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a6dc3d36 | 1 | #include "../cache.h" |
36bf1958 | 2 | #include "../alloc.h" |
44c2339e | 3 | #include "../config.h" |
f394e093 | 4 | #include "../gettext.h" |
41771fa4 | 5 | #include "../hex.h" |
67be7c5a MH |
6 | #include "../refs.h" |
7 | #include "refs-internal.h" | |
67be7c5a MH |
8 | #include "packed-backend.h" |
9 | #include "../iterator.h" | |
10 | #include "../lockfile.h" | |
fb9c2d27 | 11 | #include "../chdir-notify.h" |
65156bb7 | 12 | #include "../wrapper.h" |
d48be35c | 13 | #include "../write-or-die.h" |
67be7c5a | 14 | |
5b633610 MH |
15 | enum mmap_strategy { |
16 | /* | |
17 | * Don't use mmap() at all for reading `packed-refs`. | |
18 | */ | |
19 | MMAP_NONE, | |
67be7c5a MH |
20 | |
21 | /* | |
5b633610 MH |
22 | * Can use mmap() for reading `packed-refs`, but the file must |
23 | * not remain mmapped. This is the usual option on Windows, | |
24 | * where you cannot rename a new version of a file onto a file | |
25 | * that is currently mmapped. | |
67be7c5a | 26 | */ |
5b633610 | 27 | MMAP_TEMPORARY, |
67be7c5a | 28 | |
5b633610 MH |
29 | /* |
30 | * It is OK to leave the `packed-refs` file mmapped while | |
31 | * arbitrary other code is running. | |
32 | */ | |
33 | MMAP_OK | |
67be7c5a MH |
34 | }; |
35 | ||
5b633610 MH |
36 | #if defined(NO_MMAP) |
37 | static enum mmap_strategy mmap_strategy = MMAP_NONE; | |
38 | #elif defined(MMAP_PREVENTS_DELETE) | |
39 | static enum mmap_strategy mmap_strategy = MMAP_TEMPORARY; | |
40 | #else | |
41 | static enum mmap_strategy mmap_strategy = MMAP_OK; | |
42 | #endif | |
43 | ||
f0a7dc86 | 44 | struct packed_ref_store; |
67be7c5a MH |
45 | |
46 | /* | |
cff28ca9 MH |
47 | * A `snapshot` represents one snapshot of a `packed-refs` file. |
48 | * | |
49 | * Normally, this will be a mmapped view of the contents of the | |
50 | * `packed-refs` file at the time the snapshot was created. However, | |
51 | * if the `packed-refs` file was not sorted, this might point at heap | |
52 | * memory holding the contents of the `packed-refs` file with its | |
53 | * records sorted by refname. | |
54 | * | |
55 | * `snapshot` instances are reference counted (via | |
56 | * `acquire_snapshot()` and `release_snapshot()`). This is to prevent | |
57 | * an instance from disappearing while an iterator is still iterating | |
58 | * over it. Instances are garbage collected when their `referrers` | |
59 | * count goes to zero. | |
60 | * | |
61 | * The most recent `snapshot`, if available, is referenced by the | |
62 | * `packed_ref_store`. Its freshness is checked whenever | |
63 | * `get_snapshot()` is called; if the existing snapshot is obsolete, a | |
64 | * new snapshot is taken. | |
67be7c5a | 65 | */ |
cff28ca9 | 66 | struct snapshot { |
f0a7dc86 MH |
67 | /* |
68 | * A back-pointer to the packed_ref_store with which this | |
cff28ca9 | 69 | * snapshot is associated: |
f0a7dc86 MH |
70 | */ |
71 | struct packed_ref_store *refs; | |
72 | ||
5b633610 MH |
73 | /* Is the `packed-refs` file currently mmapped? */ |
74 | int mmapped; | |
75 | ||
76 | /* | |
4a2854f7 MH |
77 | * The contents of the `packed-refs` file: |
78 | * | |
79 | * - buf -- a pointer to the start of the memory | |
80 | * - start -- a pointer to the first byte of actual references | |
81 | * (i.e., after the header line, if one is present) | |
82 | * - eof -- a pointer just past the end of the reference | |
83 | * contents | |
84 | * | |
85 | * If the `packed-refs` file was already sorted, `buf` points | |
86 | * at the mmapped contents of the file. If not, it points at | |
87 | * heap-allocated memory containing the contents, sorted. If | |
88 | * there were no contents (e.g., because the file didn't | |
89 | * exist), `buf`, `start`, and `eof` are all NULL. | |
5b633610 | 90 | */ |
4a2854f7 | 91 | char *buf, *start, *eof; |
5b633610 | 92 | |
daa45408 | 93 | /* |
cff28ca9 MH |
94 | * What is the peeled state of the `packed-refs` file that |
95 | * this snapshot represents? (This is usually determined from | |
96 | * the file's header.) | |
daa45408 MH |
97 | */ |
98 | enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled; | |
99 | ||
67be7c5a | 100 | /* |
cff28ca9 MH |
101 | * Count of references to this instance, including the pointer |
102 | * from `packed_ref_store::snapshot`, if any. The instance | |
103 | * will not be freed as long as the reference count is | |
104 | * nonzero. | |
67be7c5a MH |
105 | */ |
106 | unsigned int referrers; | |
107 | ||
cff28ca9 MH |
108 | /* |
109 | * The metadata of the `packed-refs` file from which this | |
110 | * snapshot was created, used to tell if the file has been | |
111 | * replaced since we read it. | |
112 | */ | |
67be7c5a MH |
113 | struct stat_validity validity; |
114 | }; | |
67be7c5a MH |
115 | |
116 | /* | |
cff28ca9 MH |
117 | * A `ref_store` representing references stored in a `packed-refs` |
118 | * file. It implements the `ref_store` interface, though it has some | |
119 | * limitations: | |
120 | * | |
121 | * - It cannot store symbolic references. | |
122 | * | |
123 | * - It cannot store reflogs. | |
124 | * | |
125 | * - It does not support reference renaming (though it could). | |
126 | * | |
127 | * On the other hand, it can be locked outside of a reference | |
128 | * transaction. In that case, it remains locked even after the | |
129 | * transaction is done and the new `packed-refs` file is activated. | |
67be7c5a MH |
130 | */ |
131 | struct packed_ref_store { | |
e0cc8ac8 MH |
132 | struct ref_store base; |
133 | ||
67be7c5a MH |
134 | unsigned int store_flags; |
135 | ||
136 | /* The path of the "packed-refs" file: */ | |
137 | char *path; | |
138 | ||
139 | /* | |
cff28ca9 MH |
140 | * A snapshot of the values read from the `packed-refs` file, |
141 | * if it might still be current; otherwise, NULL. | |
67be7c5a | 142 | */ |
cff28ca9 | 143 | struct snapshot *snapshot; |
67be7c5a MH |
144 | |
145 | /* | |
146 | * Lock used for the "packed-refs" file. Note that this (and | |
147 | * thus the enclosing `packed_ref_store`) must not be freed. | |
148 | */ | |
149 | struct lock_file lock; | |
42dfa7ec MH |
150 | |
151 | /* | |
152 | * Temporary file used when rewriting new contents to the | |
153 | * "packed-refs" file. Note that this (and thus the enclosing | |
154 | * `packed_ref_store`) must not be freed. | |
155 | */ | |
076aa2cb | 156 | struct tempfile *tempfile; |
67be7c5a MH |
157 | }; |
158 | ||
14b3c344 | 159 | /* |
cff28ca9 | 160 | * Increment the reference count of `*snapshot`. |
14b3c344 | 161 | */ |
cff28ca9 | 162 | static void acquire_snapshot(struct snapshot *snapshot) |
14b3c344 | 163 | { |
cff28ca9 | 164 | snapshot->referrers++; |
14b3c344 MH |
165 | } |
166 | ||
5b633610 | 167 | /* |
cff28ca9 | 168 | * If the buffer in `snapshot` is active, then either munmap the |
5b633610 MH |
169 | * memory and close the file, or free the memory. Then set the buffer |
170 | * pointers to NULL. | |
171 | */ | |
cff28ca9 | 172 | static void clear_snapshot_buffer(struct snapshot *snapshot) |
5b633610 | 173 | { |
cff28ca9 MH |
174 | if (snapshot->mmapped) { |
175 | if (munmap(snapshot->buf, snapshot->eof - snapshot->buf)) | |
5b633610 | 176 | die_errno("error ummapping packed-refs file %s", |
cff28ca9 MH |
177 | snapshot->refs->path); |
178 | snapshot->mmapped = 0; | |
5b633610 | 179 | } else { |
cff28ca9 | 180 | free(snapshot->buf); |
5b633610 | 181 | } |
4a2854f7 | 182 | snapshot->buf = snapshot->start = snapshot->eof = NULL; |
5b633610 MH |
183 | } |
184 | ||
14b3c344 | 185 | /* |
cff28ca9 MH |
186 | * Decrease the reference count of `*snapshot`. If it goes to zero, |
187 | * free `*snapshot` and return true; otherwise return false. | |
14b3c344 | 188 | */ |
cff28ca9 | 189 | static int release_snapshot(struct snapshot *snapshot) |
14b3c344 | 190 | { |
cff28ca9 MH |
191 | if (!--snapshot->referrers) { |
192 | stat_validity_clear(&snapshot->validity); | |
193 | clear_snapshot_buffer(snapshot); | |
194 | free(snapshot); | |
14b3c344 MH |
195 | return 1; |
196 | } else { | |
197 | return 0; | |
198 | } | |
199 | } | |
200 | ||
34224e14 | 201 | struct ref_store *packed_ref_store_create(struct repository *repo, |
99f0d97b | 202 | const char *gitdir, |
e0cc8ac8 | 203 | unsigned int store_flags) |
67be7c5a MH |
204 | { |
205 | struct packed_ref_store *refs = xcalloc(1, sizeof(*refs)); | |
e0cc8ac8 | 206 | struct ref_store *ref_store = (struct ref_store *)refs; |
99f0d97b | 207 | struct strbuf sb = STRBUF_INIT; |
67be7c5a | 208 | |
f9f7fd3b | 209 | base_ref_store_init(ref_store, repo, gitdir, &refs_be_packed); |
67be7c5a | 210 | refs->store_flags = store_flags; |
f9f7fd3b | 211 | |
99f0d97b HWN |
212 | strbuf_addf(&sb, "%s/packed-refs", gitdir); |
213 | refs->path = strbuf_detach(&sb, NULL); | |
fb9c2d27 | 214 | chdir_notify_reparent("packed-refs", &refs->path); |
e0cc8ac8 | 215 | return ref_store; |
67be7c5a MH |
216 | } |
217 | ||
e0cc8ac8 MH |
218 | /* |
219 | * Downcast `ref_store` to `packed_ref_store`. Die if `ref_store` is | |
220 | * not a `packed_ref_store`. Also die if `packed_ref_store` doesn't | |
221 | * support at least the flags specified in `required_flags`. `caller` | |
222 | * is used in any necessary error messages. | |
223 | */ | |
224 | static struct packed_ref_store *packed_downcast(struct ref_store *ref_store, | |
225 | unsigned int required_flags, | |
226 | const char *caller) | |
227 | { | |
228 | struct packed_ref_store *refs; | |
229 | ||
230 | if (ref_store->be != &refs_be_packed) | |
033abf97 | 231 | BUG("ref_store is type \"%s\" not \"packed\" in %s", |
e0cc8ac8 MH |
232 | ref_store->be->name, caller); |
233 | ||
234 | refs = (struct packed_ref_store *)ref_store; | |
235 | ||
236 | if ((refs->store_flags & required_flags) != required_flags) | |
033abf97 | 237 | BUG("unallowed operation (%s), requires %x, has %x\n", |
e0cc8ac8 MH |
238 | caller, required_flags, refs->store_flags); |
239 | ||
240 | return refs; | |
241 | } | |
242 | ||
cff28ca9 | 243 | static void clear_snapshot(struct packed_ref_store *refs) |
67be7c5a | 244 | { |
cff28ca9 MH |
245 | if (refs->snapshot) { |
246 | struct snapshot *snapshot = refs->snapshot; | |
67be7c5a | 247 | |
cff28ca9 MH |
248 | refs->snapshot = NULL; |
249 | release_snapshot(snapshot); | |
67be7c5a MH |
250 | } |
251 | } | |
252 | ||
735267aa MH |
253 | static NORETURN void die_unterminated_line(const char *path, |
254 | const char *p, size_t len) | |
67be7c5a | 255 | { |
735267aa MH |
256 | if (len < 80) |
257 | die("unterminated line in %s: %.*s", path, (int)len, p); | |
258 | else | |
259 | die("unterminated line in %s: %.75s...", path, p); | |
260 | } | |
67be7c5a | 261 | |
735267aa MH |
262 | static NORETURN void die_invalid_line(const char *path, |
263 | const char *p, size_t len) | |
264 | { | |
265 | const char *eol = memchr(p, '\n', len); | |
266 | ||
267 | if (!eol) | |
268 | die_unterminated_line(path, p, len); | |
269 | else if (eol - p < 80) | |
270 | die("unexpected line in %s: %.*s", path, (int)(eol - p), p); | |
271 | else | |
272 | die("unexpected line in %s: %.75s...", path, p); | |
273 | ||
274 | } | |
275 | ||
cff28ca9 | 276 | struct snapshot_record { |
02b920f3 MH |
277 | const char *start; |
278 | size_t len; | |
279 | }; | |
280 | ||
cff28ca9 | 281 | static int cmp_packed_ref_records(const void *v1, const void *v2) |
02b920f3 | 282 | { |
cff28ca9 | 283 | const struct snapshot_record *e1 = v1, *e2 = v2; |
49d16608 | 284 | const char *r1 = e1->start + the_hash_algo->hexsz + 1; |
285 | const char *r2 = e2->start + the_hash_algo->hexsz + 1; | |
02b920f3 MH |
286 | |
287 | while (1) { | |
288 | if (*r1 == '\n') | |
289 | return *r2 == '\n' ? 0 : -1; | |
290 | if (*r1 != *r2) { | |
291 | if (*r2 == '\n') | |
292 | return 1; | |
293 | else | |
294 | return (unsigned char)*r1 < (unsigned char)*r2 ? -1 : +1; | |
295 | } | |
296 | r1++; | |
297 | r2++; | |
67be7c5a MH |
298 | } |
299 | } | |
300 | ||
d1cf1551 | 301 | /* |
cff28ca9 MH |
302 | * Compare a snapshot record at `rec` to the specified NUL-terminated |
303 | * refname. | |
d1cf1551 | 304 | */ |
cff28ca9 | 305 | static int cmp_record_to_refname(const char *rec, const char *refname) |
d1cf1551 | 306 | { |
49d16608 | 307 | const char *r1 = rec + the_hash_algo->hexsz + 1; |
d1cf1551 MH |
308 | const char *r2 = refname; |
309 | ||
310 | while (1) { | |
311 | if (*r1 == '\n') | |
312 | return *r2 ? -1 : 0; | |
313 | if (!*r2) | |
314 | return 1; | |
315 | if (*r1 != *r2) | |
316 | return (unsigned char)*r1 < (unsigned char)*r2 ? -1 : +1; | |
317 | r1++; | |
318 | r2++; | |
319 | } | |
320 | } | |
67be7c5a MH |
321 | |
322 | /* | |
cff28ca9 MH |
323 | * `snapshot->buf` is not known to be sorted. Check whether it is, and |
324 | * if not, sort it into new memory and munmap/free the old storage. | |
67be7c5a | 325 | */ |
cff28ca9 | 326 | static void sort_snapshot(struct snapshot *snapshot) |
67be7c5a | 327 | { |
cff28ca9 | 328 | struct snapshot_record *records = NULL; |
02b920f3 MH |
329 | size_t alloc = 0, nr = 0; |
330 | int sorted = 1; | |
331 | const char *pos, *eof, *eol; | |
332 | size_t len, i; | |
333 | char *new_buffer, *dst; | |
67be7c5a | 334 | |
4a2854f7 | 335 | pos = snapshot->start; |
cff28ca9 | 336 | eof = snapshot->eof; |
67be7c5a | 337 | |
4a2854f7 | 338 | if (pos == eof) |
02b920f3 | 339 | return; |
67be7c5a | 340 | |
4a2854f7 MH |
341 | len = eof - pos; |
342 | ||
02b920f3 | 343 | /* |
cff28ca9 | 344 | * Initialize records based on a crude estimate of the number |
02b920f3 MH |
345 | * of references in the file (we'll grow it below if needed): |
346 | */ | |
cff28ca9 | 347 | ALLOC_GROW(records, len / 80 + 20, alloc); |
02b920f3 MH |
348 | |
349 | while (pos < eof) { | |
350 | eol = memchr(pos, '\n', eof - pos); | |
351 | if (!eol) | |
352 | /* The safety check should prevent this. */ | |
353 | BUG("unterminated line found in packed-refs"); | |
49d16608 | 354 | if (eol - pos < the_hash_algo->hexsz + 2) |
cff28ca9 | 355 | die_invalid_line(snapshot->refs->path, |
02b920f3 MH |
356 | pos, eof - pos); |
357 | eol++; | |
358 | if (eol < eof && *eol == '^') { | |
359 | /* | |
360 | * Keep any peeled line together with its | |
361 | * reference: | |
362 | */ | |
363 | const char *peeled_start = eol; | |
364 | ||
365 | eol = memchr(peeled_start, '\n', eof - peeled_start); | |
366 | if (!eol) | |
367 | /* The safety check should prevent this. */ | |
368 | BUG("unterminated peeled line found in packed-refs"); | |
369 | eol++; | |
370 | } | |
371 | ||
cff28ca9 MH |
372 | ALLOC_GROW(records, nr + 1, alloc); |
373 | records[nr].start = pos; | |
374 | records[nr].len = eol - pos; | |
02b920f3 MH |
375 | nr++; |
376 | ||
377 | if (sorted && | |
378 | nr > 1 && | |
cff28ca9 MH |
379 | cmp_packed_ref_records(&records[nr - 2], |
380 | &records[nr - 1]) >= 0) | |
02b920f3 | 381 | sorted = 0; |
67be7c5a | 382 | |
02b920f3 MH |
383 | pos = eol; |
384 | } | |
385 | ||
386 | if (sorted) | |
387 | goto cleanup; | |
388 | ||
cff28ca9 MH |
389 | /* We need to sort the memory. First we sort the records array: */ |
390 | QSORT(records, nr, cmp_packed_ref_records); | |
02b920f3 MH |
391 | |
392 | /* | |
393 | * Allocate a new chunk of memory, and copy the old memory to | |
cff28ca9 | 394 | * the new in the order indicated by `records` (not bothering |
02b920f3 MH |
395 | * with the header line): |
396 | */ | |
397 | new_buffer = xmalloc(len); | |
398 | for (dst = new_buffer, i = 0; i < nr; i++) { | |
cff28ca9 MH |
399 | memcpy(dst, records[i].start, records[i].len); |
400 | dst += records[i].len; | |
02b920f3 MH |
401 | } |
402 | ||
403 | /* | |
404 | * Now munmap the old buffer and use the sorted buffer in its | |
405 | * place: | |
406 | */ | |
cff28ca9 | 407 | clear_snapshot_buffer(snapshot); |
4a2854f7 | 408 | snapshot->buf = snapshot->start = new_buffer; |
cff28ca9 | 409 | snapshot->eof = new_buffer + len; |
02b920f3 MH |
410 | |
411 | cleanup: | |
cff28ca9 | 412 | free(records); |
67be7c5a MH |
413 | } |
414 | ||
415 | /* | |
02b920f3 MH |
416 | * Return a pointer to the start of the record that contains the |
417 | * character `*p` (which must be within the buffer). If no other | |
418 | * record start is found, return `buf`. | |
419 | */ | |
420 | static const char *find_start_of_record(const char *buf, const char *p) | |
421 | { | |
422 | while (p > buf && (p[-1] != '\n' || p[0] == '^')) | |
423 | p--; | |
424 | return p; | |
425 | } | |
426 | ||
d1cf1551 MH |
427 | /* |
428 | * Return a pointer to the start of the record following the record | |
429 | * that contains `*p`. If none is found before `end`, return `end`. | |
430 | */ | |
431 | static const char *find_end_of_record(const char *p, const char *end) | |
432 | { | |
433 | while (++p < end && (p[-1] != '\n' || p[0] == '^')) | |
434 | ; | |
435 | return p; | |
436 | } | |
437 | ||
02b920f3 MH |
438 | /* |
439 | * We want to be able to compare mmapped reference records quickly, | |
440 | * without totally parsing them. We can do so because the records are | |
441 | * LF-terminated, and the refname should start exactly (GIT_SHA1_HEXSZ | |
442 | * + 1) bytes past the beginning of the record. | |
443 | * | |
444 | * But what if the `packed-refs` file contains garbage? We're willing | |
445 | * to tolerate not detecting the problem, as long as we don't produce | |
446 | * totally garbled output (we can't afford to check the integrity of | |
447 | * the whole file during every Git invocation). But we do want to be | |
448 | * sure that we never read past the end of the buffer in memory and | |
449 | * perform an illegal memory access. | |
450 | * | |
451 | * Guarantee that minimum level of safety by verifying that the last | |
452 | * record in the file is LF-terminated, and that it has at least | |
453 | * (GIT_SHA1_HEXSZ + 1) characters before the LF. Die if either of | |
454 | * these checks fails. | |
455 | */ | |
cff28ca9 | 456 | static void verify_buffer_safe(struct snapshot *snapshot) |
02b920f3 | 457 | { |
4a2854f7 | 458 | const char *start = snapshot->start; |
cff28ca9 | 459 | const char *eof = snapshot->eof; |
02b920f3 MH |
460 | const char *last_line; |
461 | ||
4a2854f7 | 462 | if (start == eof) |
02b920f3 MH |
463 | return; |
464 | ||
4a2854f7 | 465 | last_line = find_start_of_record(start, eof - 1); |
49d16608 | 466 | if (*(eof - 1) != '\n' || eof - last_line < the_hash_algo->hexsz + 2) |
cff28ca9 | 467 | die_invalid_line(snapshot->refs->path, |
02b920f3 MH |
468 | last_line, eof - last_line); |
469 | } | |
470 | ||
ba41a8b6 KG |
471 | #define SMALL_FILE_SIZE (32*1024) |
472 | ||
5b633610 MH |
473 | /* |
474 | * Depending on `mmap_strategy`, either mmap or read the contents of | |
cff28ca9 | 475 | * the `packed-refs` file into the snapshot. Return 1 if the file |
01caf20d MH |
476 | * existed and was read, or 0 if the file was absent or empty. Die on |
477 | * errors. | |
5b633610 | 478 | */ |
cff28ca9 | 479 | static int load_contents(struct snapshot *snapshot) |
5b633610 MH |
480 | { |
481 | int fd; | |
482 | struct stat st; | |
483 | size_t size; | |
484 | ssize_t bytes_read; | |
485 | ||
cff28ca9 | 486 | fd = open(snapshot->refs->path, O_RDONLY); |
5b633610 MH |
487 | if (fd < 0) { |
488 | if (errno == ENOENT) { | |
489 | /* | |
490 | * This is OK; it just means that no | |
491 | * "packed-refs" file has been written yet, | |
492 | * which is equivalent to it being empty, | |
493 | * which is its state when initialized with | |
494 | * zeros. | |
495 | */ | |
496 | return 0; | |
497 | } else { | |
cff28ca9 | 498 | die_errno("couldn't read %s", snapshot->refs->path); |
5b633610 MH |
499 | } |
500 | } | |
501 | ||
cff28ca9 | 502 | stat_validity_update(&snapshot->validity, fd); |
5b633610 MH |
503 | |
504 | if (fstat(fd, &st) < 0) | |
cff28ca9 | 505 | die_errno("couldn't stat %s", snapshot->refs->path); |
5b633610 MH |
506 | size = xsize_t(st.st_size); |
507 | ||
01caf20d | 508 | if (!size) { |
09427e83 | 509 | close(fd); |
01caf20d | 510 | return 0; |
ba41a8b6 | 511 | } else if (mmap_strategy == MMAP_NONE || size <= SMALL_FILE_SIZE) { |
cff28ca9 MH |
512 | snapshot->buf = xmalloc(size); |
513 | bytes_read = read_in_full(fd, snapshot->buf, size); | |
5b633610 | 514 | if (bytes_read < 0 || bytes_read != size) |
cff28ca9 | 515 | die_errno("couldn't read %s", snapshot->refs->path); |
cff28ca9 | 516 | snapshot->mmapped = 0; |
01caf20d | 517 | } else { |
cff28ca9 | 518 | snapshot->buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0); |
cff28ca9 | 519 | snapshot->mmapped = 1; |
5b633610 MH |
520 | } |
521 | close(fd); | |
522 | ||
4a2854f7 MH |
523 | snapshot->start = snapshot->buf; |
524 | snapshot->eof = snapshot->buf + size; | |
525 | ||
5b633610 MH |
526 | return 1; |
527 | } | |
528 | ||
d1cf1551 | 529 | /* |
cff28ca9 | 530 | * Find the place in `snapshot->buf` where the start of the record for |
d1cf1551 MH |
531 | * `refname` starts. If `mustexist` is true and the reference doesn't |
532 | * exist, then return NULL. If `mustexist` is false and the reference | |
533 | * doesn't exist, then return the point where that reference would be | |
4a14f8d0 MH |
534 | * inserted, or `snapshot->eof` (which might be NULL) if it would be |
535 | * inserted at the end of the file. In the latter mode, `refname` | |
536 | * doesn't have to be a proper reference name; for example, one could | |
537 | * search for "refs/replace/" to find the start of any replace | |
538 | * references. | |
d1cf1551 | 539 | * |
cff28ca9 MH |
540 | * The record is sought using a binary search, so `snapshot->buf` must |
541 | * be sorted. | |
d1cf1551 | 542 | */ |
cff28ca9 | 543 | static const char *find_reference_location(struct snapshot *snapshot, |
d1cf1551 MH |
544 | const char *refname, int mustexist) |
545 | { | |
546 | /* | |
547 | * This is not *quite* a garden-variety binary search, because | |
548 | * the data we're searching is made up of records, and we | |
549 | * always need to find the beginning of a record to do a | |
550 | * comparison. A "record" here is one line for the reference | |
551 | * itself and zero or one peel lines that start with '^'. Our | |
552 | * loop invariant is described in the next two comments. | |
553 | */ | |
554 | ||
555 | /* | |
556 | * A pointer to the character at the start of a record whose | |
557 | * preceding records all have reference names that come | |
558 | * *before* `refname`. | |
559 | */ | |
4a2854f7 | 560 | const char *lo = snapshot->start; |
d1cf1551 MH |
561 | |
562 | /* | |
563 | * A pointer to a the first character of a record whose | |
564 | * reference name comes *after* `refname`. | |
565 | */ | |
cff28ca9 | 566 | const char *hi = snapshot->eof; |
d1cf1551 | 567 | |
4a14f8d0 | 568 | while (lo != hi) { |
d1cf1551 MH |
569 | const char *mid, *rec; |
570 | int cmp; | |
571 | ||
572 | mid = lo + (hi - lo) / 2; | |
573 | rec = find_start_of_record(lo, mid); | |
cff28ca9 | 574 | cmp = cmp_record_to_refname(rec, refname); |
d1cf1551 MH |
575 | if (cmp < 0) { |
576 | lo = find_end_of_record(mid, hi); | |
577 | } else if (cmp > 0) { | |
578 | hi = rec; | |
579 | } else { | |
580 | return rec; | |
581 | } | |
582 | } | |
583 | ||
584 | if (mustexist) | |
585 | return NULL; | |
586 | else | |
587 | return lo; | |
588 | } | |
589 | ||
67be7c5a | 590 | /* |
cff28ca9 MH |
591 | * Create a newly-allocated `snapshot` of the `packed-refs` file in |
592 | * its current state and return it. The return value will already have | |
593 | * its reference count incremented. | |
67be7c5a MH |
594 | * |
595 | * A comment line of the form "# pack-refs with: " may contain zero or | |
596 | * more traits. We interpret the traits as follows: | |
597 | * | |
02b920f3 | 598 | * Neither `peeled` nor `fully-peeled`: |
67be7c5a MH |
599 | * |
600 | * Probably no references are peeled. But if the file contains a | |
601 | * peeled value for a reference, we will use it. | |
602 | * | |
02b920f3 | 603 | * `peeled`: |
67be7c5a MH |
604 | * |
605 | * References under "refs/tags/", if they *can* be peeled, *are* | |
606 | * peeled in this file. References outside of "refs/tags/" are | |
607 | * probably not peeled even if they could have been, but if we find | |
608 | * a peeled value for such a reference we will use it. | |
609 | * | |
02b920f3 | 610 | * `fully-peeled`: |
67be7c5a MH |
611 | * |
612 | * All references in the file that can be peeled are peeled. | |
613 | * Inversely (and this is more important), any references in the | |
614 | * file for which no peeled value is recorded is not peelable. This | |
615 | * trait should typically be written alongside "peeled" for | |
616 | * compatibility with older clients, but we do not require it | |
617 | * (i.e., "peeled" is a no-op if "fully-peeled" is set). | |
02b920f3 MH |
618 | * |
619 | * `sorted`: | |
620 | * | |
621 | * The references in this file are known to be sorted by refname. | |
67be7c5a | 622 | */ |
cff28ca9 | 623 | static struct snapshot *create_snapshot(struct packed_ref_store *refs) |
67be7c5a | 624 | { |
cff28ca9 | 625 | struct snapshot *snapshot = xcalloc(1, sizeof(*snapshot)); |
02b920f3 | 626 | int sorted = 0; |
67be7c5a | 627 | |
cff28ca9 MH |
628 | snapshot->refs = refs; |
629 | acquire_snapshot(snapshot); | |
630 | snapshot->peeled = PEELED_NONE; | |
67be7c5a | 631 | |
cff28ca9 MH |
632 | if (!load_contents(snapshot)) |
633 | return snapshot; | |
67be7c5a | 634 | |
36f23534 | 635 | /* If the file has a header line, process it: */ |
cff28ca9 | 636 | if (snapshot->buf < snapshot->eof && *snapshot->buf == '#') { |
27a41841 | 637 | char *tmp, *p, *eol; |
a8811695 | 638 | struct string_list traits = STRING_LIST_INIT_NODUP; |
9308b7f3 | 639 | |
cff28ca9 MH |
640 | eol = memchr(snapshot->buf, '\n', |
641 | snapshot->eof - snapshot->buf); | |
36f23534 | 642 | if (!eol) |
5b633610 | 643 | die_unterminated_line(refs->path, |
cff28ca9 MH |
644 | snapshot->buf, |
645 | snapshot->eof - snapshot->buf); | |
67be7c5a | 646 | |
27a41841 | 647 | tmp = xmemdupz(snapshot->buf, eol - snapshot->buf); |
67be7c5a | 648 | |
27a41841 | 649 | if (!skip_prefix(tmp, "# pack-refs with:", (const char **)&p)) |
5b633610 | 650 | die_invalid_line(refs->path, |
cff28ca9 MH |
651 | snapshot->buf, |
652 | snapshot->eof - snapshot->buf); | |
36f23534 | 653 | |
a8811695 MH |
654 | string_list_split_in_place(&traits, p, ' ', -1); |
655 | ||
656 | if (unsorted_string_list_has_string(&traits, "fully-peeled")) | |
cff28ca9 | 657 | snapshot->peeled = PEELED_FULLY; |
a8811695 | 658 | else if (unsorted_string_list_has_string(&traits, "peeled")) |
cff28ca9 | 659 | snapshot->peeled = PEELED_TAGS; |
02b920f3 MH |
660 | |
661 | sorted = unsorted_string_list_has_string(&traits, "sorted"); | |
662 | ||
36f23534 MH |
663 | /* perhaps other traits later as well */ |
664 | ||
665 | /* The "+ 1" is for the LF character. */ | |
4a2854f7 | 666 | snapshot->start = eol + 1; |
a8811695 MH |
667 | |
668 | string_list_clear(&traits, 0); | |
27a41841 | 669 | free(tmp); |
67be7c5a MH |
670 | } |
671 | ||
cff28ca9 | 672 | verify_buffer_safe(snapshot); |
67be7c5a | 673 | |
02b920f3 | 674 | if (!sorted) { |
cff28ca9 | 675 | sort_snapshot(snapshot); |
02b920f3 MH |
676 | |
677 | /* | |
678 | * Reordering the records might have moved a short one | |
679 | * to the end of the buffer, so verify the buffer's | |
680 | * safety again: | |
681 | */ | |
cff28ca9 | 682 | verify_buffer_safe(snapshot); |
02b920f3 MH |
683 | } |
684 | ||
cff28ca9 | 685 | if (mmap_strategy != MMAP_OK && snapshot->mmapped) { |
02b920f3 MH |
686 | /* |
687 | * We don't want to leave the file mmapped, so we are | |
688 | * forced to make a copy now: | |
689 | */ | |
4a2854f7 | 690 | size_t size = snapshot->eof - snapshot->start; |
02b920f3 MH |
691 | char *buf_copy = xmalloc(size); |
692 | ||
4a2854f7 | 693 | memcpy(buf_copy, snapshot->start, size); |
cff28ca9 | 694 | clear_snapshot_buffer(snapshot); |
4a2854f7 | 695 | snapshot->buf = snapshot->start = buf_copy; |
cff28ca9 | 696 | snapshot->eof = buf_copy + size; |
02b920f3 MH |
697 | } |
698 | ||
cff28ca9 | 699 | return snapshot; |
67be7c5a MH |
700 | } |
701 | ||
702 | /* | |
cff28ca9 MH |
703 | * Check that `refs->snapshot` (if present) still reflects the |
704 | * contents of the `packed-refs` file. If not, clear the snapshot. | |
67be7c5a | 705 | */ |
cff28ca9 | 706 | static void validate_snapshot(struct packed_ref_store *refs) |
67be7c5a | 707 | { |
cff28ca9 MH |
708 | if (refs->snapshot && |
709 | !stat_validity_check(&refs->snapshot->validity, refs->path)) | |
710 | clear_snapshot(refs); | |
67be7c5a MH |
711 | } |
712 | ||
713 | /* | |
cff28ca9 MH |
714 | * Get the `snapshot` for the specified packed_ref_store, creating and |
715 | * populating it if it hasn't been read before or if the file has been | |
716 | * changed (according to its `validity` field) since it was last read. | |
717 | * On the other hand, if we hold the lock, then assume that the file | |
718 | * hasn't been changed out from under us, so skip the extra `stat()` | |
719 | * call in `stat_validity_check()`. This function does *not* increase | |
720 | * the snapshot's reference count on behalf of the caller. | |
67be7c5a | 721 | */ |
cff28ca9 | 722 | static struct snapshot *get_snapshot(struct packed_ref_store *refs) |
67be7c5a MH |
723 | { |
724 | if (!is_lock_file_locked(&refs->lock)) | |
cff28ca9 | 725 | validate_snapshot(refs); |
67be7c5a | 726 | |
cff28ca9 MH |
727 | if (!refs->snapshot) |
728 | refs->snapshot = create_snapshot(refs); | |
67be7c5a | 729 | |
cff28ca9 | 730 | return refs->snapshot; |
67be7c5a MH |
731 | } |
732 | ||
5b12e16b | 733 | static int packed_read_raw_ref(struct ref_store *ref_store, const char *refname, |
5cf88fd8 | 734 | struct object_id *oid, struct strbuf *referent UNUSED, |
5b12e16b | 735 | unsigned int *type, int *failure_errno) |
67be7c5a | 736 | { |
e0cc8ac8 MH |
737 | struct packed_ref_store *refs = |
738 | packed_downcast(ref_store, REF_STORE_READ, "read_raw_ref"); | |
cff28ca9 | 739 | struct snapshot *snapshot = get_snapshot(refs); |
f3987ab3 | 740 | const char *rec; |
67be7c5a MH |
741 | |
742 | *type = 0; | |
743 | ||
cff28ca9 | 744 | rec = find_reference_location(snapshot, refname, 1); |
f3987ab3 MH |
745 | |
746 | if (!rec) { | |
747 | /* refname is not a packed reference. */ | |
5b12e16b | 748 | *failure_errno = ENOENT; |
67be7c5a MH |
749 | return -1; |
750 | } | |
751 | ||
99afe91a | 752 | if (get_oid_hex(rec, oid)) |
cff28ca9 | 753 | die_invalid_line(refs->path, rec, snapshot->eof - rec); |
f3987ab3 | 754 | |
67be7c5a MH |
755 | *type = REF_ISPACKED; |
756 | return 0; | |
757 | } | |
758 | ||
523ee2d7 MH |
759 | /* |
760 | * This value is set in `base.flags` if the peeled value of the | |
761 | * current reference is known. In that case, `peeled` contains the | |
78fb4579 | 762 | * correct peeled value for the reference, which might be `null_oid` |
523ee2d7 MH |
763 | * if the reference is not a tag or if it is broken. |
764 | */ | |
765 | #define REF_KNOWS_PEELED 0x40 | |
67be7c5a | 766 | |
523ee2d7 | 767 | /* |
cff28ca9 | 768 | * An iterator over a snapshot of a `packed-refs` file. |
523ee2d7 | 769 | */ |
67be7c5a MH |
770 | struct packed_ref_iterator { |
771 | struct ref_iterator base; | |
772 | ||
cff28ca9 | 773 | struct snapshot *snapshot; |
523ee2d7 | 774 | |
cff28ca9 | 775 | /* The current position in the snapshot's buffer: */ |
523ee2d7 MH |
776 | const char *pos; |
777 | ||
cff28ca9 | 778 | /* The end of the part of the buffer that will be iterated over: */ |
523ee2d7 MH |
779 | const char *eof; |
780 | ||
cff28ca9 | 781 | /* Scratch space for current values: */ |
523ee2d7 | 782 | struct object_id oid, peeled; |
523ee2d7 MH |
783 | struct strbuf refname_buf; |
784 | ||
9bc45a28 | 785 | struct repository *repo; |
67be7c5a MH |
786 | unsigned int flags; |
787 | }; | |
788 | ||
cff28ca9 MH |
789 | /* |
790 | * Move the iterator to the next record in the snapshot, without | |
791 | * respect for whether the record is actually required by the current | |
792 | * iteration. Adjust the fields in `iter` and return `ITER_OK` or | |
793 | * `ITER_DONE`. This function does not free the iterator in the case | |
794 | * of `ITER_DONE`. | |
795 | */ | |
523ee2d7 MH |
796 | static int next_record(struct packed_ref_iterator *iter) |
797 | { | |
798 | const char *p = iter->pos, *eol; | |
799 | ||
800 | strbuf_reset(&iter->refname_buf); | |
801 | ||
802 | if (iter->pos == iter->eof) | |
803 | return ITER_DONE; | |
804 | ||
805 | iter->base.flags = REF_ISPACKED; | |
806 | ||
49d16608 | 807 | if (iter->eof - p < the_hash_algo->hexsz + 2 || |
523ee2d7 MH |
808 | parse_oid_hex(p, &iter->oid, &p) || |
809 | !isspace(*p++)) | |
cff28ca9 | 810 | die_invalid_line(iter->snapshot->refs->path, |
523ee2d7 MH |
811 | iter->pos, iter->eof - iter->pos); |
812 | ||
813 | eol = memchr(p, '\n', iter->eof - p); | |
814 | if (!eol) | |
cff28ca9 | 815 | die_unterminated_line(iter->snapshot->refs->path, |
523ee2d7 MH |
816 | iter->pos, iter->eof - iter->pos); |
817 | ||
818 | strbuf_add(&iter->refname_buf, p, eol - p); | |
819 | iter->base.refname = iter->refname_buf.buf; | |
820 | ||
821 | if (check_refname_format(iter->base.refname, REFNAME_ALLOW_ONELEVEL)) { | |
822 | if (!refname_is_safe(iter->base.refname)) | |
823 | die("packed refname is dangerous: %s", | |
824 | iter->base.refname); | |
825 | oidclr(&iter->oid); | |
826 | iter->base.flags |= REF_BAD_NAME | REF_ISBROKEN; | |
827 | } | |
cff28ca9 MH |
828 | if (iter->snapshot->peeled == PEELED_FULLY || |
829 | (iter->snapshot->peeled == PEELED_TAGS && | |
523ee2d7 MH |
830 | starts_with(iter->base.refname, "refs/tags/"))) |
831 | iter->base.flags |= REF_KNOWS_PEELED; | |
832 | ||
833 | iter->pos = eol + 1; | |
834 | ||
835 | if (iter->pos < iter->eof && *iter->pos == '^') { | |
836 | p = iter->pos + 1; | |
49d16608 | 837 | if (iter->eof - p < the_hash_algo->hexsz + 1 || |
523ee2d7 MH |
838 | parse_oid_hex(p, &iter->peeled, &p) || |
839 | *p++ != '\n') | |
cff28ca9 | 840 | die_invalid_line(iter->snapshot->refs->path, |
523ee2d7 MH |
841 | iter->pos, iter->eof - iter->pos); |
842 | iter->pos = p; | |
843 | ||
844 | /* | |
845 | * Regardless of what the file header said, we | |
846 | * definitely know the value of *this* reference. But | |
847 | * we suppress it if the reference is broken: | |
848 | */ | |
849 | if ((iter->base.flags & REF_ISBROKEN)) { | |
850 | oidclr(&iter->peeled); | |
851 | iter->base.flags &= ~REF_KNOWS_PEELED; | |
852 | } else { | |
853 | iter->base.flags |= REF_KNOWS_PEELED; | |
854 | } | |
855 | } else { | |
856 | oidclr(&iter->peeled); | |
857 | } | |
858 | ||
859 | return ITER_OK; | |
860 | } | |
861 | ||
67be7c5a MH |
862 | static int packed_ref_iterator_advance(struct ref_iterator *ref_iterator) |
863 | { | |
864 | struct packed_ref_iterator *iter = | |
865 | (struct packed_ref_iterator *)ref_iterator; | |
866 | int ok; | |
867 | ||
523ee2d7 | 868 | while ((ok = next_record(iter)) == ITER_OK) { |
67be7c5a | 869 | if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY && |
71e54734 | 870 | !is_per_worktree_ref(iter->base.refname)) |
67be7c5a MH |
871 | continue; |
872 | ||
873 | if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) && | |
9bc45a28 JT |
874 | !ref_resolves_to_object(iter->base.refname, iter->repo, |
875 | &iter->oid, iter->flags)) | |
67be7c5a MH |
876 | continue; |
877 | ||
67be7c5a MH |
878 | return ITER_OK; |
879 | } | |
880 | ||
67be7c5a MH |
881 | if (ref_iterator_abort(ref_iterator) != ITER_DONE) |
882 | ok = ITER_ERROR; | |
883 | ||
884 | return ok; | |
885 | } | |
886 | ||
887 | static int packed_ref_iterator_peel(struct ref_iterator *ref_iterator, | |
888 | struct object_id *peeled) | |
889 | { | |
890 | struct packed_ref_iterator *iter = | |
891 | (struct packed_ref_iterator *)ref_iterator; | |
892 | ||
8788195c JT |
893 | if (iter->repo != the_repository) |
894 | BUG("peeling for non-the_repository is not supported"); | |
895 | ||
523ee2d7 MH |
896 | if ((iter->base.flags & REF_KNOWS_PEELED)) { |
897 | oidcpy(peeled, &iter->peeled); | |
898 | return is_null_oid(&iter->peeled) ? -1 : 0; | |
899 | } else if ((iter->base.flags & (REF_ISBROKEN | REF_ISSYMREF))) { | |
900 | return -1; | |
901 | } else { | |
617480d7 | 902 | return peel_object(&iter->oid, peeled) ? -1 : 0; |
523ee2d7 | 903 | } |
67be7c5a MH |
904 | } |
905 | ||
906 | static int packed_ref_iterator_abort(struct ref_iterator *ref_iterator) | |
907 | { | |
908 | struct packed_ref_iterator *iter = | |
909 | (struct packed_ref_iterator *)ref_iterator; | |
910 | int ok = ITER_DONE; | |
911 | ||
523ee2d7 | 912 | strbuf_release(&iter->refname_buf); |
cff28ca9 | 913 | release_snapshot(iter->snapshot); |
67be7c5a MH |
914 | base_ref_iterator_free(ref_iterator); |
915 | return ok; | |
916 | } | |
917 | ||
918 | static struct ref_iterator_vtable packed_ref_iterator_vtable = { | |
e2f8acb6 ÆAB |
919 | .advance = packed_ref_iterator_advance, |
920 | .peel = packed_ref_iterator_peel, | |
921 | .abort = packed_ref_iterator_abort | |
67be7c5a MH |
922 | }; |
923 | ||
e0cc8ac8 MH |
924 | static struct ref_iterator *packed_ref_iterator_begin( |
925 | struct ref_store *ref_store, | |
67be7c5a MH |
926 | const char *prefix, unsigned int flags) |
927 | { | |
e0cc8ac8 | 928 | struct packed_ref_store *refs; |
cff28ca9 | 929 | struct snapshot *snapshot; |
d1cf1551 | 930 | const char *start; |
67be7c5a MH |
931 | struct packed_ref_iterator *iter; |
932 | struct ref_iterator *ref_iterator; | |
e0cc8ac8 MH |
933 | unsigned int required_flags = REF_STORE_READ; |
934 | ||
935 | if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) | |
936 | required_flags |= REF_STORE_ODB; | |
937 | refs = packed_downcast(ref_store, required_flags, "ref_iterator_begin"); | |
67be7c5a | 938 | |
cff28ca9 MH |
939 | /* |
940 | * Note that `get_snapshot()` internally checks whether the | |
941 | * snapshot is up to date with what is on disk, and re-reads | |
942 | * it if not. | |
943 | */ | |
944 | snapshot = get_snapshot(refs); | |
523ee2d7 | 945 | |
f3424297 MH |
946 | if (prefix && *prefix) |
947 | start = find_reference_location(snapshot, prefix, 0); | |
948 | else | |
949 | start = snapshot->start; | |
950 | ||
951 | if (start == snapshot->eof) | |
523ee2d7 MH |
952 | return empty_ref_iterator_begin(); |
953 | ||
ca56dadb | 954 | CALLOC_ARRAY(iter, 1); |
67be7c5a | 955 | ref_iterator = &iter->base; |
8738a8a4 | 956 | base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable, 1); |
67be7c5a | 957 | |
cff28ca9 MH |
958 | iter->snapshot = snapshot; |
959 | acquire_snapshot(snapshot); | |
67be7c5a | 960 | |
523ee2d7 | 961 | iter->pos = start; |
cff28ca9 | 962 | iter->eof = snapshot->eof; |
523ee2d7 MH |
963 | strbuf_init(&iter->refname_buf, 0); |
964 | ||
965 | iter->base.oid = &iter->oid; | |
67be7c5a | 966 | |
9bc45a28 | 967 | iter->repo = ref_store->repo; |
67be7c5a MH |
968 | iter->flags = flags; |
969 | ||
d1cf1551 MH |
970 | if (prefix && *prefix) |
971 | /* Stop iteration after we've gone *past* prefix: */ | |
972 | ref_iterator = prefix_ref_iterator_begin(ref_iterator, prefix, 0); | |
973 | ||
67be7c5a MH |
974 | return ref_iterator; |
975 | } | |
976 | ||
977 | /* | |
978 | * Write an entry to the packed-refs file for the specified refname. | |
3478983b MH |
979 | * If peeled is non-NULL, write it as the entry's peeled value. On |
980 | * error, return a nonzero value and leave errno set at the value left | |
981 | * by the failing call to `fprintf()`. | |
67be7c5a | 982 | */ |
3478983b | 983 | static int write_packed_entry(FILE *fh, const char *refname, |
41701882 MH |
984 | const struct object_id *oid, |
985 | const struct object_id *peeled) | |
67be7c5a | 986 | { |
41701882 MH |
987 | if (fprintf(fh, "%s %s\n", oid_to_hex(oid), refname) < 0 || |
988 | (peeled && fprintf(fh, "^%s\n", oid_to_hex(peeled)) < 0)) | |
3478983b MH |
989 | return -1; |
990 | ||
991 | return 0; | |
67be7c5a MH |
992 | } |
993 | ||
c8bed835 | 994 | int packed_refs_lock(struct ref_store *ref_store, int flags, struct strbuf *err) |
67be7c5a | 995 | { |
e0cc8ac8 MH |
996 | struct packed_ref_store *refs = |
997 | packed_downcast(ref_store, REF_STORE_WRITE | REF_STORE_MAIN, | |
b7de57d8 | 998 | "packed_refs_lock"); |
67be7c5a MH |
999 | static int timeout_configured = 0; |
1000 | static int timeout_value = 1000; | |
67be7c5a | 1001 | |
67be7c5a MH |
1002 | if (!timeout_configured) { |
1003 | git_config_get_int("core.packedrefstimeout", &timeout_value); | |
1004 | timeout_configured = 1; | |
1005 | } | |
1006 | ||
42dfa7ec MH |
1007 | /* |
1008 | * Note that we close the lockfile immediately because we | |
1009 | * don't write new content to it, but rather to a separate | |
1010 | * tempfile. | |
1011 | */ | |
67be7c5a MH |
1012 | if (hold_lock_file_for_update_timeout( |
1013 | &refs->lock, | |
1014 | refs->path, | |
c8bed835 MH |
1015 | flags, timeout_value) < 0) { |
1016 | unable_to_lock_message(refs->path, errno, err); | |
1017 | return -1; | |
1018 | } | |
1019 | ||
83a3069a | 1020 | if (close_lock_file_gently(&refs->lock)) { |
c8bed835 | 1021 | strbuf_addf(err, "unable to close %s: %s", refs->path, strerror(errno)); |
83a3069a | 1022 | rollback_lock_file(&refs->lock); |
67be7c5a | 1023 | return -1; |
c8bed835 | 1024 | } |
67be7c5a MH |
1025 | |
1026 | /* | |
a613d4f8 SC |
1027 | * There is a stat-validity problem might cause `update-ref -d` |
1028 | * lost the newly commit of a ref, because a new `packed-refs` | |
1029 | * file might has the same on-disk file attributes such as | |
1030 | * timestamp, file size and inode value, but has a changed | |
1031 | * ref value. | |
1032 | * | |
1033 | * This could happen with a very small chance when | |
1034 | * `update-ref -d` is called and at the same time another | |
1035 | * `pack-refs --all` process is running. | |
1036 | * | |
1037 | * Now that we hold the `packed-refs` lock, it is important | |
1038 | * to make sure we could read the latest version of | |
1039 | * `packed-refs` file no matter we have just mmap it or not. | |
1040 | * So what need to do is clear the snapshot if we hold it | |
1041 | * already. | |
67be7c5a | 1042 | */ |
a613d4f8 | 1043 | clear_snapshot(refs); |
67be7c5a | 1044 | |
39c8df0c MH |
1045 | /* |
1046 | * Now make sure that the packed-refs file as it exists in the | |
cff28ca9 | 1047 | * locked state is loaded into the snapshot: |
39c8df0c | 1048 | */ |
cff28ca9 | 1049 | get_snapshot(refs); |
67be7c5a MH |
1050 | return 0; |
1051 | } | |
1052 | ||
49aebcf4 MH |
1053 | void packed_refs_unlock(struct ref_store *ref_store) |
1054 | { | |
1055 | struct packed_ref_store *refs = packed_downcast( | |
1056 | ref_store, | |
1057 | REF_STORE_READ | REF_STORE_WRITE, | |
1058 | "packed_refs_unlock"); | |
1059 | ||
1060 | if (!is_lock_file_locked(&refs->lock)) | |
033abf97 | 1061 | BUG("packed_refs_unlock() called when not locked"); |
49aebcf4 | 1062 | rollback_lock_file(&refs->lock); |
49aebcf4 MH |
1063 | } |
1064 | ||
1065 | int packed_refs_is_locked(struct ref_store *ref_store) | |
1066 | { | |
1067 | struct packed_ref_store *refs = packed_downcast( | |
1068 | ref_store, | |
1069 | REF_STORE_READ | REF_STORE_WRITE, | |
1070 | "packed_refs_is_locked"); | |
1071 | ||
1072 | return is_lock_file_locked(&refs->lock); | |
1073 | } | |
1074 | ||
67be7c5a | 1075 | /* |
cff28ca9 MH |
1076 | * The packed-refs header line that we write out. Perhaps other traits |
1077 | * will be added later. | |
a8811695 MH |
1078 | * |
1079 | * Note that earlier versions of Git used to parse these traits by | |
1080 | * looking for " trait " in the line. For this reason, the space after | |
1081 | * the colon and the trailing space are required. | |
67be7c5a MH |
1082 | */ |
1083 | static const char PACKED_REFS_HEADER[] = | |
02b920f3 | 1084 | "# pack-refs with: peeled fully-peeled sorted \n"; |
67be7c5a | 1085 | |
5cf88fd8 ÆAB |
1086 | static int packed_init_db(struct ref_store *ref_store UNUSED, |
1087 | struct strbuf *err UNUSED) | |
e0cc8ac8 MH |
1088 | { |
1089 | /* Nothing to do. */ | |
1090 | return 0; | |
1091 | } | |
1092 | ||
67be7c5a | 1093 | /* |
cff28ca9 MH |
1094 | * Write the packed refs from the current snapshot to the packed-refs |
1095 | * tempfile, incorporating any changes from `updates`. `updates` must | |
1096 | * be a sorted string list whose keys are the refnames and whose util | |
2775d872 MH |
1097 | * values are `struct ref_update *`. On error, rollback the tempfile, |
1098 | * write an error message to `err`, and return a nonzero value. | |
1099 | * | |
1100 | * The packfile must be locked before calling this function and will | |
1101 | * remain locked when it is done. | |
67be7c5a | 1102 | */ |
2775d872 MH |
1103 | static int write_with_updates(struct packed_ref_store *refs, |
1104 | struct string_list *updates, | |
1105 | struct strbuf *err) | |
67be7c5a | 1106 | { |
2775d872 MH |
1107 | struct ref_iterator *iter = NULL; |
1108 | size_t i; | |
3478983b | 1109 | int ok; |
67be7c5a | 1110 | FILE *out; |
2775d872 | 1111 | struct strbuf sb = STRBUF_INIT; |
198b808e | 1112 | char *packed_refs_path; |
67be7c5a | 1113 | |
67be7c5a | 1114 | if (!is_lock_file_locked(&refs->lock)) |
033abf97 | 1115 | BUG("write_with_updates() called while unlocked"); |
67be7c5a | 1116 | |
198b808e MH |
1117 | /* |
1118 | * If packed-refs is a symlink, we want to overwrite the | |
1119 | * symlinked-to file, not the symlink itself. Also, put the | |
1120 | * staging file next to it: | |
1121 | */ | |
1122 | packed_refs_path = get_locked_file_path(&refs->lock); | |
1123 | strbuf_addf(&sb, "%s.new", packed_refs_path); | |
2775d872 | 1124 | free(packed_refs_path); |
076aa2cb JK |
1125 | refs->tempfile = create_tempfile(sb.buf); |
1126 | if (!refs->tempfile) { | |
42dfa7ec MH |
1127 | strbuf_addf(err, "unable to create file %s: %s", |
1128 | sb.buf, strerror(errno)); | |
1129 | strbuf_release(&sb); | |
2775d872 | 1130 | return -1; |
42dfa7ec MH |
1131 | } |
1132 | strbuf_release(&sb); | |
1133 | ||
076aa2cb | 1134 | out = fdopen_tempfile(refs->tempfile, "w"); |
3478983b MH |
1135 | if (!out) { |
1136 | strbuf_addf(err, "unable to fdopen packed-refs tempfile: %s", | |
1137 | strerror(errno)); | |
1138 | goto error; | |
1139 | } | |
67be7c5a | 1140 | |
2775d872 MH |
1141 | if (fprintf(out, "%s", PACKED_REFS_HEADER) < 0) |
1142 | goto write_error; | |
1143 | ||
1144 | /* | |
1145 | * We iterate in parallel through the current list of refs and | |
1146 | * the list of updates, processing an entry from at least one | |
1147 | * of the lists each time through the loop. When the current | |
1148 | * list of refs is exhausted, set iter to NULL. When the list | |
1149 | * of updates is exhausted, leave i set to updates->nr. | |
1150 | */ | |
1151 | iter = packed_ref_iterator_begin(&refs->base, "", | |
1152 | DO_FOR_EACH_INCLUDE_BROKEN); | |
1153 | if ((ok = ref_iterator_advance(iter)) != ITER_OK) | |
1154 | iter = NULL; | |
1155 | ||
1156 | i = 0; | |
67be7c5a | 1157 | |
2775d872 MH |
1158 | while (iter || i < updates->nr) { |
1159 | struct ref_update *update = NULL; | |
1160 | int cmp; | |
1161 | ||
1162 | if (i >= updates->nr) { | |
1163 | cmp = -1; | |
1164 | } else { | |
1165 | update = updates->items[i].util; | |
1166 | ||
1167 | if (!iter) | |
1168 | cmp = +1; | |
1169 | else | |
1170 | cmp = strcmp(iter->refname, update->refname); | |
1171 | } | |
1172 | ||
1173 | if (!cmp) { | |
1174 | /* | |
1175 | * There is both an old value and an update | |
1176 | * for this reference. Check the old value if | |
1177 | * necessary: | |
1178 | */ | |
1179 | if ((update->flags & REF_HAVE_OLD)) { | |
1180 | if (is_null_oid(&update->old_oid)) { | |
1181 | strbuf_addf(err, "cannot update ref '%s': " | |
1182 | "reference already exists", | |
1183 | update->refname); | |
1184 | goto error; | |
9001dc2a | 1185 | } else if (!oideq(&update->old_oid, iter->oid)) { |
2775d872 MH |
1186 | strbuf_addf(err, "cannot update ref '%s': " |
1187 | "is at %s but expected %s", | |
1188 | update->refname, | |
1189 | oid_to_hex(iter->oid), | |
1190 | oid_to_hex(&update->old_oid)); | |
1191 | goto error; | |
1192 | } | |
1193 | } | |
1194 | ||
1195 | /* Now figure out what to use for the new value: */ | |
1196 | if ((update->flags & REF_HAVE_NEW)) { | |
1197 | /* | |
1198 | * The update takes precedence. Skip | |
1199 | * the iterator over the unneeded | |
1200 | * value. | |
1201 | */ | |
1202 | if ((ok = ref_iterator_advance(iter)) != ITER_OK) | |
1203 | iter = NULL; | |
1204 | cmp = +1; | |
1205 | } else { | |
1206 | /* | |
1207 | * The update doesn't actually want to | |
1208 | * change anything. We're done with it. | |
1209 | */ | |
1210 | i++; | |
1211 | cmp = -1; | |
1212 | } | |
1213 | } else if (cmp > 0) { | |
1214 | /* | |
1215 | * There is no old value but there is an | |
1216 | * update for this reference. Make sure that | |
1217 | * the update didn't expect an existing value: | |
1218 | */ | |
1219 | if ((update->flags & REF_HAVE_OLD) && | |
1220 | !is_null_oid(&update->old_oid)) { | |
1221 | strbuf_addf(err, "cannot update ref '%s': " | |
1222 | "reference is missing but expected %s", | |
1223 | update->refname, | |
1224 | oid_to_hex(&update->old_oid)); | |
1225 | goto error; | |
1226 | } | |
1227 | } | |
1228 | ||
1229 | if (cmp < 0) { | |
1230 | /* Pass the old reference through. */ | |
1231 | ||
1232 | struct object_id peeled; | |
1233 | int peel_error = ref_iterator_peel(iter, &peeled); | |
1234 | ||
1235 | if (write_packed_entry(out, iter->refname, | |
41701882 MH |
1236 | iter->oid, |
1237 | peel_error ? NULL : &peeled)) | |
2775d872 MH |
1238 | goto write_error; |
1239 | ||
1240 | if ((ok = ref_iterator_advance(iter)) != ITER_OK) | |
1241 | iter = NULL; | |
1242 | } else if (is_null_oid(&update->new_oid)) { | |
1243 | /* | |
1244 | * The update wants to delete the reference, | |
1245 | * and the reference either didn't exist or we | |
1246 | * have already skipped it. So we're done with | |
1247 | * the update (and don't have to write | |
1248 | * anything). | |
1249 | */ | |
1250 | i++; | |
1251 | } else { | |
1252 | struct object_id peeled; | |
ac2ed0d7 | 1253 | int peel_error = peel_object(&update->new_oid, |
1254 | &peeled); | |
2775d872 MH |
1255 | |
1256 | if (write_packed_entry(out, update->refname, | |
41701882 MH |
1257 | &update->new_oid, |
1258 | peel_error ? NULL : &peeled)) | |
2775d872 MH |
1259 | goto write_error; |
1260 | ||
1261 | i++; | |
3478983b | 1262 | } |
67be7c5a MH |
1263 | } |
1264 | ||
3478983b | 1265 | if (ok != ITER_DONE) { |
72d4a9a7 RS |
1266 | strbuf_addstr(err, "unable to write packed-refs file: " |
1267 | "error iterating over old contents"); | |
3478983b MH |
1268 | goto error; |
1269 | } | |
67be7c5a | 1270 | |
ce54672f PS |
1271 | if (fflush(out) || |
1272 | fsync_component(FSYNC_COMPONENT_REFERENCE, get_tempfile_fd(refs->tempfile)) || | |
bc22d845 | 1273 | close_tempfile_gently(refs->tempfile)) { |
2775d872 | 1274 | strbuf_addf(err, "error closing file %s: %s", |
07f0542d | 1275 | get_tempfile_path(refs->tempfile), |
2775d872 MH |
1276 | strerror(errno)); |
1277 | strbuf_release(&sb); | |
07f0542d | 1278 | delete_tempfile(&refs->tempfile); |
2775d872 | 1279 | return -1; |
67be7c5a | 1280 | } |
3478983b | 1281 | |
2775d872 MH |
1282 | return 0; |
1283 | ||
1284 | write_error: | |
1285 | strbuf_addf(err, "error writing to %s: %s", | |
07f0542d | 1286 | get_tempfile_path(refs->tempfile), strerror(errno)); |
3478983b MH |
1287 | |
1288 | error: | |
2775d872 MH |
1289 | if (iter) |
1290 | ref_iterator_abort(iter); | |
198b808e | 1291 | |
2775d872 MH |
1292 | delete_tempfile(&refs->tempfile); |
1293 | return -1; | |
67be7c5a MH |
1294 | } |
1295 | ||
7c6bd25c MH |
1296 | int is_packed_transaction_needed(struct ref_store *ref_store, |
1297 | struct ref_transaction *transaction) | |
1298 | { | |
1299 | struct packed_ref_store *refs = packed_downcast( | |
1300 | ref_store, | |
1301 | REF_STORE_READ, | |
1302 | "is_packed_transaction_needed"); | |
1303 | struct strbuf referent = STRBUF_INIT; | |
1304 | size_t i; | |
1305 | int ret; | |
1306 | ||
1307 | if (!is_lock_file_locked(&refs->lock)) | |
1308 | BUG("is_packed_transaction_needed() called while unlocked"); | |
1309 | ||
1310 | /* | |
1311 | * We're only going to bother returning false for the common, | |
1312 | * trivial case that references are only being deleted, their | |
1313 | * old values are not being checked, and the old `packed-refs` | |
1314 | * file doesn't contain any of those reference(s). This gives | |
1315 | * false positives for some other cases that could | |
1316 | * theoretically be optimized away: | |
1317 | * | |
1318 | * 1. It could be that the old value is being verified without | |
1319 | * setting a new value. In this case, we could verify the | |
1320 | * old value here and skip the update if it agrees. If it | |
1321 | * disagrees, we could either let the update go through | |
1322 | * (the actual commit would re-detect and report the | |
1323 | * problem), or come up with a way of reporting such an | |
1324 | * error to *our* caller. | |
1325 | * | |
1326 | * 2. It could be that a new value is being set, but that it | |
1327 | * is identical to the current packed value of the | |
1328 | * reference. | |
1329 | * | |
1330 | * Neither of these cases will come up in the current code, | |
1331 | * because the only caller of this function passes to it a | |
1332 | * transaction that only includes `delete` updates with no | |
1333 | * `old_id`. Even if that ever changes, false positives only | |
1334 | * cause an optimization to be missed; they do not affect | |
1335 | * correctness. | |
1336 | */ | |
1337 | ||
1338 | /* | |
1339 | * Start with the cheap checks that don't require old | |
1340 | * reference values to be read: | |
1341 | */ | |
1342 | for (i = 0; i < transaction->nr; i++) { | |
1343 | struct ref_update *update = transaction->updates[i]; | |
1344 | ||
1345 | if (update->flags & REF_HAVE_OLD) | |
1346 | /* Have to check the old value -> needed. */ | |
1347 | return 1; | |
1348 | ||
1349 | if ((update->flags & REF_HAVE_NEW) && !is_null_oid(&update->new_oid)) | |
1350 | /* Have to set a new value -> needed. */ | |
1351 | return 1; | |
1352 | } | |
1353 | ||
1354 | /* | |
1355 | * The transaction isn't checking any old values nor is it | |
1356 | * setting any nonzero new values, so it still might be able | |
1357 | * to be skipped. Now do the more expensive check: the update | |
1358 | * is needed if any of the updates is a delete, and the old | |
1359 | * `packed-refs` file contains a value for that reference. | |
1360 | */ | |
1361 | ret = 0; | |
1362 | for (i = 0; i < transaction->nr; i++) { | |
1363 | struct ref_update *update = transaction->updates[i]; | |
8b72fea7 | 1364 | int failure_errno; |
7c6bd25c MH |
1365 | unsigned int type; |
1366 | struct object_id oid; | |
1367 | ||
1368 | if (!(update->flags & REF_HAVE_NEW)) | |
1369 | /* | |
1370 | * This reference isn't being deleted -> not | |
1371 | * needed. | |
1372 | */ | |
1373 | continue; | |
1374 | ||
8b72fea7 HWN |
1375 | if (!refs_read_raw_ref(ref_store, update->refname, &oid, |
1376 | &referent, &type, &failure_errno) || | |
1377 | failure_errno != ENOENT) { | |
7c6bd25c MH |
1378 | /* |
1379 | * We have to actually delete that reference | |
1380 | * -> this transaction is needed. | |
1381 | */ | |
1382 | ret = 1; | |
1383 | break; | |
1384 | } | |
1385 | } | |
1386 | ||
1387 | strbuf_release(&referent); | |
1388 | return ret; | |
1389 | } | |
1390 | ||
2775d872 MH |
1391 | struct packed_transaction_backend_data { |
1392 | /* True iff the transaction owns the packed-refs lock. */ | |
1393 | int own_lock; | |
1394 | ||
1395 | struct string_list updates; | |
1396 | }; | |
1397 | ||
1398 | static void packed_transaction_cleanup(struct packed_ref_store *refs, | |
1399 | struct ref_transaction *transaction) | |
67be7c5a | 1400 | { |
2775d872 | 1401 | struct packed_transaction_backend_data *data = transaction->backend_data; |
67be7c5a | 1402 | |
2775d872 MH |
1403 | if (data) { |
1404 | string_list_clear(&data->updates, 0); | |
67be7c5a | 1405 | |
07f0542d | 1406 | if (is_tempfile_active(refs->tempfile)) |
2775d872 | 1407 | delete_tempfile(&refs->tempfile); |
e5cc7d7d | 1408 | |
2775d872 MH |
1409 | if (data->own_lock && is_lock_file_locked(&refs->lock)) { |
1410 | packed_refs_unlock(&refs->base); | |
1411 | data->own_lock = 0; | |
67be7c5a | 1412 | } |
67be7c5a | 1413 | |
2775d872 MH |
1414 | free(data); |
1415 | transaction->backend_data = NULL; | |
67be7c5a MH |
1416 | } |
1417 | ||
2775d872 | 1418 | transaction->state = REF_TRANSACTION_CLOSED; |
e0cc8ac8 MH |
1419 | } |
1420 | ||
1421 | static int packed_transaction_prepare(struct ref_store *ref_store, | |
1422 | struct ref_transaction *transaction, | |
1423 | struct strbuf *err) | |
1424 | { | |
2775d872 MH |
1425 | struct packed_ref_store *refs = packed_downcast( |
1426 | ref_store, | |
1427 | REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB, | |
1428 | "ref_transaction_prepare"); | |
1429 | struct packed_transaction_backend_data *data; | |
1430 | size_t i; | |
1431 | int ret = TRANSACTION_GENERIC_ERROR; | |
1432 | ||
1433 | /* | |
1434 | * Note that we *don't* skip transactions with zero updates, | |
1435 | * because such a transaction might be executed for the side | |
cff28ca9 MH |
1436 | * effect of ensuring that all of the references are peeled or |
1437 | * ensuring that the `packed-refs` file is sorted. If the | |
1438 | * caller wants to optimize away empty transactions, it should | |
1439 | * do so itself. | |
2775d872 MH |
1440 | */ |
1441 | ||
ca56dadb | 1442 | CALLOC_ARRAY(data, 1); |
bc40dfb1 | 1443 | string_list_init_nodup(&data->updates); |
2775d872 MH |
1444 | |
1445 | transaction->backend_data = data; | |
1446 | ||
1447 | /* | |
1448 | * Stick the updates in a string list by refname so that we | |
1449 | * can sort them: | |
1450 | */ | |
1451 | for (i = 0; i < transaction->nr; i++) { | |
1452 | struct ref_update *update = transaction->updates[i]; | |
1453 | struct string_list_item *item = | |
1454 | string_list_append(&data->updates, update->refname); | |
1455 | ||
1456 | /* Store a pointer to update in item->util: */ | |
1457 | item->util = update; | |
1458 | } | |
1459 | string_list_sort(&data->updates); | |
1460 | ||
1461 | if (ref_update_reject_duplicates(&data->updates, err)) | |
1462 | goto failure; | |
1463 | ||
1464 | if (!is_lock_file_locked(&refs->lock)) { | |
1465 | if (packed_refs_lock(ref_store, 0, err)) | |
1466 | goto failure; | |
1467 | data->own_lock = 1; | |
1468 | } | |
1469 | ||
1470 | if (write_with_updates(refs, &data->updates, err)) | |
1471 | goto failure; | |
1472 | ||
1473 | transaction->state = REF_TRANSACTION_PREPARED; | |
1474 | return 0; | |
1475 | ||
1476 | failure: | |
1477 | packed_transaction_cleanup(refs, transaction); | |
1478 | return ret; | |
e0cc8ac8 MH |
1479 | } |
1480 | ||
1481 | static int packed_transaction_abort(struct ref_store *ref_store, | |
1482 | struct ref_transaction *transaction, | |
5cf88fd8 | 1483 | struct strbuf *err UNUSED) |
e0cc8ac8 | 1484 | { |
2775d872 MH |
1485 | struct packed_ref_store *refs = packed_downcast( |
1486 | ref_store, | |
1487 | REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB, | |
1488 | "ref_transaction_abort"); | |
1489 | ||
1490 | packed_transaction_cleanup(refs, transaction); | |
1491 | return 0; | |
e0cc8ac8 MH |
1492 | } |
1493 | ||
1494 | static int packed_transaction_finish(struct ref_store *ref_store, | |
1495 | struct ref_transaction *transaction, | |
1496 | struct strbuf *err) | |
1497 | { | |
2775d872 MH |
1498 | struct packed_ref_store *refs = packed_downcast( |
1499 | ref_store, | |
1500 | REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB, | |
1501 | "ref_transaction_finish"); | |
1502 | int ret = TRANSACTION_GENERIC_ERROR; | |
1503 | char *packed_refs_path; | |
1504 | ||
cff28ca9 | 1505 | clear_snapshot(refs); |
5b633610 | 1506 | |
2775d872 MH |
1507 | packed_refs_path = get_locked_file_path(&refs->lock); |
1508 | if (rename_tempfile(&refs->tempfile, packed_refs_path)) { | |
1509 | strbuf_addf(err, "error replacing %s: %s", | |
1510 | refs->path, strerror(errno)); | |
1511 | goto cleanup; | |
1512 | } | |
1513 | ||
2775d872 MH |
1514 | ret = 0; |
1515 | ||
1516 | cleanup: | |
1517 | free(packed_refs_path); | |
1518 | packed_transaction_cleanup(refs, transaction); | |
1519 | return ret; | |
e0cc8ac8 MH |
1520 | } |
1521 | ||
5cf88fd8 | 1522 | static int packed_initial_transaction_commit(struct ref_store *ref_store UNUSED, |
e0cc8ac8 MH |
1523 | struct ref_transaction *transaction, |
1524 | struct strbuf *err) | |
1525 | { | |
1526 | return ref_transaction_commit(transaction, err); | |
1527 | } | |
1528 | ||
1529 | static int packed_delete_refs(struct ref_store *ref_store, const char *msg, | |
1530 | struct string_list *refnames, unsigned int flags) | |
1531 | { | |
c6da34a6 JH |
1532 | struct packed_ref_store *refs = |
1533 | packed_downcast(ref_store, REF_STORE_WRITE, "delete_refs"); | |
2fb330ca MH |
1534 | struct strbuf err = STRBUF_INIT; |
1535 | struct ref_transaction *transaction; | |
c6da34a6 | 1536 | struct string_list_item *item; |
2fb330ca MH |
1537 | int ret; |
1538 | ||
c6da34a6 JH |
1539 | (void)refs; /* We need the check above, but don't use the variable */ |
1540 | ||
2fb330ca MH |
1541 | if (!refnames->nr) |
1542 | return 0; | |
1543 | ||
1544 | /* | |
1545 | * Since we don't check the references' old_oids, the | |
1546 | * individual updates can't fail, so we can pack all of the | |
1547 | * updates into a single transaction. | |
1548 | */ | |
1549 | ||
c6da34a6 | 1550 | transaction = ref_store_transaction_begin(ref_store, &err); |
2fb330ca MH |
1551 | if (!transaction) |
1552 | return -1; | |
1553 | ||
1554 | for_each_string_list_item(item, refnames) { | |
1555 | if (ref_transaction_delete(transaction, item->string, NULL, | |
1556 | flags, msg, &err)) { | |
1557 | warning(_("could not delete reference %s: %s"), | |
1558 | item->string, err.buf); | |
1559 | strbuf_reset(&err); | |
1560 | } | |
1561 | } | |
1562 | ||
1563 | ret = ref_transaction_commit(transaction, &err); | |
1564 | ||
1565 | if (ret) { | |
1566 | if (refnames->nr == 1) | |
1567 | error(_("could not delete reference %s: %s"), | |
1568 | refnames->items[0].string, err.buf); | |
1569 | else | |
1570 | error(_("could not delete references: %s"), err.buf); | |
1571 | } | |
1572 | ||
c6da34a6 | 1573 | ref_transaction_free(transaction); |
2fb330ca MH |
1574 | strbuf_release(&err); |
1575 | return ret; | |
e0cc8ac8 MH |
1576 | } |
1577 | ||
5cf88fd8 ÆAB |
1578 | static int packed_pack_refs(struct ref_store *ref_store UNUSED, |
1579 | unsigned int flags UNUSED) | |
e0cc8ac8 MH |
1580 | { |
1581 | /* | |
1582 | * Packed refs are already packed. It might be that loose refs | |
1583 | * are packed *into* a packed refs store, but that is done by | |
1584 | * updating the packed references via a transaction. | |
1585 | */ | |
1586 | return 0; | |
1587 | } | |
1588 | ||
5cf88fd8 | 1589 | static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_store UNUSED) |
e0cc8ac8 MH |
1590 | { |
1591 | return empty_ref_iterator_begin(); | |
1592 | } | |
1593 | ||
e0cc8ac8 | 1594 | struct ref_storage_be refs_be_packed = { |
32bff617 ÆAB |
1595 | .next = NULL, |
1596 | .name = "packed", | |
1597 | .init = packed_ref_store_create, | |
1598 | .init_db = packed_init_db, | |
1599 | .transaction_prepare = packed_transaction_prepare, | |
1600 | .transaction_finish = packed_transaction_finish, | |
1601 | .transaction_abort = packed_transaction_abort, | |
1602 | .initial_transaction_commit = packed_initial_transaction_commit, | |
1603 | ||
1604 | .pack_refs = packed_pack_refs, | |
ca40893a | 1605 | .create_symref = NULL, |
32bff617 | 1606 | .delete_refs = packed_delete_refs, |
ca40893a ÆAB |
1607 | .rename_ref = NULL, |
1608 | .copy_ref = NULL, | |
32bff617 ÆAB |
1609 | |
1610 | .iterator_begin = packed_ref_iterator_begin, | |
1611 | .read_raw_ref = packed_read_raw_ref, | |
1612 | .read_symbolic_ref = NULL, | |
1613 | ||
1614 | .reflog_iterator_begin = packed_reflog_iterator_begin, | |
ca40893a ÆAB |
1615 | .for_each_reflog_ent = NULL, |
1616 | .for_each_reflog_ent_reverse = NULL, | |
1617 | .reflog_exists = NULL, | |
1618 | .create_reflog = NULL, | |
1619 | .delete_reflog = NULL, | |
1620 | .reflog_expire = NULL, | |
e0cc8ac8 | 1621 | }; |