summaryrefslogtreecommitdiff
path: root/sparse-index.c
blob: 7b7ff79e0443a89d37409620a0fd6b04ef9cdc10 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
#include "cache.h"
#include "repository.h"
#include "sparse-index.h"
#include "tree.h"
#include "pathspec.h"
#include "trace2.h"
#include "cache-tree.h"
#include "config.h"
#include "dir.h"
#include "fsmonitor.h"

static struct cache_entry *construct_sparse_dir_entry(
				struct index_state *istate,
				const char *sparse_dir,
				struct cache_tree *tree)
{
	struct cache_entry *de;

	de = make_cache_entry(istate, S_IFDIR, &tree->oid, sparse_dir, 0, 0);

	de->ce_flags |= CE_SKIP_WORKTREE;
	return de;
}

/*
 * Returns the number of entries "inserted" into the index.
 */
static int convert_to_sparse_rec(struct index_state *istate,
				 int num_converted,
				 int start, int end,
				 const char *ct_path, size_t ct_pathlen,
				 struct cache_tree *ct)
{
	int i, can_convert = 1;
	int start_converted = num_converted;
	struct strbuf child_path = STRBUF_INIT;

	/*
	 * Is the current path outside of the sparse cone?
	 * Then check if the region can be replaced by a sparse
	 * directory entry (everything is sparse and merged).
	 */
	if (path_in_sparse_checkout(ct_path, istate))
		can_convert = 0;

	for (i = start; can_convert && i < end; i++) {
		struct cache_entry *ce = istate->cache[i];

		if (ce_stage(ce) ||
		    S_ISGITLINK(ce->ce_mode) ||
		    !(ce->ce_flags & CE_SKIP_WORKTREE))
			can_convert = 0;
	}

	if (can_convert) {
		struct cache_entry *se;
		se = construct_sparse_dir_entry(istate, ct_path, ct);

		istate->cache[num_converted++] = se;
		return 1;
	}

	for (i = start; i < end; ) {
		int count, span, pos = -1;
		const char *base, *slash;
		struct cache_entry *ce = istate->cache[i];

		/*
		 * Detect if this is a normal entry outside of any subtree
		 * entry.
		 */
		base = ce->name + ct_pathlen;
		slash = strchr(base, '/');

		if (slash)
			pos = cache_tree_subtree_pos(ct, base, slash - base);

		if (pos < 0) {
			istate->cache[num_converted++] = ce;
			i++;
			continue;
		}

		strbuf_setlen(&child_path, 0);
		strbuf_add(&child_path, ce->name, slash - ce->name + 1);

		span = ct->down[pos]->cache_tree->entry_count;
		count = convert_to_sparse_rec(istate,
					      num_converted, i, i + span,
					      child_path.buf, child_path.len,
					      ct->down[pos]->cache_tree);
		num_converted += count;
		i += span;
	}

	strbuf_release(&child_path);
	return num_converted - start_converted;
}

int set_sparse_index_config(struct repository *repo, int enable)
{
	int res;
	char *config_path = repo_git_path(repo, "config.worktree");
	res = git_config_set_in_file_gently(config_path,
					    "index.sparse",
					    enable ? "true" : NULL);
	free(config_path);

	prepare_repo_settings(repo);
	repo->settings.sparse_index = enable;
	return res;
}

static int index_has_unmerged_entries(struct index_state *istate)
{
	int i;
	for (i = 0; i < istate->cache_nr; i++) {
		if (ce_stage(istate->cache[i]))
			return 1;
	}

	return 0;
}

int convert_to_sparse(struct index_state *istate, int flags)
{
	int test_env;
	if (istate->sparse_index || !istate->cache_nr ||
	    !core_apply_sparse_checkout || !core_sparse_checkout_cone)
		return 0;

	if (!istate->repo)
		istate->repo = the_repository;

	if (!(flags & SPARSE_INDEX_MEMORY_ONLY)) {
		/*
		 * The sparse index is not (yet) integrated with a split index.
		 */
		if (istate->split_index)
			return 0;
		/*
		 * The GIT_TEST_SPARSE_INDEX environment variable triggers the
		 * index.sparse config variable to be on.
		 */
		test_env = git_env_bool("GIT_TEST_SPARSE_INDEX", -1);
		if (test_env >= 0)
			set_sparse_index_config(istate->repo, test_env);

		/*
		 * Only convert to sparse if index.sparse is set.
		 */
		prepare_repo_settings(istate->repo);
		if (!istate->repo->settings.sparse_index)
			return 0;
	}

	if (init_sparse_checkout_patterns(istate))
		return 0;

	/*
	 * We need cone-mode patterns to use sparse-index. If a user edits
	 * their sparse-checkout file manually, then we can detect during
	 * parsing that they are not actually using cone-mode patterns and
	 * hence we need to abort this conversion _without error_. Warnings
	 * already exist in the pattern parsing to inform the user of their
	 * bad patterns.
	 */
	if (!istate->sparse_checkout_patterns->use_cone_patterns)
		return 0;

	/*
	 * NEEDSWORK: If we have unmerged entries, then stay full.
	 * Unmerged entries prevent the cache-tree extension from working.
	 */
	if (index_has_unmerged_entries(istate))
		return 0;

	/* Clear and recompute the cache-tree */
	cache_tree_free(&istate->cache_tree);
	/*
	 * Silently return if there is a problem with the cache tree update,
	 * which might just be due to a conflict state in some entry.
	 *
	 * This might create new tree objects, so be sure to use
	 * WRITE_TREE_MISSING_OK.
	 */
	if (cache_tree_update(istate, WRITE_TREE_MISSING_OK))
		return 0;

	remove_fsmonitor(istate);

	trace2_region_enter("index", "convert_to_sparse", istate->repo);
	istate->cache_nr = convert_to_sparse_rec(istate,
						 0, 0, istate->cache_nr,
						 "", 0, istate->cache_tree);

	/* Clear and recompute the cache-tree */
	cache_tree_free(&istate->cache_tree);
	cache_tree_update(istate, 0);

	istate->fsmonitor_has_run_once = 0;
	FREE_AND_NULL(istate->fsmonitor_dirty);
	FREE_AND_NULL(istate->fsmonitor_last_update);

	istate->sparse_index = 1;
	trace2_region_leave("index", "convert_to_sparse", istate->repo);
	return 0;
}

static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
{
	ALLOC_GROW(istate->cache, nr + 1, istate->cache_alloc);

	istate->cache[nr] = ce;
	add_name_hash(istate, ce);
}

static int add_path_to_index(const struct object_id *oid,
			     struct strbuf *base, const char *path,
			     unsigned int mode, void *context)
{
	struct index_state *istate = (struct index_state *)context;
	struct cache_entry *ce;
	size_t len = base->len;

	if (S_ISDIR(mode))
		return READ_TREE_RECURSIVE;

	strbuf_addstr(base, path);

	ce = make_cache_entry(istate, mode, oid, base->buf, 0, 0);
	ce->ce_flags |= CE_SKIP_WORKTREE | CE_EXTENDED;
	set_index_entry(istate, istate->cache_nr++, ce);

	strbuf_setlen(base, len);
	return 0;
}

void ensure_full_index(struct index_state *istate)
{
	int i;
	struct index_state *full;
	struct strbuf base = STRBUF_INIT;

	if (!istate || !istate->sparse_index)
		return;

	if (!istate->repo)
		istate->repo = the_repository;

	trace2_region_enter("index", "ensure_full_index", istate->repo);

	/* initialize basics of new index */
	full = xcalloc(1, sizeof(struct index_state));
	memcpy(full, istate, sizeof(struct index_state));

	/* then change the necessary things */
	full->sparse_index = 0;
	full->cache_alloc = (3 * istate->cache_alloc) / 2;
	full->cache_nr = 0;
	ALLOC_ARRAY(full->cache, full->cache_alloc);

	for (i = 0; i < istate->cache_nr; i++) {
		struct cache_entry *ce = istate->cache[i];
		struct tree *tree;
		struct pathspec ps;

		if (!S_ISSPARSEDIR(ce->ce_mode)) {
			set_index_entry(full, full->cache_nr++, ce);
			continue;
		}
		if (!(ce->ce_flags & CE_SKIP_WORKTREE))
			warning(_("index entry is a directory, but not sparse (%08x)"),
				ce->ce_flags);

		/* recursively walk into cd->name */
		tree = lookup_tree(istate->repo, &ce->oid);

		memset(&ps, 0, sizeof(ps));
		ps.recursive = 1;
		ps.has_wildcard = 1;
		ps.max_depth = -1;

		strbuf_setlen(&base, 0);
		strbuf_add(&base, ce->name, strlen(ce->name));

		read_tree_at(istate->repo, tree, &base, &ps,
			     add_path_to_index, full);

		/* free directory entries. full entries are re-used */
		discard_cache_entry(ce);
	}

	/* Copy back into original index. */
	memcpy(&istate->name_hash, &full->name_hash, sizeof(full->name_hash));
	memcpy(&istate->dir_hash, &full->dir_hash, sizeof(full->dir_hash));
	istate->sparse_index = 0;
	free(istate->cache);
	istate->cache = full->cache;
	istate->cache_nr = full->cache_nr;
	istate->cache_alloc = full->cache_alloc;
	istate->fsmonitor_has_run_once = 0;
	FREE_AND_NULL(istate->fsmonitor_dirty);
	FREE_AND_NULL(istate->fsmonitor_last_update);

	strbuf_release(&base);
	free(full);

	/* Clear and recompute the cache-tree */
	cache_tree_free(&istate->cache_tree);
	cache_tree_update(istate, 0);

	trace2_region_leave("index", "ensure_full_index", istate->repo);
}

/*
 * This static global helps avoid infinite recursion between
 * expand_to_path() and index_file_exists().
 */
static int in_expand_to_path = 0;

void expand_to_path(struct index_state *istate,
		    const char *path, size_t pathlen, int icase)
{
	struct strbuf path_mutable = STRBUF_INIT;
	size_t substr_len;

	/* prevent extra recursion */
	if (in_expand_to_path)
		return;

	if (!istate || !istate->sparse_index)
		return;

	if (!istate->repo)
		istate->repo = the_repository;

	in_expand_to_path = 1;

	/*
	 * We only need to actually expand a region if the
	 * following are both true:
	 *
	 * 1. 'path' is not already in the index.
	 * 2. Some parent directory of 'path' is a sparse directory.
	 */

	if (index_file_exists(istate, path, pathlen, icase))
		goto cleanup;

	strbuf_add(&path_mutable, path, pathlen);
	strbuf_addch(&path_mutable, '/');

	/* Check the name hash for all parent directories */
	substr_len = 0;
	while (substr_len < pathlen) {
		char temp;
		char *replace = strchr(path_mutable.buf + substr_len, '/');

		if (!replace)
			break;

		/* replace the character _after_ the slash */
		replace++;
		temp = *replace;
		*replace = '\0';
		if (index_file_exists(istate, path_mutable.buf,
				      path_mutable.len, icase)) {
			/*
			 * We found a parent directory in the name-hash
			 * hashtable, because only sparse directory entries
			 * have a trailing '/' character.  Since "path" wasn't
			 * in the index, perhaps it exists within this
			 * sparse-directory.  Expand accordingly.
			 */
			ensure_full_index(istate);
			break;
		}

		*replace = temp;
		substr_len = replace - path_mutable.buf;
	}

cleanup:
	strbuf_release(&path_mutable);
	in_expand_to_path = 0;
}