p2000: add sparse-index repos
[git] / 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;
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 static int set_index_sparse_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 = 1;
116         return res;
117 }
118
119 int set_sparse_index_config(struct repository *repo, int enable)
120 {
121         int res = set_index_sparse_config(repo, enable);
122
123         prepare_repo_settings(repo);
124         repo->settings.sparse_index = enable;
125         return res;
126 }
127
128 int convert_to_sparse(struct index_state *istate)
129 {
130         int test_env;
131         if (istate->split_index || istate->sparse_index ||
132             !core_apply_sparse_checkout || !core_sparse_checkout_cone)
133                 return 0;
134
135         if (!istate->repo)
136                 istate->repo = the_repository;
137
138         /*
139          * The GIT_TEST_SPARSE_INDEX environment variable triggers the
140          * index.sparse config variable to be on.
141          */
142         test_env = git_env_bool("GIT_TEST_SPARSE_INDEX", -1);
143         if (test_env >= 0)
144                 set_sparse_index_config(istate->repo, test_env);
145
146         /*
147          * Only convert to sparse if index.sparse is set.
148          */
149         prepare_repo_settings(istate->repo);
150         if (!istate->repo->settings.sparse_index)
151                 return 0;
152
153         if (!istate->sparse_checkout_patterns) {
154                 istate->sparse_checkout_patterns = xcalloc(1, sizeof(struct pattern_list));
155                 if (get_sparse_checkout_patterns(istate->sparse_checkout_patterns) < 0)
156                         return 0;
157         }
158
159         if (!istate->sparse_checkout_patterns->use_cone_patterns) {
160                 warning(_("attempting to use sparse-index without cone mode"));
161                 return -1;
162         }
163
164         if (cache_tree_update(istate, 0)) {
165                 warning(_("unable to update cache-tree, staying full"));
166                 return -1;
167         }
168
169         remove_fsmonitor(istate);
170
171         trace2_region_enter("index", "convert_to_sparse", istate->repo);
172         istate->cache_nr = convert_to_sparse_rec(istate,
173                                                  0, 0, istate->cache_nr,
174                                                  "", 0, istate->cache_tree);
175
176         /* Clear and recompute the cache-tree */
177         cache_tree_free(&istate->cache_tree);
178         cache_tree_update(istate, 0);
179
180         istate->sparse_index = 1;
181         trace2_region_leave("index", "convert_to_sparse", istate->repo);
182         return 0;
183 }
184
185 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
186 {
187         ALLOC_GROW(istate->cache, nr + 1, istate->cache_alloc);
188
189         istate->cache[nr] = ce;
190         add_name_hash(istate, ce);
191 }
192
193 static int add_path_to_index(const struct object_id *oid,
194                              struct strbuf *base, const char *path,
195                              unsigned int mode, void *context)
196 {
197         struct index_state *istate = (struct index_state *)context;
198         struct cache_entry *ce;
199         size_t len = base->len;
200
201         if (S_ISDIR(mode))
202                 return READ_TREE_RECURSIVE;
203
204         strbuf_addstr(base, path);
205
206         ce = make_cache_entry(istate, mode, oid, base->buf, 0, 0);
207         ce->ce_flags |= CE_SKIP_WORKTREE;
208         set_index_entry(istate, istate->cache_nr++, ce);
209
210         strbuf_setlen(base, len);
211         return 0;
212 }
213
214 void ensure_full_index(struct index_state *istate)
215 {
216         int i;
217         struct index_state *full;
218         struct strbuf base = STRBUF_INIT;
219
220         if (!istate || !istate->sparse_index)
221                 return;
222
223         if (!istate->repo)
224                 istate->repo = the_repository;
225
226         trace2_region_enter("index", "ensure_full_index", istate->repo);
227
228         /* initialize basics of new index */
229         full = xcalloc(1, sizeof(struct index_state));
230         memcpy(full, istate, sizeof(struct index_state));
231
232         /* then change the necessary things */
233         full->sparse_index = 0;
234         full->cache_alloc = (3 * istate->cache_alloc) / 2;
235         full->cache_nr = 0;
236         ALLOC_ARRAY(full->cache, full->cache_alloc);
237
238         for (i = 0; i < istate->cache_nr; i++) {
239                 struct cache_entry *ce = istate->cache[i];
240                 struct tree *tree;
241                 struct pathspec ps;
242
243                 if (!S_ISSPARSEDIR(ce->ce_mode)) {
244                         set_index_entry(full, full->cache_nr++, ce);
245                         continue;
246                 }
247                 if (!(ce->ce_flags & CE_SKIP_WORKTREE))
248                         warning(_("index entry is a directory, but not sparse (%08x)"),
249                                 ce->ce_flags);
250
251                 /* recursively walk into cd->name */
252                 tree = lookup_tree(istate->repo, &ce->oid);
253
254                 memset(&ps, 0, sizeof(ps));
255                 ps.recursive = 1;
256                 ps.has_wildcard = 1;
257                 ps.max_depth = -1;
258
259                 strbuf_setlen(&base, 0);
260                 strbuf_add(&base, ce->name, strlen(ce->name));
261
262                 read_tree_at(istate->repo, tree, &base, &ps,
263                              add_path_to_index, full);
264
265                 /* free directory entries. full entries are re-used */
266                 discard_cache_entry(ce);
267         }
268
269         /* Copy back into original index. */
270         memcpy(&istate->name_hash, &full->name_hash, sizeof(full->name_hash));
271         istate->sparse_index = 0;
272         free(istate->cache);
273         istate->cache = full->cache;
274         istate->cache_nr = full->cache_nr;
275         istate->cache_alloc = full->cache_alloc;
276
277         strbuf_release(&base);
278         free(full);
279
280         /* Clear and recompute the cache-tree */
281         cache_tree_free(&istate->cache_tree);
282         cache_tree_update(istate, 0);
283
284         trace2_region_leave("index", "ensure_full_index", istate->repo);
285 }