x = ir;
87 break;
88 }
89 if (in != ir + 1) {
90 x = ir+1; // generally in, but if allowInconsistent==true and \r is not followed by \n, then
91 // cases like "one \r two \r\n three" shall be processed correctly (second pair would be ignored if x==in)
92 lookupStart = ir+1;
93 } else {
94 x = in;
95 lookupStart = x+1; // skip \n for next lookup
96 }
97 }
98 src.position(x); // mark we've consumed up to x
99 return dst == null ? src : (ByteBuffer) dst.flip();
100 }
101
102 private ByteBuffer nix2win(ByteBuffer src) {
103 int x = src.position();
104 ByteBuffer dst = null;
105 while (x < src.limit()) {
106 int in = indexOf('\n', src, x);
107 int ir = indexOf('\r', src, x, in == -1 ? src.limit() : in);
108 if (in == -1) {
109 if (ir == -1 || allowInconsistent) {
110 break;
111 } else {
112 fail(src, ir);
113 }
114 } else if (ir != -1 && !allowInconsistent) {
115 fail(src, ir);
116 }
117
118 // x <= in < src.limit
119 // allowInconsistent && x <= ir < in || ir == -1
120 if (dst == null) {
121 // buffer full of \n grows as much as twice in size
122 dst = ByteBuffer.allocate(src.remaining() * 2);
123 }
124 copySlice(src, x, in, dst);
125 if (ir == -1 || ir+1 != in) {
126 dst.put((byte) '\r');
127 } // otherwise (ir!=-1 && ir+1==in) we found \r\n pair, don't convert to \r\r\n
128 // we may copy \n at src[in] on the next iteration, but would need extra lookupIndex variable then.
129 dst.put((byte) '\n');
130 x = in+1;
131 }
132 src.position(x);
133 return dst == null ? src : (ByteBuffer) dst.flip();
134 }
135
136
137 private void fail(ByteBuffer b, int pos) {
138 throw new RuntimeException(String.format("Inconsistent newline characters in the stream (char 0x%x, local index:%d)", b.get(pos), pos));
139 }
140
141 private static int indexOf(char ch, ByteBuffer b, int from) {
142 return indexOf(ch, b, from, b.limit());
143 }
144
145 // looks up in buf[from..to)
146 private static int indexOf(char ch, ByteBuffer b, int from, int to) {
147 for (int i = from; i < to; i++) {
148 byte c = b.get(i);
149 if (ch == c) {
150 return i;
151 }
152 }
153 return -1;
154 }
155
156 public static class Factory implements Filter.Factory {
157 private final boolean localIsWin = File.separatorChar == '\\'; // FIXME
158 private final boolean failIfInconsistent = true;
159
160 public Filter create(HgRepository hgRepo, Path path, Options opts) {
161 if (opts.getDirection() == FromRepo) {
162 } else if (opts.getDirection() == ToRepo) {
163 }
164 return new NewlineFilter(failIfInconsistent, 1);
165 }
166 }
167
168 public static void main(String[] args) throws Exception {
169 FileInputStream fis = new FileInputStream(new File("/temp/design.lf.txt"));
170 FileOutputStream fos = new FileOutputStream(new File("/temp/design.newline.out"));
171 ByteBuffer b = ByteBuffer.allocate(12);
172 NewlineFilter nlFilter = new NewlineFilter(true, 1);
173 while (fis.getChannel().read(b) != -1) {
174 b.flip(); // get ready to be read
175 ByteBuffer f = nlFilter.filter(b);
176 fos.getChannel().write(f); // XXX in fact, f may not be fully consumed
177 if (b.hasRemaining()) {
178 b.compact();
179 } else {
180 b.clear();
181 }
182 }
183 fis.close();
184 fos.flush();
185 fos.close();
186 }
187
188 }