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         enum pattern_match_result match;
  37         int dtype = DT_UNKNOWN;
  38         struct strbuf child_path = STRBUF_INIT;
  39         struct pattern_list *pl = istate->sparse_checkout_patterns;
  40
  41         /*
  42          * Is the current path outside of the sparse cone?
  43          * Then check if the region can be replaced by a sparse
  44          * directory entry (everything is sparse and merged).
  45          */
  46         match = path_matches_pattern_list(ct_path, ct_pathlen,
  47                                           NULL, &dtype, pl, istate);
  48         if (match != NOT_MATCHED)
  49                 can_convert = 0;
  50
  51         for (i = start; can_convert && i < end; i++) {
  52                 struct cache_entry *ce = istate->cache[i];
  53
  54                 if (ce_stage(ce) ||
  55                     S_ISGITLINK(ce->ce_mode) ||
  56                     !(ce->ce_flags & CE_SKIP_WORKTREE))
  57                         can_convert = 0;
  58         }
  59
  60         if (can_convert) {
  61                 struct cache_entry *se;
  62                 se = construct_sparse_dir_entry(istate, ct_path, ct);
  63
  64                 istate->cache[num_converted++] = se;
  65                 return 1;
  66         }
  67
  68         for (i = start; i < end; ) {
  69                 int count, span, pos = -1;
  70                 const char *base, *slash;
  71                 struct cache_entry *ce = istate->cache[i];
  72
  73                 /*
  74                  * Detect if this is a normal entry outside of any subtree
  75                  * entry.
  76                  */
  77                 base = ce->name + ct_pathlen;
  78                 slash = strchr(base, '/');
  79
  80                 if (slash)
  81                         pos = cache_tree_subtree_pos(ct, base, slash - base);
  82
  83                 if (pos < 0) {
  84                         istate->cache[num_converted++] = ce;
  85                         i++;
  86                         continue;
  87                 }
  88
  89                 strbuf_setlen(&child_path, 0);
  90                 strbuf_add(&child_path, ce->name, slash - ce->name + 1);
  91
  92                 span = ct->down[pos]->cache_tree->entry_count;
  93                 count = convert_to_sparse_rec(istate,
  94                                               num_converted, i, i + span,
  95                                               child_path.buf, child_path.len,
  96                                               ct->down[pos]->cache_tree);
  97                 num_converted += count;
  98                 i += span;
  99         }
 100
 101         strbuf_release(&child_path);
 102         return num_converted - start_converted;
 103 }
 104
 105 int set_sparse_index_config(struct repository *repo, int enable)
 106 {
 107         int res;
 108         char *config_path = repo_git_path(repo, "config.worktree");
 109         res = git_config_set_in_file_gently(config_path,
 110                                             "index.sparse",
 111                                             enable ? "true" : NULL);
 112         free(config_path);
 113
 114         prepare_repo_settings(repo);
 115         repo->settings.sparse_index = enable;
 116         return res;
 117 }
 118
 119 static int index_has_unmerged_entries(struct index_state *istate)
 120 {
 121         int i;
 122         for (i = 0; i < istate->cache_nr; i++) {
 123                 if (ce_stage(istate->cache[i]))
 124                         return 1;
 125         }
 126
 127         return 0;
 128 }
 129
 130 int convert_to_sparse(struct index_state *istate)
 131 {
 132         int test_env;
 133         if (istate->split_index || istate->sparse_index ||
 134             !core_apply_sparse_checkout || !core_sparse_checkout_cone)
 135                 return 0;
 136
 137         if (!istate->repo)
 138                 istate->repo = the_repository;
 139
 140         /*
 141          * The GIT_TEST_SPARSE_INDEX environment variable triggers the
 142          * index.sparse config variable to be on.
 143          */
 144         test_env = git_env_bool("GIT_TEST_SPARSE_INDEX", -1);
 145         if (test_env >= 0)
 146                 set_sparse_index_config(istate->repo, test_env);
 147
 148         /*
 149          * Only convert to sparse if index.sparse is set.
 150          */
 151         prepare_repo_settings(istate->repo);
 152         if (!istate->repo->settings.sparse_index)
 153                 return 0;
 154
 155         if (!istate->sparse_checkout_patterns) {
 156                 istate->sparse_checkout_patterns = xcalloc(1, sizeof(struct pattern_list));
 157                 if (get_sparse_checkout_patterns(istate->sparse_checkout_patterns) < 0)
 158                         return 0;
 159         }
 160
 161         if (!istate->sparse_checkout_patterns->use_cone_patterns) {
 162                 warning(_("attempting to use sparse-index without cone mode"));
 163                 return -1;
 164         }
 165
 166         /*
 167          * NEEDSWORK: If we have unmerged entries, then stay full.
 168          * Unmerged entries prevent the cache-tree extension from working.
 169          */
 170         if (index_has_unmerged_entries(istate))
 171                 return 0;
 172
 173         if (cache_tree_update(istate, 0)) {
 174                 warning(_("unable to update cache-tree, staying full"));
 175                 return -1;
 176         }
 177
 178         remove_fsmonitor(istate);
 179
 180         trace2_region_enter("index", "convert_to_sparse", istate->repo);
 181         istate->cache_nr = convert_to_sparse_rec(istate,
 182                                                  0, 0, istate->cache_nr,
 183                                                  "", 0, istate->cache_tree);
 184
 185         /* Clear and recompute the cache-tree */
 186         cache_tree_free(&istate->cache_tree);
 187         cache_tree_update(istate, 0);
 188
 189         istate->sparse_index = 1;
 190         trace2_region_leave("index", "convert_to_sparse", istate->repo);
 191         return 0;
 192 }
 193
 194 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
 195 {
 196         ALLOC_GROW(istate->cache, nr + 1, istate->cache_alloc);
 197
 198         istate->cache[nr] = ce;
 199         add_name_hash(istate, ce);
 200 }
 201
 202 static int add_path_to_index(const struct object_id *oid,
 203                              struct strbuf *base, const char *path,
 204                              unsigned int mode, void *context)
 205 {
 206         struct index_state *istate = (struct index_state *)context;
 207         struct cache_entry *ce;
 208         size_t len = base->len;
 209
 210         if (S_ISDIR(mode))
 211                 return READ_TREE_RECURSIVE;
 212
 213         strbuf_addstr(base, path);
 214
 215         ce = make_cache_entry(istate, mode, oid, base->buf, 0, 0);
 216         ce->ce_flags |= CE_SKIP_WORKTREE | CE_EXTENDED;
 217         set_index_entry(istate, istate->cache_nr++, ce);
 218
 219         strbuf_setlen(base, len);
 220         return 0;
 221 }
 222
 223 void ensure_full_index(struct index_state *istate)
 224 {
 225         int i;
 226         struct index_state *full;
 227         struct strbuf base = STRBUF_INIT;
 228
 229         if (!istate || !istate->sparse_index)
 230                 return;
 231
 232         if (!istate->repo)
 233                 istate->repo = the_repository;
 234
 235         trace2_region_enter("index", "ensure_full_index", istate->repo);
 236
 237         /* initialize basics of new index */
 238         full = xcalloc(1, sizeof(struct index_state));
 239         memcpy(full, istate, sizeof(struct index_state));
 240
 241         /* then change the necessary things */
 242         full->sparse_index = 0;
 243         full->cache_alloc = (3 * istate->cache_alloc) / 2;
 244         full->cache_nr = 0;
 245         ALLOC_ARRAY(full->cache, full->cache_alloc);
 246
 247         for (i = 0; i < istate->cache_nr; i++) {
 248                 struct cache_entry *ce = istate->cache[i];
 249                 struct tree *tree;
 250                 struct pathspec ps;
 251
 252                 if (!S_ISSPARSEDIR(ce->ce_mode)) {
 253                         set_index_entry(full, full->cache_nr++, ce);
 254                         continue;
 255                 }
 256                 if (!(ce->ce_flags & CE_SKIP_WORKTREE))
 257                         warning(_("index entry is a directory, but not sparse (%08x)"),
 258                                 ce->ce_flags);
 259
 260                 /* recursively walk into cd->name */
 261                 tree = lookup_tree(istate->repo, &ce->oid);
 262
 263                 memset(&ps, 0, sizeof(ps));
 264                 ps.recursive = 1;
 265                 ps.has_wildcard = 1;
 266                 ps.max_depth = -1;
 267
 268                 strbuf_setlen(&base, 0);
 269                 strbuf_add(&base, ce->name, strlen(ce->name));
 270
 271                 read_tree_at(istate->repo, tree, &base, &ps,
 272                              add_path_to_index, full);
 273
 274                 /* free directory entries. full entries are re-used */
 275                 discard_cache_entry(ce);
 276         }
 277
 278         /* Copy back into original index. */
 279         memcpy(&istate->name_hash, &full->name_hash, sizeof(full->name_hash));
 280         istate->sparse_index = 0;
 281         free(istate->cache);
 282         istate->cache = full->cache;
 283         istate->cache_nr = full->cache_nr;
 284         istate->cache_alloc = full->cache_alloc;
 285
 286         strbuf_release(&base);
 287         free(full);
 288
 289         /* Clear and recompute the cache-tree */
 290         cache_tree_free(&istate->cache_tree);
 291         cache_tree_update(istate, 0);
 292
 293         trace2_region_leave("index", "ensure_full_index", istate->repo);
 294 }
 295
 296 /*
 297  * This static global helps avoid infinite recursion between
 298  * expand_to_path() and index_file_exists().
 299  */
 300 static int in_expand_to_path = 0;
 301
 302 void expand_to_path(struct index_state *istate,
 303                     const char *path, size_t pathlen, int icase)
 304 {
 305         struct strbuf path_mutable = STRBUF_INIT;
 306         size_t substr_len;
 307
 308         /* prevent extra recursion */
 309         if (in_expand_to_path)
 310                 return;
 311
 312         if (!istate || !istate->sparse_index)
 313                 return;
 314
 315         if (!istate->repo)
 316                 istate->repo = the_repository;
 317
 318         in_expand_to_path = 1;
 319
 320         /*
 321          * We only need to actually expand a region if the
 322          * following are both true:
 323          *
 324          * 1. 'path' is not already in the index.
 325          * 2. Some parent directory of 'path' is a sparse directory.
 326          */
 327
 328         if (index_file_exists(istate, path, pathlen, icase))
 329                 goto cleanup;
 330
 331         strbuf_add(&path_mutable, path, pathlen);
 332         strbuf_addch(&path_mutable, '/');
 333
 334         /* Check the name hash for all parent directories */
 335         substr_len = 0;
 336         while (substr_len < pathlen) {
 337                 char temp;
 338                 char *replace = strchr(path_mutable.buf + substr_len, '/');
 339
 340                 if (!replace)
 341                         break;
 342
 343                 /* replace the character _after_ the slash */
 344                 replace++;
 345                 temp = *replace;
 346                 *replace = '\0';
 347                 if (index_file_exists(istate, path_mutable.buf,
 348                                       path_mutable.len, icase)) {
 349                         /*
 350                          * We found a parent directory in the name-hash
 351                          * hashtable, because only sparse directory entries
 352                          * have a trailing '/' character.  Since "path" wasn't
 353                          * in the index, perhaps it exists within this
 354                          * sparse-directory.  Expand accordingly.
 355                          */
 356                         ensure_full_index(istate);
 357                         break;
 358                 }
 359
 360                 *replace = temp;
 361                 substr_len = replace - path_mutable.buf;
 362         }
 363
 364 cleanup:
 365         strbuf_release(&path_mutable);
 366         in_expand_to_path = 0;
 367 }