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 int convert_to_sparse(struct index_state *istate, int flags)
 126 {
 127         int test_env;
 128         if (istate->sparse_index || !istate->cache_nr ||
 129             !core_apply_sparse_checkout || !core_sparse_checkout_cone)
 130                 return 0;
 131
 132         if (!istate->repo)
 133                 istate->repo = the_repository;
 134
 135         if (!(flags & SPARSE_INDEX_MEMORY_ONLY)) {
 136                 /*
 137                  * The sparse index is not (yet) integrated with a split index.
 138                  */
 139                 if (istate->split_index)
 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         /*
 172          * NEEDSWORK: If we have unmerged entries, then stay full.
 173          * Unmerged entries prevent the cache-tree extension from working.
 174          */
 175         if (index_has_unmerged_entries(istate))
 176                 return 0;
 177
 178         /* Clear and recompute the cache-tree */
 179         cache_tree_free(&istate->cache_tree);
 180         /*
 181          * Silently return if there is a problem with the cache tree update,
 182          * which might just be due to a conflict state in some entry.
 183          *
 184          * This might create new tree objects, so be sure to use
 185          * WRITE_TREE_MISSING_OK.
 186          */
 187         if (cache_tree_update(istate, WRITE_TREE_MISSING_OK))
 188                 return 0;
 189
 190         remove_fsmonitor(istate);
 191
 192         trace2_region_enter("index", "convert_to_sparse", istate->repo);
 193         istate->cache_nr = convert_to_sparse_rec(istate,
 194                                                  0, 0, istate->cache_nr,
 195                                                  "", 0, istate->cache_tree);
 196
 197         /* Clear and recompute the cache-tree */
 198         cache_tree_free(&istate->cache_tree);
 199         cache_tree_update(istate, 0);
 200
 201         istate->fsmonitor_has_run_once = 0;
 202         FREE_AND_NULL(istate->fsmonitor_dirty);
 203         FREE_AND_NULL(istate->fsmonitor_last_update);
 204
 205         istate->sparse_index = 1;
 206         trace2_region_leave("index", "convert_to_sparse", istate->repo);
 207         return 0;
 208 }
 209
 210 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
 211 {
 212         ALLOC_GROW(istate->cache, nr + 1, istate->cache_alloc);
 213
 214         istate->cache[nr] = ce;
 215         add_name_hash(istate, ce);
 216 }
 217
 218 static int add_path_to_index(const struct object_id *oid,
 219                              struct strbuf *base, const char *path,
 220                              unsigned int mode, void *context)
 221 {
 222         struct index_state *istate = (struct index_state *)context;
 223         struct cache_entry *ce;
 224         size_t len = base->len;
 225
 226         if (S_ISDIR(mode))
 227                 return READ_TREE_RECURSIVE;
 228
 229         strbuf_addstr(base, path);
 230
 231         ce = make_cache_entry(istate, mode, oid, base->buf, 0, 0);
 232         ce->ce_flags |= CE_SKIP_WORKTREE | CE_EXTENDED;
 233         set_index_entry(istate, istate->cache_nr++, ce);
 234
 235         strbuf_setlen(base, len);
 236         return 0;
 237 }
 238
 239 void ensure_full_index(struct index_state *istate)
 240 {
 241         int i;
 242         struct index_state *full;
 243         struct strbuf base = STRBUF_INIT;
 244
 245         if (!istate || !istate->sparse_index)
 246                 return;
 247
 248         if (!istate->repo)
 249                 istate->repo = the_repository;
 250
 251         trace2_region_enter("index", "ensure_full_index", istate->repo);
 252
 253         /* initialize basics of new index */
 254         full = xcalloc(1, sizeof(struct index_state));
 255         memcpy(full, istate, sizeof(struct index_state));
 256
 257         /* then change the necessary things */
 258         full->sparse_index = 0;
 259         full->cache_alloc = (3 * istate->cache_alloc) / 2;
 260         full->cache_nr = 0;
 261         ALLOC_ARRAY(full->cache, full->cache_alloc);
 262
 263         for (i = 0; i < istate->cache_nr; i++) {
 264                 struct cache_entry *ce = istate->cache[i];
 265                 struct tree *tree;
 266                 struct pathspec ps;
 267
 268                 if (!S_ISSPARSEDIR(ce->ce_mode)) {
 269                         set_index_entry(full, full->cache_nr++, ce);
 270                         continue;
 271                 }
 272                 if (!(ce->ce_flags & CE_SKIP_WORKTREE))
 273                         warning(_("index entry is a directory, but not sparse (%08x)"),
 274                                 ce->ce_flags);
 275
 276                 /* recursively walk into cd->name */
 277                 tree = lookup_tree(istate->repo, &ce->oid);
 278
 279                 memset(&ps, 0, sizeof(ps));
 280                 ps.recursive = 1;
 281                 ps.has_wildcard = 1;
 282                 ps.max_depth = -1;
 283
 284                 strbuf_setlen(&base, 0);
 285                 strbuf_add(&base, ce->name, strlen(ce->name));
 286
 287                 read_tree_at(istate->repo, tree, &base, &ps,
 288                              add_path_to_index, full);
 289
 290                 /* free directory entries. full entries are re-used */
 291                 discard_cache_entry(ce);
 292         }
 293
 294         /* Copy back into original index. */
 295         memcpy(&istate->name_hash, &full->name_hash, sizeof(full->name_hash));
 296         istate->sparse_index = 0;
 297         free(istate->cache);
 298         istate->cache = full->cache;
 299         istate->cache_nr = full->cache_nr;
 300         istate->cache_alloc = full->cache_alloc;
 301         istate->fsmonitor_has_run_once = 0;
 302         FREE_AND_NULL(istate->fsmonitor_dirty);
 303         FREE_AND_NULL(istate->fsmonitor_last_update);
 304
 305         strbuf_release(&base);
 306         free(full);
 307
 308         /* Clear and recompute the cache-tree */
 309         cache_tree_free(&istate->cache_tree);
 310         cache_tree_update(istate, 0);
 311
 312         trace2_region_leave("index", "ensure_full_index", istate->repo);
 313 }
 314
 315 /*
 316  * This static global helps avoid infinite recursion between
 317  * expand_to_path() and index_file_exists().
 318  */
 319 static int in_expand_to_path = 0;
 320
 321 void expand_to_path(struct index_state *istate,
 322                     const char *path, size_t pathlen, int icase)
 323 {
 324         struct strbuf path_mutable = STRBUF_INIT;
 325         size_t substr_len;
 326
 327         /* prevent extra recursion */
 328         if (in_expand_to_path)
 329                 return;
 330
 331         if (!istate || !istate->sparse_index)
 332                 return;
 333
 334         if (!istate->repo)
 335                 istate->repo = the_repository;
 336
 337         in_expand_to_path = 1;
 338
 339         /*
 340          * We only need to actually expand a region if the
 341          * following are both true:
 342          *
 343          * 1. 'path' is not already in the index.
 344          * 2. Some parent directory of 'path' is a sparse directory.
 345          */
 346
 347         if (index_file_exists(istate, path, pathlen, icase))
 348                 goto cleanup;
 349
 350         strbuf_add(&path_mutable, path, pathlen);
 351         strbuf_addch(&path_mutable, '/');
 352
 353         /* Check the name hash for all parent directories */
 354         substr_len = 0;
 355         while (substr_len < pathlen) {
 356                 char temp;
 357                 char *replace = strchr(path_mutable.buf + substr_len, '/');
 358
 359                 if (!replace)
 360                         break;
 361
 362                 /* replace the character _after_ the slash */
 363                 replace++;
 364                 temp = *replace;
 365                 *replace = '\0';
 366                 if (index_file_exists(istate, path_mutable.buf,
 367                                       path_mutable.len, icase)) {
 368                         /*
 369                          * We found a parent directory in the name-hash
 370                          * hashtable, because only sparse directory entries
 371                          * have a trailing '/' character.  Since "path" wasn't
 372                          * in the index, perhaps it exists within this
 373                          * sparse-directory.  Expand accordingly.
 374                          */
 375                         ensure_full_index(istate);
 376                         break;
 377                 }
 378
 379                 *replace = temp;
 380                 substr_len = replace - path_mutable.buf;
 381         }
 382
 383 cleanup:
 384         strbuf_release(&path_mutable);
 385         in_expand_to_path = 0;
 386 }