git.oblomov.eu Git - git/blob - cache-tree.c

   1 #include "cache.h"
   2 #include "strbuf.h"
   3 #include "tree.h"
   4 #include "cache-tree.h"
   5
   6 #ifndef DEBUG
   7 #define DEBUG 0
   8 #endif
   9
  10 struct cache_tree *cache_tree(void)
  11 {
  12         struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
  13         it->entry_count = -1;
  14         return it;
  15 }
  16
  17 void cache_tree_free(struct cache_tree **it_p)
  18 {
  19         int i;
  20         struct cache_tree *it = *it_p;
  21
  22         if (!it)
  23                 return;
  24         for (i = 0; i < it->subtree_nr; i++)
  25                 if (it->down[i])
  26                         cache_tree_free(&it->down[i]->cache_tree);
  27         free(it->down);
  28         free(it);
  29         *it_p = NULL;
  30 }
  31
  32 static int subtree_name_cmp(const char *one, int onelen,
  33                             const char *two, int twolen)
  34 {
  35         if (onelen < twolen)
  36                 return -1;
  37         if (twolen < onelen)
  38                 return 1;
  39         return memcmp(one, two, onelen);
  40 }
  41
  42 static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
  43 {
  44         struct cache_tree_sub **down = it->down;
  45         int lo, hi;
  46         lo = 0;
  47         hi = it->subtree_nr;
  48         while (lo < hi) {
  49                 int mi = (lo + hi) / 2;
  50                 struct cache_tree_sub *mdl = down[mi];
  51                 int cmp = subtree_name_cmp(path, pathlen,
  52                                            mdl->name, mdl->namelen);
  53                 if (!cmp)
  54                         return mi;
  55                 if (cmp < 0)
  56                         hi = mi;
  57                 else
  58                         lo = mi + 1;
  59         }
  60         return -lo-1;
  61 }
  62
  63 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
  64                                            const char *path,
  65                                            int pathlen,
  66                                            int create)
  67 {
  68         struct cache_tree_sub *down;
  69         int pos = subtree_pos(it, path, pathlen);
  70         if (0 <= pos)
  71                 return it->down[pos];
  72         if (!create)
  73                 return NULL;
  74
  75         pos = -pos-1;
  76         if (it->subtree_alloc <= it->subtree_nr) {
  77                 it->subtree_alloc = alloc_nr(it->subtree_alloc);
  78                 it->down = xrealloc(it->down, it->subtree_alloc *
  79                                     sizeof(*it->down));
  80         }
  81         it->subtree_nr++;
  82
  83         down = xmalloc(sizeof(*down) + pathlen + 1);
  84         down->cache_tree = NULL;
  85         down->namelen = pathlen;
  86         memcpy(down->name, path, pathlen);
  87         down->name[pathlen] = 0;
  88
  89         if (pos < it->subtree_nr)
  90                 memmove(it->down + pos + 1,
  91                         it->down + pos,
  92                         sizeof(down) * (it->subtree_nr - pos - 1));
  93         it->down[pos] = down;
  94         return down;
  95 }
  96
  97 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
  98 {
  99         int pathlen = strlen(path);
 100         return find_subtree(it, path, pathlen, 1);
 101 }
 102
 103 void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
 104 {
 105         /* a/b/c
 106          * ==> invalidate self
 107          * ==> find "a", have it invalidate "b/c"
 108          * a
 109          * ==> invalidate self
 110          * ==> if "a" exists as a subtree, remove it.
 111          */
 112         const char *slash;
 113         int namelen;
 114         struct cache_tree_sub *down;
 115
 116 #if DEBUG
 117         fprintf(stderr, "cache-tree invalidate <%s>\n", path);
 118 #endif
 119
 120         if (!it)
 121                 return;
 122         slash = strchr(path, '/');
 123         it->entry_count = -1;
 124         if (!slash) {
 125                 int pos;
 126                 namelen = strlen(path);
 127                 pos = subtree_pos(it, path, namelen);
 128                 if (0 <= pos) {
 129                         cache_tree_free(&it->down[pos]->cache_tree);
 130                         free(it->down[pos]);
 131                         /* 0 1 2 3 4 5
 132                          *       ^     ^subtree_nr = 6
 133                          *       pos
 134                          * move 4 and 5 up one place (2 entries)
 135                          * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
 136                          */
 137                         memmove(it->down+pos, it->down+pos+1,
 138                                 sizeof(struct cache_tree_sub *) *
 139                                 (it->subtree_nr - pos - 1));
 140                         it->subtree_nr--;
 141                 }
 142                 return;
 143         }
 144         namelen = slash - path;
 145         down = find_subtree(it, path, namelen, 0);
 146         if (down)
 147                 cache_tree_invalidate_path(down->cache_tree, slash + 1);
 148 }
 149
 150 static int verify_cache(struct cache_entry **cache,
 151                         int entries)
 152 {
 153         int i, funny;
 154
 155         /* Verify that the tree is merged */
 156         funny = 0;
 157         for (i = 0; i < entries; i++) {
 158                 struct cache_entry *ce = cache[i];
 159                 if (ce_stage(ce)) {
 160                         if (10 < ++funny) {
 161                                 fprintf(stderr, "...\n");
 162                                 break;
 163                         }
 164                         fprintf(stderr, "%s: unmerged (%s)\n",
 165                                 ce->name, sha1_to_hex(ce->sha1));
 166                 }
 167         }
 168         if (funny)
 169                 return -1;
 170
 171         /* Also verify that the cache does not have path and path/file
 172          * at the same time.  At this point we know the cache has only
 173          * stage 0 entries.
 174          */
 175         funny = 0;
 176         for (i = 0; i < entries - 1; i++) {
 177                 /* path/file always comes after path because of the way
 178                  * the cache is sorted.  Also path can appear only once,
 179                  * which means conflicting one would immediately follow.
 180                  */
 181                 const char *this_name = cache[i]->name;
 182                 const char *next_name = cache[i+1]->name;
 183                 int this_len = strlen(this_name);
 184                 if (this_len < strlen(next_name) &&
 185                     strncmp(this_name, next_name, this_len) == 0 &&
 186                     next_name[this_len] == '/') {
 187                         if (10 < ++funny) {
 188                                 fprintf(stderr, "...\n");
 189                                 break;
 190                         }
 191                         fprintf(stderr, "You have both %s and %s\n",
 192                                 this_name, next_name);
 193                 }
 194         }
 195         if (funny)
 196                 return -1;
 197         return 0;
 198 }
 199
 200 static void discard_unused_subtrees(struct cache_tree *it)
 201 {
 202         struct cache_tree_sub **down = it->down;
 203         int nr = it->subtree_nr;
 204         int dst, src;
 205         for (dst = src = 0; src < nr; src++) {
 206                 struct cache_tree_sub *s = down[src];
 207                 if (s->used)
 208                         down[dst++] = s;
 209                 else {
 210                         cache_tree_free(&s->cache_tree);
 211                         free(s);
 212                         it->subtree_nr--;
 213                 }
 214         }
 215 }
 216
 217 int cache_tree_fully_valid(struct cache_tree *it)
 218 {
 219         int i;
 220         if (!it)
 221                 return 0;
 222         if (it->entry_count < 0 || !has_sha1_file(it->sha1))
 223                 return 0;
 224         for (i = 0; i < it->subtree_nr; i++) {
 225                 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
 226                         return 0;
 227         }
 228         return 1;
 229 }
 230
 231 static int update_one(struct cache_tree *it,
 232                       struct cache_entry **cache,
 233                       int entries,
 234                       const char *base,
 235                       int baselen,
 236                       int missing_ok,
 237                       int dryrun)
 238 {
 239         struct strbuf buffer;
 240         int i;
 241
 242         if (0 <= it->entry_count && has_sha1_file(it->sha1))
 243                 return it->entry_count;
 244
 245         /*
 246          * We first scan for subtrees and update them; we start by
 247          * marking existing subtrees -- the ones that are unmarked
 248          * should not be in the result.
 249          */
 250         for (i = 0; i < it->subtree_nr; i++)
 251                 it->down[i]->used = 0;
 252
 253         /*
 254          * Find the subtrees and update them.
 255          */
 256         for (i = 0; i < entries; i++) {
 257                 struct cache_entry *ce = cache[i];
 258                 struct cache_tree_sub *sub;
 259                 const char *path, *slash;
 260                 int pathlen, sublen, subcnt;
 261
 262                 path = ce->name;
 263                 pathlen = ce_namelen(ce);
 264                 if (pathlen <= baselen || memcmp(base, path, baselen))
 265                         break; /* at the end of this level */
 266
 267                 slash = strchr(path + baselen, '/');
 268                 if (!slash)
 269                         continue;
 270                 /*
 271                  * a/bbb/c (base = a/, slash = /c)
 272                  * ==>
 273                  * path+baselen = bbb/c, sublen = 3
 274                  */
 275                 sublen = slash - (path + baselen);
 276                 sub = find_subtree(it, path + baselen, sublen, 1);
 277                 if (!sub->cache_tree)
 278                         sub->cache_tree = cache_tree();
 279                 subcnt = update_one(sub->cache_tree,
 280                                     cache + i, entries - i,
 281                                     path,
 282                                     baselen + sublen + 1,
 283                                     missing_ok,
 284                                     dryrun);
 285                 if (subcnt < 0)
 286                         return subcnt;
 287                 i += subcnt - 1;
 288                 sub->used = 1;
 289         }
 290
 291         discard_unused_subtrees(it);
 292
 293         /*
 294          * Then write out the tree object for this level.
 295          */
 296         strbuf_init(&buffer);
 297         strbuf_grow(&buffer, 8192);
 298
 299         for (i = 0; i < entries; i++) {
 300                 struct cache_entry *ce = cache[i];
 301                 struct cache_tree_sub *sub;
 302                 const char *path, *slash;
 303                 int pathlen, entlen;
 304                 const unsigned char *sha1;
 305                 unsigned mode;
 306
 307                 path = ce->name;
 308                 pathlen = ce_namelen(ce);
 309                 if (pathlen <= baselen || memcmp(base, path, baselen))
 310                         break; /* at the end of this level */
 311
 312                 slash = strchr(path + baselen, '/');
 313                 if (slash) {
 314                         entlen = slash - (path + baselen);
 315                         sub = find_subtree(it, path + baselen, entlen, 0);
 316                         if (!sub)
 317                                 die("cache-tree.c: '%.*s' in '%s' not found",
 318                                     entlen, path + baselen, path);
 319                         i += sub->cache_tree->entry_count - 1;
 320                         sha1 = sub->cache_tree->sha1;
 321                         mode = S_IFDIR;
 322                 }
 323                 else {
 324                         sha1 = ce->sha1;
 325                         mode = ntohl(ce->ce_mode);
 326                         entlen = pathlen - baselen;
 327                 }
 328                 if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1))
 329                         return error("invalid object %s", sha1_to_hex(sha1));
 330
 331                 if (!ce->ce_mode)
 332                         continue; /* entry being removed */
 333
 334                 strbuf_grow(&buffer, entlen + 100);
 335                 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
 336                 strbuf_add(&buffer, sha1, 20);
 337
 338 #if DEBUG
 339                 fprintf(stderr, "cache-tree update-one %o %.*s\n",
 340                         mode, entlen, path + baselen);
 341 #endif
 342         }
 343
 344         if (dryrun)
 345                 hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
 346         else
 347                 write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
 348         strbuf_release(&buffer);
 349         it->entry_count = i;
 350 #if DEBUG
 351         fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
 352                 it->entry_count, it->subtree_nr,
 353                 sha1_to_hex(it->sha1));
 354 #endif
 355         return i;
 356 }
 357
 358 int cache_tree_update(struct cache_tree *it,
 359                       struct cache_entry **cache,
 360                       int entries,
 361                       int missing_ok,
 362                       int dryrun)
 363 {
 364         int i;
 365         i = verify_cache(cache, entries);
 366         if (i)
 367                 return i;
 368         i = update_one(it, cache, entries, "", 0, missing_ok, dryrun);
 369         if (i < 0)
 370                 return i;
 371         return 0;
 372 }
 373
 374 static void write_one(struct cache_tree *it,
 375                        char *path,
 376                        int pathlen,
 377                            struct strbuf *buffer)
 378 {
 379         int i;
 380
 381         /* One "cache-tree" entry consists of the following:
 382          * path (NUL terminated)
 383          * entry_count, subtree_nr ("%d %d\n")
 384          * tree-sha1 (missing if invalid)
 385          * subtree_nr "cache-tree" entries for subtrees.
 386          */
 387         strbuf_grow(buffer, pathlen + 100);
 388         strbuf_add(buffer, path, pathlen);
 389         strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
 390
 391 #if DEBUG
 392         if (0 <= it->entry_count)
 393                 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
 394                         pathlen, path, it->entry_count, it->subtree_nr,
 395                         sha1_to_hex(it->sha1));
 396         else
 397                 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
 398                         pathlen, path, it->subtree_nr);
 399 #endif
 400
 401         if (0 <= it->entry_count) {
 402                 strbuf_add(buffer, it->sha1, 20);
 403         }
 404         for (i = 0; i < it->subtree_nr; i++) {
 405                 struct cache_tree_sub *down = it->down[i];
 406                 if (i) {
 407                         struct cache_tree_sub *prev = it->down[i-1];
 408                         if (subtree_name_cmp(down->name, down->namelen,
 409                                              prev->name, prev->namelen) <= 0)
 410                                 die("fatal - unsorted cache subtree");
 411                 }
 412                 write_one(down->cache_tree, down->name, down->namelen, buffer);
 413         }
 414 }
 415
 416 void *cache_tree_write(struct cache_tree *root, unsigned long *size_p)
 417 {
 418         char path[PATH_MAX];
 419         struct strbuf buffer;
 420
 421         path[0] = 0;
 422         strbuf_init(&buffer);
 423         write_one(root, path, 0, &buffer);
 424         *size_p = buffer.len;
 425         return strbuf_detach(&buffer);
 426 }
 427
 428 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 429 {
 430         const char *buf = *buffer;
 431         unsigned long size = *size_p;
 432         const char *cp;
 433         char *ep;
 434         struct cache_tree *it;
 435         int i, subtree_nr;
 436
 437         it = NULL;
 438         /* skip name, but make sure name exists */
 439         while (size && *buf) {
 440                 size--;
 441                 buf++;
 442         }
 443         if (!size)
 444                 goto free_return;
 445         buf++; size--;
 446         it = cache_tree();
 447
 448         cp = buf;
 449         it->entry_count = strtol(cp, &ep, 10);
 450         if (cp == ep)
 451                 goto free_return;
 452         cp = ep;
 453         subtree_nr = strtol(cp, &ep, 10);
 454         if (cp == ep)
 455                 goto free_return;
 456         while (size && *buf && *buf != '\n') {
 457                 size--;
 458                 buf++;
 459         }
 460         if (!size)
 461                 goto free_return;
 462         buf++; size--;
 463         if (0 <= it->entry_count) {
 464                 if (size < 20)
 465                         goto free_return;
 466                 hashcpy(it->sha1, (const unsigned char*)buf);
 467                 buf += 20;
 468                 size -= 20;
 469         }
 470
 471 #if DEBUG
 472         if (0 <= it->entry_count)
 473                 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
 474                         *buffer, it->entry_count, subtree_nr,
 475                         sha1_to_hex(it->sha1));
 476         else
 477                 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
 478                         *buffer, subtree_nr);
 479 #endif
 480
 481         /*
 482          * Just a heuristic -- we do not add directories that often but
 483          * we do not want to have to extend it immediately when we do,
 484          * hence +2.
 485          */
 486         it->subtree_alloc = subtree_nr + 2;
 487         it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
 488         for (i = 0; i < subtree_nr; i++) {
 489                 /* read each subtree */
 490                 struct cache_tree *sub;
 491                 struct cache_tree_sub *subtree;
 492                 const char *name = buf;
 493
 494                 sub = read_one(&buf, &size);
 495                 if (!sub)
 496                         goto free_return;
 497                 subtree = cache_tree_sub(it, name);
 498                 subtree->cache_tree = sub;
 499         }
 500         if (subtree_nr != it->subtree_nr)
 501                 die("cache-tree: internal error");
 502         *buffer = buf;
 503         *size_p = size;
 504         return it;
 505
 506  free_return:
 507         cache_tree_free(&it);
 508         return NULL;
 509 }
 510
 511 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 512 {
 513         if (buffer[0])
 514                 return NULL; /* not the whole tree */
 515         return read_one(&buffer, &size);
 516 }
 517
 518 struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
 519 {
 520         while (*path) {
 521                 const char *slash;
 522                 struct cache_tree_sub *sub;
 523
 524                 slash = strchr(path, '/');
 525                 if (!slash)
 526                         slash = path + strlen(path);
 527                 /* between path and slash is the name of the
 528                  * subtree to look for.
 529                  */
 530                 sub = find_subtree(it, path, slash - path, 0);
 531                 if (!sub)
 532                         return NULL;
 533                 it = sub->cache_tree;
 534                 if (slash)
 535                         while (*slash && *slash == '/')
 536                                 slash++;
 537                 if (!slash || !*slash)
 538                         return it; /* prefix ended with slashes */
 539                 path = slash;
 540         }
 541         return it;
 542 }