blame.c

   1 /*
   2  * Copyright (C) 2006, Fredrik Kuivinen <freku045@student.liu.se>
   3  */
   4
   5 #include <assert.h>
   6 #include <time.h>
   7 #include <sys/time.h>
   8
   9 #include "cache.h"
  10 #include "refs.h"
  11 #include "tag.h"
  12 #include "commit.h"
  13 #include "tree.h"
  14 #include "blob.h"
  15 #include "diff.h"
  16 #include "revision.h"
  17
  18 #define DEBUG 0
  19
  20 struct commit **blame_lines;
  21 int num_blame_lines;
  22
  23 struct util_info {
  24         int *line_map;
  25         unsigned char sha1[20]; /* blob sha, not commit! */
  26         char *buf;
  27         unsigned long size;
  28         int num_lines;
  29 //    const char* path;
  30 };
  31
  32 struct chunk {
  33         int off1, len1; // ---
  34         int off2, len2; // +++
  35 };
  36
  37 struct patch {
  38         struct chunk *chunks;
  39         int num;
  40 };
  41
  42 static void get_blob(struct commit *commit);
  43
  44 /* Only used for statistics */
  45 static int num_get_patch = 0;
  46 static int num_commits = 0;
  47 static int patch_time = 0;
  48
  49 #define TEMPFILE_PATH_LEN 60
  50 static struct patch *get_patch(struct commit *commit, struct commit *other)
  51 {
  52         struct patch *ret;
  53         struct util_info *info_c = (struct util_info *)commit->object.util;
  54         struct util_info *info_o = (struct util_info *)other->object.util;
  55         char tmp_path1[TEMPFILE_PATH_LEN], tmp_path2[TEMPFILE_PATH_LEN];
  56         char diff_cmd[TEMPFILE_PATH_LEN*2 + 20];
  57         struct timeval tv_start, tv_end;
  58         int fd;
  59         FILE *fin;
  60         char buf[1024];
  61
  62         ret = xmalloc(sizeof(struct patch));
  63         ret->chunks = NULL;
  64         ret->num = 0;
  65
  66         get_blob(commit);
  67         get_blob(other);
  68
  69         gettimeofday(&tv_start, NULL);
  70
  71         fd = git_mkstemp(tmp_path1, TEMPFILE_PATH_LEN, "git-blame-XXXXXX");
  72         if (fd < 0)
  73                 die("unable to create temp-file: %s", strerror(errno));
  74
  75         if (xwrite(fd, info_c->buf, info_c->size) != info_c->size)
  76                 die("write failed: %s", strerror(errno));
  77         close(fd);
  78
  79         fd = git_mkstemp(tmp_path2, TEMPFILE_PATH_LEN, "git-blame-XXXXXX");
  80         if (fd < 0)
  81                 die("unable to create temp-file: %s", strerror(errno));
  82
  83         if (xwrite(fd, info_o->buf, info_o->size) != info_o->size)
  84                 die("write failed: %s", strerror(errno));
  85         close(fd);
  86
  87         sprintf(diff_cmd, "diff -u0 %s %s", tmp_path1, tmp_path2);
  88         fin = popen(diff_cmd, "r");
  89         if (!fin)
  90                 die("popen failed: %s", strerror(errno));
  91
  92         while (fgets(buf, sizeof(buf), fin)) {
  93                 struct chunk *chunk;
  94                 char *start, *sp;
  95
  96                 if (buf[0] != '@' || buf[1] != '@')
  97                         continue;
  98
  99                 if (DEBUG)
 100                         printf("chunk line: %s", buf);
 101                 ret->num++;
 102                 ret->chunks = xrealloc(ret->chunks,
 103                                        sizeof(struct chunk) * ret->num);
 104                 chunk = &ret->chunks[ret->num - 1];
 105
 106                 assert(!strncmp(buf, "@@ -", 4));
 107
 108                 start = buf + 4;
 109                 sp = index(start, ' ');
 110                 *sp = '\0';
 111                 if (index(start, ',')) {
 112                         int ret =
 113                             sscanf(start, "%d,%d", &chunk->off1, &chunk->len1);
 114                         assert(ret == 2);
 115                 } else {
 116                         int ret = sscanf(start, "%d", &chunk->off1);
 117                         assert(ret == 1);
 118                         chunk->len1 = 1;
 119                 }
 120                 *sp = ' ';
 121
 122                 start = sp + 1;
 123                 sp = index(start, ' ');
 124                 *sp = '\0';
 125                 if (index(start, ',')) {
 126                         int ret =
 127                             sscanf(start, "%d,%d", &chunk->off2, &chunk->len2);
 128                         assert(ret == 2);
 129                 } else {
 130                         int ret = sscanf(start, "%d", &chunk->off2);
 131                         assert(ret == 1);
 132                         chunk->len2 = 1;
 133                 }
 134                 *sp = ' ';
 135
 136                 if (chunk->len1 == 0)
 137                         chunk->off1++;
 138                 if (chunk->len2 == 0)
 139                         chunk->off2++;
 140
 141                 if (chunk->off1 > 0)
 142                         chunk->off1--;
 143                 if (chunk->off2 > 0)
 144                         chunk->off2--;
 145
 146                 assert(chunk->off1 >= 0);
 147                 assert(chunk->off2 >= 0);
 148         }
 149         pclose(fin);
 150         unlink(tmp_path1);
 151         unlink(tmp_path2);
 152
 153         gettimeofday(&tv_end, NULL);
 154         patch_time += 1000000 * (tv_end.tv_sec - tv_start.tv_sec) +
 155                 tv_end.tv_usec - tv_start.tv_usec;
 156
 157         num_get_patch++;
 158         return ret;
 159 }
 160
 161 static void free_patch(struct patch *p)
 162 {
 163         free(p->chunks);
 164         free(p);
 165 }
 166
 167 static int get_blob_sha1_internal(unsigned char *sha1, const char *base,
 168                                   int baselen, const char *pathname,
 169                                   unsigned mode, int stage);
 170
 171 static unsigned char blob_sha1[20];
 172 static int get_blob_sha1(struct tree *t, const char *pathname,
 173                          unsigned char *sha1)
 174 {
 175         int i;
 176         const char *pathspec[2];
 177         pathspec[0] = pathname;
 178         pathspec[1] = NULL;
 179         memset(blob_sha1, 0, sizeof(blob_sha1));
 180         read_tree_recursive(t, "", 0, 0, pathspec, get_blob_sha1_internal);
 181
 182         for (i = 0; i < 20; i++) {
 183                 if (blob_sha1[i] != 0)
 184                         break;
 185         }
 186
 187         if (i == 20)
 188                 return -1;
 189
 190         memcpy(sha1, blob_sha1, 20);
 191         return 0;
 192 }
 193
 194 static int get_blob_sha1_internal(unsigned char *sha1, const char *base,
 195                                   int baselen, const char *pathname,
 196                                   unsigned mode, int stage)
 197 {
 198         if (S_ISDIR(mode))
 199                 return READ_TREE_RECURSIVE;
 200
 201         memcpy(blob_sha1, sha1, 20);
 202         return -1;
 203 }
 204
 205 static void get_blob(struct commit *commit)
 206 {
 207         struct util_info *info = commit->object.util;
 208         char type[20];
 209
 210         if (info->buf)
 211                 return;
 212
 213         info->buf = read_sha1_file(info->sha1, type, &info->size);
 214
 215         assert(!strcmp(type, "blob"));
 216 }
 217
 218 /* For debugging only */
 219 static void print_patch(struct patch *p)
 220 {
 221         int i;
 222         printf("Num chunks: %d\n", p->num);
 223         for (i = 0; i < p->num; i++) {
 224                 printf("%d,%d %d,%d\n", p->chunks[i].off1, p->chunks[i].len1,
 225                        p->chunks[i].off2, p->chunks[i].len2);
 226         }
 227 }
 228
 229 #if 0
 230 /* For debugging only */
 231 static void print_map(struct commit *cmit, struct commit *other)
 232 {
 233         struct util_info *util = cmit->object.util;
 234         struct util_info *util2 = other->object.util;
 235
 236         int i;
 237         int max =
 238             util->num_lines >
 239             util2->num_lines ? util->num_lines : util2->num_lines;
 240         int num;
 241
 242         for (i = 0; i < max; i++) {
 243                 printf("i: %d ", i);
 244                 num = -1;
 245
 246                 if (i < util->num_lines) {
 247                         num = util->line_map[i];
 248                         printf("%d\t", num);
 249                 } else
 250                         printf("\t");
 251
 252                 if (i < util2->num_lines) {
 253                         int num2 = util2->line_map[i];
 254                         printf("%d\t", num2);
 255                         if (num != -1 && num2 != num)
 256                                 printf("---");
 257                 } else
 258                         printf("\t");
 259
 260                 printf("\n");
 261         }
 262 }
 263 #endif
 264
 265 // p is a patch from commit to other.
 266 static void fill_line_map(struct commit *commit, struct commit *other,
 267                           struct patch *p)
 268 {
 269         struct util_info *util = commit->object.util;
 270         struct util_info *util2 = other->object.util;
 271         int *map = util->line_map;
 272         int *map2 = util2->line_map;
 273         int cur_chunk = 0;
 274         int i1, i2;
 275
 276         if (p->num && DEBUG)
 277                 print_patch(p);
 278
 279         if (DEBUG)
 280                 printf("num lines 1: %d num lines 2: %d\n", util->num_lines,
 281                        util2->num_lines);
 282
 283         for (i1 = 0, i2 = 0; i1 < util->num_lines; i1++, i2++) {
 284                 struct chunk *chunk = NULL;
 285                 if (cur_chunk < p->num)
 286                         chunk = &p->chunks[cur_chunk];
 287
 288                 if (chunk && chunk->off1 == i1) {
 289                         if (DEBUG && i2 != chunk->off2)
 290                                 printf("i2: %d off2: %d\n", i2, chunk->off2);
 291
 292                         assert(i2 == chunk->off2);
 293
 294                         i1--;
 295                         i2--;
 296                         if (chunk->len1 > 0)
 297                                 i1 += chunk->len1;
 298
 299                         if (chunk->len2 > 0)
 300                                 i2 += chunk->len2;
 301
 302                         cur_chunk++;
 303                 } else {
 304                         if (i2 >= util2->num_lines)
 305                                 break;
 306
 307                         if (map[i1] != map2[i2] && map[i1] != -1) {
 308                                 if (DEBUG)
 309                                         printf("map: i1: %d %d %p i2: %d %d %p\n",
 310                                                i1, map[i1],
 311                                                i1 != -1 ? blame_lines[map[i1]] : NULL,
 312                                                i2, map2[i2],
 313                                                i2 != -1 ? blame_lines[map2[i2]] : NULL);
 314                                 if (map2[i2] != -1 &&
 315                                     blame_lines[map[i1]] &&
 316                                     !blame_lines[map2[i2]])
 317                                         map[i1] = map2[i2];
 318                         }
 319
 320                         if (map[i1] == -1 && map2[i2] != -1)
 321                                 map[i1] = map2[i2];
 322                 }
 323
 324                 if (DEBUG > 1)
 325                         printf("l1: %d l2: %d i1: %d i2: %d\n",
 326                                map[i1], map2[i2], i1, i2);
 327         }
 328 }
 329
 330 static int map_line(struct commit *commit, int line)
 331 {
 332         struct util_info *info = commit->object.util;
 333         assert(line >= 0 && line < info->num_lines);
 334         return info->line_map[line];
 335 }
 336
 337 static int fill_util_info(struct commit *commit, const char *path)
 338 {
 339         struct util_info *util;
 340         if (commit->object.util)
 341                 return 0;
 342
 343         util = xmalloc(sizeof(struct util_info));
 344
 345         if (get_blob_sha1(commit->tree, path, util->sha1)) {
 346                 free(util);
 347                 return 1;
 348         } else {
 349                 util->buf = NULL;
 350                 util->size = 0;
 351                 util->line_map = NULL;
 352                 util->num_lines = -1;
 353                 commit->object.util = util;
 354                 return 0;
 355         }
 356 }
 357
 358 static void alloc_line_map(struct commit *commit)
 359 {
 360         struct util_info *util = commit->object.util;
 361         int i;
 362
 363         if (util->line_map)
 364                 return;
 365
 366         get_blob(commit);
 367
 368         util->num_lines = 0;
 369         for (i = 0; i < util->size; i++) {
 370                 if (util->buf[i] == '\n')
 371                         util->num_lines++;
 372         }
 373         if(util->buf[util->size - 1] != '\n')
 374                 util->num_lines++;
 375
 376         util->line_map = xmalloc(sizeof(int) * util->num_lines);
 377
 378         for (i = 0; i < util->num_lines; i++)
 379                 util->line_map[i] = -1;
 380 }
 381
 382 static void init_first_commit(struct commit* commit, const char* filename)
 383 {
 384         struct util_info* util;
 385         int i;
 386
 387         if (fill_util_info(commit, filename))
 388                 die("fill_util_info failed");
 389
 390         alloc_line_map(commit);
 391
 392         util = commit->object.util;
 393         num_blame_lines = util->num_lines;
 394
 395         for (i = 0; i < num_blame_lines; i++)
 396                 util->line_map[i] = i;
 397 }
 398
 399
 400 static void process_commits(struct rev_info *rev, const char *path,
 401                             struct commit** initial)
 402 {
 403         int i;
 404         struct util_info* util;
 405         int lines_left;
 406         int *blame_p;
 407         int *new_lines;
 408         int new_lines_len;
 409
 410         struct commit* commit = get_revision(rev);
 411         assert(commit);
 412         init_first_commit(commit, path);
 413
 414         util = commit->object.util;
 415         num_blame_lines = util->num_lines;
 416         blame_lines = xmalloc(sizeof(struct commit *) * num_blame_lines);
 417         for (i = 0; i < num_blame_lines; i++)
 418                 blame_lines[i] = NULL;
 419
 420         lines_left = num_blame_lines;
 421         blame_p = xmalloc(sizeof(int) * num_blame_lines);
 422         new_lines = xmalloc(sizeof(int) * num_blame_lines);
 423         do {
 424                 struct commit_list *parents;
 425                 int num_parents;
 426                 struct util_info *util;
 427
 428                 if (DEBUG)
 429                         printf("\nProcessing commit: %d %s\n", num_commits,
 430                                sha1_to_hex(commit->object.sha1));
 431
 432                 if (lines_left == 0)
 433                         return;
 434
 435                 num_commits++;
 436                 memset(blame_p, 0, sizeof(int) * num_blame_lines);
 437                 new_lines_len = 0;
 438                 num_parents = 0;
 439                 for (parents = commit->parents;
 440                      parents != NULL; parents = parents->next)
 441                         num_parents++;
 442
 443                 if(num_parents == 0)
 444                         *initial = commit;
 445
 446                 if(fill_util_info(commit, path))
 447                         continue;
 448
 449                 alloc_line_map(commit);
 450                 util = commit->object.util;
 451
 452                 for (parents = commit->parents;
 453                      parents != NULL; parents = parents->next) {
 454                         struct commit *parent = parents->item;
 455                         struct patch *patch;
 456
 457                         if (parse_commit(parent) < 0)
 458                                 die("parse_commit error");
 459
 460                         if (DEBUG)
 461                                 printf("parent: %s\n",
 462                                        sha1_to_hex(parent->object.sha1));
 463
 464                         if(fill_util_info(parent, path)) {
 465                                 num_parents--;
 466                                 continue;
 467                         }
 468
 469                         patch = get_patch(parent, commit);
 470                         alloc_line_map(parent);
 471                         fill_line_map(parent, commit, patch);
 472
 473                         for (i = 0; i < patch->num; i++) {
 474                             int l;
 475                             for (l = 0; l < patch->chunks[i].len2; l++) {
 476                                 int mapped_line =
 477                                     map_line(commit, patch->chunks[i].off2 + l);
 478                                 if (mapped_line != -1) {
 479                                     blame_p[mapped_line]++;
 480                                     if (blame_p[mapped_line] == num_parents)
 481                                         new_lines[new_lines_len++] = mapped_line;
 482                                 }
 483                             }
 484                         }
 485                         free_patch(patch);
 486                 }
 487
 488                 if (DEBUG)
 489                         printf("parents: %d\n", num_parents);
 490
 491                 for (i = 0; i < new_lines_len; i++) {
 492                         int mapped_line = new_lines[i];
 493                         if (blame_lines[mapped_line] == NULL) {
 494                                 blame_lines[mapped_line] = commit;
 495                                 lines_left--;
 496                                 if (DEBUG)
 497                                         printf("blame: mapped: %d i: %d\n",
 498                                                mapped_line, i);
 499                         }
 500                 }
 501         } while ((commit = get_revision(rev)) != NULL);
 502 }
 503
 504 int main(int argc, const char **argv)
 505 {
 506         int i;
 507         struct commit *initial = NULL;
 508         unsigned char sha1[20];
 509         const char* filename;
 510         int num_args;
 511         const char* args[10];
 512         struct rev_info rev;
 513
 514         setup_git_directory();
 515
 516         if (argc != 3)
 517                 die("Usage: blame commit-ish file");
 518
 519
 520         filename = argv[2];
 521
 522         {
 523                 struct commit* commit;
 524                 if (get_sha1(argv[1], sha1))
 525                         die("get_sha1 failed");
 526                 commit = lookup_commit_reference(sha1);
 527
 528                 if (fill_util_info(commit, filename)) {
 529                         printf("%s not found in %s\n", filename, argv[1]);
 530                         return 1;
 531                 }
 532         }
 533
 534         num_args = 0;
 535         args[num_args++] = NULL;
 536         args[num_args++] = "--topo-order";
 537         args[num_args++] = "--remove-empty";
 538         args[num_args++] = argv[1];
 539         args[num_args++] = "--";
 540         args[num_args++] = filename;
 541         args[num_args] = NULL;
 542
 543         setup_revisions(num_args, args, &rev, "HEAD");
 544         prepare_revision_walk(&rev);
 545         process_commits(&rev, filename, &initial);
 546
 547         for (i = 0; i < num_blame_lines; i++) {
 548                 struct commit *c = blame_lines[i];
 549                 if (!c)
 550                         c = initial;
 551
 552                 printf("%d %.8s\n", i, sha1_to_hex(c->object.sha1));
 553 // printf("%d %s\n", i, find_unique_abbrev(blame_lines[i]->object.sha1, 6));
 554         }
 555
 556         if (DEBUG) {
 557                 printf("num get patch: %d\n", num_get_patch);
 558                 printf("num commits: %d\n", num_commits);
 559                 printf("patch time: %f\n", patch_time / 1000000.0);
 560                 printf("initial: %s\n", sha1_to_hex(initial->object.sha1));
 561         }
 562
 563         return 0;
 564 }