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67be7c5a | 1 | #include "../cache.h" |
44c2339e | 2 | #include "../config.h" |
67be7c5a MH |
3 | #include "../refs.h" |
4 | #include "refs-internal.h" | |
67be7c5a MH |
5 | #include "packed-backend.h" |
6 | #include "../iterator.h" | |
7 | #include "../lockfile.h" | |
8 | ||
5b633610 MH |
9 | enum mmap_strategy { |
10 | /* | |
11 | * Don't use mmap() at all for reading `packed-refs`. | |
12 | */ | |
13 | MMAP_NONE, | |
67be7c5a MH |
14 | |
15 | /* | |
5b633610 MH |
16 | * Can use mmap() for reading `packed-refs`, but the file must |
17 | * not remain mmapped. This is the usual option on Windows, | |
18 | * where you cannot rename a new version of a file onto a file | |
19 | * that is currently mmapped. | |
67be7c5a | 20 | */ |
5b633610 | 21 | MMAP_TEMPORARY, |
67be7c5a | 22 | |
5b633610 MH |
23 | /* |
24 | * It is OK to leave the `packed-refs` file mmapped while | |
25 | * arbitrary other code is running. | |
26 | */ | |
27 | MMAP_OK | |
67be7c5a MH |
28 | }; |
29 | ||
5b633610 MH |
30 | #if defined(NO_MMAP) |
31 | static enum mmap_strategy mmap_strategy = MMAP_NONE; | |
32 | #elif defined(MMAP_PREVENTS_DELETE) | |
33 | static enum mmap_strategy mmap_strategy = MMAP_TEMPORARY; | |
34 | #else | |
35 | static enum mmap_strategy mmap_strategy = MMAP_OK; | |
36 | #endif | |
37 | ||
f0a7dc86 | 38 | struct packed_ref_store; |
67be7c5a MH |
39 | |
40 | /* | |
cff28ca9 MH |
41 | * A `snapshot` represents one snapshot of a `packed-refs` file. |
42 | * | |
43 | * Normally, this will be a mmapped view of the contents of the | |
44 | * `packed-refs` file at the time the snapshot was created. However, | |
45 | * if the `packed-refs` file was not sorted, this might point at heap | |
46 | * memory holding the contents of the `packed-refs` file with its | |
47 | * records sorted by refname. | |
48 | * | |
49 | * `snapshot` instances are reference counted (via | |
50 | * `acquire_snapshot()` and `release_snapshot()`). This is to prevent | |
51 | * an instance from disappearing while an iterator is still iterating | |
52 | * over it. Instances are garbage collected when their `referrers` | |
53 | * count goes to zero. | |
54 | * | |
55 | * The most recent `snapshot`, if available, is referenced by the | |
56 | * `packed_ref_store`. Its freshness is checked whenever | |
57 | * `get_snapshot()` is called; if the existing snapshot is obsolete, a | |
58 | * new snapshot is taken. | |
67be7c5a | 59 | */ |
cff28ca9 | 60 | struct snapshot { |
f0a7dc86 MH |
61 | /* |
62 | * A back-pointer to the packed_ref_store with which this | |
cff28ca9 | 63 | * snapshot is associated: |
f0a7dc86 MH |
64 | */ |
65 | struct packed_ref_store *refs; | |
66 | ||
5b633610 MH |
67 | /* Is the `packed-refs` file currently mmapped? */ |
68 | int mmapped; | |
69 | ||
70 | /* | |
02b920f3 MH |
71 | * The contents of the `packed-refs` file. If the file was |
72 | * already sorted, this points at the mmapped contents of the | |
73 | * file. If not, this points at heap-allocated memory | |
74 | * containing the contents, sorted. If there were no contents | |
75 | * (e.g., because the file didn't exist), `buf` and `eof` are | |
76 | * both NULL. | |
5b633610 MH |
77 | */ |
78 | char *buf, *eof; | |
79 | ||
80 | /* The size of the header line, if any; otherwise, 0: */ | |
81 | size_t header_len; | |
82 | ||
daa45408 | 83 | /* |
cff28ca9 MH |
84 | * What is the peeled state of the `packed-refs` file that |
85 | * this snapshot represents? (This is usually determined from | |
86 | * the file's header.) | |
daa45408 MH |
87 | */ |
88 | enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled; | |
89 | ||
67be7c5a | 90 | /* |
cff28ca9 MH |
91 | * Count of references to this instance, including the pointer |
92 | * from `packed_ref_store::snapshot`, if any. The instance | |
93 | * will not be freed as long as the reference count is | |
94 | * nonzero. | |
67be7c5a MH |
95 | */ |
96 | unsigned int referrers; | |
97 | ||
cff28ca9 MH |
98 | /* |
99 | * The metadata of the `packed-refs` file from which this | |
100 | * snapshot was created, used to tell if the file has been | |
101 | * replaced since we read it. | |
102 | */ | |
67be7c5a MH |
103 | struct stat_validity validity; |
104 | }; | |
67be7c5a MH |
105 | |
106 | /* | |
cff28ca9 MH |
107 | * A `ref_store` representing references stored in a `packed-refs` |
108 | * file. It implements the `ref_store` interface, though it has some | |
109 | * limitations: | |
110 | * | |
111 | * - It cannot store symbolic references. | |
112 | * | |
113 | * - It cannot store reflogs. | |
114 | * | |
115 | * - It does not support reference renaming (though it could). | |
116 | * | |
117 | * On the other hand, it can be locked outside of a reference | |
118 | * transaction. In that case, it remains locked even after the | |
119 | * transaction is done and the new `packed-refs` file is activated. | |
67be7c5a MH |
120 | */ |
121 | struct packed_ref_store { | |
e0cc8ac8 MH |
122 | struct ref_store base; |
123 | ||
67be7c5a MH |
124 | unsigned int store_flags; |
125 | ||
126 | /* The path of the "packed-refs" file: */ | |
127 | char *path; | |
128 | ||
129 | /* | |
cff28ca9 MH |
130 | * A snapshot of the values read from the `packed-refs` file, |
131 | * if it might still be current; otherwise, NULL. | |
67be7c5a | 132 | */ |
cff28ca9 | 133 | struct snapshot *snapshot; |
67be7c5a MH |
134 | |
135 | /* | |
136 | * Lock used for the "packed-refs" file. Note that this (and | |
137 | * thus the enclosing `packed_ref_store`) must not be freed. | |
138 | */ | |
139 | struct lock_file lock; | |
42dfa7ec MH |
140 | |
141 | /* | |
142 | * Temporary file used when rewriting new contents to the | |
143 | * "packed-refs" file. Note that this (and thus the enclosing | |
144 | * `packed_ref_store`) must not be freed. | |
145 | */ | |
076aa2cb | 146 | struct tempfile *tempfile; |
67be7c5a MH |
147 | }; |
148 | ||
14b3c344 | 149 | /* |
cff28ca9 | 150 | * Increment the reference count of `*snapshot`. |
14b3c344 | 151 | */ |
cff28ca9 | 152 | static void acquire_snapshot(struct snapshot *snapshot) |
14b3c344 | 153 | { |
cff28ca9 | 154 | snapshot->referrers++; |
14b3c344 MH |
155 | } |
156 | ||
5b633610 | 157 | /* |
cff28ca9 | 158 | * If the buffer in `snapshot` is active, then either munmap the |
5b633610 MH |
159 | * memory and close the file, or free the memory. Then set the buffer |
160 | * pointers to NULL. | |
161 | */ | |
cff28ca9 | 162 | static void clear_snapshot_buffer(struct snapshot *snapshot) |
5b633610 | 163 | { |
cff28ca9 MH |
164 | if (snapshot->mmapped) { |
165 | if (munmap(snapshot->buf, snapshot->eof - snapshot->buf)) | |
5b633610 | 166 | die_errno("error ummapping packed-refs file %s", |
cff28ca9 MH |
167 | snapshot->refs->path); |
168 | snapshot->mmapped = 0; | |
5b633610 | 169 | } else { |
cff28ca9 | 170 | free(snapshot->buf); |
5b633610 | 171 | } |
cff28ca9 MH |
172 | snapshot->buf = snapshot->eof = NULL; |
173 | snapshot->header_len = 0; | |
5b633610 MH |
174 | } |
175 | ||
14b3c344 | 176 | /* |
cff28ca9 MH |
177 | * Decrease the reference count of `*snapshot`. If it goes to zero, |
178 | * free `*snapshot` and return true; otherwise return false. | |
14b3c344 | 179 | */ |
cff28ca9 | 180 | static int release_snapshot(struct snapshot *snapshot) |
14b3c344 | 181 | { |
cff28ca9 MH |
182 | if (!--snapshot->referrers) { |
183 | stat_validity_clear(&snapshot->validity); | |
184 | clear_snapshot_buffer(snapshot); | |
185 | free(snapshot); | |
14b3c344 MH |
186 | return 1; |
187 | } else { | |
188 | return 0; | |
189 | } | |
190 | } | |
191 | ||
e0cc8ac8 MH |
192 | struct ref_store *packed_ref_store_create(const char *path, |
193 | unsigned int store_flags) | |
67be7c5a MH |
194 | { |
195 | struct packed_ref_store *refs = xcalloc(1, sizeof(*refs)); | |
e0cc8ac8 | 196 | struct ref_store *ref_store = (struct ref_store *)refs; |
67be7c5a | 197 | |
e0cc8ac8 | 198 | base_ref_store_init(ref_store, &refs_be_packed); |
67be7c5a | 199 | refs->store_flags = store_flags; |
e0cc8ac8 | 200 | |
67be7c5a | 201 | refs->path = xstrdup(path); |
e0cc8ac8 | 202 | return ref_store; |
67be7c5a MH |
203 | } |
204 | ||
e0cc8ac8 MH |
205 | /* |
206 | * Downcast `ref_store` to `packed_ref_store`. Die if `ref_store` is | |
207 | * not a `packed_ref_store`. Also die if `packed_ref_store` doesn't | |
208 | * support at least the flags specified in `required_flags`. `caller` | |
209 | * is used in any necessary error messages. | |
210 | */ | |
211 | static struct packed_ref_store *packed_downcast(struct ref_store *ref_store, | |
212 | unsigned int required_flags, | |
213 | const char *caller) | |
214 | { | |
215 | struct packed_ref_store *refs; | |
216 | ||
217 | if (ref_store->be != &refs_be_packed) | |
218 | die("BUG: ref_store is type \"%s\" not \"packed\" in %s", | |
219 | ref_store->be->name, caller); | |
220 | ||
221 | refs = (struct packed_ref_store *)ref_store; | |
222 | ||
223 | if ((refs->store_flags & required_flags) != required_flags) | |
224 | die("BUG: unallowed operation (%s), requires %x, has %x\n", | |
225 | caller, required_flags, refs->store_flags); | |
226 | ||
227 | return refs; | |
228 | } | |
229 | ||
cff28ca9 | 230 | static void clear_snapshot(struct packed_ref_store *refs) |
67be7c5a | 231 | { |
cff28ca9 MH |
232 | if (refs->snapshot) { |
233 | struct snapshot *snapshot = refs->snapshot; | |
67be7c5a | 234 | |
cff28ca9 MH |
235 | refs->snapshot = NULL; |
236 | release_snapshot(snapshot); | |
67be7c5a MH |
237 | } |
238 | } | |
239 | ||
735267aa MH |
240 | static NORETURN void die_unterminated_line(const char *path, |
241 | const char *p, size_t len) | |
67be7c5a | 242 | { |
735267aa MH |
243 | if (len < 80) |
244 | die("unterminated line in %s: %.*s", path, (int)len, p); | |
245 | else | |
246 | die("unterminated line in %s: %.75s...", path, p); | |
247 | } | |
67be7c5a | 248 | |
735267aa MH |
249 | static NORETURN void die_invalid_line(const char *path, |
250 | const char *p, size_t len) | |
251 | { | |
252 | const char *eol = memchr(p, '\n', len); | |
253 | ||
254 | if (!eol) | |
255 | die_unterminated_line(path, p, len); | |
256 | else if (eol - p < 80) | |
257 | die("unexpected line in %s: %.*s", path, (int)(eol - p), p); | |
258 | else | |
259 | die("unexpected line in %s: %.75s...", path, p); | |
260 | ||
261 | } | |
262 | ||
cff28ca9 | 263 | struct snapshot_record { |
02b920f3 MH |
264 | const char *start; |
265 | size_t len; | |
266 | }; | |
267 | ||
cff28ca9 | 268 | static int cmp_packed_ref_records(const void *v1, const void *v2) |
02b920f3 | 269 | { |
cff28ca9 | 270 | const struct snapshot_record *e1 = v1, *e2 = v2; |
02b920f3 MH |
271 | const char *r1 = e1->start + GIT_SHA1_HEXSZ + 1; |
272 | const char *r2 = e2->start + GIT_SHA1_HEXSZ + 1; | |
273 | ||
274 | while (1) { | |
275 | if (*r1 == '\n') | |
276 | return *r2 == '\n' ? 0 : -1; | |
277 | if (*r1 != *r2) { | |
278 | if (*r2 == '\n') | |
279 | return 1; | |
280 | else | |
281 | return (unsigned char)*r1 < (unsigned char)*r2 ? -1 : +1; | |
282 | } | |
283 | r1++; | |
284 | r2++; | |
67be7c5a MH |
285 | } |
286 | } | |
287 | ||
d1cf1551 | 288 | /* |
cff28ca9 MH |
289 | * Compare a snapshot record at `rec` to the specified NUL-terminated |
290 | * refname. | |
d1cf1551 | 291 | */ |
cff28ca9 | 292 | static int cmp_record_to_refname(const char *rec, const char *refname) |
d1cf1551 MH |
293 | { |
294 | const char *r1 = rec + GIT_SHA1_HEXSZ + 1; | |
295 | const char *r2 = refname; | |
296 | ||
297 | while (1) { | |
298 | if (*r1 == '\n') | |
299 | return *r2 ? -1 : 0; | |
300 | if (!*r2) | |
301 | return 1; | |
302 | if (*r1 != *r2) | |
303 | return (unsigned char)*r1 < (unsigned char)*r2 ? -1 : +1; | |
304 | r1++; | |
305 | r2++; | |
306 | } | |
307 | } | |
67be7c5a MH |
308 | |
309 | /* | |
cff28ca9 MH |
310 | * `snapshot->buf` is not known to be sorted. Check whether it is, and |
311 | * if not, sort it into new memory and munmap/free the old storage. | |
67be7c5a | 312 | */ |
cff28ca9 | 313 | static void sort_snapshot(struct snapshot *snapshot) |
67be7c5a | 314 | { |
cff28ca9 | 315 | struct snapshot_record *records = NULL; |
02b920f3 MH |
316 | size_t alloc = 0, nr = 0; |
317 | int sorted = 1; | |
318 | const char *pos, *eof, *eol; | |
319 | size_t len, i; | |
320 | char *new_buffer, *dst; | |
67be7c5a | 321 | |
cff28ca9 MH |
322 | pos = snapshot->buf + snapshot->header_len; |
323 | eof = snapshot->eof; | |
02b920f3 | 324 | len = eof - pos; |
67be7c5a | 325 | |
02b920f3 MH |
326 | if (!len) |
327 | return; | |
67be7c5a | 328 | |
02b920f3 | 329 | /* |
cff28ca9 | 330 | * Initialize records based on a crude estimate of the number |
02b920f3 MH |
331 | * of references in the file (we'll grow it below if needed): |
332 | */ | |
cff28ca9 | 333 | ALLOC_GROW(records, len / 80 + 20, alloc); |
02b920f3 MH |
334 | |
335 | while (pos < eof) { | |
336 | eol = memchr(pos, '\n', eof - pos); | |
337 | if (!eol) | |
338 | /* The safety check should prevent this. */ | |
339 | BUG("unterminated line found in packed-refs"); | |
340 | if (eol - pos < GIT_SHA1_HEXSZ + 2) | |
cff28ca9 | 341 | die_invalid_line(snapshot->refs->path, |
02b920f3 MH |
342 | pos, eof - pos); |
343 | eol++; | |
344 | if (eol < eof && *eol == '^') { | |
345 | /* | |
346 | * Keep any peeled line together with its | |
347 | * reference: | |
348 | */ | |
349 | const char *peeled_start = eol; | |
350 | ||
351 | eol = memchr(peeled_start, '\n', eof - peeled_start); | |
352 | if (!eol) | |
353 | /* The safety check should prevent this. */ | |
354 | BUG("unterminated peeled line found in packed-refs"); | |
355 | eol++; | |
356 | } | |
357 | ||
cff28ca9 MH |
358 | ALLOC_GROW(records, nr + 1, alloc); |
359 | records[nr].start = pos; | |
360 | records[nr].len = eol - pos; | |
02b920f3 MH |
361 | nr++; |
362 | ||
363 | if (sorted && | |
364 | nr > 1 && | |
cff28ca9 MH |
365 | cmp_packed_ref_records(&records[nr - 2], |
366 | &records[nr - 1]) >= 0) | |
02b920f3 | 367 | sorted = 0; |
67be7c5a | 368 | |
02b920f3 MH |
369 | pos = eol; |
370 | } | |
371 | ||
372 | if (sorted) | |
373 | goto cleanup; | |
374 | ||
cff28ca9 MH |
375 | /* We need to sort the memory. First we sort the records array: */ |
376 | QSORT(records, nr, cmp_packed_ref_records); | |
02b920f3 MH |
377 | |
378 | /* | |
379 | * Allocate a new chunk of memory, and copy the old memory to | |
cff28ca9 | 380 | * the new in the order indicated by `records` (not bothering |
02b920f3 MH |
381 | * with the header line): |
382 | */ | |
383 | new_buffer = xmalloc(len); | |
384 | for (dst = new_buffer, i = 0; i < nr; i++) { | |
cff28ca9 MH |
385 | memcpy(dst, records[i].start, records[i].len); |
386 | dst += records[i].len; | |
02b920f3 MH |
387 | } |
388 | ||
389 | /* | |
390 | * Now munmap the old buffer and use the sorted buffer in its | |
391 | * place: | |
392 | */ | |
cff28ca9 MH |
393 | clear_snapshot_buffer(snapshot); |
394 | snapshot->buf = new_buffer; | |
395 | snapshot->eof = new_buffer + len; | |
396 | snapshot->header_len = 0; | |
02b920f3 MH |
397 | |
398 | cleanup: | |
cff28ca9 | 399 | free(records); |
67be7c5a MH |
400 | } |
401 | ||
402 | /* | |
02b920f3 MH |
403 | * Return a pointer to the start of the record that contains the |
404 | * character `*p` (which must be within the buffer). If no other | |
405 | * record start is found, return `buf`. | |
406 | */ | |
407 | static const char *find_start_of_record(const char *buf, const char *p) | |
408 | { | |
409 | while (p > buf && (p[-1] != '\n' || p[0] == '^')) | |
410 | p--; | |
411 | return p; | |
412 | } | |
413 | ||
d1cf1551 MH |
414 | /* |
415 | * Return a pointer to the start of the record following the record | |
416 | * that contains `*p`. If none is found before `end`, return `end`. | |
417 | */ | |
418 | static const char *find_end_of_record(const char *p, const char *end) | |
419 | { | |
420 | while (++p < end && (p[-1] != '\n' || p[0] == '^')) | |
421 | ; | |
422 | return p; | |
423 | } | |
424 | ||
02b920f3 MH |
425 | /* |
426 | * We want to be able to compare mmapped reference records quickly, | |
427 | * without totally parsing them. We can do so because the records are | |
428 | * LF-terminated, and the refname should start exactly (GIT_SHA1_HEXSZ | |
429 | * + 1) bytes past the beginning of the record. | |
430 | * | |
431 | * But what if the `packed-refs` file contains garbage? We're willing | |
432 | * to tolerate not detecting the problem, as long as we don't produce | |
433 | * totally garbled output (we can't afford to check the integrity of | |
434 | * the whole file during every Git invocation). But we do want to be | |
435 | * sure that we never read past the end of the buffer in memory and | |
436 | * perform an illegal memory access. | |
437 | * | |
438 | * Guarantee that minimum level of safety by verifying that the last | |
439 | * record in the file is LF-terminated, and that it has at least | |
440 | * (GIT_SHA1_HEXSZ + 1) characters before the LF. Die if either of | |
441 | * these checks fails. | |
442 | */ | |
cff28ca9 | 443 | static void verify_buffer_safe(struct snapshot *snapshot) |
02b920f3 | 444 | { |
cff28ca9 MH |
445 | const char *buf = snapshot->buf + snapshot->header_len; |
446 | const char *eof = snapshot->eof; | |
02b920f3 MH |
447 | const char *last_line; |
448 | ||
449 | if (buf == eof) | |
450 | return; | |
451 | ||
452 | last_line = find_start_of_record(buf, eof - 1); | |
453 | if (*(eof - 1) != '\n' || eof - last_line < GIT_SHA1_HEXSZ + 2) | |
cff28ca9 | 454 | die_invalid_line(snapshot->refs->path, |
02b920f3 MH |
455 | last_line, eof - last_line); |
456 | } | |
457 | ||
5b633610 MH |
458 | /* |
459 | * Depending on `mmap_strategy`, either mmap or read the contents of | |
cff28ca9 MH |
460 | * the `packed-refs` file into the snapshot. Return 1 if the file |
461 | * existed and was read, or 0 if the file was absent. Die on errors. | |
5b633610 | 462 | */ |
cff28ca9 | 463 | static int load_contents(struct snapshot *snapshot) |
5b633610 MH |
464 | { |
465 | int fd; | |
466 | struct stat st; | |
467 | size_t size; | |
468 | ssize_t bytes_read; | |
469 | ||
cff28ca9 | 470 | fd = open(snapshot->refs->path, O_RDONLY); |
5b633610 MH |
471 | if (fd < 0) { |
472 | if (errno == ENOENT) { | |
473 | /* | |
474 | * This is OK; it just means that no | |
475 | * "packed-refs" file has been written yet, | |
476 | * which is equivalent to it being empty, | |
477 | * which is its state when initialized with | |
478 | * zeros. | |
479 | */ | |
480 | return 0; | |
481 | } else { | |
cff28ca9 | 482 | die_errno("couldn't read %s", snapshot->refs->path); |
5b633610 MH |
483 | } |
484 | } | |
485 | ||
cff28ca9 | 486 | stat_validity_update(&snapshot->validity, fd); |
5b633610 MH |
487 | |
488 | if (fstat(fd, &st) < 0) | |
cff28ca9 | 489 | die_errno("couldn't stat %s", snapshot->refs->path); |
5b633610 MH |
490 | size = xsize_t(st.st_size); |
491 | ||
492 | switch (mmap_strategy) { | |
493 | case MMAP_NONE: | |
cff28ca9 MH |
494 | snapshot->buf = xmalloc(size); |
495 | bytes_read = read_in_full(fd, snapshot->buf, size); | |
5b633610 | 496 | if (bytes_read < 0 || bytes_read != size) |
cff28ca9 MH |
497 | die_errno("couldn't read %s", snapshot->refs->path); |
498 | snapshot->eof = snapshot->buf + size; | |
499 | snapshot->mmapped = 0; | |
5b633610 | 500 | break; |
02b920f3 | 501 | case MMAP_TEMPORARY: |
5b633610 | 502 | case MMAP_OK: |
cff28ca9 MH |
503 | snapshot->buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0); |
504 | snapshot->eof = snapshot->buf + size; | |
505 | snapshot->mmapped = 1; | |
5b633610 MH |
506 | break; |
507 | } | |
508 | close(fd); | |
509 | ||
510 | return 1; | |
511 | } | |
512 | ||
d1cf1551 | 513 | /* |
cff28ca9 | 514 | * Find the place in `snapshot->buf` where the start of the record for |
d1cf1551 MH |
515 | * `refname` starts. If `mustexist` is true and the reference doesn't |
516 | * exist, then return NULL. If `mustexist` is false and the reference | |
517 | * doesn't exist, then return the point where that reference would be | |
518 | * inserted. In the latter mode, `refname` doesn't have to be a proper | |
519 | * reference name; for example, one could search for "refs/replace/" | |
520 | * to find the start of any replace references. | |
521 | * | |
cff28ca9 MH |
522 | * The record is sought using a binary search, so `snapshot->buf` must |
523 | * be sorted. | |
d1cf1551 | 524 | */ |
cff28ca9 | 525 | static const char *find_reference_location(struct snapshot *snapshot, |
d1cf1551 MH |
526 | const char *refname, int mustexist) |
527 | { | |
528 | /* | |
529 | * This is not *quite* a garden-variety binary search, because | |
530 | * the data we're searching is made up of records, and we | |
531 | * always need to find the beginning of a record to do a | |
532 | * comparison. A "record" here is one line for the reference | |
533 | * itself and zero or one peel lines that start with '^'. Our | |
534 | * loop invariant is described in the next two comments. | |
535 | */ | |
536 | ||
537 | /* | |
538 | * A pointer to the character at the start of a record whose | |
539 | * preceding records all have reference names that come | |
540 | * *before* `refname`. | |
541 | */ | |
cff28ca9 | 542 | const char *lo = snapshot->buf + snapshot->header_len; |
d1cf1551 MH |
543 | |
544 | /* | |
545 | * A pointer to a the first character of a record whose | |
546 | * reference name comes *after* `refname`. | |
547 | */ | |
cff28ca9 | 548 | const char *hi = snapshot->eof; |
d1cf1551 MH |
549 | |
550 | while (lo < hi) { | |
551 | const char *mid, *rec; | |
552 | int cmp; | |
553 | ||
554 | mid = lo + (hi - lo) / 2; | |
555 | rec = find_start_of_record(lo, mid); | |
cff28ca9 | 556 | cmp = cmp_record_to_refname(rec, refname); |
d1cf1551 MH |
557 | if (cmp < 0) { |
558 | lo = find_end_of_record(mid, hi); | |
559 | } else if (cmp > 0) { | |
560 | hi = rec; | |
561 | } else { | |
562 | return rec; | |
563 | } | |
564 | } | |
565 | ||
566 | if (mustexist) | |
567 | return NULL; | |
568 | else | |
569 | return lo; | |
570 | } | |
571 | ||
67be7c5a | 572 | /* |
cff28ca9 MH |
573 | * Create a newly-allocated `snapshot` of the `packed-refs` file in |
574 | * its current state and return it. The return value will already have | |
575 | * its reference count incremented. | |
67be7c5a MH |
576 | * |
577 | * A comment line of the form "# pack-refs with: " may contain zero or | |
578 | * more traits. We interpret the traits as follows: | |
579 | * | |
02b920f3 | 580 | * Neither `peeled` nor `fully-peeled`: |
67be7c5a MH |
581 | * |
582 | * Probably no references are peeled. But if the file contains a | |
583 | * peeled value for a reference, we will use it. | |
584 | * | |
02b920f3 | 585 | * `peeled`: |
67be7c5a MH |
586 | * |
587 | * References under "refs/tags/", if they *can* be peeled, *are* | |
588 | * peeled in this file. References outside of "refs/tags/" are | |
589 | * probably not peeled even if they could have been, but if we find | |
590 | * a peeled value for such a reference we will use it. | |
591 | * | |
02b920f3 | 592 | * `fully-peeled`: |
67be7c5a MH |
593 | * |
594 | * All references in the file that can be peeled are peeled. | |
595 | * Inversely (and this is more important), any references in the | |
596 | * file for which no peeled value is recorded is not peelable. This | |
597 | * trait should typically be written alongside "peeled" for | |
598 | * compatibility with older clients, but we do not require it | |
599 | * (i.e., "peeled" is a no-op if "fully-peeled" is set). | |
02b920f3 MH |
600 | * |
601 | * `sorted`: | |
602 | * | |
603 | * The references in this file are known to be sorted by refname. | |
67be7c5a | 604 | */ |
cff28ca9 | 605 | static struct snapshot *create_snapshot(struct packed_ref_store *refs) |
67be7c5a | 606 | { |
cff28ca9 | 607 | struct snapshot *snapshot = xcalloc(1, sizeof(*snapshot)); |
02b920f3 | 608 | int sorted = 0; |
67be7c5a | 609 | |
cff28ca9 MH |
610 | snapshot->refs = refs; |
611 | acquire_snapshot(snapshot); | |
612 | snapshot->peeled = PEELED_NONE; | |
67be7c5a | 613 | |
cff28ca9 MH |
614 | if (!load_contents(snapshot)) |
615 | return snapshot; | |
67be7c5a | 616 | |
36f23534 | 617 | /* If the file has a header line, process it: */ |
cff28ca9 | 618 | if (snapshot->buf < snapshot->eof && *snapshot->buf == '#') { |
9cfb3dc0 | 619 | struct strbuf tmp = STRBUF_INIT; |
a8811695 | 620 | char *p; |
9cfb3dc0 | 621 | const char *eol; |
a8811695 | 622 | struct string_list traits = STRING_LIST_INIT_NODUP; |
9308b7f3 | 623 | |
cff28ca9 MH |
624 | eol = memchr(snapshot->buf, '\n', |
625 | snapshot->eof - snapshot->buf); | |
36f23534 | 626 | if (!eol) |
5b633610 | 627 | die_unterminated_line(refs->path, |
cff28ca9 MH |
628 | snapshot->buf, |
629 | snapshot->eof - snapshot->buf); | |
67be7c5a | 630 | |
cff28ca9 | 631 | strbuf_add(&tmp, snapshot->buf, eol - snapshot->buf); |
67be7c5a | 632 | |
6a9bc403 | 633 | if (!skip_prefix(tmp.buf, "# pack-refs with:", (const char **)&p)) |
5b633610 | 634 | die_invalid_line(refs->path, |
cff28ca9 MH |
635 | snapshot->buf, |
636 | snapshot->eof - snapshot->buf); | |
36f23534 | 637 | |
a8811695 MH |
638 | string_list_split_in_place(&traits, p, ' ', -1); |
639 | ||
640 | if (unsorted_string_list_has_string(&traits, "fully-peeled")) | |
cff28ca9 | 641 | snapshot->peeled = PEELED_FULLY; |
a8811695 | 642 | else if (unsorted_string_list_has_string(&traits, "peeled")) |
cff28ca9 | 643 | snapshot->peeled = PEELED_TAGS; |
02b920f3 MH |
644 | |
645 | sorted = unsorted_string_list_has_string(&traits, "sorted"); | |
646 | ||
36f23534 MH |
647 | /* perhaps other traits later as well */ |
648 | ||
649 | /* The "+ 1" is for the LF character. */ | |
cff28ca9 | 650 | snapshot->header_len = eol + 1 - snapshot->buf; |
a8811695 MH |
651 | |
652 | string_list_clear(&traits, 0); | |
9cfb3dc0 | 653 | strbuf_release(&tmp); |
67be7c5a MH |
654 | } |
655 | ||
cff28ca9 | 656 | verify_buffer_safe(snapshot); |
67be7c5a | 657 | |
02b920f3 | 658 | if (!sorted) { |
cff28ca9 | 659 | sort_snapshot(snapshot); |
02b920f3 MH |
660 | |
661 | /* | |
662 | * Reordering the records might have moved a short one | |
663 | * to the end of the buffer, so verify the buffer's | |
664 | * safety again: | |
665 | */ | |
cff28ca9 | 666 | verify_buffer_safe(snapshot); |
02b920f3 MH |
667 | } |
668 | ||
cff28ca9 | 669 | if (mmap_strategy != MMAP_OK && snapshot->mmapped) { |
02b920f3 MH |
670 | /* |
671 | * We don't want to leave the file mmapped, so we are | |
672 | * forced to make a copy now: | |
673 | */ | |
cff28ca9 MH |
674 | size_t size = snapshot->eof - |
675 | (snapshot->buf + snapshot->header_len); | |
02b920f3 MH |
676 | char *buf_copy = xmalloc(size); |
677 | ||
cff28ca9 MH |
678 | memcpy(buf_copy, snapshot->buf + snapshot->header_len, size); |
679 | clear_snapshot_buffer(snapshot); | |
680 | snapshot->buf = buf_copy; | |
681 | snapshot->eof = buf_copy + size; | |
02b920f3 MH |
682 | } |
683 | ||
cff28ca9 | 684 | return snapshot; |
67be7c5a MH |
685 | } |
686 | ||
687 | /* | |
cff28ca9 MH |
688 | * Check that `refs->snapshot` (if present) still reflects the |
689 | * contents of the `packed-refs` file. If not, clear the snapshot. | |
67be7c5a | 690 | */ |
cff28ca9 | 691 | static void validate_snapshot(struct packed_ref_store *refs) |
67be7c5a | 692 | { |
cff28ca9 MH |
693 | if (refs->snapshot && |
694 | !stat_validity_check(&refs->snapshot->validity, refs->path)) | |
695 | clear_snapshot(refs); | |
67be7c5a MH |
696 | } |
697 | ||
698 | /* | |
cff28ca9 MH |
699 | * Get the `snapshot` for the specified packed_ref_store, creating and |
700 | * populating it if it hasn't been read before or if the file has been | |
701 | * changed (according to its `validity` field) since it was last read. | |
702 | * On the other hand, if we hold the lock, then assume that the file | |
703 | * hasn't been changed out from under us, so skip the extra `stat()` | |
704 | * call in `stat_validity_check()`. This function does *not* increase | |
705 | * the snapshot's reference count on behalf of the caller. | |
67be7c5a | 706 | */ |
cff28ca9 | 707 | static struct snapshot *get_snapshot(struct packed_ref_store *refs) |
67be7c5a MH |
708 | { |
709 | if (!is_lock_file_locked(&refs->lock)) | |
cff28ca9 | 710 | validate_snapshot(refs); |
67be7c5a | 711 | |
cff28ca9 MH |
712 | if (!refs->snapshot) |
713 | refs->snapshot = create_snapshot(refs); | |
67be7c5a | 714 | |
cff28ca9 | 715 | return refs->snapshot; |
67be7c5a MH |
716 | } |
717 | ||
e0cc8ac8 | 718 | static int packed_read_raw_ref(struct ref_store *ref_store, |
99afe91a | 719 | const char *refname, struct object_id *oid, |
e0cc8ac8 | 720 | struct strbuf *referent, unsigned int *type) |
67be7c5a | 721 | { |
e0cc8ac8 MH |
722 | struct packed_ref_store *refs = |
723 | packed_downcast(ref_store, REF_STORE_READ, "read_raw_ref"); | |
cff28ca9 | 724 | struct snapshot *snapshot = get_snapshot(refs); |
f3987ab3 | 725 | const char *rec; |
67be7c5a MH |
726 | |
727 | *type = 0; | |
728 | ||
cff28ca9 | 729 | rec = find_reference_location(snapshot, refname, 1); |
f3987ab3 MH |
730 | |
731 | if (!rec) { | |
732 | /* refname is not a packed reference. */ | |
67be7c5a MH |
733 | errno = ENOENT; |
734 | return -1; | |
735 | } | |
736 | ||
99afe91a | 737 | if (get_oid_hex(rec, oid)) |
cff28ca9 | 738 | die_invalid_line(refs->path, rec, snapshot->eof - rec); |
f3987ab3 | 739 | |
67be7c5a MH |
740 | *type = REF_ISPACKED; |
741 | return 0; | |
742 | } | |
743 | ||
523ee2d7 MH |
744 | /* |
745 | * This value is set in `base.flags` if the peeled value of the | |
746 | * current reference is known. In that case, `peeled` contains the | |
78fb4579 | 747 | * correct peeled value for the reference, which might be `null_oid` |
523ee2d7 MH |
748 | * if the reference is not a tag or if it is broken. |
749 | */ | |
750 | #define REF_KNOWS_PEELED 0x40 | |
67be7c5a | 751 | |
523ee2d7 | 752 | /* |
cff28ca9 | 753 | * An iterator over a snapshot of a `packed-refs` file. |
523ee2d7 | 754 | */ |
67be7c5a MH |
755 | struct packed_ref_iterator { |
756 | struct ref_iterator base; | |
757 | ||
cff28ca9 | 758 | struct snapshot *snapshot; |
523ee2d7 | 759 | |
cff28ca9 | 760 | /* The current position in the snapshot's buffer: */ |
523ee2d7 MH |
761 | const char *pos; |
762 | ||
cff28ca9 | 763 | /* The end of the part of the buffer that will be iterated over: */ |
523ee2d7 MH |
764 | const char *eof; |
765 | ||
cff28ca9 | 766 | /* Scratch space for current values: */ |
523ee2d7 | 767 | struct object_id oid, peeled; |
523ee2d7 MH |
768 | struct strbuf refname_buf; |
769 | ||
67be7c5a MH |
770 | unsigned int flags; |
771 | }; | |
772 | ||
cff28ca9 MH |
773 | /* |
774 | * Move the iterator to the next record in the snapshot, without | |
775 | * respect for whether the record is actually required by the current | |
776 | * iteration. Adjust the fields in `iter` and return `ITER_OK` or | |
777 | * `ITER_DONE`. This function does not free the iterator in the case | |
778 | * of `ITER_DONE`. | |
779 | */ | |
523ee2d7 MH |
780 | static int next_record(struct packed_ref_iterator *iter) |
781 | { | |
782 | const char *p = iter->pos, *eol; | |
783 | ||
784 | strbuf_reset(&iter->refname_buf); | |
785 | ||
786 | if (iter->pos == iter->eof) | |
787 | return ITER_DONE; | |
788 | ||
789 | iter->base.flags = REF_ISPACKED; | |
790 | ||
791 | if (iter->eof - p < GIT_SHA1_HEXSZ + 2 || | |
792 | parse_oid_hex(p, &iter->oid, &p) || | |
793 | !isspace(*p++)) | |
cff28ca9 | 794 | die_invalid_line(iter->snapshot->refs->path, |
523ee2d7 MH |
795 | iter->pos, iter->eof - iter->pos); |
796 | ||
797 | eol = memchr(p, '\n', iter->eof - p); | |
798 | if (!eol) | |
cff28ca9 | 799 | die_unterminated_line(iter->snapshot->refs->path, |
523ee2d7 MH |
800 | iter->pos, iter->eof - iter->pos); |
801 | ||
802 | strbuf_add(&iter->refname_buf, p, eol - p); | |
803 | iter->base.refname = iter->refname_buf.buf; | |
804 | ||
805 | if (check_refname_format(iter->base.refname, REFNAME_ALLOW_ONELEVEL)) { | |
806 | if (!refname_is_safe(iter->base.refname)) | |
807 | die("packed refname is dangerous: %s", | |
808 | iter->base.refname); | |
809 | oidclr(&iter->oid); | |
810 | iter->base.flags |= REF_BAD_NAME | REF_ISBROKEN; | |
811 | } | |
cff28ca9 MH |
812 | if (iter->snapshot->peeled == PEELED_FULLY || |
813 | (iter->snapshot->peeled == PEELED_TAGS && | |
523ee2d7 MH |
814 | starts_with(iter->base.refname, "refs/tags/"))) |
815 | iter->base.flags |= REF_KNOWS_PEELED; | |
816 | ||
817 | iter->pos = eol + 1; | |
818 | ||
819 | if (iter->pos < iter->eof && *iter->pos == '^') { | |
820 | p = iter->pos + 1; | |
821 | if (iter->eof - p < GIT_SHA1_HEXSZ + 1 || | |
822 | parse_oid_hex(p, &iter->peeled, &p) || | |
823 | *p++ != '\n') | |
cff28ca9 | 824 | die_invalid_line(iter->snapshot->refs->path, |
523ee2d7 MH |
825 | iter->pos, iter->eof - iter->pos); |
826 | iter->pos = p; | |
827 | ||
828 | /* | |
829 | * Regardless of what the file header said, we | |
830 | * definitely know the value of *this* reference. But | |
831 | * we suppress it if the reference is broken: | |
832 | */ | |
833 | if ((iter->base.flags & REF_ISBROKEN)) { | |
834 | oidclr(&iter->peeled); | |
835 | iter->base.flags &= ~REF_KNOWS_PEELED; | |
836 | } else { | |
837 | iter->base.flags |= REF_KNOWS_PEELED; | |
838 | } | |
839 | } else { | |
840 | oidclr(&iter->peeled); | |
841 | } | |
842 | ||
843 | return ITER_OK; | |
844 | } | |
845 | ||
67be7c5a MH |
846 | static int packed_ref_iterator_advance(struct ref_iterator *ref_iterator) |
847 | { | |
848 | struct packed_ref_iterator *iter = | |
849 | (struct packed_ref_iterator *)ref_iterator; | |
850 | int ok; | |
851 | ||
523ee2d7 | 852 | while ((ok = next_record(iter)) == ITER_OK) { |
67be7c5a | 853 | if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY && |
523ee2d7 | 854 | ref_type(iter->base.refname) != REF_TYPE_PER_WORKTREE) |
67be7c5a MH |
855 | continue; |
856 | ||
857 | if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) && | |
523ee2d7 MH |
858 | !ref_resolves_to_object(iter->base.refname, &iter->oid, |
859 | iter->flags)) | |
67be7c5a MH |
860 | continue; |
861 | ||
67be7c5a MH |
862 | return ITER_OK; |
863 | } | |
864 | ||
67be7c5a MH |
865 | if (ref_iterator_abort(ref_iterator) != ITER_DONE) |
866 | ok = ITER_ERROR; | |
867 | ||
868 | return ok; | |
869 | } | |
870 | ||
871 | static int packed_ref_iterator_peel(struct ref_iterator *ref_iterator, | |
872 | struct object_id *peeled) | |
873 | { | |
874 | struct packed_ref_iterator *iter = | |
875 | (struct packed_ref_iterator *)ref_iterator; | |
876 | ||
523ee2d7 MH |
877 | if ((iter->base.flags & REF_KNOWS_PEELED)) { |
878 | oidcpy(peeled, &iter->peeled); | |
879 | return is_null_oid(&iter->peeled) ? -1 : 0; | |
880 | } else if ((iter->base.flags & (REF_ISBROKEN | REF_ISSYMREF))) { | |
881 | return -1; | |
882 | } else { | |
ac2ed0d7 | 883 | return !!peel_object(&iter->oid, peeled); |
523ee2d7 | 884 | } |
67be7c5a MH |
885 | } |
886 | ||
887 | static int packed_ref_iterator_abort(struct ref_iterator *ref_iterator) | |
888 | { | |
889 | struct packed_ref_iterator *iter = | |
890 | (struct packed_ref_iterator *)ref_iterator; | |
891 | int ok = ITER_DONE; | |
892 | ||
523ee2d7 | 893 | strbuf_release(&iter->refname_buf); |
cff28ca9 | 894 | release_snapshot(iter->snapshot); |
67be7c5a MH |
895 | base_ref_iterator_free(ref_iterator); |
896 | return ok; | |
897 | } | |
898 | ||
899 | static struct ref_iterator_vtable packed_ref_iterator_vtable = { | |
900 | packed_ref_iterator_advance, | |
901 | packed_ref_iterator_peel, | |
902 | packed_ref_iterator_abort | |
903 | }; | |
904 | ||
e0cc8ac8 MH |
905 | static struct ref_iterator *packed_ref_iterator_begin( |
906 | struct ref_store *ref_store, | |
67be7c5a MH |
907 | const char *prefix, unsigned int flags) |
908 | { | |
e0cc8ac8 | 909 | struct packed_ref_store *refs; |
cff28ca9 | 910 | struct snapshot *snapshot; |
d1cf1551 | 911 | const char *start; |
67be7c5a MH |
912 | struct packed_ref_iterator *iter; |
913 | struct ref_iterator *ref_iterator; | |
e0cc8ac8 MH |
914 | unsigned int required_flags = REF_STORE_READ; |
915 | ||
916 | if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) | |
917 | required_flags |= REF_STORE_ODB; | |
918 | refs = packed_downcast(ref_store, required_flags, "ref_iterator_begin"); | |
67be7c5a | 919 | |
cff28ca9 MH |
920 | /* |
921 | * Note that `get_snapshot()` internally checks whether the | |
922 | * snapshot is up to date with what is on disk, and re-reads | |
923 | * it if not. | |
924 | */ | |
925 | snapshot = get_snapshot(refs); | |
523ee2d7 | 926 | |
cff28ca9 | 927 | if (!snapshot->buf) |
523ee2d7 MH |
928 | return empty_ref_iterator_begin(); |
929 | ||
67be7c5a MH |
930 | iter = xcalloc(1, sizeof(*iter)); |
931 | ref_iterator = &iter->base; | |
8738a8a4 | 932 | base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable, 1); |
67be7c5a | 933 | |
cff28ca9 MH |
934 | iter->snapshot = snapshot; |
935 | acquire_snapshot(snapshot); | |
67be7c5a | 936 | |
d1cf1551 | 937 | if (prefix && *prefix) |
cff28ca9 | 938 | start = find_reference_location(snapshot, prefix, 0); |
d1cf1551 | 939 | else |
cff28ca9 | 940 | start = snapshot->buf + snapshot->header_len; |
67be7c5a | 941 | |
523ee2d7 | 942 | iter->pos = start; |
cff28ca9 | 943 | iter->eof = snapshot->eof; |
523ee2d7 MH |
944 | strbuf_init(&iter->refname_buf, 0); |
945 | ||
946 | iter->base.oid = &iter->oid; | |
67be7c5a MH |
947 | |
948 | iter->flags = flags; | |
949 | ||
d1cf1551 MH |
950 | if (prefix && *prefix) |
951 | /* Stop iteration after we've gone *past* prefix: */ | |
952 | ref_iterator = prefix_ref_iterator_begin(ref_iterator, prefix, 0); | |
953 | ||
67be7c5a MH |
954 | return ref_iterator; |
955 | } | |
956 | ||
957 | /* | |
958 | * Write an entry to the packed-refs file for the specified refname. | |
3478983b MH |
959 | * If peeled is non-NULL, write it as the entry's peeled value. On |
960 | * error, return a nonzero value and leave errno set at the value left | |
961 | * by the failing call to `fprintf()`. | |
67be7c5a | 962 | */ |
3478983b | 963 | static int write_packed_entry(FILE *fh, const char *refname, |
41701882 MH |
964 | const struct object_id *oid, |
965 | const struct object_id *peeled) | |
67be7c5a | 966 | { |
41701882 MH |
967 | if (fprintf(fh, "%s %s\n", oid_to_hex(oid), refname) < 0 || |
968 | (peeled && fprintf(fh, "^%s\n", oid_to_hex(peeled)) < 0)) | |
3478983b MH |
969 | return -1; |
970 | ||
971 | return 0; | |
67be7c5a MH |
972 | } |
973 | ||
c8bed835 | 974 | int packed_refs_lock(struct ref_store *ref_store, int flags, struct strbuf *err) |
67be7c5a | 975 | { |
e0cc8ac8 MH |
976 | struct packed_ref_store *refs = |
977 | packed_downcast(ref_store, REF_STORE_WRITE | REF_STORE_MAIN, | |
b7de57d8 | 978 | "packed_refs_lock"); |
67be7c5a MH |
979 | static int timeout_configured = 0; |
980 | static int timeout_value = 1000; | |
67be7c5a | 981 | |
67be7c5a MH |
982 | if (!timeout_configured) { |
983 | git_config_get_int("core.packedrefstimeout", &timeout_value); | |
984 | timeout_configured = 1; | |
985 | } | |
986 | ||
42dfa7ec MH |
987 | /* |
988 | * Note that we close the lockfile immediately because we | |
989 | * don't write new content to it, but rather to a separate | |
990 | * tempfile. | |
991 | */ | |
67be7c5a MH |
992 | if (hold_lock_file_for_update_timeout( |
993 | &refs->lock, | |
994 | refs->path, | |
c8bed835 MH |
995 | flags, timeout_value) < 0) { |
996 | unable_to_lock_message(refs->path, errno, err); | |
997 | return -1; | |
998 | } | |
999 | ||
83a3069a | 1000 | if (close_lock_file_gently(&refs->lock)) { |
c8bed835 | 1001 | strbuf_addf(err, "unable to close %s: %s", refs->path, strerror(errno)); |
83a3069a | 1002 | rollback_lock_file(&refs->lock); |
67be7c5a | 1003 | return -1; |
c8bed835 | 1004 | } |
67be7c5a MH |
1005 | |
1006 | /* | |
1007 | * Now that we hold the `packed-refs` lock, make sure that our | |
cff28ca9 MH |
1008 | * snapshot matches the current version of the file. Normally |
1009 | * `get_snapshot()` does that for us, but that function | |
1010 | * assumes that when the file is locked, any existing snapshot | |
1011 | * is still valid. We've just locked the file, but it might | |
1012 | * have changed the moment *before* we locked it. | |
67be7c5a | 1013 | */ |
cff28ca9 | 1014 | validate_snapshot(refs); |
67be7c5a | 1015 | |
39c8df0c MH |
1016 | /* |
1017 | * Now make sure that the packed-refs file as it exists in the | |
cff28ca9 | 1018 | * locked state is loaded into the snapshot: |
39c8df0c | 1019 | */ |
cff28ca9 | 1020 | get_snapshot(refs); |
67be7c5a MH |
1021 | return 0; |
1022 | } | |
1023 | ||
49aebcf4 MH |
1024 | void packed_refs_unlock(struct ref_store *ref_store) |
1025 | { | |
1026 | struct packed_ref_store *refs = packed_downcast( | |
1027 | ref_store, | |
1028 | REF_STORE_READ | REF_STORE_WRITE, | |
1029 | "packed_refs_unlock"); | |
1030 | ||
1031 | if (!is_lock_file_locked(&refs->lock)) | |
1032 | die("BUG: packed_refs_unlock() called when not locked"); | |
1033 | rollback_lock_file(&refs->lock); | |
49aebcf4 MH |
1034 | } |
1035 | ||
1036 | int packed_refs_is_locked(struct ref_store *ref_store) | |
1037 | { | |
1038 | struct packed_ref_store *refs = packed_downcast( | |
1039 | ref_store, | |
1040 | REF_STORE_READ | REF_STORE_WRITE, | |
1041 | "packed_refs_is_locked"); | |
1042 | ||
1043 | return is_lock_file_locked(&refs->lock); | |
1044 | } | |
1045 | ||
67be7c5a | 1046 | /* |
cff28ca9 MH |
1047 | * The packed-refs header line that we write out. Perhaps other traits |
1048 | * will be added later. | |
a8811695 MH |
1049 | * |
1050 | * Note that earlier versions of Git used to parse these traits by | |
1051 | * looking for " trait " in the line. For this reason, the space after | |
1052 | * the colon and the trailing space are required. | |
67be7c5a MH |
1053 | */ |
1054 | static const char PACKED_REFS_HEADER[] = | |
02b920f3 | 1055 | "# pack-refs with: peeled fully-peeled sorted \n"; |
67be7c5a | 1056 | |
e0cc8ac8 MH |
1057 | static int packed_init_db(struct ref_store *ref_store, struct strbuf *err) |
1058 | { | |
1059 | /* Nothing to do. */ | |
1060 | return 0; | |
1061 | } | |
1062 | ||
67be7c5a | 1063 | /* |
cff28ca9 MH |
1064 | * Write the packed refs from the current snapshot to the packed-refs |
1065 | * tempfile, incorporating any changes from `updates`. `updates` must | |
1066 | * be a sorted string list whose keys are the refnames and whose util | |
2775d872 MH |
1067 | * values are `struct ref_update *`. On error, rollback the tempfile, |
1068 | * write an error message to `err`, and return a nonzero value. | |
1069 | * | |
1070 | * The packfile must be locked before calling this function and will | |
1071 | * remain locked when it is done. | |
67be7c5a | 1072 | */ |
2775d872 MH |
1073 | static int write_with_updates(struct packed_ref_store *refs, |
1074 | struct string_list *updates, | |
1075 | struct strbuf *err) | |
67be7c5a | 1076 | { |
2775d872 MH |
1077 | struct ref_iterator *iter = NULL; |
1078 | size_t i; | |
3478983b | 1079 | int ok; |
67be7c5a | 1080 | FILE *out; |
2775d872 | 1081 | struct strbuf sb = STRBUF_INIT; |
198b808e | 1082 | char *packed_refs_path; |
67be7c5a | 1083 | |
67be7c5a | 1084 | if (!is_lock_file_locked(&refs->lock)) |
2775d872 | 1085 | die("BUG: write_with_updates() called while unlocked"); |
67be7c5a | 1086 | |
198b808e MH |
1087 | /* |
1088 | * If packed-refs is a symlink, we want to overwrite the | |
1089 | * symlinked-to file, not the symlink itself. Also, put the | |
1090 | * staging file next to it: | |
1091 | */ | |
1092 | packed_refs_path = get_locked_file_path(&refs->lock); | |
1093 | strbuf_addf(&sb, "%s.new", packed_refs_path); | |
2775d872 | 1094 | free(packed_refs_path); |
076aa2cb JK |
1095 | refs->tempfile = create_tempfile(sb.buf); |
1096 | if (!refs->tempfile) { | |
42dfa7ec MH |
1097 | strbuf_addf(err, "unable to create file %s: %s", |
1098 | sb.buf, strerror(errno)); | |
1099 | strbuf_release(&sb); | |
2775d872 | 1100 | return -1; |
42dfa7ec MH |
1101 | } |
1102 | strbuf_release(&sb); | |
1103 | ||
076aa2cb | 1104 | out = fdopen_tempfile(refs->tempfile, "w"); |
3478983b MH |
1105 | if (!out) { |
1106 | strbuf_addf(err, "unable to fdopen packed-refs tempfile: %s", | |
1107 | strerror(errno)); | |
1108 | goto error; | |
1109 | } | |
67be7c5a | 1110 | |
2775d872 MH |
1111 | if (fprintf(out, "%s", PACKED_REFS_HEADER) < 0) |
1112 | goto write_error; | |
1113 | ||
1114 | /* | |
1115 | * We iterate in parallel through the current list of refs and | |
1116 | * the list of updates, processing an entry from at least one | |
1117 | * of the lists each time through the loop. When the current | |
1118 | * list of refs is exhausted, set iter to NULL. When the list | |
1119 | * of updates is exhausted, leave i set to updates->nr. | |
1120 | */ | |
1121 | iter = packed_ref_iterator_begin(&refs->base, "", | |
1122 | DO_FOR_EACH_INCLUDE_BROKEN); | |
1123 | if ((ok = ref_iterator_advance(iter)) != ITER_OK) | |
1124 | iter = NULL; | |
1125 | ||
1126 | i = 0; | |
67be7c5a | 1127 | |
2775d872 MH |
1128 | while (iter || i < updates->nr) { |
1129 | struct ref_update *update = NULL; | |
1130 | int cmp; | |
1131 | ||
1132 | if (i >= updates->nr) { | |
1133 | cmp = -1; | |
1134 | } else { | |
1135 | update = updates->items[i].util; | |
1136 | ||
1137 | if (!iter) | |
1138 | cmp = +1; | |
1139 | else | |
1140 | cmp = strcmp(iter->refname, update->refname); | |
1141 | } | |
1142 | ||
1143 | if (!cmp) { | |
1144 | /* | |
1145 | * There is both an old value and an update | |
1146 | * for this reference. Check the old value if | |
1147 | * necessary: | |
1148 | */ | |
1149 | if ((update->flags & REF_HAVE_OLD)) { | |
1150 | if (is_null_oid(&update->old_oid)) { | |
1151 | strbuf_addf(err, "cannot update ref '%s': " | |
1152 | "reference already exists", | |
1153 | update->refname); | |
1154 | goto error; | |
1155 | } else if (oidcmp(&update->old_oid, iter->oid)) { | |
1156 | strbuf_addf(err, "cannot update ref '%s': " | |
1157 | "is at %s but expected %s", | |
1158 | update->refname, | |
1159 | oid_to_hex(iter->oid), | |
1160 | oid_to_hex(&update->old_oid)); | |
1161 | goto error; | |
1162 | } | |
1163 | } | |
1164 | ||
1165 | /* Now figure out what to use for the new value: */ | |
1166 | if ((update->flags & REF_HAVE_NEW)) { | |
1167 | /* | |
1168 | * The update takes precedence. Skip | |
1169 | * the iterator over the unneeded | |
1170 | * value. | |
1171 | */ | |
1172 | if ((ok = ref_iterator_advance(iter)) != ITER_OK) | |
1173 | iter = NULL; | |
1174 | cmp = +1; | |
1175 | } else { | |
1176 | /* | |
1177 | * The update doesn't actually want to | |
1178 | * change anything. We're done with it. | |
1179 | */ | |
1180 | i++; | |
1181 | cmp = -1; | |
1182 | } | |
1183 | } else if (cmp > 0) { | |
1184 | /* | |
1185 | * There is no old value but there is an | |
1186 | * update for this reference. Make sure that | |
1187 | * the update didn't expect an existing value: | |
1188 | */ | |
1189 | if ((update->flags & REF_HAVE_OLD) && | |
1190 | !is_null_oid(&update->old_oid)) { | |
1191 | strbuf_addf(err, "cannot update ref '%s': " | |
1192 | "reference is missing but expected %s", | |
1193 | update->refname, | |
1194 | oid_to_hex(&update->old_oid)); | |
1195 | goto error; | |
1196 | } | |
1197 | } | |
1198 | ||
1199 | if (cmp < 0) { | |
1200 | /* Pass the old reference through. */ | |
1201 | ||
1202 | struct object_id peeled; | |
1203 | int peel_error = ref_iterator_peel(iter, &peeled); | |
1204 | ||
1205 | if (write_packed_entry(out, iter->refname, | |
41701882 MH |
1206 | iter->oid, |
1207 | peel_error ? NULL : &peeled)) | |
2775d872 MH |
1208 | goto write_error; |
1209 | ||
1210 | if ((ok = ref_iterator_advance(iter)) != ITER_OK) | |
1211 | iter = NULL; | |
1212 | } else if (is_null_oid(&update->new_oid)) { | |
1213 | /* | |
1214 | * The update wants to delete the reference, | |
1215 | * and the reference either didn't exist or we | |
1216 | * have already skipped it. So we're done with | |
1217 | * the update (and don't have to write | |
1218 | * anything). | |
1219 | */ | |
1220 | i++; | |
1221 | } else { | |
1222 | struct object_id peeled; | |
ac2ed0d7 | 1223 | int peel_error = peel_object(&update->new_oid, |
1224 | &peeled); | |
2775d872 MH |
1225 | |
1226 | if (write_packed_entry(out, update->refname, | |
41701882 MH |
1227 | &update->new_oid, |
1228 | peel_error ? NULL : &peeled)) | |
2775d872 MH |
1229 | goto write_error; |
1230 | ||
1231 | i++; | |
3478983b | 1232 | } |
67be7c5a MH |
1233 | } |
1234 | ||
3478983b | 1235 | if (ok != ITER_DONE) { |
72d4a9a7 RS |
1236 | strbuf_addstr(err, "unable to write packed-refs file: " |
1237 | "error iterating over old contents"); | |
3478983b MH |
1238 | goto error; |
1239 | } | |
67be7c5a | 1240 | |
07f0542d | 1241 | if (close_tempfile_gently(refs->tempfile)) { |
2775d872 | 1242 | strbuf_addf(err, "error closing file %s: %s", |
07f0542d | 1243 | get_tempfile_path(refs->tempfile), |
2775d872 MH |
1244 | strerror(errno)); |
1245 | strbuf_release(&sb); | |
07f0542d | 1246 | delete_tempfile(&refs->tempfile); |
2775d872 | 1247 | return -1; |
67be7c5a | 1248 | } |
3478983b | 1249 | |
2775d872 MH |
1250 | return 0; |
1251 | ||
1252 | write_error: | |
1253 | strbuf_addf(err, "error writing to %s: %s", | |
07f0542d | 1254 | get_tempfile_path(refs->tempfile), strerror(errno)); |
3478983b MH |
1255 | |
1256 | error: | |
2775d872 MH |
1257 | if (iter) |
1258 | ref_iterator_abort(iter); | |
198b808e | 1259 | |
2775d872 MH |
1260 | delete_tempfile(&refs->tempfile); |
1261 | return -1; | |
67be7c5a MH |
1262 | } |
1263 | ||
7c6bd25c MH |
1264 | int is_packed_transaction_needed(struct ref_store *ref_store, |
1265 | struct ref_transaction *transaction) | |
1266 | { | |
1267 | struct packed_ref_store *refs = packed_downcast( | |
1268 | ref_store, | |
1269 | REF_STORE_READ, | |
1270 | "is_packed_transaction_needed"); | |
1271 | struct strbuf referent = STRBUF_INIT; | |
1272 | size_t i; | |
1273 | int ret; | |
1274 | ||
1275 | if (!is_lock_file_locked(&refs->lock)) | |
1276 | BUG("is_packed_transaction_needed() called while unlocked"); | |
1277 | ||
1278 | /* | |
1279 | * We're only going to bother returning false for the common, | |
1280 | * trivial case that references are only being deleted, their | |
1281 | * old values are not being checked, and the old `packed-refs` | |
1282 | * file doesn't contain any of those reference(s). This gives | |
1283 | * false positives for some other cases that could | |
1284 | * theoretically be optimized away: | |
1285 | * | |
1286 | * 1. It could be that the old value is being verified without | |
1287 | * setting a new value. In this case, we could verify the | |
1288 | * old value here and skip the update if it agrees. If it | |
1289 | * disagrees, we could either let the update go through | |
1290 | * (the actual commit would re-detect and report the | |
1291 | * problem), or come up with a way of reporting such an | |
1292 | * error to *our* caller. | |
1293 | * | |
1294 | * 2. It could be that a new value is being set, but that it | |
1295 | * is identical to the current packed value of the | |
1296 | * reference. | |
1297 | * | |
1298 | * Neither of these cases will come up in the current code, | |
1299 | * because the only caller of this function passes to it a | |
1300 | * transaction that only includes `delete` updates with no | |
1301 | * `old_id`. Even if that ever changes, false positives only | |
1302 | * cause an optimization to be missed; they do not affect | |
1303 | * correctness. | |
1304 | */ | |
1305 | ||
1306 | /* | |
1307 | * Start with the cheap checks that don't require old | |
1308 | * reference values to be read: | |
1309 | */ | |
1310 | for (i = 0; i < transaction->nr; i++) { | |
1311 | struct ref_update *update = transaction->updates[i]; | |
1312 | ||
1313 | if (update->flags & REF_HAVE_OLD) | |
1314 | /* Have to check the old value -> needed. */ | |
1315 | return 1; | |
1316 | ||
1317 | if ((update->flags & REF_HAVE_NEW) && !is_null_oid(&update->new_oid)) | |
1318 | /* Have to set a new value -> needed. */ | |
1319 | return 1; | |
1320 | } | |
1321 | ||
1322 | /* | |
1323 | * The transaction isn't checking any old values nor is it | |
1324 | * setting any nonzero new values, so it still might be able | |
1325 | * to be skipped. Now do the more expensive check: the update | |
1326 | * is needed if any of the updates is a delete, and the old | |
1327 | * `packed-refs` file contains a value for that reference. | |
1328 | */ | |
1329 | ret = 0; | |
1330 | for (i = 0; i < transaction->nr; i++) { | |
1331 | struct ref_update *update = transaction->updates[i]; | |
1332 | unsigned int type; | |
1333 | struct object_id oid; | |
1334 | ||
1335 | if (!(update->flags & REF_HAVE_NEW)) | |
1336 | /* | |
1337 | * This reference isn't being deleted -> not | |
1338 | * needed. | |
1339 | */ | |
1340 | continue; | |
1341 | ||
1342 | if (!refs_read_raw_ref(ref_store, update->refname, | |
ffb0b576 | 1343 | &oid, &referent, &type) || |
7c6bd25c MH |
1344 | errno != ENOENT) { |
1345 | /* | |
1346 | * We have to actually delete that reference | |
1347 | * -> this transaction is needed. | |
1348 | */ | |
1349 | ret = 1; | |
1350 | break; | |
1351 | } | |
1352 | } | |
1353 | ||
1354 | strbuf_release(&referent); | |
1355 | return ret; | |
1356 | } | |
1357 | ||
2775d872 MH |
1358 | struct packed_transaction_backend_data { |
1359 | /* True iff the transaction owns the packed-refs lock. */ | |
1360 | int own_lock; | |
1361 | ||
1362 | struct string_list updates; | |
1363 | }; | |
1364 | ||
1365 | static void packed_transaction_cleanup(struct packed_ref_store *refs, | |
1366 | struct ref_transaction *transaction) | |
67be7c5a | 1367 | { |
2775d872 | 1368 | struct packed_transaction_backend_data *data = transaction->backend_data; |
67be7c5a | 1369 | |
2775d872 MH |
1370 | if (data) { |
1371 | string_list_clear(&data->updates, 0); | |
67be7c5a | 1372 | |
07f0542d | 1373 | if (is_tempfile_active(refs->tempfile)) |
2775d872 | 1374 | delete_tempfile(&refs->tempfile); |
e5cc7d7d | 1375 | |
2775d872 MH |
1376 | if (data->own_lock && is_lock_file_locked(&refs->lock)) { |
1377 | packed_refs_unlock(&refs->base); | |
1378 | data->own_lock = 0; | |
67be7c5a | 1379 | } |
67be7c5a | 1380 | |
2775d872 MH |
1381 | free(data); |
1382 | transaction->backend_data = NULL; | |
67be7c5a MH |
1383 | } |
1384 | ||
2775d872 | 1385 | transaction->state = REF_TRANSACTION_CLOSED; |
e0cc8ac8 MH |
1386 | } |
1387 | ||
1388 | static int packed_transaction_prepare(struct ref_store *ref_store, | |
1389 | struct ref_transaction *transaction, | |
1390 | struct strbuf *err) | |
1391 | { | |
2775d872 MH |
1392 | struct packed_ref_store *refs = packed_downcast( |
1393 | ref_store, | |
1394 | REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB, | |
1395 | "ref_transaction_prepare"); | |
1396 | struct packed_transaction_backend_data *data; | |
1397 | size_t i; | |
1398 | int ret = TRANSACTION_GENERIC_ERROR; | |
1399 | ||
1400 | /* | |
1401 | * Note that we *don't* skip transactions with zero updates, | |
1402 | * because such a transaction might be executed for the side | |
cff28ca9 MH |
1403 | * effect of ensuring that all of the references are peeled or |
1404 | * ensuring that the `packed-refs` file is sorted. If the | |
1405 | * caller wants to optimize away empty transactions, it should | |
1406 | * do so itself. | |
2775d872 MH |
1407 | */ |
1408 | ||
1409 | data = xcalloc(1, sizeof(*data)); | |
1410 | string_list_init(&data->updates, 0); | |
1411 | ||
1412 | transaction->backend_data = data; | |
1413 | ||
1414 | /* | |
1415 | * Stick the updates in a string list by refname so that we | |
1416 | * can sort them: | |
1417 | */ | |
1418 | for (i = 0; i < transaction->nr; i++) { | |
1419 | struct ref_update *update = transaction->updates[i]; | |
1420 | struct string_list_item *item = | |
1421 | string_list_append(&data->updates, update->refname); | |
1422 | ||
1423 | /* Store a pointer to update in item->util: */ | |
1424 | item->util = update; | |
1425 | } | |
1426 | string_list_sort(&data->updates); | |
1427 | ||
1428 | if (ref_update_reject_duplicates(&data->updates, err)) | |
1429 | goto failure; | |
1430 | ||
1431 | if (!is_lock_file_locked(&refs->lock)) { | |
1432 | if (packed_refs_lock(ref_store, 0, err)) | |
1433 | goto failure; | |
1434 | data->own_lock = 1; | |
1435 | } | |
1436 | ||
1437 | if (write_with_updates(refs, &data->updates, err)) | |
1438 | goto failure; | |
1439 | ||
1440 | transaction->state = REF_TRANSACTION_PREPARED; | |
1441 | return 0; | |
1442 | ||
1443 | failure: | |
1444 | packed_transaction_cleanup(refs, transaction); | |
1445 | return ret; | |
e0cc8ac8 MH |
1446 | } |
1447 | ||
1448 | static int packed_transaction_abort(struct ref_store *ref_store, | |
1449 | struct ref_transaction *transaction, | |
1450 | struct strbuf *err) | |
1451 | { | |
2775d872 MH |
1452 | struct packed_ref_store *refs = packed_downcast( |
1453 | ref_store, | |
1454 | REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB, | |
1455 | "ref_transaction_abort"); | |
1456 | ||
1457 | packed_transaction_cleanup(refs, transaction); | |
1458 | return 0; | |
e0cc8ac8 MH |
1459 | } |
1460 | ||
1461 | static int packed_transaction_finish(struct ref_store *ref_store, | |
1462 | struct ref_transaction *transaction, | |
1463 | struct strbuf *err) | |
1464 | { | |
2775d872 MH |
1465 | struct packed_ref_store *refs = packed_downcast( |
1466 | ref_store, | |
1467 | REF_STORE_READ | REF_STORE_WRITE | REF_STORE_ODB, | |
1468 | "ref_transaction_finish"); | |
1469 | int ret = TRANSACTION_GENERIC_ERROR; | |
1470 | char *packed_refs_path; | |
1471 | ||
cff28ca9 | 1472 | clear_snapshot(refs); |
5b633610 | 1473 | |
2775d872 MH |
1474 | packed_refs_path = get_locked_file_path(&refs->lock); |
1475 | if (rename_tempfile(&refs->tempfile, packed_refs_path)) { | |
1476 | strbuf_addf(err, "error replacing %s: %s", | |
1477 | refs->path, strerror(errno)); | |
1478 | goto cleanup; | |
1479 | } | |
1480 | ||
2775d872 MH |
1481 | ret = 0; |
1482 | ||
1483 | cleanup: | |
1484 | free(packed_refs_path); | |
1485 | packed_transaction_cleanup(refs, transaction); | |
1486 | return ret; | |
e0cc8ac8 MH |
1487 | } |
1488 | ||
1489 | static int packed_initial_transaction_commit(struct ref_store *ref_store, | |
1490 | struct ref_transaction *transaction, | |
1491 | struct strbuf *err) | |
1492 | { | |
1493 | return ref_transaction_commit(transaction, err); | |
1494 | } | |
1495 | ||
1496 | static int packed_delete_refs(struct ref_store *ref_store, const char *msg, | |
1497 | struct string_list *refnames, unsigned int flags) | |
1498 | { | |
2fb330ca MH |
1499 | struct packed_ref_store *refs = |
1500 | packed_downcast(ref_store, REF_STORE_WRITE, "delete_refs"); | |
1501 | struct strbuf err = STRBUF_INIT; | |
1502 | struct ref_transaction *transaction; | |
1503 | struct string_list_item *item; | |
1504 | int ret; | |
1505 | ||
1506 | (void)refs; /* We need the check above, but don't use the variable */ | |
1507 | ||
1508 | if (!refnames->nr) | |
1509 | return 0; | |
1510 | ||
1511 | /* | |
1512 | * Since we don't check the references' old_oids, the | |
1513 | * individual updates can't fail, so we can pack all of the | |
1514 | * updates into a single transaction. | |
1515 | */ | |
1516 | ||
1517 | transaction = ref_store_transaction_begin(ref_store, &err); | |
1518 | if (!transaction) | |
1519 | return -1; | |
1520 | ||
1521 | for_each_string_list_item(item, refnames) { | |
1522 | if (ref_transaction_delete(transaction, item->string, NULL, | |
1523 | flags, msg, &err)) { | |
1524 | warning(_("could not delete reference %s: %s"), | |
1525 | item->string, err.buf); | |
1526 | strbuf_reset(&err); | |
1527 | } | |
1528 | } | |
1529 | ||
1530 | ret = ref_transaction_commit(transaction, &err); | |
1531 | ||
1532 | if (ret) { | |
1533 | if (refnames->nr == 1) | |
1534 | error(_("could not delete reference %s: %s"), | |
1535 | refnames->items[0].string, err.buf); | |
1536 | else | |
1537 | error(_("could not delete references: %s"), err.buf); | |
1538 | } | |
1539 | ||
1540 | ref_transaction_free(transaction); | |
1541 | strbuf_release(&err); | |
1542 | return ret; | |
e0cc8ac8 MH |
1543 | } |
1544 | ||
1545 | static int packed_pack_refs(struct ref_store *ref_store, unsigned int flags) | |
1546 | { | |
1547 | /* | |
1548 | * Packed refs are already packed. It might be that loose refs | |
1549 | * are packed *into* a packed refs store, but that is done by | |
1550 | * updating the packed references via a transaction. | |
1551 | */ | |
1552 | return 0; | |
1553 | } | |
1554 | ||
1555 | static int packed_create_symref(struct ref_store *ref_store, | |
1556 | const char *refname, const char *target, | |
1557 | const char *logmsg) | |
1558 | { | |
1559 | die("BUG: packed reference store does not support symrefs"); | |
1560 | } | |
1561 | ||
1562 | static int packed_rename_ref(struct ref_store *ref_store, | |
1563 | const char *oldrefname, const char *newrefname, | |
1564 | const char *logmsg) | |
1565 | { | |
1566 | die("BUG: packed reference store does not support renaming references"); | |
1567 | } | |
1568 | ||
3b48045c JH |
1569 | static int packed_copy_ref(struct ref_store *ref_store, |
1570 | const char *oldrefname, const char *newrefname, | |
1571 | const char *logmsg) | |
1572 | { | |
1573 | die("BUG: packed reference store does not support copying references"); | |
1574 | } | |
1575 | ||
e0cc8ac8 MH |
1576 | static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_store) |
1577 | { | |
1578 | return empty_ref_iterator_begin(); | |
1579 | } | |
1580 | ||
1581 | static int packed_for_each_reflog_ent(struct ref_store *ref_store, | |
1582 | const char *refname, | |
1583 | each_reflog_ent_fn fn, void *cb_data) | |
1584 | { | |
1585 | return 0; | |
1586 | } | |
1587 | ||
1588 | static int packed_for_each_reflog_ent_reverse(struct ref_store *ref_store, | |
1589 | const char *refname, | |
1590 | each_reflog_ent_fn fn, | |
1591 | void *cb_data) | |
1592 | { | |
1593 | return 0; | |
1594 | } | |
1595 | ||
1596 | static int packed_reflog_exists(struct ref_store *ref_store, | |
1597 | const char *refname) | |
1598 | { | |
1599 | return 0; | |
1600 | } | |
1601 | ||
1602 | static int packed_create_reflog(struct ref_store *ref_store, | |
1603 | const char *refname, int force_create, | |
1604 | struct strbuf *err) | |
1605 | { | |
1606 | die("BUG: packed reference store does not support reflogs"); | |
1607 | } | |
1608 | ||
1609 | static int packed_delete_reflog(struct ref_store *ref_store, | |
1610 | const char *refname) | |
1611 | { | |
1612 | return 0; | |
1613 | } | |
1614 | ||
1615 | static int packed_reflog_expire(struct ref_store *ref_store, | |
0155f710 | 1616 | const char *refname, const struct object_id *oid, |
e0cc8ac8 MH |
1617 | unsigned int flags, |
1618 | reflog_expiry_prepare_fn prepare_fn, | |
1619 | reflog_expiry_should_prune_fn should_prune_fn, | |
1620 | reflog_expiry_cleanup_fn cleanup_fn, | |
1621 | void *policy_cb_data) | |
1622 | { | |
1623 | return 0; | |
1624 | } | |
1625 | ||
1626 | struct ref_storage_be refs_be_packed = { | |
1627 | NULL, | |
1628 | "packed", | |
1629 | packed_ref_store_create, | |
1630 | packed_init_db, | |
1631 | packed_transaction_prepare, | |
1632 | packed_transaction_finish, | |
1633 | packed_transaction_abort, | |
1634 | packed_initial_transaction_commit, | |
1635 | ||
1636 | packed_pack_refs, | |
e0cc8ac8 MH |
1637 | packed_create_symref, |
1638 | packed_delete_refs, | |
1639 | packed_rename_ref, | |
3b48045c | 1640 | packed_copy_ref, |
e0cc8ac8 MH |
1641 | |
1642 | packed_ref_iterator_begin, | |
1643 | packed_read_raw_ref, | |
1644 | ||
1645 | packed_reflog_iterator_begin, | |
1646 | packed_for_each_reflog_ent, | |
1647 | packed_for_each_reflog_ent_reverse, | |
1648 | packed_reflog_exists, | |
1649 | packed_create_reflog, | |
1650 | packed_delete_reflog, | |
1651 | packed_reflog_expire | |
1652 | }; |