cache-tree.c

   1 #define USE_THE_REPOSITORY_VARIABLE
   2
   3 #include "git-compat-util.h"
   4 #include "gettext.h"
   5 #include "hex.h"
   6 #include "lockfile.h"
   7 #include "tree.h"
   8 #include "tree-walk.h"
   9 #include "cache-tree.h"
  10 #include "bulk-checkin.h"
  11 #include "object-file.h"
  12 #include "object-store-ll.h"
  13 #include "read-cache-ll.h"
  14 #include "replace-object.h"
  15 #include "repository.h"
  16 #include "promisor-remote.h"
  17 #include "trace.h"
  18 #include "trace2.h"
  19
  20 #ifndef DEBUG_CACHE_TREE
  21 #define DEBUG_CACHE_TREE 0
  22 #endif
  23
  24 struct cache_tree *cache_tree(void)
  25 {
  26         struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
  27         it->entry_count = -1;
  28         return it;
  29 }
  30
  31 void cache_tree_free(struct cache_tree **it_p)
  32 {
  33         int i;
  34         struct cache_tree *it = *it_p;
  35
  36         if (!it)
  37                 return;
  38         for (i = 0; i < it->subtree_nr; i++)
  39                 if (it->down[i]) {
  40                         cache_tree_free(&it->down[i]->cache_tree);
  41                         free(it->down[i]);
  42                 }
  43         free(it->down);
  44         free(it);
  45         *it_p = NULL;
  46 }
  47
  48 static int subtree_name_cmp(const char *one, int onelen,
  49                             const char *two, int twolen)
  50 {
  51         if (onelen < twolen)
  52                 return -1;
  53         if (twolen < onelen)
  54                 return 1;
  55         return memcmp(one, two, onelen);
  56 }
  57
  58 int cache_tree_subtree_pos(struct cache_tree *it, const char *path, int pathlen)
  59 {
  60         struct cache_tree_sub **down = it->down;
  61         int lo, hi;
  62         lo = 0;
  63         hi = it->subtree_nr;
  64         while (lo < hi) {
  65                 int mi = lo + (hi - lo) / 2;
  66                 struct cache_tree_sub *mdl = down[mi];
  67                 int cmp = subtree_name_cmp(path, pathlen,
  68                                            mdl->name, mdl->namelen);
  69                 if (!cmp)
  70                         return mi;
  71                 if (cmp < 0)
  72                         hi = mi;
  73                 else
  74                         lo = mi + 1;
  75         }
  76         return -lo-1;
  77 }
  78
  79 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
  80                                            const char *path,
  81                                            int pathlen,
  82                                            int create)
  83 {
  84         struct cache_tree_sub *down;
  85         int pos = cache_tree_subtree_pos(it, path, pathlen);
  86         if (0 <= pos)
  87                 return it->down[pos];
  88         if (!create)
  89                 return NULL;
  90
  91         pos = -pos-1;
  92         ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
  93         it->subtree_nr++;
  94
  95         FLEX_ALLOC_MEM(down, name, path, pathlen);
  96         down->cache_tree = NULL;
  97         down->namelen = pathlen;
  98
  99         if (pos < it->subtree_nr)
 100                 MOVE_ARRAY(it->down + pos + 1, it->down + pos,
 101                            it->subtree_nr - pos - 1);
 102         it->down[pos] = down;
 103         return down;
 104 }
 105
 106 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
 107 {
 108         int pathlen = strlen(path);
 109         return find_subtree(it, path, pathlen, 1);
 110 }
 111
 112 static int do_invalidate_path(struct cache_tree *it, const char *path)
 113 {
 114         /* a/b/c
 115          * ==> invalidate self
 116          * ==> find "a", have it invalidate "b/c"
 117          * a
 118          * ==> invalidate self
 119          * ==> if "a" exists as a subtree, remove it.
 120          */
 121         const char *slash;
 122         int namelen;
 123         struct cache_tree_sub *down;
 124
 125 #if DEBUG_CACHE_TREE
 126         fprintf(stderr, "cache-tree invalidate <%s>\n", path);
 127 #endif
 128
 129         if (!it)
 130                 return 0;
 131         slash = strchrnul(path, '/');
 132         namelen = slash - path;
 133         it->entry_count = -1;
 134         if (!*slash) {
 135                 int pos;
 136                 pos = cache_tree_subtree_pos(it, path, namelen);
 137                 if (0 <= pos) {
 138                         cache_tree_free(&it->down[pos]->cache_tree);
 139                         free(it->down[pos]);
 140                         /* 0 1 2 3 4 5
 141                          *       ^     ^subtree_nr = 6
 142                          *       pos
 143                          * move 4 and 5 up one place (2 entries)
 144                          * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
 145                          */
 146                         MOVE_ARRAY(it->down + pos, it->down + pos + 1,
 147                                    it->subtree_nr - pos - 1);
 148                         it->subtree_nr--;
 149                 }
 150                 return 1;
 151         }
 152         down = find_subtree(it, path, namelen, 0);
 153         if (down)
 154                 do_invalidate_path(down->cache_tree, slash + 1);
 155         return 1;
 156 }
 157
 158 void cache_tree_invalidate_path(struct index_state *istate, const char *path)
 159 {
 160         if (do_invalidate_path(istate->cache_tree, path))
 161                 istate->cache_changed |= CACHE_TREE_CHANGED;
 162 }
 163
 164 static int verify_cache(struct index_state *istate, int flags)
 165 {
 166         unsigned i, funny;
 167         int silent = flags & WRITE_TREE_SILENT;
 168
 169         /* Verify that the tree is merged */
 170         funny = 0;
 171         for (i = 0; i < istate->cache_nr; i++) {
 172                 const struct cache_entry *ce = istate->cache[i];
 173                 if (ce_stage(ce)) {
 174                         if (silent)
 175                                 return -1;
 176                         if (10 < ++funny) {
 177                                 fprintf(stderr, "...\n");
 178                                 break;
 179                         }
 180                         fprintf(stderr, "%s: unmerged (%s)\n",
 181                                 ce->name, oid_to_hex(&ce->oid));
 182                 }
 183         }
 184         if (funny)
 185                 return -1;
 186
 187         /* Also verify that the cache does not have path and path/file
 188          * at the same time.  At this point we know the cache has only
 189          * stage 0 entries.
 190          */
 191         funny = 0;
 192         for (i = 0; i + 1 < istate->cache_nr; i++) {
 193                 /* path/file always comes after path because of the way
 194                  * the cache is sorted.  Also path can appear only once,
 195                  * which means conflicting one would immediately follow.
 196                  */
 197                 const struct cache_entry *this_ce = istate->cache[i];
 198                 const struct cache_entry *next_ce = istate->cache[i + 1];
 199                 const char *this_name = this_ce->name;
 200                 const char *next_name = next_ce->name;
 201                 int this_len = ce_namelen(this_ce);
 202                 if (this_len < ce_namelen(next_ce) &&
 203                     next_name[this_len] == '/' &&
 204                     strncmp(this_name, next_name, this_len) == 0) {
 205                         if (10 < ++funny) {
 206                                 fprintf(stderr, "...\n");
 207                                 break;
 208                         }
 209                         fprintf(stderr, "You have both %s and %s\n",
 210                                 this_name, next_name);
 211                 }
 212         }
 213         if (funny)
 214                 return -1;
 215         return 0;
 216 }
 217
 218 static void discard_unused_subtrees(struct cache_tree *it)
 219 {
 220         struct cache_tree_sub **down = it->down;
 221         int nr = it->subtree_nr;
 222         int dst, src;
 223         for (dst = src = 0; src < nr; src++) {
 224                 struct cache_tree_sub *s = down[src];
 225                 if (s->used)
 226                         down[dst++] = s;
 227                 else {
 228                         cache_tree_free(&s->cache_tree);
 229                         free(s);
 230                         it->subtree_nr--;
 231                 }
 232         }
 233 }
 234
 235 int cache_tree_fully_valid(struct cache_tree *it)
 236 {
 237         int i;
 238         if (!it)
 239                 return 0;
 240         if (it->entry_count < 0 || !repo_has_object_file(the_repository, &it->oid))
 241                 return 0;
 242         for (i = 0; i < it->subtree_nr; i++) {
 243                 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
 244                         return 0;
 245         }
 246         return 1;
 247 }
 248
 249 static int must_check_existence(const struct cache_entry *ce)
 250 {
 251         return !(repo_has_promisor_remote(the_repository) && ce_skip_worktree(ce));
 252 }
 253
 254 static int update_one(struct cache_tree *it,
 255                       struct cache_entry **cache,
 256                       int entries,
 257                       const char *base,
 258                       int baselen,
 259                       int *skip_count,
 260                       int flags)
 261 {
 262         struct strbuf buffer;
 263         int missing_ok = flags & WRITE_TREE_MISSING_OK;
 264         int dryrun = flags & WRITE_TREE_DRY_RUN;
 265         int repair = flags & WRITE_TREE_REPAIR;
 266         int to_invalidate = 0;
 267         int i;
 268
 269         assert(!(dryrun && repair));
 270
 271         *skip_count = 0;
 272
 273         /*
 274          * If the first entry of this region is a sparse directory
 275          * entry corresponding exactly to 'base', then this cache_tree
 276          * struct is a "leaf" in the data structure, pointing to the
 277          * tree OID specified in the entry.
 278          */
 279         if (entries > 0) {
 280                 const struct cache_entry *ce = cache[0];
 281
 282                 if (S_ISSPARSEDIR(ce->ce_mode) &&
 283                     ce->ce_namelen == baselen &&
 284                     !strncmp(ce->name, base, baselen)) {
 285                         it->entry_count = 1;
 286                         oidcpy(&it->oid, &ce->oid);
 287                         return 1;
 288                 }
 289         }
 290
 291         if (0 <= it->entry_count && repo_has_object_file(the_repository, &it->oid))
 292                 return it->entry_count;
 293
 294         /*
 295          * We first scan for subtrees and update them; we start by
 296          * marking existing subtrees -- the ones that are unmarked
 297          * should not be in the result.
 298          */
 299         for (i = 0; i < it->subtree_nr; i++)
 300                 it->down[i]->used = 0;
 301
 302         /*
 303          * Find the subtrees and update them.
 304          */
 305         i = 0;
 306         while (i < entries) {
 307                 const struct cache_entry *ce = cache[i];
 308                 struct cache_tree_sub *sub;
 309                 const char *path, *slash;
 310                 int pathlen, sublen, subcnt, subskip;
 311
 312                 path = ce->name;
 313                 pathlen = ce_namelen(ce);
 314                 if (pathlen <= baselen || memcmp(base, path, baselen))
 315                         break; /* at the end of this level */
 316
 317                 slash = strchr(path + baselen, '/');
 318                 if (!slash) {
 319                         i++;
 320                         continue;
 321                 }
 322                 /*
 323                  * a/bbb/c (base = a/, slash = /c)
 324                  * ==>
 325                  * path+baselen = bbb/c, sublen = 3
 326                  */
 327                 sublen = slash - (path + baselen);
 328                 sub = find_subtree(it, path + baselen, sublen, 1);
 329                 if (!sub->cache_tree)
 330                         sub->cache_tree = cache_tree();
 331                 subcnt = update_one(sub->cache_tree,
 332                                     cache + i, entries - i,
 333                                     path,
 334                                     baselen + sublen + 1,
 335                                     &subskip,
 336                                     flags);
 337                 if (subcnt < 0)
 338                         return subcnt;
 339                 if (!subcnt)
 340                         die("index cache-tree records empty sub-tree");
 341                 i += subcnt;
 342                 sub->count = subcnt; /* to be used in the next loop */
 343                 *skip_count += subskip;
 344                 sub->used = 1;
 345         }
 346
 347         discard_unused_subtrees(it);
 348
 349         /*
 350          * Then write out the tree object for this level.
 351          */
 352         strbuf_init(&buffer, 8192);
 353
 354         i = 0;
 355         while (i < entries) {
 356                 const struct cache_entry *ce = cache[i];
 357                 struct cache_tree_sub *sub = NULL;
 358                 const char *path, *slash;
 359                 int pathlen, entlen;
 360                 const struct object_id *oid;
 361                 unsigned mode;
 362                 int expected_missing = 0;
 363                 int contains_ita = 0;
 364                 int ce_missing_ok;
 365
 366                 path = ce->name;
 367                 pathlen = ce_namelen(ce);
 368                 if (pathlen <= baselen || memcmp(base, path, baselen))
 369                         break; /* at the end of this level */
 370
 371                 slash = strchr(path + baselen, '/');
 372                 if (slash) {
 373                         entlen = slash - (path + baselen);
 374                         sub = find_subtree(it, path + baselen, entlen, 0);
 375                         if (!sub)
 376                                 die("cache-tree.c: '%.*s' in '%s' not found",
 377                                     entlen, path + baselen, path);
 378                         i += sub->count;
 379                         oid = &sub->cache_tree->oid;
 380                         mode = S_IFDIR;
 381                         contains_ita = sub->cache_tree->entry_count < 0;
 382                         if (contains_ita) {
 383                                 to_invalidate = 1;
 384                                 expected_missing = 1;
 385                         }
 386                 }
 387                 else {
 388                         oid = &ce->oid;
 389                         mode = ce->ce_mode;
 390                         entlen = pathlen - baselen;
 391                         i++;
 392                 }
 393
 394                 ce_missing_ok = mode == S_IFGITLINK || missing_ok ||
 395                         !must_check_existence(ce);
 396                 if (is_null_oid(oid) ||
 397                     (!ce_missing_ok && !repo_has_object_file(the_repository, oid))) {
 398                         strbuf_release(&buffer);
 399                         if (expected_missing)
 400                                 return -1;
 401                         return error("invalid object %06o %s for '%.*s'",
 402                                 mode, oid_to_hex(oid), entlen+baselen, path);
 403                 }
 404
 405                 /*
 406                  * CE_REMOVE entries are removed before the index is
 407                  * written to disk. Skip them to remain consistent
 408                  * with the future on-disk index.
 409                  */
 410                 if (ce->ce_flags & CE_REMOVE) {
 411                         *skip_count = *skip_count + 1;
 412                         continue;
 413                 }
 414
 415                 /*
 416                  * CE_INTENT_TO_ADD entries exist in on-disk index but
 417                  * they are not part of generated trees. Invalidate up
 418                  * to root to force cache-tree users to read elsewhere.
 419                  */
 420                 if (!sub && ce_intent_to_add(ce)) {
 421                         to_invalidate = 1;
 422                         continue;
 423                 }
 424
 425                 /*
 426                  * "sub" can be an empty tree if all subentries are i-t-a.
 427                  */
 428                 if (contains_ita && is_empty_tree_oid(oid, the_repository->hash_algo))
 429                         continue;
 430
 431                 strbuf_grow(&buffer, entlen + 100);
 432                 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
 433                 strbuf_add(&buffer, oid->hash, the_hash_algo->rawsz);
 434
 435 #if DEBUG_CACHE_TREE
 436                 fprintf(stderr, "cache-tree update-one %o %.*s\n",
 437                         mode, entlen, path + baselen);
 438 #endif
 439         }
 440
 441         if (repair) {
 442                 struct object_id oid;
 443                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
 444                                  OBJ_TREE, &oid);
 445                 if (repo_has_object_file_with_flags(the_repository, &oid, OBJECT_INFO_SKIP_FETCH_OBJECT))
 446                         oidcpy(&it->oid, &oid);
 447                 else
 448                         to_invalidate = 1;
 449         } else if (dryrun) {
 450                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
 451                                  OBJ_TREE, &it->oid);
 452         } else if (write_object_file_flags(buffer.buf, buffer.len, OBJ_TREE,
 453                                            &it->oid, NULL, flags & WRITE_TREE_SILENT
 454                                            ? HASH_SILENT : 0)) {
 455                 strbuf_release(&buffer);
 456                 return -1;
 457         }
 458
 459         strbuf_release(&buffer);
 460         it->entry_count = to_invalidate ? -1 : i - *skip_count;
 461 #if DEBUG_CACHE_TREE
 462         fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
 463                 it->entry_count, it->subtree_nr,
 464                 oid_to_hex(&it->oid));
 465 #endif
 466         return i;
 467 }
 468
 469 int cache_tree_update(struct index_state *istate, int flags)
 470 {
 471         int skip, i;
 472
 473         i = verify_cache(istate, flags);
 474
 475         if (i)
 476                 return i;
 477
 478         if (!istate->cache_tree)
 479                 istate->cache_tree = cache_tree();
 480
 481         if (!(flags & WRITE_TREE_MISSING_OK) && repo_has_promisor_remote(the_repository))
 482                 prefetch_cache_entries(istate, must_check_existence);
 483
 484         trace_performance_enter();
 485         trace2_region_enter("cache_tree", "update", the_repository);
 486         begin_odb_transaction();
 487         i = update_one(istate->cache_tree, istate->cache, istate->cache_nr,
 488                        "", 0, &skip, flags);
 489         end_odb_transaction();
 490         trace2_region_leave("cache_tree", "update", the_repository);
 491         trace_performance_leave("cache_tree_update");
 492         if (i < 0)
 493                 return i;
 494         istate->cache_changed |= CACHE_TREE_CHANGED;
 495         return 0;
 496 }
 497
 498 static void write_one(struct strbuf *buffer, struct cache_tree *it,
 499                       const char *path, int pathlen)
 500 {
 501         int i;
 502
 503         /* One "cache-tree" entry consists of the following:
 504          * path (NUL terminated)
 505          * entry_count, subtree_nr ("%d %d\n")
 506          * tree-sha1 (missing if invalid)
 507          * subtree_nr "cache-tree" entries for subtrees.
 508          */
 509         strbuf_grow(buffer, pathlen + 100);
 510         strbuf_add(buffer, path, pathlen);
 511         strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
 512
 513 #if DEBUG_CACHE_TREE
 514         if (0 <= it->entry_count)
 515                 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
 516                         pathlen, path, it->entry_count, it->subtree_nr,
 517                         oid_to_hex(&it->oid));
 518         else
 519                 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
 520                         pathlen, path, it->subtree_nr);
 521 #endif
 522
 523         if (0 <= it->entry_count) {
 524                 strbuf_add(buffer, it->oid.hash, the_hash_algo->rawsz);
 525         }
 526         for (i = 0; i < it->subtree_nr; i++) {
 527                 struct cache_tree_sub *down = it->down[i];
 528                 if (i) {
 529                         struct cache_tree_sub *prev = it->down[i-1];
 530                         if (subtree_name_cmp(down->name, down->namelen,
 531                                              prev->name, prev->namelen) <= 0)
 532                                 die("fatal - unsorted cache subtree");
 533                 }
 534                 write_one(buffer, down->cache_tree, down->name, down->namelen);
 535         }
 536 }
 537
 538 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
 539 {
 540         trace2_region_enter("cache_tree", "write", the_repository);
 541         write_one(sb, root, "", 0);
 542         trace2_region_leave("cache_tree", "write", the_repository);
 543 }
 544
 545 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 546 {
 547         const char *buf = *buffer;
 548         unsigned long size = *size_p;
 549         const char *cp;
 550         char *ep;
 551         struct cache_tree *it;
 552         int i, subtree_nr;
 553         const unsigned rawsz = the_hash_algo->rawsz;
 554
 555         it = NULL;
 556         /* skip name, but make sure name exists */
 557         while (size && *buf) {
 558                 size--;
 559                 buf++;
 560         }
 561         if (!size)
 562                 goto free_return;
 563         buf++; size--;
 564         it = cache_tree();
 565
 566         cp = buf;
 567         it->entry_count = strtol(cp, &ep, 10);
 568         if (cp == ep)
 569                 goto free_return;
 570         cp = ep;
 571         subtree_nr = strtol(cp, &ep, 10);
 572         if (cp == ep)
 573                 goto free_return;
 574         while (size && *buf && *buf != '\n') {
 575                 size--;
 576                 buf++;
 577         }
 578         if (!size)
 579                 goto free_return;
 580         buf++; size--;
 581         if (0 <= it->entry_count) {
 582                 if (size < rawsz)
 583                         goto free_return;
 584                 oidread(&it->oid, (const unsigned char *)buf,
 585                         the_repository->hash_algo);
 586                 buf += rawsz;
 587                 size -= rawsz;
 588         }
 589
 590 #if DEBUG_CACHE_TREE
 591         if (0 <= it->entry_count)
 592                 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
 593                         *buffer, it->entry_count, subtree_nr,
 594                         oid_to_hex(&it->oid));
 595         else
 596                 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
 597                         *buffer, subtree_nr);
 598 #endif
 599
 600         /*
 601          * Just a heuristic -- we do not add directories that often but
 602          * we do not want to have to extend it immediately when we do,
 603          * hence +2.
 604          */
 605         it->subtree_alloc = subtree_nr + 2;
 606         CALLOC_ARRAY(it->down, it->subtree_alloc);
 607         for (i = 0; i < subtree_nr; i++) {
 608                 /* read each subtree */
 609                 struct cache_tree *sub;
 610                 struct cache_tree_sub *subtree;
 611                 const char *name = buf;
 612
 613                 sub = read_one(&buf, &size);
 614                 if (!sub)
 615                         goto free_return;
 616                 subtree = cache_tree_sub(it, name);
 617                 subtree->cache_tree = sub;
 618         }
 619         if (subtree_nr != it->subtree_nr)
 620                 die("cache-tree: internal error");
 621         *buffer = buf;
 622         *size_p = size;
 623         return it;
 624
 625  free_return:
 626         cache_tree_free(&it);
 627         return NULL;
 628 }
 629
 630 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 631 {
 632         struct cache_tree *result;
 633
 634         if (buffer[0])
 635                 return NULL; /* not the whole tree */
 636
 637         trace2_region_enter("cache_tree", "read", the_repository);
 638         result = read_one(&buffer, &size);
 639         trace2_region_leave("cache_tree", "read", the_repository);
 640
 641         return result;
 642 }
 643
 644 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
 645 {
 646         if (!it)
 647                 return NULL;
 648         while (*path) {
 649                 const char *slash;
 650                 struct cache_tree_sub *sub;
 651
 652                 slash = strchrnul(path, '/');
 653                 /*
 654                  * Between path and slash is the name of the subtree
 655                  * to look for.
 656                  */
 657                 sub = find_subtree(it, path, slash - path, 0);
 658                 if (!sub)
 659                         return NULL;
 660                 it = sub->cache_tree;
 661
 662                 path = slash;
 663                 while (*path == '/')
 664                         path++;
 665         }
 666         return it;
 667 }
 668
 669 static int write_index_as_tree_internal(struct object_id *oid,
 670                                         struct index_state *index_state,
 671                                         int cache_tree_valid,
 672                                         int flags,
 673                                         const char *prefix)
 674 {
 675         if (flags & WRITE_TREE_IGNORE_CACHE_TREE) {
 676                 cache_tree_free(&index_state->cache_tree);
 677                 cache_tree_valid = 0;
 678         }
 679
 680         if (!cache_tree_valid && cache_tree_update(index_state, flags) < 0)
 681                 return WRITE_TREE_UNMERGED_INDEX;
 682
 683         if (prefix) {
 684                 struct cache_tree *subtree;
 685                 subtree = cache_tree_find(index_state->cache_tree, prefix);
 686                 if (!subtree)
 687                         return WRITE_TREE_PREFIX_ERROR;
 688                 oidcpy(oid, &subtree->oid);
 689         }
 690         else
 691                 oidcpy(oid, &index_state->cache_tree->oid);
 692
 693         return 0;
 694 }
 695
 696 struct tree* write_in_core_index_as_tree(struct repository *repo) {
 697         struct object_id o;
 698         int was_valid, ret;
 699
 700         struct index_state *index_state = repo->index;
 701         was_valid = index_state->cache_tree &&
 702                     cache_tree_fully_valid(index_state->cache_tree);
 703
 704         ret = write_index_as_tree_internal(&o, index_state, was_valid, 0, NULL);
 705         if (ret == WRITE_TREE_UNMERGED_INDEX) {
 706                 int i;
 707                 bug("there are unmerged index entries:");
 708                 for (i = 0; i < index_state->cache_nr; i++) {
 709                         const struct cache_entry *ce = index_state->cache[i];
 710                         if (ce_stage(ce))
 711                                 bug("%d %.*s", ce_stage(ce),
 712                                     (int)ce_namelen(ce), ce->name);
 713                 }
 714                 BUG("unmerged index entries when writing in-core index");
 715         }
 716
 717         return lookup_tree(repo, &index_state->cache_tree->oid);
 718 }
 719
 720
 721 int write_index_as_tree(struct object_id *oid, struct index_state *index_state, const char *index_path, int flags, const char *prefix)
 722 {
 723         int entries, was_valid;
 724         struct lock_file lock_file = LOCK_INIT;
 725         int ret;
 726
 727         hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR);
 728
 729         entries = read_index_from(index_state, index_path,
 730                                   repo_get_git_dir(the_repository));
 731         if (entries < 0) {
 732                 ret = WRITE_TREE_UNREADABLE_INDEX;
 733                 goto out;
 734         }
 735
 736         was_valid = !(flags & WRITE_TREE_IGNORE_CACHE_TREE) &&
 737                     index_state->cache_tree &&
 738                     cache_tree_fully_valid(index_state->cache_tree);
 739
 740         ret = write_index_as_tree_internal(oid, index_state, was_valid, flags,
 741                                            prefix);
 742         if (!ret && !was_valid) {
 743                 write_locked_index(index_state, &lock_file, COMMIT_LOCK);
 744                 /* Not being able to write is fine -- we are only interested
 745                  * in updating the cache-tree part, and if the next caller
 746                  * ends up using the old index with unupdated cache-tree part
 747                  * it misses the work we did here, but that is just a
 748                  * performance penalty and not a big deal.
 749                  */
 750         }
 751
 752 out:
 753         rollback_lock_file(&lock_file);
 754         return ret;
 755 }
 756
 757 static void prime_cache_tree_sparse_dir(struct cache_tree *it,
 758                                         struct tree *tree)
 759 {
 760
 761         oidcpy(&it->oid, &tree->object.oid);
 762         it->entry_count = 1;
 763 }
 764
 765 static void prime_cache_tree_rec(struct repository *r,
 766                                  struct cache_tree *it,
 767                                  struct tree *tree,
 768                                  struct strbuf *tree_path)
 769 {
 770         struct tree_desc desc;
 771         struct name_entry entry;
 772         int cnt;
 773         size_t base_path_len = tree_path->len;
 774
 775         oidcpy(&it->oid, &tree->object.oid);
 776
 777         init_tree_desc(&desc, &tree->object.oid, tree->buffer, tree->size);
 778         cnt = 0;
 779         while (tree_entry(&desc, &entry)) {
 780                 if (!S_ISDIR(entry.mode))
 781                         cnt++;
 782                 else {
 783                         struct cache_tree_sub *sub;
 784                         struct tree *subtree = lookup_tree(r, &entry.oid);
 785
 786                         if (parse_tree(subtree) < 0)
 787                                 exit(128);
 788                         sub = cache_tree_sub(it, entry.path);
 789                         sub->cache_tree = cache_tree();
 790
 791                         /*
 792                          * Recursively-constructed subtree path is only needed when working
 793                          * in a sparse index (where it's used to determine whether the
 794                          * subtree is a sparse directory in the index).
 795                          */
 796                         if (r->index->sparse_index) {
 797                                 strbuf_setlen(tree_path, base_path_len);
 798                                 strbuf_add(tree_path, entry.path, entry.pathlen);
 799                                 strbuf_addch(tree_path, '/');
 800                         }
 801
 802                         /*
 803                          * If a sparse index is in use, the directory being processed may be
 804                          * sparse. To confirm that, we can check whether an entry with that
 805                          * exact name exists in the index. If it does, the created subtree
 806                          * should be sparse. Otherwise, cache tree expansion should continue
 807                          * as normal.
 808                          */
 809                         if (r->index->sparse_index &&
 810                             index_entry_exists(r->index, tree_path->buf, tree_path->len))
 811                                 prime_cache_tree_sparse_dir(sub->cache_tree, subtree);
 812                         else
 813                                 prime_cache_tree_rec(r, sub->cache_tree, subtree, tree_path);
 814                         cnt += sub->cache_tree->entry_count;
 815                 }
 816         }
 817
 818         it->entry_count = cnt;
 819 }
 820
 821 void prime_cache_tree(struct repository *r,
 822                       struct index_state *istate,
 823                       struct tree *tree)
 824 {
 825         struct strbuf tree_path = STRBUF_INIT;
 826
 827         trace2_region_enter("cache-tree", "prime_cache_tree", r);
 828         cache_tree_free(&istate->cache_tree);
 829         istate->cache_tree = cache_tree();
 830
 831         prime_cache_tree_rec(r, istate->cache_tree, tree, &tree_path);
 832         strbuf_release(&tree_path);
 833         istate->cache_changed |= CACHE_TREE_CHANGED;
 834         trace2_region_leave("cache-tree", "prime_cache_tree", r);
 835 }
 836
 837 /*
 838  * find the cache_tree that corresponds to the current level without
 839  * exploding the full path into textual form.  The root of the
 840  * cache tree is given as "root", and our current level is "info".
 841  * (1) When at root level, info->prev is NULL, so it is "root" itself.
 842  * (2) Otherwise, find the cache_tree that corresponds to one level
 843  *     above us, and find ourselves in there.
 844  */
 845 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
 846                                                          struct traverse_info *info)
 847 {
 848         struct cache_tree *our_parent;
 849
 850         if (!info->prev)
 851                 return root;
 852         our_parent = find_cache_tree_from_traversal(root, info->prev);
 853         return cache_tree_find(our_parent, info->name);
 854 }
 855
 856 int cache_tree_matches_traversal(struct cache_tree *root,
 857                                  struct name_entry *ent,
 858                                  struct traverse_info *info)
 859 {
 860         struct cache_tree *it;
 861
 862         it = find_cache_tree_from_traversal(root, info);
 863         it = cache_tree_find(it, ent->path);
 864         if (it && it->entry_count > 0 && oideq(&ent->oid, &it->oid))
 865                 return it->entry_count;
 866         return 0;
 867 }
 868
 869 static int verify_one_sparse(struct index_state *istate,
 870                              struct strbuf *path,
 871                              int pos)
 872 {
 873         struct cache_entry *ce = istate->cache[pos];
 874         if (!S_ISSPARSEDIR(ce->ce_mode))
 875                 return error(_("directory '%s' is present in index, but not sparse"),
 876                              path->buf);
 877         return 0;
 878 }
 879
 880 /*
 881  * Returns:
 882  *  0 - Verification completed.
 883  *  1 - Restart verification - a call to ensure_full_index() freed the cache
 884  *      tree that is being verified and verification needs to be restarted from
 885  *      the new toplevel cache tree.
 886  *  -1 - Verification failed.
 887  */
 888 static int verify_one(struct repository *r,
 889                       struct index_state *istate,
 890                       struct cache_tree *it,
 891                       struct strbuf *path)
 892 {
 893         int i, pos, len = path->len;
 894         struct strbuf tree_buf = STRBUF_INIT;
 895         struct object_id new_oid;
 896         int ret;
 897
 898         for (i = 0; i < it->subtree_nr; i++) {
 899                 strbuf_addf(path, "%s/", it->down[i]->name);
 900                 ret = verify_one(r, istate, it->down[i]->cache_tree, path);
 901                 if (ret)
 902                         goto out;
 903
 904                 strbuf_setlen(path, len);
 905         }
 906
 907         if (it->entry_count < 0 ||
 908             /* no verification on tests (t7003) that replace trees */
 909             lookup_replace_object(r, &it->oid) != &it->oid) {
 910                 ret = 0;
 911                 goto out;
 912         }
 913
 914         if (path->len) {
 915                 /*
 916                  * If the index is sparse and the cache tree is not
 917                  * index_name_pos() may trigger ensure_full_index() which will
 918                  * free the tree that is being verified.
 919                  */
 920                 int is_sparse = istate->sparse_index;
 921                 pos = index_name_pos(istate, path->buf, path->len);
 922                 if (is_sparse && !istate->sparse_index) {
 923                         ret = 1;
 924                         goto out;
 925                 }
 926
 927                 if (pos >= 0) {
 928                         ret = verify_one_sparse(istate, path, pos);
 929                         goto out;
 930                 }
 931
 932                 pos = -pos - 1;
 933         } else {
 934                 pos = 0;
 935         }
 936
 937         if (it->entry_count + pos > istate->cache_nr) {
 938                 ret = error(_("corrupted cache-tree has entries not present in index"));
 939                 goto out;
 940         }
 941
 942         i = 0;
 943         while (i < it->entry_count) {
 944                 struct cache_entry *ce = istate->cache[pos + i];
 945                 const char *slash;
 946                 struct cache_tree_sub *sub = NULL;
 947                 const struct object_id *oid;
 948                 const char *name;
 949                 unsigned mode;
 950                 int entlen;
 951
 952                 if (ce->ce_flags & (CE_STAGEMASK | CE_INTENT_TO_ADD | CE_REMOVE)) {
 953                         ret = error(_("%s with flags 0x%x should not be in cache-tree"),
 954                                     ce->name, ce->ce_flags);
 955                         goto out;
 956                 }
 957
 958                 name = ce->name + path->len;
 959                 slash = strchr(name, '/');
 960                 if (slash) {
 961                         entlen = slash - name;
 962
 963                         sub = find_subtree(it, ce->name + path->len, entlen, 0);
 964                         if (!sub || sub->cache_tree->entry_count < 0) {
 965                                 ret = error(_("bad subtree '%.*s'"), entlen, name);
 966                                 goto out;
 967                         }
 968
 969                         oid = &sub->cache_tree->oid;
 970                         mode = S_IFDIR;
 971                         i += sub->cache_tree->entry_count;
 972                 } else {
 973                         oid = &ce->oid;
 974                         mode = ce->ce_mode;
 975                         entlen = ce_namelen(ce) - path->len;
 976                         i++;
 977                 }
 978                 strbuf_addf(&tree_buf, "%o %.*s%c", mode, entlen, name, '\0');
 979                 strbuf_add(&tree_buf, oid->hash, r->hash_algo->rawsz);
 980         }
 981
 982         hash_object_file(r->hash_algo, tree_buf.buf, tree_buf.len, OBJ_TREE,
 983                          &new_oid);
 984
 985         if (!oideq(&new_oid, &it->oid)) {
 986                 ret = error(_("cache-tree for path %.*s does not match. "
 987                               "Expected %s got %s"), len, path->buf,
 988                             oid_to_hex(&new_oid), oid_to_hex(&it->oid));
 989                 goto out;
 990         }
 991
 992         ret = 0;
 993 out:
 994         strbuf_setlen(path, len);
 995         strbuf_release(&tree_buf);
 996         return ret;
 997 }
 998
 999 int cache_tree_verify(struct repository *r, struct index_state *istate)
1000 {
1001         struct strbuf path = STRBUF_INIT;
1002         int ret;
1003
1004         if (!istate->cache_tree) {
1005                 ret = 0;
1006                 goto out;
1007         }
1008
1009         ret = verify_one(r, istate, istate->cache_tree, &path);
1010         if (ret < 0)
1011                 goto out;
1012         if (ret > 0) {
1013                 strbuf_reset(&path);
1014
1015                 ret = verify_one(r, istate, istate->cache_tree, &path);
1016                 if (ret < 0)
1017                         goto out;
1018                 if (ret > 0)
1019                         BUG("ensure_full_index() called twice while verifying cache tree");
1020         }
1021
1022         ret = 0;
1023
1024 out:
1025         strbuf_release(&path);
1026         return ret;
1027 }