sparse-index.c

   1 #include "cache.h"
   2 #include "repository.h"
   3 #include "sparse-index.h"
   4 #include "tree.h"
   5 #include "pathspec.h"
   6 #include "trace2.h"
   7 #include "cache-tree.h"
   8 #include "config.h"
   9 #include "dir.h"
  10 #include "fsmonitor.h"
  11
  12 static struct cache_entry *construct_sparse_dir_entry(
  13                                 struct index_state *istate,
  14                                 const char *sparse_dir,
  15                                 struct cache_tree *tree)
  16 {
  17         struct cache_entry *de;
  18
  19         de = make_cache_entry(istate, S_IFDIR, &tree->oid, sparse_dir, 0, 0);
  20
  21         de->ce_flags |= CE_SKIP_WORKTREE;
  22         return de;
  23 }
  24
  25 /*
  26  * Returns the number of entries "inserted" into the index.
  27  */
  28 static int convert_to_sparse_rec(struct index_state *istate,
  29                                  int num_converted,
  30                                  int start, int end,
  31                                  const char *ct_path, size_t ct_pathlen,
  32                                  struct cache_tree *ct)
  33 {
  34         int i, can_convert = 1;
  35         int start_converted = num_converted;
  36         struct strbuf child_path = STRBUF_INIT;
  37
  38         /*
  39          * Is the current path outside of the sparse cone?
  40          * Then check if the region can be replaced by a sparse
  41          * directory entry (everything is sparse and merged).
  42          */
  43         if (path_in_sparse_checkout(ct_path, istate))
  44                 can_convert = 0;
  45
  46         for (i = start; can_convert && i < end; i++) {
  47                 struct cache_entry *ce = istate->cache[i];
  48
  49                 if (ce_stage(ce) ||
  50                     S_ISGITLINK(ce->ce_mode) ||
  51                     !(ce->ce_flags & CE_SKIP_WORKTREE))
  52                         can_convert = 0;
  53         }
  54
  55         if (can_convert) {
  56                 struct cache_entry *se;
  57                 se = construct_sparse_dir_entry(istate, ct_path, ct);
  58
  59                 istate->cache[num_converted++] = se;
  60                 return 1;
  61         }
  62
  63         for (i = start; i < end; ) {
  64                 int count, span, pos = -1;
  65                 const char *base, *slash;
  66                 struct cache_entry *ce = istate->cache[i];
  67
  68                 /*
  69                  * Detect if this is a normal entry outside of any subtree
  70                  * entry.
  71                  */
  72                 base = ce->name + ct_pathlen;
  73                 slash = strchr(base, '/');
  74
  75                 if (slash)
  76                         pos = cache_tree_subtree_pos(ct, base, slash - base);
  77
  78                 if (pos < 0) {
  79                         istate->cache[num_converted++] = ce;
  80                         i++;
  81                         continue;
  82                 }
  83
  84                 strbuf_setlen(&child_path, 0);
  85                 strbuf_add(&child_path, ce->name, slash - ce->name + 1);
  86
  87                 span = ct->down[pos]->cache_tree->entry_count;
  88                 count = convert_to_sparse_rec(istate,
  89                                               num_converted, i, i + span,
  90                                               child_path.buf, child_path.len,
  91                                               ct->down[pos]->cache_tree);
  92                 num_converted += count;
  93                 i += span;
  94         }
  95
  96         strbuf_release(&child_path);
  97         return num_converted - start_converted;
  98 }
  99
 100 int set_sparse_index_config(struct repository *repo, int enable)
 101 {
 102         int res;
 103         char *config_path = repo_git_path(repo, "config.worktree");
 104         res = git_config_set_in_file_gently(config_path,
 105                                             "index.sparse",
 106                                             enable ? "true" : NULL);
 107         free(config_path);
 108
 109         prepare_repo_settings(repo);
 110         repo->settings.sparse_index = enable;
 111         return res;
 112 }
 113
 114 static int index_has_unmerged_entries(struct index_state *istate)
 115 {
 116         int i;
 117         for (i = 0; i < istate->cache_nr; i++) {
 118                 if (ce_stage(istate->cache[i]))
 119                         return 1;
 120         }
 121
 122         return 0;
 123 }
 124
 125 static int is_sparse_index_allowed(struct index_state *istate, int flags)
 126 {
 127         if (!core_apply_sparse_checkout || !core_sparse_checkout_cone)
 128                 return 0;
 129
 130         if (!istate->repo)
 131                 istate->repo = the_repository;
 132
 133         if (!(flags & SPARSE_INDEX_MEMORY_ONLY)) {
 134                 int test_env;
 135
 136                 /*
 137                  * The sparse index is not (yet) integrated with a split index.
 138                  */
 139                 if (istate->split_index || git_env_bool("GIT_TEST_SPLIT_INDEX", 0))
 140                         return 0;
 141                 /*
 142                  * The GIT_TEST_SPARSE_INDEX environment variable triggers the
 143                  * index.sparse config variable to be on.
 144                  */
 145                 test_env = git_env_bool("GIT_TEST_SPARSE_INDEX", -1);
 146                 if (test_env >= 0)
 147                         set_sparse_index_config(istate->repo, test_env);
 148
 149                 /*
 150                  * Only convert to sparse if index.sparse is set.
 151                  */
 152                 prepare_repo_settings(istate->repo);
 153                 if (!istate->repo->settings.sparse_index)
 154                         return 0;
 155         }
 156
 157         if (init_sparse_checkout_patterns(istate))
 158                 return 0;
 159
 160         /*
 161          * We need cone-mode patterns to use sparse-index. If a user edits
 162          * their sparse-checkout file manually, then we can detect during
 163          * parsing that they are not actually using cone-mode patterns and
 164          * hence we need to abort this conversion _without error_. Warnings
 165          * already exist in the pattern parsing to inform the user of their
 166          * bad patterns.
 167          */
 168         if (!istate->sparse_checkout_patterns->use_cone_patterns)
 169                 return 0;
 170
 171         return 1;
 172 }
 173
 174 int convert_to_sparse(struct index_state *istate, int flags)
 175 {
 176         /*
 177          * If the index is already sparse, empty, or otherwise
 178          * cannot be converted to sparse, do not convert.
 179          */
 180         if (istate->sparse_index || !istate->cache_nr ||
 181             !is_sparse_index_allowed(istate, flags))
 182                 return 0;
 183
 184         /*
 185          * NEEDSWORK: If we have unmerged entries, then stay full.
 186          * Unmerged entries prevent the cache-tree extension from working.
 187          */
 188         if (index_has_unmerged_entries(istate))
 189                 return 0;
 190
 191         if (!cache_tree_fully_valid(istate->cache_tree)) {
 192                 /* Clear and recompute the cache-tree */
 193                 cache_tree_free(&istate->cache_tree);
 194
 195                 /*
 196                  * Silently return if there is a problem with the cache tree update,
 197                  * which might just be due to a conflict state in some entry.
 198                  *
 199                  * This might create new tree objects, so be sure to use
 200                  * WRITE_TREE_MISSING_OK.
 201                  */
 202                 if (cache_tree_update(istate, WRITE_TREE_MISSING_OK))
 203                         return 0;
 204         }
 205
 206         remove_fsmonitor(istate);
 207
 208         trace2_region_enter("index", "convert_to_sparse", istate->repo);
 209         istate->cache_nr = convert_to_sparse_rec(istate,
 210                                                  0, 0, istate->cache_nr,
 211                                                  "", 0, istate->cache_tree);
 212
 213         /* Clear and recompute the cache-tree */
 214         cache_tree_free(&istate->cache_tree);
 215         cache_tree_update(istate, 0);
 216
 217         istate->fsmonitor_has_run_once = 0;
 218         FREE_AND_NULL(istate->fsmonitor_dirty);
 219         FREE_AND_NULL(istate->fsmonitor_last_update);
 220
 221         istate->sparse_index = 1;
 222         trace2_region_leave("index", "convert_to_sparse", istate->repo);
 223         return 0;
 224 }
 225
 226 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
 227 {
 228         ALLOC_GROW(istate->cache, nr + 1, istate->cache_alloc);
 229
 230         istate->cache[nr] = ce;
 231         add_name_hash(istate, ce);
 232 }
 233
 234 static int add_path_to_index(const struct object_id *oid,
 235                              struct strbuf *base, const char *path,
 236                              unsigned int mode, void *context)
 237 {
 238         struct index_state *istate = (struct index_state *)context;
 239         struct cache_entry *ce;
 240         size_t len = base->len;
 241
 242         if (S_ISDIR(mode))
 243                 return READ_TREE_RECURSIVE;
 244
 245         strbuf_addstr(base, path);
 246
 247         ce = make_cache_entry(istate, mode, oid, base->buf, 0, 0);
 248         ce->ce_flags |= CE_SKIP_WORKTREE | CE_EXTENDED;
 249         set_index_entry(istate, istate->cache_nr++, ce);
 250
 251         strbuf_setlen(base, len);
 252         return 0;
 253 }
 254
 255 void ensure_full_index(struct index_state *istate)
 256 {
 257         int i;
 258         struct index_state *full;
 259         struct strbuf base = STRBUF_INIT;
 260
 261         if (!istate || !istate->sparse_index)
 262                 return;
 263
 264         if (!istate->repo)
 265                 istate->repo = the_repository;
 266
 267         trace2_region_enter("index", "ensure_full_index", istate->repo);
 268
 269         /* initialize basics of new index */
 270         full = xcalloc(1, sizeof(struct index_state));
 271         memcpy(full, istate, sizeof(struct index_state));
 272
 273         /* then change the necessary things */
 274         full->sparse_index = 0;
 275         full->cache_alloc = (3 * istate->cache_alloc) / 2;
 276         full->cache_nr = 0;
 277         ALLOC_ARRAY(full->cache, full->cache_alloc);
 278
 279         for (i = 0; i < istate->cache_nr; i++) {
 280                 struct cache_entry *ce = istate->cache[i];
 281                 struct tree *tree;
 282                 struct pathspec ps;
 283
 284                 if (!S_ISSPARSEDIR(ce->ce_mode)) {
 285                         set_index_entry(full, full->cache_nr++, ce);
 286                         continue;
 287                 }
 288                 if (!(ce->ce_flags & CE_SKIP_WORKTREE))
 289                         warning(_("index entry is a directory, but not sparse (%08x)"),
 290                                 ce->ce_flags);
 291
 292                 /* recursively walk into cd->name */
 293                 tree = lookup_tree(istate->repo, &ce->oid);
 294
 295                 memset(&ps, 0, sizeof(ps));
 296                 ps.recursive = 1;
 297                 ps.has_wildcard = 1;
 298                 ps.max_depth = -1;
 299
 300                 strbuf_setlen(&base, 0);
 301                 strbuf_add(&base, ce->name, strlen(ce->name));
 302
 303                 read_tree_at(istate->repo, tree, &base, &ps,
 304                              add_path_to_index, full);
 305
 306                 /* free directory entries. full entries are re-used */
 307                 discard_cache_entry(ce);
 308         }
 309
 310         /* Copy back into original index. */
 311         memcpy(&istate->name_hash, &full->name_hash, sizeof(full->name_hash));
 312         memcpy(&istate->dir_hash, &full->dir_hash, sizeof(full->dir_hash));
 313         istate->sparse_index = 0;
 314         free(istate->cache);
 315         istate->cache = full->cache;
 316         istate->cache_nr = full->cache_nr;
 317         istate->cache_alloc = full->cache_alloc;
 318         istate->fsmonitor_has_run_once = 0;
 319         FREE_AND_NULL(istate->fsmonitor_dirty);
 320         FREE_AND_NULL(istate->fsmonitor_last_update);
 321
 322         strbuf_release(&base);
 323         free(full);
 324
 325         /* Clear and recompute the cache-tree */
 326         cache_tree_free(&istate->cache_tree);
 327         cache_tree_update(istate, 0);
 328
 329         trace2_region_leave("index", "ensure_full_index", istate->repo);
 330 }
 331
 332 void ensure_correct_sparsity(struct index_state *istate)
 333 {
 334         /*
 335          * If the index can be sparse, make it sparse. Otherwise,
 336          * ensure the index is full.
 337          */
 338         if (is_sparse_index_allowed(istate, 0))
 339                 convert_to_sparse(istate, 0);
 340         else
 341                 ensure_full_index(istate);
 342 }
 343
 344 /*
 345  * This static global helps avoid infinite recursion between
 346  * expand_to_path() and index_file_exists().
 347  */
 348 static int in_expand_to_path = 0;
 349
 350 void expand_to_path(struct index_state *istate,
 351                     const char *path, size_t pathlen, int icase)
 352 {
 353         struct strbuf path_mutable = STRBUF_INIT;
 354         size_t substr_len;
 355
 356         /* prevent extra recursion */
 357         if (in_expand_to_path)
 358                 return;
 359
 360         if (!istate || !istate->sparse_index)
 361                 return;
 362
 363         if (!istate->repo)
 364                 istate->repo = the_repository;
 365
 366         in_expand_to_path = 1;
 367
 368         /*
 369          * We only need to actually expand a region if the
 370          * following are both true:
 371          *
 372          * 1. 'path' is not already in the index.
 373          * 2. Some parent directory of 'path' is a sparse directory.
 374          */
 375
 376         if (index_file_exists(istate, path, pathlen, icase))
 377                 goto cleanup;
 378
 379         strbuf_add(&path_mutable, path, pathlen);
 380         strbuf_addch(&path_mutable, '/');
 381
 382         /* Check the name hash for all parent directories */
 383         substr_len = 0;
 384         while (substr_len < pathlen) {
 385                 char temp;
 386                 char *replace = strchr(path_mutable.buf + substr_len, '/');
 387
 388                 if (!replace)
 389                         break;
 390
 391                 /* replace the character _after_ the slash */
 392                 replace++;
 393                 temp = *replace;
 394                 *replace = '\0';
 395                 if (index_file_exists(istate, path_mutable.buf,
 396                                       path_mutable.len, icase)) {
 397                         /*
 398                          * We found a parent directory in the name-hash
 399                          * hashtable, because only sparse directory entries
 400                          * have a trailing '/' character.  Since "path" wasn't
 401                          * in the index, perhaps it exists within this
 402                          * sparse-directory.  Expand accordingly.
 403                          */
 404                         ensure_full_index(istate);
 405                         break;
 406                 }
 407
 408                 *replace = temp;
 409                 substr_len = replace - path_mutable.buf;
 410         }
 411
 412 cleanup:
 413         strbuf_release(&path_mutable);
 414         in_expand_to_path = 0;
 415 }