org.spearce.jgit/src/org/spearce/jgit/patch/FileHeader.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.lib.Constants.encodeASCII;
  41 import static org.spearce.jgit.util.RawParseUtils.decode;
  42 import static org.spearce.jgit.util.RawParseUtils.match;
  43 import static org.spearce.jgit.util.RawParseUtils.nextLF;
  44 import static org.spearce.jgit.util.RawParseUtils.parseBase10;
  45
  46 import java.util.ArrayList;
  47 import java.util.Collections;
  48 import java.util.List;
  49
  50 import org.spearce.jgit.lib.AbbreviatedObjectId;
  51 import org.spearce.jgit.lib.Constants;
  52 import org.spearce.jgit.lib.FileMode;
  53 import org.spearce.jgit.util.QuotedString;
  54
  55 /** Patch header describing an action for a single file path. */
  56 public class FileHeader {
  57         /** Magical file name used for file adds or deletes. */
  58         public static final String DEV_NULL = "/dev/null";
  59
  60         private static final byte[] OLD_MODE = encodeASCII("old mode ");
  61
  62         private static final byte[] NEW_MODE = encodeASCII("new mode ");
  63
  64         private static final byte[] DELETED_FILE_MODE = encodeASCII("deleted file mode ");
  65
  66         private static final byte[] NEW_FILE_MODE = encodeASCII("new file mode ");
  67
  68         private static final byte[] COPY_FROM = encodeASCII("copy from ");
  69
  70         private static final byte[] COPY_TO = encodeASCII("copy to ");
  71
  72         private static final byte[] RENAME_OLD = encodeASCII("rename old ");
  73
  74         private static final byte[] RENAME_NEW = encodeASCII("rename new ");
  75
  76         private static final byte[] RENAME_FROM = encodeASCII("rename from ");
  77
  78         private static final byte[] RENAME_TO = encodeASCII("rename to ");
  79
  80         private static final byte[] SIMILARITY_INDEX = encodeASCII("similarity index ");
  81
  82         private static final byte[] DISSIMILARITY_INDEX = encodeASCII("dissimilarity index ");
  83
  84         private static final byte[] INDEX = encodeASCII("index ");
  85
  86         static final byte[] OLD_NAME = encodeASCII("--- ");
  87
  88         static final byte[] NEW_NAME = encodeASCII("+++ ");
  89
  90         static final byte[] HUNK_HDR = encodeASCII("@@ -");
  91
  92         /** General type of change a single file-level patch describes. */
  93         public static enum ChangeType {
  94                 /** Add a new file to the project */
  95                 ADD,
  96
  97                 /** Modify an existing file in the project (content and/or mode) */
  98                 MODIFY,
  99
 100                 /** Delete an existing file from the project */
 101                 DELETE,
 102
 103                 /** Rename an existing file to a new location */
 104                 RENAME,
 105
 106                 /** Copy an existing file to a new location, keeping the original */
 107                 COPY;
 108         }
 109
 110         /** Type of patch used by this file. */
 111         public static enum PatchType {
 112                 /** A traditional unified diff style patch of a text file. */
 113                 UNIFIED,
 114
 115                 /** An empty patch with a message "Binary files ... differ" */
 116                 BINARY,
 117
 118                 /** A Git binary patch, holding pre and post image deltas */
 119                 GIT_BINARY;
 120         }
 121
 122         /** Buffer holding the patch data for this file. */
 123         final byte[] buf;
 124
 125         /** Offset within {@link #buf} to the "diff ..." line. */
 126         final int startOffset;
 127
 128         /** Position 1 past the end of this file within {@link #buf}. */
 129         int endOffset;
 130
 131         /** File name of the old (pre-image). */
 132         private String oldName;
 133
 134         /** File name of the new (post-image). */
 135         private String newName;
 136
 137         /** Old mode of the file, if described by the patch, else null. */
 138         private FileMode oldMode;
 139
 140         /** New mode of the file, if described by the patch, else null. */
 141         private FileMode newMode;
 142
 143         /** General type of change indicated by the patch. */
 144         private ChangeType changeType;
 145
 146         /** Similarity score if {@link #changeType} is a copy or rename. */
 147         private int score;
 148
 149         /** ObjectId listed on the index line for the old (pre-image) */
 150         private AbbreviatedObjectId oldId;
 151
 152         /** ObjectId listed on the index line for the new (post-image) */
 153         private AbbreviatedObjectId newId;
 154
 155         /** Type of patch used to modify this file */
 156         PatchType patchType;
 157
 158         /** The hunks of this file */
 159         private List<HunkHeader> hunks;
 160
 161         FileHeader(final byte[] b, final int offset) {
 162                 buf = b;
 163                 startOffset = offset;
 164                 changeType = ChangeType.MODIFY; // unless otherwise designated
 165                 patchType = PatchType.UNIFIED;
 166         }
 167
 168         /**
 169          * Get the old name associated with this file.
 170          * <p>
 171          * The meaning of the old name can differ depending on the semantic meaning
 172          * of this patch:
 173          * <ul>
 174          * <li><i>file add</i>: always <code>/dev/null</code></li>
 175          * <li><i>file modify</i>: always {@link #getNewName()}</li>
 176          * <li><i>file delete</i>: always the file being deleted</li>
 177          * <li><i>file copy</i>: source file the copy originates from</li>
 178          * <li><i>file rename</i>: source file the rename originates from</li>
 179          * </ul>
 180          *
 181          * @return old name for this file.
 182          */
 183         public String getOldName() {
 184                 return oldName;
 185         }
 186
 187         /**
 188          * Get the new name associated with this file.
 189          * <p>
 190          * The meaning of the new name can differ depending on the semantic meaning
 191          * of this patch:
 192          * <ul>
 193          * <li><i>file add</i>: always the file being created</li>
 194          * <li><i>file modify</i>: always {@link #getOldName()}</li>
 195          * <li><i>file delete</i>: always <code>/dev/null</code></li>
 196          * <li><i>file copy</i>: destination file the copy ends up at</li>
 197          * <li><i>file rename</i>: destination file the rename ends up at/li>
 198          * </ul>
 199          *
 200          * @return new name for this file.
 201          */
 202         public String getNewName() {
 203                 return newName;
 204         }
 205
 206         /** @return the old file mode, if described in the patch */
 207         public FileMode getOldMode() {
 208                 return oldMode;
 209         }
 210
 211         /** @return the new file mode, if described in the patch */
 212         public FileMode getNewMode() {
 213                 return newMode;
 214         }
 215
 216         /** @return the type of change this patch makes on {@link #getNewName()} */
 217         public ChangeType getChangeType() {
 218                 return changeType;
 219         }
 220
 221         /**
 222          * @return similarity score between {@link #getOldName()} and
 223          *         {@link #getNewName()} if {@link #getChangeType()} is
 224          *         {@link ChangeType#COPY} or {@link ChangeType#RENAME}.
 225          */
 226         public int getScore() {
 227                 return score;
 228         }
 229
 230         /**
 231          * Get the old object id from the <code>index</code>.
 232          *
 233          * @return the object id; null if there is no index line
 234          */
 235         public AbbreviatedObjectId getOldId() {
 236                 return oldId;
 237         }
 238
 239         /**
 240          * Get the new object id from the <code>index</code>.
 241          *
 242          * @return the object id; null if there is no index line
 243          */
 244         public AbbreviatedObjectId getNewId() {
 245                 return newId;
 246         }
 247
 248         /** @return style of patch used to modify this file */
 249         public PatchType getPatchType() {
 250                 return patchType;
 251         }
 252
 253         /** @return hunks altering this file; in order of appearance in patch */
 254         public List<HunkHeader> getHunks() {
 255                 if (hunks == null)
 256                         return Collections.emptyList();
 257                 return hunks;
 258         }
 259
 260         void addHunk(final HunkHeader h) {
 261                 if (h.getFileHeader() != this)
 262                         throw new IllegalArgumentException("Hunk belongs to another file");
 263                 if (hunks == null)
 264                         hunks = new ArrayList<HunkHeader>();
 265                 hunks.add(h);
 266         }
 267
 268         /**
 269          * Parse a "diff --git" or "diff --cc" line.
 270          *
 271          * @param ptr
 272          *            first character after the "diff --git " or "diff --cc " part.
 273          * @return first character after the LF at the end of the line; -1 on error.
 274          */
 275         int parseGitFileName(int ptr) {
 276                 final int eol = nextLF(buf, ptr);
 277                 final int bol = ptr;
 278                 if (eol >= buf.length) {
 279                         return -1;
 280                 }
 281
 282                 // buffer[ptr..eol] looks like "a/foo b/foo\n". After the first
 283                 // A regex to match this is "^[^/]+/(.*?) [^/+]+/\1\n$". There
 284                 // is only one way to split the line such that text to the left
 285                 // of the space matches the text to the right, excluding the part
 286                 // before the first slash.
 287                 //
 288
 289                 final int aStart = nextLF(buf, ptr, '/');
 290                 if (aStart >= eol)
 291                         return eol;
 292
 293                 while (ptr < eol) {
 294                         final int sp = nextLF(buf, ptr, ' ');
 295                         if (sp >= eol) {
 296                                 // We can't split the header, it isn't valid.
 297                                 // This may be OK if this is a rename patch.
 298                                 //
 299                                 return eol;
 300                         }
 301                         final int bStart = nextLF(buf, sp, '/');
 302                         if (bStart >= eol)
 303                                 return eol;
 304
 305                         // If buffer[aStart..sp - 1] = buffer[bStart..eol - 1]
 306                         // we have a valid split.
 307                         //
 308                         if (eq(aStart, sp - 1, bStart, eol - 1)) {
 309                                 if (buf[bol] == '"') {
 310                                         // We're a double quoted name. The region better end
 311                                         // in a double quote too, and we need to decode the
 312                                         // characters before reading the name.
 313                                         //
 314                                         if (buf[sp - 2] != '"') {
 315                                                 return eol;
 316                                         }
 317                                         oldName = QuotedString.GIT_PATH.dequote(buf, bol, sp - 1);
 318                                         oldName = p1(oldName);
 319                                 } else {
 320                                         oldName = decode(Constants.CHARSET, buf, aStart, sp - 1);
 321                                 }
 322                                 newName = oldName;
 323                                 return eol;
 324                         }
 325
 326                         // This split wasn't correct. Move past the space and try
 327                         // another split as the space must be part of the file name.
 328                         //
 329                         ptr = sp;
 330                 }
 331
 332                 return eol;
 333         }
 334
 335         int parseGitHeaders(int ptr) {
 336                 final int sz = buf.length;
 337                 while (ptr < sz) {
 338                         final int eol = nextLF(buf, ptr);
 339                         if (match(buf, ptr, HUNK_HDR) >= 0) {
 340                                 // First hunk header; break out and parse them later.
 341                                 break;
 342
 343                         } else if (match(buf, ptr, OLD_NAME) >= 0) {
 344                                 oldName = p1(parseName(oldName, ptr + OLD_NAME.length, eol));
 345                                 if (oldName == DEV_NULL)
 346                                         changeType = ChangeType.ADD;
 347
 348                         } else if (match(buf, ptr, NEW_NAME) >= 0) {
 349                                 newName = p1(parseName(newName, ptr + NEW_NAME.length, eol));
 350                                 if (newName == DEV_NULL)
 351                                         changeType = ChangeType.DELETE;
 352
 353                         } else if (match(buf, ptr, OLD_MODE) >= 0) {
 354                                 oldMode = parseFileMode(ptr + OLD_MODE.length, eol);
 355
 356                         } else if (match(buf, ptr, NEW_MODE) >= 0) {
 357                                 newMode = parseFileMode(ptr + NEW_MODE.length, eol);
 358
 359                         } else if (match(buf, ptr, DELETED_FILE_MODE) >= 0) {
 360                                 oldMode = parseFileMode(ptr + DELETED_FILE_MODE.length, eol);
 361                                 changeType = ChangeType.DELETE;
 362
 363                         } else if (match(buf, ptr, NEW_FILE_MODE) >= 0) {
 364                                 newMode = parseFileMode(ptr + NEW_FILE_MODE.length, eol);
 365                                 changeType = ChangeType.ADD;
 366
 367                         } else if (match(buf, ptr, COPY_FROM) >= 0) {
 368                                 oldName = parseName(oldName, ptr + COPY_FROM.length, eol);
 369                                 changeType = ChangeType.COPY;
 370
 371                         } else if (match(buf, ptr, COPY_TO) >= 0) {
 372                                 newName = parseName(newName, ptr + COPY_TO.length, eol);
 373                                 changeType = ChangeType.COPY;
 374
 375                         } else if (match(buf, ptr, RENAME_OLD) >= 0) {
 376                                 oldName = parseName(oldName, ptr + RENAME_OLD.length, eol);
 377                                 changeType = ChangeType.RENAME;
 378
 379                         } else if (match(buf, ptr, RENAME_NEW) >= 0) {
 380                                 newName = parseName(newName, ptr + RENAME_NEW.length, eol);
 381                                 changeType = ChangeType.RENAME;
 382
 383                         } else if (match(buf, ptr, RENAME_FROM) >= 0) {
 384                                 oldName = parseName(oldName, ptr + RENAME_FROM.length, eol);
 385                                 changeType = ChangeType.RENAME;
 386
 387                         } else if (match(buf, ptr, RENAME_TO) >= 0) {
 388                                 newName = parseName(newName, ptr + RENAME_TO.length, eol);
 389                                 changeType = ChangeType.RENAME;
 390
 391                         } else if (match(buf, ptr, SIMILARITY_INDEX) >= 0) {
 392                                 score = parseBase10(buf, ptr + SIMILARITY_INDEX.length, null);
 393
 394                         } else if (match(buf, ptr, DISSIMILARITY_INDEX) >= 0) {
 395                                 score = parseBase10(buf, ptr + DISSIMILARITY_INDEX.length, null);
 396
 397                         } else if (match(buf, ptr, INDEX) >= 0) {
 398                                 parseIndexLine(ptr + INDEX.length, eol);
 399
 400                         } else {
 401                                 // Probably an empty patch (stat dirty).
 402                                 break;
 403                         }
 404
 405                         ptr = eol;
 406                 }
 407                 return ptr;
 408         }
 409
 410         int parseTraditionalHeaders(int ptr) {
 411                 final int sz = buf.length;
 412                 while (ptr < sz) {
 413                         final int eol = nextLF(buf, ptr);
 414                         if (match(buf, ptr, HUNK_HDR) >= 0) {
 415                                 // First hunk header; break out and parse them later.
 416                                 break;
 417
 418                         } else if (match(buf, ptr, OLD_NAME) >= 0) {
 419                                 oldName = p1(parseName(oldName, ptr + OLD_NAME.length, eol));
 420                                 if (oldName == DEV_NULL)
 421                                         changeType = ChangeType.ADD;
 422
 423                         } else if (match(buf, ptr, NEW_NAME) >= 0) {
 424                                 newName = p1(parseName(newName, ptr + NEW_NAME.length, eol));
 425                                 if (newName == DEV_NULL)
 426                                         changeType = ChangeType.DELETE;
 427
 428                         } else {
 429                                 // Possibly an empty patch.
 430                                 break;
 431                         }
 432
 433                         ptr = eol;
 434                 }
 435                 return ptr;
 436         }
 437
 438         private String parseName(final String expect, int ptr, final int end) {
 439                 if (ptr == end)
 440                         return expect;
 441
 442                 String r;
 443                 if (buf[ptr] == '"') {
 444                         // New style GNU diff format
 445                         //
 446                         r = QuotedString.GIT_PATH.dequote(buf, ptr, end - 1);
 447                 } else {
 448                         // Older style GNU diff format, an optional tab ends the name.
 449                         //
 450                         int tab = end;
 451                         while (ptr < tab && buf[tab - 1] != '\t')
 452                                 tab--;
 453                         if (ptr == tab)
 454                                 tab = end;
 455                         r = decode(Constants.CHARSET, buf, ptr, tab - 1);
 456                 }
 457
 458                 if (r.equals(DEV_NULL))
 459                         r = DEV_NULL;
 460                 return r;
 461         }
 462
 463         private static String p1(final String r) {
 464                 final int s = r.indexOf('/');
 465                 return s > 0 ? r.substring(s + 1) : r;
 466         }
 467
 468         private FileMode parseFileMode(int ptr, final int end) {
 469                 int tmp = 0;
 470                 while (ptr < end - 1) {
 471                         tmp <<= 3;
 472                         tmp += buf[ptr++] - '0';
 473                 }
 474                 return FileMode.fromBits(tmp);
 475         }
 476
 477         private void parseIndexLine(int ptr, final int end) {
 478                 // "index $asha1..$bsha1[ $mode]" where $asha1 and $bsha1
 479                 // can be unique abbreviations
 480                 //
 481                 final int dot2 = nextLF(buf, ptr, '.');
 482                 final int mode = nextLF(buf, dot2, ' ');
 483
 484                 oldId = AbbreviatedObjectId.fromString(buf, ptr, dot2 - 1);
 485                 newId = AbbreviatedObjectId.fromString(buf, dot2 + 1, mode - 1);
 486
 487                 if (mode < end)
 488                         newMode = oldMode = parseFileMode(mode, end);
 489         }
 490
 491         private boolean eq(int aPtr, int aEnd, int bPtr, int bEnd) {
 492                 if (aEnd - aPtr != bEnd - bPtr) {
 493                         return false;
 494                 }
 495                 while (aPtr < aEnd) {
 496                         if (buf[aPtr++] != buf[bPtr++])
 497                                 return false;
 498                 }
 499                 return true;
 500         }
 501 }