28b78f88effe9ea766ff780fc948592c5fab51bf
   1#include "cache.h"
   2#include "tree.h"
   3#include "cache-tree.h"
   4
   5#define DEBUG 0
   6
   7struct cache_tree *cache_tree(void)
   8{
   9        struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
  10        it->entry_count = -1;
  11        return it;
  12}
  13
  14void cache_tree_free(struct cache_tree **it_p)
  15{
  16        int i;
  17        struct cache_tree *it = *it_p;
  18
  19        if (!it)
  20                return;
  21        for (i = 0; i < it->subtree_nr; i++)
  22                if (it->down[i])
  23                        cache_tree_free(&it->down[i]->cache_tree);
  24        free(it->down);
  25        free(it);
  26        *it_p = NULL;
  27}
  28
  29static int subtree_name_cmp(const char *one, int onelen,
  30                            const char *two, int twolen)
  31{
  32        if (onelen < twolen)
  33                return -1;
  34        if (twolen < onelen)
  35                return 1;
  36        return memcmp(one, two, onelen);
  37}
  38
  39static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
  40{
  41        struct cache_tree_sub **down = it->down;
  42        int lo, hi;
  43        lo = 0;
  44        hi = it->subtree_nr;
  45        while (lo < hi) {
  46                int mi = (lo + hi) / 2;
  47                struct cache_tree_sub *mdl = down[mi];
  48                int cmp = subtree_name_cmp(path, pathlen,
  49                                           mdl->name, mdl->namelen);
  50                if (!cmp)
  51                        return mi;
  52                if (cmp < 0)
  53                        hi = mi;
  54                else
  55                        lo = mi + 1;
  56        }
  57        return -lo-1;
  58}
  59
  60static struct cache_tree_sub *find_subtree(struct cache_tree *it,
  61                                           const char *path,
  62                                           int pathlen,
  63                                           int create)
  64{
  65        struct cache_tree_sub *down;
  66        int pos = subtree_pos(it, path, pathlen);
  67        if (0 <= pos)
  68                return it->down[pos];
  69        if (!create)
  70                return NULL;
  71
  72        pos = -pos-1;
  73        if (it->subtree_alloc <= it->subtree_nr) {
  74                it->subtree_alloc = alloc_nr(it->subtree_alloc);
  75                it->down = xrealloc(it->down, it->subtree_alloc *
  76                                    sizeof(*it->down));
  77        }
  78        it->subtree_nr++;
  79
  80        down = xmalloc(sizeof(*down) + pathlen + 1);
  81        down->cache_tree = NULL;
  82        down->namelen = pathlen;
  83        memcpy(down->name, path, pathlen);
  84        down->name[pathlen] = 0;
  85
  86        if (pos < it->subtree_nr)
  87                memmove(it->down + pos + 1,
  88                        it->down + pos,
  89                        sizeof(down) * (it->subtree_nr - pos - 1));
  90        it->down[pos] = down;
  91        return down;
  92}
  93
  94struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
  95{
  96        int pathlen = strlen(path);
  97        return find_subtree(it, path, pathlen, 1);
  98}
  99
 100void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
 101{
 102        /* a/b/c
 103         * ==> invalidate self
 104         * ==> find "a", have it invalidate "b/c"
 105         * a
 106         * ==> invalidate self
 107         * ==> if "a" exists as a subtree, remove it.
 108         */
 109        const char *slash;
 110        int namelen;
 111        struct cache_tree_sub *down;
 112
 113        if (!it)
 114                return;
 115        slash = strchr(path, '/');
 116        it->entry_count = -1;
 117        if (!slash) {
 118                int pos;
 119                namelen = strlen(path);
 120                pos = subtree_pos(it, path, namelen);
 121                if (0 <= pos) {
 122                        cache_tree_free(&it->down[pos]->cache_tree);
 123                        free(it->down[pos]);
 124                        /* 0 1 2 3 4 5
 125                         *       ^     ^subtree_nr = 6
 126                         *       pos
 127                         * move 4 and 5 up one place (2 entries)
 128                         * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
 129                         */
 130                        memmove(it->down+pos, it->down+pos+1,
 131                                sizeof(struct cache_tree_sub *) *
 132                                (it->subtree_nr - pos - 1));
 133                        it->subtree_nr--;
 134                }
 135                return;
 136        }
 137        namelen = slash - path;
 138        down = find_subtree(it, path, namelen, 0);
 139        if (down)
 140                cache_tree_invalidate_path(down->cache_tree, slash + 1);
 141}
 142
 143static int verify_cache(struct cache_entry **cache,
 144                        int entries)
 145{
 146        int i, funny;
 147
 148        /* Verify that the tree is merged */
 149        funny = 0;
 150        for (i = 0; i < entries; i++) {
 151                struct cache_entry *ce = cache[i];
 152                if (ce_stage(ce)) {
 153                        if (10 < ++funny) {
 154                                fprintf(stderr, "...\n");
 155                                break;
 156                        }
 157                        fprintf(stderr, "%s: unmerged (%s)\n",
 158                                ce->name, sha1_to_hex(ce->sha1));
 159                }
 160        }
 161        if (funny)
 162                return -1;
 163
 164        /* Also verify that the cache does not have path and path/file
 165         * at the same time.  At this point we know the cache has only
 166         * stage 0 entries.
 167         */
 168        funny = 0;
 169        for (i = 0; i < entries - 1; i++) {
 170                /* path/file always comes after path because of the way
 171                 * the cache is sorted.  Also path can appear only once,
 172                 * which means conflicting one would immediately follow.
 173                 */
 174                const char *this_name = cache[i]->name;
 175                const char *next_name = cache[i+1]->name;
 176                int this_len = strlen(this_name);
 177                if (this_len < strlen(next_name) &&
 178                    strncmp(this_name, next_name, this_len) == 0 &&
 179                    next_name[this_len] == '/') {
 180                        if (10 < ++funny) {
 181                                fprintf(stderr, "...\n");
 182                                break;
 183                        }
 184                        fprintf(stderr, "You have both %s and %s\n",
 185                                this_name, next_name);
 186                }
 187        }
 188        if (funny)
 189                return -1;
 190        return 0;
 191}
 192
 193static void discard_unused_subtrees(struct cache_tree *it)
 194{
 195        struct cache_tree_sub **down = it->down;
 196        int nr = it->subtree_nr;
 197        int dst, src;
 198        for (dst = src = 0; src < nr; src++) {
 199                struct cache_tree_sub *s = down[src];
 200                if (s->used)
 201                        down[dst++] = s;
 202                else {
 203                        cache_tree_free(&s->cache_tree);
 204                        free(s);
 205                        it->subtree_nr--;
 206                }
 207        }
 208}
 209
 210int cache_tree_fully_valid(struct cache_tree *it)
 211{
 212        int i;
 213        if (!it)
 214                return 0;
 215        if (it->entry_count < 0 || !has_sha1_file(it->sha1))
 216                return 0;
 217        for (i = 0; i < it->subtree_nr; i++) {
 218                if (!cache_tree_fully_valid(it->down[i]->cache_tree))
 219                        return 0;
 220        }
 221        return 1;
 222}
 223
 224static int update_one(struct cache_tree *it,
 225                      struct cache_entry **cache,
 226                      int entries,
 227                      const char *base,
 228                      int baselen,
 229                      int missing_ok,
 230                      int dryrun)
 231{
 232        unsigned long size, offset;
 233        char *buffer;
 234        int i;
 235
 236        if (0 <= it->entry_count && has_sha1_file(it->sha1))
 237                return it->entry_count;
 238
 239        /*
 240         * We first scan for subtrees and update them; we start by
 241         * marking existing subtrees -- the ones that are unmarked
 242         * should not be in the result.
 243         */
 244        for (i = 0; i < it->subtree_nr; i++)
 245                it->down[i]->used = 0;
 246
 247        /*
 248         * Find the subtrees and update them.
 249         */
 250        for (i = 0; i < entries; i++) {
 251                struct cache_entry *ce = cache[i];
 252                struct cache_tree_sub *sub;
 253                const char *path, *slash;
 254                int pathlen, sublen, subcnt;
 255
 256                path = ce->name;
 257                pathlen = ce_namelen(ce);
 258                if (pathlen <= baselen || memcmp(base, path, baselen))
 259                        break; /* at the end of this level */
 260
 261                slash = strchr(path + baselen, '/');
 262                if (!slash)
 263                        continue;
 264                /*
 265                 * a/bbb/c (base = a/, slash = /c)
 266                 * ==>
 267                 * path+baselen = bbb/c, sublen = 3
 268                 */
 269                sublen = slash - (path + baselen);
 270                sub = find_subtree(it, path + baselen, sublen, 1);
 271                if (!sub->cache_tree)
 272                        sub->cache_tree = cache_tree();
 273                subcnt = update_one(sub->cache_tree,
 274                                    cache + i, entries - i,
 275                                    path,
 276                                    baselen + sublen + 1,
 277                                    missing_ok,
 278                                    dryrun);
 279                i += subcnt - 1;
 280                sub->used = 1;
 281        }
 282
 283        discard_unused_subtrees(it);
 284
 285        /*
 286         * Then write out the tree object for this level.
 287         */
 288        size = 8192;
 289        buffer = xmalloc(size);
 290        offset = 0;
 291
 292        for (i = 0; i < entries; i++) {
 293                struct cache_entry *ce = cache[i];
 294                struct cache_tree_sub *sub;
 295                const char *path, *slash;
 296                int pathlen, entlen;
 297                const unsigned char *sha1;
 298                unsigned mode;
 299
 300                path = ce->name;
 301                pathlen = ce_namelen(ce);
 302                if (pathlen <= baselen || memcmp(base, path, baselen))
 303                        break; /* at the end of this level */
 304
 305                slash = strchr(path + baselen, '/');
 306                if (slash) {
 307                        entlen = slash - (path + baselen);
 308                        sub = find_subtree(it, path + baselen, entlen, 0);
 309                        if (!sub)
 310                                die("cache-tree.c: '%.*s' in '%s' not found",
 311                                    entlen, path + baselen, path);
 312                        i += sub->cache_tree->entry_count - 1;
 313                        sha1 = sub->cache_tree->sha1;
 314                        mode = S_IFDIR;
 315                }
 316                else {
 317                        sha1 = ce->sha1;
 318                        mode = ntohl(ce->ce_mode);
 319                        entlen = pathlen - baselen;
 320                }
 321                if (!missing_ok && !has_sha1_file(sha1))
 322                        return error("invalid object %s", sha1_to_hex(sha1));
 323
 324                if (!ce->ce_mode)
 325                        continue; /* entry being removed */
 326
 327                if (size < offset + entlen + 100) {
 328                        size = alloc_nr(offset + entlen + 100);
 329                        buffer = xrealloc(buffer, size);
 330                }
 331                offset += sprintf(buffer + offset,
 332                                  "%o %.*s", mode, entlen, path + baselen);
 333                buffer[offset++] = 0;
 334                memcpy(buffer + offset, sha1, 20);
 335                offset += 20;
 336
 337#if DEBUG
 338                fprintf(stderr, "cache-tree %o %.*s\n",
 339                        mode, entlen, path + baselen);
 340#endif
 341        }
 342
 343        if (dryrun) {
 344                unsigned char hdr[200];
 345                int hdrlen;
 346                write_sha1_file_prepare(buffer, offset, tree_type, it->sha1,
 347                                        hdr, &hdrlen);
 348        }
 349        else
 350                write_sha1_file(buffer, offset, tree_type, it->sha1);
 351        free(buffer);
 352        it->entry_count = i;
 353#if DEBUG
 354        fprintf(stderr, "cache-tree (%d ent, %d subtree) %s\n",
 355                it->entry_count, it->subtree_nr,
 356                sha1_to_hex(it->sha1));
 357#endif
 358        return i;
 359}
 360
 361int cache_tree_update(struct cache_tree *it,
 362                      struct cache_entry **cache,
 363                      int entries,
 364                      int missing_ok,
 365                      int dryrun)
 366{
 367        int i;
 368        i = verify_cache(cache, entries);
 369        if (i)
 370                return i;
 371        i = update_one(it, cache, entries, "", 0, missing_ok, dryrun);
 372        if (i < 0)
 373                return i;
 374        return 0;
 375}
 376
 377static void *write_one(struct cache_tree *it,
 378                       char *path,
 379                       int pathlen,
 380                       char *buffer,
 381                       unsigned long *size,
 382                       unsigned long *offset)
 383{
 384        int i;
 385
 386        /* One "cache-tree" entry consists of the following:
 387         * path (NUL terminated)
 388         * entry_count, subtree_nr ("%d %d\n")
 389         * tree-sha1 (missing if invalid)
 390         * subtree_nr "cache-tree" entries for subtrees.
 391         */
 392        if (*size < *offset + pathlen + 100) {
 393                *size = alloc_nr(*offset + pathlen + 100);
 394                buffer = xrealloc(buffer, *size);
 395        }
 396        *offset += sprintf(buffer + *offset, "%.*s%c%d %d\n",
 397                           pathlen, path, 0,
 398                           it->entry_count, it->subtree_nr);
 399
 400#if DEBUG
 401        if (0 <= it->entry_count)
 402                fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
 403                        pathlen, path, it->entry_count, it->subtree_nr,
 404                        sha1_to_hex(it->sha1));
 405        else
 406                fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
 407                        pathlen, path, it->subtree_nr);
 408#endif
 409
 410        if (0 <= it->entry_count) {
 411                memcpy(buffer + *offset, it->sha1, 20);
 412                *offset += 20;
 413        }
 414        for (i = 0; i < it->subtree_nr; i++) {
 415                struct cache_tree_sub *down = it->down[i];
 416                if (i) {
 417                        struct cache_tree_sub *prev = it->down[i-1];
 418                        if (subtree_name_cmp(down->name, down->namelen,
 419                                             prev->name, prev->namelen) <= 0)
 420                                die("fatal - unsorted cache subtree");
 421                }
 422                buffer = write_one(down->cache_tree, down->name, down->namelen,
 423                                   buffer, size, offset);
 424        }
 425        return buffer;
 426}
 427
 428void *cache_tree_write(struct cache_tree *root, unsigned long *size_p)
 429{
 430        char path[PATH_MAX];
 431        unsigned long size = 8192;
 432        char *buffer = xmalloc(size);
 433
 434        *size_p = 0;
 435        path[0] = 0;
 436        return write_one(root, path, 0, buffer, &size, size_p);
 437}
 438
 439static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 440{
 441        const char *buf = *buffer;
 442        unsigned long size = *size_p;
 443        struct cache_tree *it;
 444        int i, subtree_nr;
 445
 446        it = NULL;
 447        /* skip name, but make sure name exists */
 448        while (size && *buf) {
 449                size--;
 450                buf++;
 451        }
 452        if (!size)
 453                goto free_return;
 454        buf++; size--;
 455        it = cache_tree();
 456        if (sscanf(buf, "%d %d\n", &it->entry_count, &subtree_nr) != 2)
 457                goto free_return;
 458        while (size && *buf && *buf != '\n') {
 459                size--;
 460                buf++;
 461        }
 462        if (!size)
 463                goto free_return;
 464        buf++; size--;
 465        if (0 <= it->entry_count) {
 466                if (size < 20)
 467                        goto free_return;
 468                memcpy(it->sha1, buf, 20);
 469                buf += 20;
 470                size -= 20;
 471        }
 472
 473#if DEBUG
 474        if (0 <= it->entry_count)
 475                fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
 476                        *buffer, it->entry_count, subtree_nr,
 477                        sha1_to_hex(it->sha1));
 478        else
 479                fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
 480                        *buffer, subtree_nr);
 481#endif
 482
 483        /*
 484         * Just a heuristic -- we do not add directories that often but
 485         * we do not want to have to extend it immediately when we do,
 486         * hence +2.
 487         */
 488        it->subtree_alloc = subtree_nr + 2;
 489        it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
 490        for (i = 0; i < subtree_nr; i++) {
 491                /* read each subtree */
 492                struct cache_tree *sub;
 493                struct cache_tree_sub *subtree;
 494                const char *name = buf;
 495
 496                sub = read_one(&buf, &size);
 497                if (!sub)
 498                        goto free_return;
 499                subtree = cache_tree_sub(it, name);
 500                subtree->cache_tree = sub;
 501        }
 502        if (subtree_nr != it->subtree_nr)
 503                die("cache-tree: internal error");
 504        *buffer = buf;
 505        *size_p = size;
 506        return it;
 507
 508 free_return:
 509        cache_tree_free(&it);
 510        return NULL;
 511}
 512
 513struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 514{
 515        if (buffer[0])
 516                return NULL; /* not the whole tree */
 517        return read_one(&buffer, &size);
 518}