org.spearce.jgit/src/org/spearce/jgit/patch/HunkHeader.java

   1 /*
   2  * Copyright (C) 2008, Google Inc.
   3  *
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or
   7  * without modification, are permitted provided that the following
   8  * conditions are met:
   9  *
  10  * - Redistributions of source code must retain the above copyright
  11  *   notice, this list of conditions and the following disclaimer.
  12  *
  13  * - Redistributions in binary form must reproduce the above
  14  *   copyright notice, this list of conditions and the following
  15  *   disclaimer in the documentation and/or other materials provided
  16  *   with the distribution.
  17  *
  18  * - Neither the name of the Git Development Community nor the
  19  *   names of its contributors may be used to endorse or promote
  20  *   products derived from this software without specific prior
  21  *   written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  24  * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  25  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  28  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  29  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  31  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  32  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  33  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  35  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 package org.spearce.jgit.patch;
  39
  40 import static org.spearce.jgit.util.RawParseUtils.match;
  41 import static org.spearce.jgit.util.RawParseUtils.nextLF;
  42 import static org.spearce.jgit.util.RawParseUtils.parseBase10;
  43
  44 import org.spearce.jgit.util.MutableInteger;
  45
  46 /** Hunk header describing the layout of a single block of lines */
  47 public class HunkHeader {
  48         private final FileHeader file;
  49
  50         /** Offset within {@link #file}.buf to the "@@ -" line. */
  51         final int startOffset;
  52
  53         /** Position 1 past the end of this hunk within {@link #file}'s buf. */
  54         int endOffset;
  55
  56         /** First line number in the pre-image file where the hunk starts */
  57         int oldStartLine;
  58
  59         /** Total number of pre-image lines this hunk covers (context + deleted) */
  60         int oldLineCount;
  61
  62         /** First line number in the post-image file where the hunk starts */
  63         int newStartLine;
  64
  65         /** Total number of post-image lines this hunk covers (context + inserted) */
  66         int newLineCount;
  67
  68         /** Total number of lines of context appearing in this hunk */
  69         int nContext;
  70
  71         /** Number of lines removed by this hunk */
  72         int nDeleted;
  73
  74         /** Number of lines added by this hunk */
  75         int nAdded;
  76
  77         HunkHeader(final FileHeader fh, final int offset) {
  78                 file = fh;
  79                 startOffset = offset;
  80         }
  81
  82         /** @return header for the file this hunk applies to */
  83         public FileHeader getFileHeader() {
  84                 return file;
  85         }
  86
  87         /** @return first line number in the pre-image file where the hunk starts */
  88         public int getOldStartLine() {
  89                 return oldStartLine;
  90         }
  91
  92         /** @return total number of pre-image lines this hunk covers */
  93         public int getOldLineCount() {
  94                 return oldLineCount;
  95         }
  96
  97         /** @return first line number in the post-image file where the hunk starts */
  98         public int getNewStartLine() {
  99                 return newStartLine;
 100         }
 101
 102         /** @return Total number of post-image lines this hunk covers */
 103         public int getNewLineCount() {
 104                 return newLineCount;
 105         }
 106
 107         /** @return total number of lines of context appearing in this hunk */
 108         public int getLinesContext() {
 109                 return nContext;
 110         }
 111
 112         /** @return number of lines removed by this hunk */
 113         public int getLinesDeleted() {
 114                 return nDeleted;
 115         }
 116
 117         /** @return number of lines added by this hunk */
 118         public int getLinesAdded() {
 119                 return nAdded;
 120         }
 121
 122         void parseHeader() {
 123                 // Parse "@@ -236,9 +236,9 @@ protected boolean"
 124                 //
 125                 final byte[] buf = file.buf;
 126                 final MutableInteger ptr = new MutableInteger();
 127                 ptr.value = nextLF(buf, startOffset, ' ');
 128                 oldStartLine = -parseBase10(buf, ptr.value, ptr);
 129                 oldLineCount = parseBase10(buf, ptr.value + 1, ptr);
 130
 131                 newStartLine = parseBase10(buf, ptr.value + 1, ptr);
 132                 newLineCount = parseBase10(buf, ptr.value + 1, ptr);
 133         }
 134
 135         int parseBody() {
 136                 final byte[] buf = file.buf;
 137                 final int sz = buf.length;
 138                 int c = nextLF(buf, startOffset), last = c;
 139
 140                 nDeleted = 0;
 141                 nAdded = 0;
 142
 143                 SCAN: for (; c < sz; last = c, c = nextLF(buf, c)) {
 144                         switch (buf[c]) {
 145                         case ' ':
 146                         case '\n':
 147                                 nContext++;
 148                                 continue;
 149
 150                         case '-':
 151                                 nDeleted++;
 152                                 continue;
 153
 154                         case '+':
 155                                 nAdded++;
 156                                 continue;
 157
 158                         case '\\': // Matches "\ No newline at end of file"
 159                                 continue;
 160
 161                         default:
 162                                 break SCAN;
 163                         }
 164                 }
 165
 166                 if (last < sz && nContext + nDeleted - 1 == oldLineCount
 167                                 && nContext + nAdded == newLineCount
 168                                 && match(buf, last, Patch.SIG_FOOTER) >= 0) {
 169                         // This is an extremely common occurrence of "corruption".
 170                         // Users add footers with their signatures after this mark,
 171                         // and git diff adds the git executable version number.
 172                         // Let it slide; the hunk otherwise looked sound.
 173                         //
 174                         nDeleted--;
 175                         return last;
 176                 }
 177
 178                 if (nContext + nDeleted != oldLineCount
 179                                 || nContext + nAdded != newLineCount) {
 180                         // TODO report on truncated hunk
 181                 }
 182
 183                 return c;
 184         }
 185 }