refs: factor update_ref steps into helpers
[git/git.git] / refs.c
CommitLineData
95fc7512 1#include "cache.h"
85023577 2#include "refs.h"
cf0adba7
JH
3#include "object.h"
4#include "tag.h"
7155b727 5#include "dir.h"
daebaa78 6#include "string-list.h"
95fc7512 7
bc5fd6d3
MH
8/*
9 * Make sure "ref" is something reasonable to have under ".git/refs/";
10 * We do not like it if:
11 *
12 * - any path component of it begins with ".", or
13 * - it has double dots "..", or
14 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
15 * - it ends with a "/".
16 * - it ends with ".lock"
17 * - it contains a "\" (backslash)
18 */
f4204ab9 19
bc5fd6d3
MH
20/* Return true iff ch is not allowed in reference names. */
21static inline int bad_ref_char(int ch)
22{
23 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
24 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
25 return 1;
26 /* 2.13 Pattern Matching Notation */
27 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
28 return 1;
29 return 0;
30}
31
32/*
33 * Try to read one refname component from the front of refname. Return
34 * the length of the component found, or -1 if the component is not
35 * legal.
36 */
37static int check_refname_component(const char *refname, int flags)
38{
39 const char *cp;
40 char last = '\0';
41
42 for (cp = refname; ; cp++) {
43 char ch = *cp;
44 if (ch == '\0' || ch == '/')
45 break;
46 if (bad_ref_char(ch))
47 return -1; /* Illegal character in refname. */
48 if (last == '.' && ch == '.')
49 return -1; /* Refname contains "..". */
50 if (last == '@' && ch == '{')
51 return -1; /* Refname contains "@{". */
52 last = ch;
53 }
54 if (cp == refname)
dac529e4 55 return 0; /* Component has zero length. */
bc5fd6d3
MH
56 if (refname[0] == '.') {
57 if (!(flags & REFNAME_DOT_COMPONENT))
58 return -1; /* Component starts with '.'. */
59 /*
60 * Even if leading dots are allowed, don't allow "."
61 * as a component (".." is prevented by a rule above).
62 */
63 if (refname[1] == '\0')
64 return -1; /* Component equals ".". */
65 }
66 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
67 return -1; /* Refname ends with ".lock". */
68 return cp - refname;
69}
70
71int check_refname_format(const char *refname, int flags)
72{
73 int component_len, component_count = 0;
74
75 while (1) {
76 /* We are at the start of a path component. */
77 component_len = check_refname_component(refname, flags);
dac529e4 78 if (component_len <= 0) {
bc5fd6d3
MH
79 if ((flags & REFNAME_REFSPEC_PATTERN) &&
80 refname[0] == '*' &&
81 (refname[1] == '\0' || refname[1] == '/')) {
82 /* Accept one wildcard as a full refname component. */
83 flags &= ~REFNAME_REFSPEC_PATTERN;
84 component_len = 1;
85 } else {
86 return -1;
87 }
88 }
89 component_count++;
90 if (refname[component_len] == '\0')
91 break;
92 /* Skip to next component. */
93 refname += component_len + 1;
94 }
95
96 if (refname[component_len - 1] == '.')
97 return -1; /* Refname ends with '.'. */
98 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
99 return -1; /* Refname has only one component. */
100 return 0;
101}
102
103struct ref_entry;
e1e22e37 104
28e6a34e
MH
105/*
106 * Information used (along with the information in ref_entry) to
107 * describe a single cached reference. This data structure only
108 * occurs embedded in a union in struct ref_entry, and only when
109 * (ref_entry->flag & REF_DIR) is zero.
110 */
593f1bb8 111struct ref_value {
6c6f58df
MH
112 /*
113 * The name of the object to which this reference resolves
114 * (which may be a tag object). If REF_ISBROKEN, this is
115 * null. If REF_ISSYMREF, then this is the name of the object
116 * referred to by the last reference in the symlink chain.
117 */
593f1bb8 118 unsigned char sha1[20];
6c6f58df
MH
119
120 /*
121 * If REF_KNOWS_PEELED, then this field holds the peeled value
122 * of this reference, or null if the reference is known not to
2312a793
MH
123 * be peelable. See the documentation for peel_ref() for an
124 * exact definition of "peelable".
6c6f58df 125 */
593f1bb8
MH
126 unsigned char peeled[20];
127};
128
f006c42a
MH
129struct ref_cache;
130
28e6a34e
MH
131/*
132 * Information used (along with the information in ref_entry) to
133 * describe a level in the hierarchy of references. This data
134 * structure only occurs embedded in a union in struct ref_entry, and
135 * only when (ref_entry.flag & REF_DIR) is set. In that case,
136 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
137 * in the directory have already been read:
138 *
139 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
140 * or packed references, already read.
141 *
142 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
143 * references that hasn't been read yet (nor has any of its
144 * subdirectories).
145 *
146 * Entries within a directory are stored within a growable array of
147 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
148 * sorted are sorted by their component name in strcmp() order and the
149 * remaining entries are unsorted.
150 *
151 * Loose references are read lazily, one directory at a time. When a
152 * directory of loose references is read, then all of the references
153 * in that directory are stored, and REF_INCOMPLETE stubs are created
154 * for any subdirectories, but the subdirectories themselves are not
155 * read. The reading is triggered by get_ref_dir().
156 */
d3177275 157struct ref_dir {
e9c4c111 158 int nr, alloc;
e6ed3ca6
MH
159
160 /*
161 * Entries with index 0 <= i < sorted are sorted by name. New
162 * entries are appended to the list unsorted, and are sorted
163 * only when required; thus we avoid the need to sort the list
164 * after the addition of every reference.
165 */
166 int sorted;
167
f006c42a
MH
168 /* A pointer to the ref_cache that contains this ref_dir. */
169 struct ref_cache *ref_cache;
170
d3177275 171 struct ref_entry **entries;
e9c4c111
JP
172};
173
89df9c84
MH
174/*
175 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
176 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
177 * refs.h.
178 */
179
180/*
181 * The field ref_entry->u.value.peeled of this value entry contains
182 * the correct peeled value for the reference, which might be
183 * null_sha1 if the reference is not a tag or if it is broken.
184 */
432ad41e 185#define REF_KNOWS_PEELED 0x08
28e6a34e
MH
186
187/* ref_entry represents a directory of references */
432ad41e 188#define REF_DIR 0x10
cf0adba7 189
28e6a34e
MH
190/*
191 * Entry has not yet been read from disk (used only for REF_DIR
192 * entries representing loose references)
193 */
194#define REF_INCOMPLETE 0x20
195
432ad41e
MH
196/*
197 * A ref_entry represents either a reference or a "subdirectory" of
28e6a34e
MH
198 * references.
199 *
200 * Each directory in the reference namespace is represented by a
201 * ref_entry with (flags & REF_DIR) set and containing a subdir member
202 * that holds the entries in that directory that have been read so
203 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
204 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
205 * used for loose reference directories.
206 *
207 * References are represented by a ref_entry with (flags & REF_DIR)
208 * unset and a value member that describes the reference's value. The
209 * flag member is at the ref_entry level, but it is also needed to
210 * interpret the contents of the value field (in other words, a
211 * ref_value object is not very much use without the enclosing
212 * ref_entry).
432ad41e
MH
213 *
214 * Reference names cannot end with slash and directories' names are
215 * always stored with a trailing slash (except for the top-level
216 * directory, which is always denoted by ""). This has two nice
217 * consequences: (1) when the entries in each subdir are sorted
218 * lexicographically by name (as they usually are), the references in
219 * a whole tree can be generated in lexicographic order by traversing
220 * the tree in left-to-right, depth-first order; (2) the names of
221 * references and subdirectories cannot conflict, and therefore the
222 * presence of an empty subdirectory does not block the creation of a
223 * similarly-named reference. (The fact that reference names with the
224 * same leading components can conflict *with each other* is a
225 * separate issue that is regulated by is_refname_available().)
226 *
227 * Please note that the name field contains the fully-qualified
228 * reference (or subdirectory) name. Space could be saved by only
229 * storing the relative names. But that would require the full names
230 * to be generated on the fly when iterating in do_for_each_ref(), and
231 * would break callback functions, who have always been able to assume
232 * that the name strings that they are passed will not be freed during
233 * the iteration.
234 */
bc5fd6d3
MH
235struct ref_entry {
236 unsigned char flag; /* ISSYMREF? ISPACKED? */
593f1bb8 237 union {
432ad41e
MH
238 struct ref_value value; /* if not (flags&REF_DIR) */
239 struct ref_dir subdir; /* if (flags&REF_DIR) */
593f1bb8 240 } u;
432ad41e
MH
241 /*
242 * The full name of the reference (e.g., "refs/heads/master")
243 * or the full name of the directory with a trailing slash
244 * (e.g., "refs/heads/"):
245 */
bc5fd6d3
MH
246 char name[FLEX_ARRAY];
247};
e1e22e37 248
28e6a34e
MH
249static void read_loose_refs(const char *dirname, struct ref_dir *dir);
250
d7826d54
MH
251static struct ref_dir *get_ref_dir(struct ref_entry *entry)
252{
28e6a34e 253 struct ref_dir *dir;
d7826d54 254 assert(entry->flag & REF_DIR);
28e6a34e
MH
255 dir = &entry->u.subdir;
256 if (entry->flag & REF_INCOMPLETE) {
257 read_loose_refs(entry->name, dir);
258 entry->flag &= ~REF_INCOMPLETE;
259 }
260 return dir;
d7826d54
MH
261}
262
cddc4258
MH
263static struct ref_entry *create_ref_entry(const char *refname,
264 const unsigned char *sha1, int flag,
265 int check_name)
e1e22e37
LT
266{
267 int len;
cddc4258 268 struct ref_entry *ref;
e1e22e37 269
09116a1c 270 if (check_name &&
dfefa935
MH
271 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
272 die("Reference has invalid format: '%s'", refname);
cddc4258
MH
273 len = strlen(refname) + 1;
274 ref = xmalloc(sizeof(struct ref_entry) + len);
593f1bb8
MH
275 hashcpy(ref->u.value.sha1, sha1);
276 hashclr(ref->u.value.peeled);
cddc4258
MH
277 memcpy(ref->name, refname, len);
278 ref->flag = flag;
279 return ref;
280}
281
432ad41e
MH
282static void clear_ref_dir(struct ref_dir *dir);
283
732134ed
MH
284static void free_ref_entry(struct ref_entry *entry)
285{
27b5587c
MH
286 if (entry->flag & REF_DIR) {
287 /*
288 * Do not use get_ref_dir() here, as that might
289 * trigger the reading of loose refs.
290 */
291 clear_ref_dir(&entry->u.subdir);
292 }
732134ed
MH
293 free(entry);
294}
295
432ad41e
MH
296/*
297 * Add a ref_entry to the end of dir (unsorted). Entry is always
298 * stored directly in dir; no recursion into subdirectories is
299 * done.
300 */
301static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
cddc4258 302{
432ad41e
MH
303 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
304 dir->entries[dir->nr++] = entry;
654ad400
MH
305 /* optimize for the case that entries are added in order */
306 if (dir->nr == 1 ||
307 (dir->nr == dir->sorted + 1 &&
308 strcmp(dir->entries[dir->nr - 2]->name,
309 dir->entries[dir->nr - 1]->name) < 0))
310 dir->sorted = dir->nr;
c774aab9
JP
311}
312
432ad41e
MH
313/*
314 * Clear and free all entries in dir, recursively.
315 */
d3177275 316static void clear_ref_dir(struct ref_dir *dir)
bc5fd6d3
MH
317{
318 int i;
d3177275
MH
319 for (i = 0; i < dir->nr; i++)
320 free_ref_entry(dir->entries[i]);
321 free(dir->entries);
322 dir->sorted = dir->nr = dir->alloc = 0;
323 dir->entries = NULL;
bc5fd6d3
MH
324}
325
432ad41e
MH
326/*
327 * Create a struct ref_entry object for the specified dirname.
328 * dirname is the name of the directory with a trailing slash (e.g.,
329 * "refs/heads/") or "" for the top-level directory.
330 */
f006c42a 331static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
b9146f51
RS
332 const char *dirname, size_t len,
333 int incomplete)
432ad41e
MH
334{
335 struct ref_entry *direntry;
432ad41e 336 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
b9146f51
RS
337 memcpy(direntry->name, dirname, len);
338 direntry->name[len] = '\0';
f006c42a 339 direntry->u.subdir.ref_cache = ref_cache;
28e6a34e 340 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
432ad41e
MH
341 return direntry;
342}
343
e9c4c111 344static int ref_entry_cmp(const void *a, const void *b)
c774aab9 345{
e9c4c111
JP
346 struct ref_entry *one = *(struct ref_entry **)a;
347 struct ref_entry *two = *(struct ref_entry **)b;
348 return strcmp(one->name, two->name);
349}
c774aab9 350
d3177275 351static void sort_ref_dir(struct ref_dir *dir);
bc5fd6d3 352
e1980c9d
JH
353struct string_slice {
354 size_t len;
355 const char *str;
356};
357
358static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
359{
c971ddfd
RS
360 const struct string_slice *key = key_;
361 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
362 int cmp = strncmp(key->str, ent->name, key->len);
e1980c9d
JH
363 if (cmp)
364 return cmp;
c971ddfd 365 return '\0' - (unsigned char)ent->name[key->len];
e1980c9d
JH
366}
367
432ad41e 368/*
9fc0a648
MH
369 * Return the index of the entry with the given refname from the
370 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
371 * no such entry is found. dir must already be complete.
432ad41e 372 */
9fc0a648 373static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
bc5fd6d3 374{
e1980c9d
JH
375 struct ref_entry **r;
376 struct string_slice key;
bc5fd6d3 377
432ad41e 378 if (refname == NULL || !dir->nr)
9fc0a648 379 return -1;
bc5fd6d3 380
d3177275 381 sort_ref_dir(dir);
e1980c9d
JH
382 key.len = len;
383 key.str = refname;
384 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
385 ref_entry_cmp_sslice);
bc5fd6d3
MH
386
387 if (r == NULL)
9fc0a648 388 return -1;
bc5fd6d3 389
9fc0a648 390 return r - dir->entries;
bc5fd6d3
MH
391}
392
f348ac92
MH
393/*
394 * Search for a directory entry directly within dir (without
395 * recursing). Sort dir if necessary. subdirname must be a directory
396 * name (i.e., end in '/'). If mkdir is set, then create the
397 * directory if it is missing; otherwise, return NULL if the desired
28e6a34e 398 * directory cannot be found. dir must already be complete.
f348ac92 399 */
3f3aa1bc 400static struct ref_dir *search_for_subdir(struct ref_dir *dir,
dd02e728
RS
401 const char *subdirname, size_t len,
402 int mkdir)
f348ac92 403{
9fc0a648
MH
404 int entry_index = search_ref_dir(dir, subdirname, len);
405 struct ref_entry *entry;
406 if (entry_index == -1) {
f348ac92
MH
407 if (!mkdir)
408 return NULL;
28e6a34e
MH
409 /*
410 * Since dir is complete, the absence of a subdir
411 * means that the subdir really doesn't exist;
412 * therefore, create an empty record for it but mark
413 * the record complete.
414 */
b9146f51 415 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
f348ac92 416 add_entry_to_dir(dir, entry);
9fc0a648
MH
417 } else {
418 entry = dir->entries[entry_index];
f348ac92 419 }
3f3aa1bc 420 return get_ref_dir(entry);
f348ac92
MH
421}
422
432ad41e
MH
423/*
424 * If refname is a reference name, find the ref_dir within the dir
425 * tree that should hold refname. If refname is a directory name
426 * (i.e., ends in '/'), then return that ref_dir itself. dir must
28e6a34e
MH
427 * represent the top-level directory and must already be complete.
428 * Sort ref_dirs and recurse into subdirectories as necessary. If
429 * mkdir is set, then create any missing directories; otherwise,
430 * return NULL if the desired directory cannot be found.
432ad41e
MH
431 */
432static struct ref_dir *find_containing_dir(struct ref_dir *dir,
433 const char *refname, int mkdir)
434{
5fa04418 435 const char *slash;
5fa04418 436 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
dd02e728 437 size_t dirnamelen = slash - refname + 1;
3f3aa1bc 438 struct ref_dir *subdir;
dd02e728 439 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
663c1295
JH
440 if (!subdir) {
441 dir = NULL;
f348ac92 442 break;
432ad41e 443 }
3f3aa1bc 444 dir = subdir;
432ad41e
MH
445 }
446
432ad41e
MH
447 return dir;
448}
449
450/*
451 * Find the value entry with the given name in dir, sorting ref_dirs
452 * and recursing into subdirectories as necessary. If the name is not
453 * found or it corresponds to a directory entry, return NULL.
454 */
455static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
456{
9fc0a648 457 int entry_index;
432ad41e
MH
458 struct ref_entry *entry;
459 dir = find_containing_dir(dir, refname, 0);
460 if (!dir)
461 return NULL;
9fc0a648
MH
462 entry_index = search_ref_dir(dir, refname, strlen(refname));
463 if (entry_index == -1)
464 return NULL;
465 entry = dir->entries[entry_index];
466 return (entry->flag & REF_DIR) ? NULL : entry;
432ad41e
MH
467}
468
506a760d
MH
469/*
470 * Remove the entry with the given name from dir, recursing into
471 * subdirectories as necessary. If refname is the name of a directory
472 * (i.e., ends with '/'), then remove the directory and its contents.
473 * If the removal was successful, return the number of entries
474 * remaining in the directory entry that contained the deleted entry.
475 * If the name was not found, return -1. Please note that this
476 * function only deletes the entry from the cache; it does not delete
477 * it from the filesystem or ensure that other cache entries (which
478 * might be symbolic references to the removed entry) are updated.
479 * Nor does it remove any containing dir entries that might be made
480 * empty by the removal. dir must represent the top-level directory
481 * and must already be complete.
482 */
483static int remove_entry(struct ref_dir *dir, const char *refname)
484{
485 int refname_len = strlen(refname);
486 int entry_index;
487 struct ref_entry *entry;
488 int is_dir = refname[refname_len - 1] == '/';
489 if (is_dir) {
490 /*
491 * refname represents a reference directory. Remove
492 * the trailing slash; otherwise we will get the
493 * directory *representing* refname rather than the
494 * one *containing* it.
495 */
496 char *dirname = xmemdupz(refname, refname_len - 1);
497 dir = find_containing_dir(dir, dirname, 0);
498 free(dirname);
499 } else {
500 dir = find_containing_dir(dir, refname, 0);
501 }
502 if (!dir)
503 return -1;
504 entry_index = search_ref_dir(dir, refname, refname_len);
505 if (entry_index == -1)
506 return -1;
507 entry = dir->entries[entry_index];
508
509 memmove(&dir->entries[entry_index],
510 &dir->entries[entry_index + 1],
511 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
512 );
513 dir->nr--;
514 if (dir->sorted > entry_index)
515 dir->sorted--;
516 free_ref_entry(entry);
517 return dir->nr;
432ad41e
MH
518}
519
520/*
521 * Add a ref_entry to the ref_dir (unsorted), recursing into
522 * subdirectories as necessary. dir must represent the top-level
523 * directory. Return 0 on success.
524 */
525static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
526{
527 dir = find_containing_dir(dir, ref->name, 1);
528 if (!dir)
529 return -1;
530 add_entry_to_dir(dir, ref);
531 return 0;
532}
533
202a56a9
MH
534/*
535 * Emit a warning and return true iff ref1 and ref2 have the same name
536 * and the same sha1. Die if they have the same name but different
537 * sha1s.
538 */
539static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
540{
432ad41e 541 if (strcmp(ref1->name, ref2->name))
202a56a9 542 return 0;
432ad41e
MH
543
544 /* Duplicate name; make sure that they don't conflict: */
545
546 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
547 /* This is impossible by construction */
548 die("Reference directory conflict: %s", ref1->name);
549
550 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
551 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
552
553 warning("Duplicated ref: %s", ref1->name);
554 return 1;
202a56a9
MH
555}
556
e6ed3ca6 557/*
432ad41e
MH
558 * Sort the entries in dir non-recursively (if they are not already
559 * sorted) and remove any duplicate entries.
e6ed3ca6 560 */
d3177275 561static void sort_ref_dir(struct ref_dir *dir)
e9c4c111 562{
202a56a9 563 int i, j;
81a79d8e 564 struct ref_entry *last = NULL;
c774aab9 565
e6ed3ca6
MH
566 /*
567 * This check also prevents passing a zero-length array to qsort(),
568 * which is a problem on some platforms.
569 */
d3177275 570 if (dir->sorted == dir->nr)
e9c4c111 571 return;
c774aab9 572
d3177275 573 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
c774aab9 574
81a79d8e
MH
575 /* Remove any duplicates: */
576 for (i = 0, j = 0; j < dir->nr; j++) {
577 struct ref_entry *entry = dir->entries[j];
578 if (last && is_dup_ref(last, entry))
579 free_ref_entry(entry);
580 else
581 last = dir->entries[i++] = entry;
e9c4c111 582 }
81a79d8e 583 dir->sorted = dir->nr = i;
e9c4c111 584}
c774aab9 585
fcce1703
MH
586/* Include broken references in a do_for_each_ref*() iteration: */
587#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
c774aab9 588
662428f4
MH
589/*
590 * Return true iff the reference described by entry can be resolved to
591 * an object in the database. Emit a warning if the referred-to
592 * object does not exist.
593 */
594static int ref_resolves_to_object(struct ref_entry *entry)
595{
596 if (entry->flag & REF_ISBROKEN)
597 return 0;
598 if (!has_sha1_file(entry->u.value.sha1)) {
599 error("%s does not point to a valid object!", entry->name);
600 return 0;
601 }
602 return 1;
603}
c774aab9 604
7d76fdc8
MH
605/*
606 * current_ref is a performance hack: when iterating over references
607 * using the for_each_ref*() functions, current_ref is set to the
608 * current reference's entry before calling the callback function. If
609 * the callback function calls peel_ref(), then peel_ref() first
610 * checks whether the reference to be peeled is the current reference
611 * (it usually is) and if so, returns that reference's peeled version
612 * if it is available. This avoids a refname lookup in a common case.
613 */
bc5fd6d3 614static struct ref_entry *current_ref;
c774aab9 615
624cac35
MH
616typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
617
618struct ref_entry_cb {
619 const char *base;
620 int trim;
621 int flags;
622 each_ref_fn *fn;
623 void *cb_data;
624};
625
fcce1703 626/*
624cac35
MH
627 * Handle one reference in a do_for_each_ref*()-style iteration,
628 * calling an each_ref_fn for each entry.
fcce1703 629 */
624cac35 630static int do_one_ref(struct ref_entry *entry, void *cb_data)
bc5fd6d3 631{
624cac35 632 struct ref_entry_cb *data = cb_data;
d0cf51e9 633 struct ref_entry *old_current_ref;
429213e4 634 int retval;
d0cf51e9 635
624cac35 636 if (prefixcmp(entry->name, data->base))
bc5fd6d3 637 return 0;
c774aab9 638
624cac35 639 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
662428f4 640 !ref_resolves_to_object(entry))
bc5fd6d3 641 return 0;
c774aab9 642
d0cf51e9
MH
643 /* Store the old value, in case this is a recursive call: */
644 old_current_ref = current_ref;
bc5fd6d3 645 current_ref = entry;
624cac35
MH
646 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
647 entry->flag, data->cb_data);
d0cf51e9 648 current_ref = old_current_ref;
429213e4 649 return retval;
bc5fd6d3 650}
c774aab9 651
c36b5bc2 652/*
d3177275 653 * Call fn for each reference in dir that has index in the range
432ad41e
MH
654 * offset <= index < dir->nr. Recurse into subdirectories that are in
655 * that index range, sorting them before iterating. This function
624cac35
MH
656 * does not sort dir itself; it should be sorted beforehand. fn is
657 * called for all references, including broken ones.
c36b5bc2 658 */
624cac35
MH
659static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
660 each_ref_entry_fn fn, void *cb_data)
c36b5bc2
MH
661{
662 int i;
d3177275
MH
663 assert(dir->sorted == dir->nr);
664 for (i = offset; i < dir->nr; i++) {
432ad41e
MH
665 struct ref_entry *entry = dir->entries[i];
666 int retval;
667 if (entry->flag & REF_DIR) {
d7826d54
MH
668 struct ref_dir *subdir = get_ref_dir(entry);
669 sort_ref_dir(subdir);
624cac35 670 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
432ad41e 671 } else {
624cac35 672 retval = fn(entry, cb_data);
432ad41e 673 }
c36b5bc2
MH
674 if (retval)
675 return retval;
676 }
677 return 0;
678}
679
b3fd060f 680/*
d3177275 681 * Call fn for each reference in the union of dir1 and dir2, in order
432ad41e
MH
682 * by refname. Recurse into subdirectories. If a value entry appears
683 * in both dir1 and dir2, then only process the version that is in
684 * dir2. The input dirs must already be sorted, but subdirs will be
624cac35
MH
685 * sorted as needed. fn is called for all references, including
686 * broken ones.
b3fd060f 687 */
624cac35
MH
688static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
689 struct ref_dir *dir2,
690 each_ref_entry_fn fn, void *cb_data)
b3fd060f
MH
691{
692 int retval;
693 int i1 = 0, i2 = 0;
694
d3177275
MH
695 assert(dir1->sorted == dir1->nr);
696 assert(dir2->sorted == dir2->nr);
432ad41e
MH
697 while (1) {
698 struct ref_entry *e1, *e2;
699 int cmp;
700 if (i1 == dir1->nr) {
624cac35 701 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
432ad41e
MH
702 }
703 if (i2 == dir2->nr) {
624cac35 704 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
432ad41e
MH
705 }
706 e1 = dir1->entries[i1];
707 e2 = dir2->entries[i2];
708 cmp = strcmp(e1->name, e2->name);
709 if (cmp == 0) {
710 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
711 /* Both are directories; descend them in parallel. */
d7826d54
MH
712 struct ref_dir *subdir1 = get_ref_dir(e1);
713 struct ref_dir *subdir2 = get_ref_dir(e2);
714 sort_ref_dir(subdir1);
715 sort_ref_dir(subdir2);
624cac35
MH
716 retval = do_for_each_entry_in_dirs(
717 subdir1, subdir2, fn, cb_data);
432ad41e
MH
718 i1++;
719 i2++;
720 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
721 /* Both are references; ignore the one from dir1. */
624cac35 722 retval = fn(e2, cb_data);
432ad41e
MH
723 i1++;
724 i2++;
725 } else {
726 die("conflict between reference and directory: %s",
727 e1->name);
728 }
b3fd060f 729 } else {
432ad41e
MH
730 struct ref_entry *e;
731 if (cmp < 0) {
732 e = e1;
b3fd060f 733 i1++;
432ad41e
MH
734 } else {
735 e = e2;
736 i2++;
737 }
738 if (e->flag & REF_DIR) {
d7826d54
MH
739 struct ref_dir *subdir = get_ref_dir(e);
740 sort_ref_dir(subdir);
624cac35
MH
741 retval = do_for_each_entry_in_dir(
742 subdir, 0, fn, cb_data);
432ad41e 743 } else {
624cac35 744 retval = fn(e, cb_data);
b3fd060f
MH
745 }
746 }
747 if (retval)
748 return retval;
749 }
b3fd060f
MH
750}
751
98eeb09e
JK
752/*
753 * Load all of the refs from the dir into our in-memory cache. The hard work
754 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
755 * through all of the sub-directories. We do not even need to care about
756 * sorting, as traversal order does not matter to us.
757 */
758static void prime_ref_dir(struct ref_dir *dir)
759{
760 int i;
761 for (i = 0; i < dir->nr; i++) {
762 struct ref_entry *entry = dir->entries[i];
763 if (entry->flag & REF_DIR)
764 prime_ref_dir(get_ref_dir(entry));
765 }
766}
d66da478
MH
767/*
768 * Return true iff refname1 and refname2 conflict with each other.
769 * Two reference names conflict if one of them exactly matches the
770 * leading components of the other; e.g., "foo/bar" conflicts with
771 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
772 * "foo/barbados".
773 */
774static int names_conflict(const char *refname1, const char *refname2)
775{
5a4d4947
MH
776 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
777 ;
778 return (*refname1 == '\0' && *refname2 == '/')
779 || (*refname1 == '/' && *refname2 == '\0');
780}
781
782struct name_conflict_cb {
783 const char *refname;
784 const char *oldrefname;
785 const char *conflicting_refname;
786};
787
624cac35 788static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
5a4d4947
MH
789{
790 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
624cac35 791 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
5a4d4947 792 return 0;
624cac35
MH
793 if (names_conflict(data->refname, entry->name)) {
794 data->conflicting_refname = entry->name;
5a4d4947 795 return 1;
d66da478 796 }
5a4d4947 797 return 0;
d66da478
MH
798}
799
bc5fd6d3
MH
800/*
801 * Return true iff a reference named refname could be created without
624cac35 802 * conflicting with the name of an existing reference in dir. If
5a4d4947
MH
803 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
804 * (e.g., because oldrefname is scheduled for deletion in the same
bc5fd6d3
MH
805 * operation).
806 */
807static int is_refname_available(const char *refname, const char *oldrefname,
d3177275 808 struct ref_dir *dir)
bc5fd6d3 809{
5a4d4947
MH
810 struct name_conflict_cb data;
811 data.refname = refname;
812 data.oldrefname = oldrefname;
813 data.conflicting_refname = NULL;
814
d3177275 815 sort_ref_dir(dir);
624cac35 816 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
5a4d4947
MH
817 error("'%s' exists; cannot create '%s'",
818 data.conflicting_refname, refname);
819 return 0;
bc5fd6d3
MH
820 }
821 return 1;
e1e22e37
LT
822}
823
2fff7812
MH
824struct packed_ref_cache {
825 struct ref_entry *root;
9f69d297 826
5f5e2a88
MH
827 /*
828 * Count of references to the data structure in this instance,
829 * including the pointer from ref_cache::packed if any. The
830 * data will not be freed as long as the reference count is
831 * nonzero.
832 */
833 unsigned int referrers;
834
9f69d297
MH
835 /*
836 * Iff the packed-refs file associated with this instance is
837 * currently locked for writing, this points at the associated
4f6b83e3
MH
838 * lock (which is owned by somebody else). The referrer count
839 * is also incremented when the file is locked and decremented
840 * when it is unlocked.
9f69d297
MH
841 */
842 struct lock_file *lock;
ca919930
JK
843
844 /* The metadata from when this packed-refs cache was read */
845 struct stat_validity validity;
2fff7812
MH
846};
847
5e290ff7
JH
848/*
849 * Future: need to be in "struct repository"
850 * when doing a full libification.
851 */
79c7ca54
MH
852static struct ref_cache {
853 struct ref_cache *next;
d12229f5 854 struct ref_entry *loose;
2fff7812 855 struct packed_ref_cache *packed;
9da31cb0
MH
856 /*
857 * The submodule name, or "" for the main repo. We allocate
858 * length 1 rather than FLEX_ARRAY so that the main ref_cache
859 * is initialized correctly.
860 */
861 char name[1];
862} ref_cache, *submodule_ref_caches;
0e88c130 863
9f69d297
MH
864/* Lock used for the main packed-refs file: */
865static struct lock_file packlock;
866
5f5e2a88
MH
867/*
868 * Increment the reference count of *packed_refs.
869 */
870static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
871{
872 packed_refs->referrers++;
873}
874
875/*
876 * Decrease the reference count of *packed_refs. If it goes to zero,
877 * free *packed_refs and return true; otherwise return false.
878 */
879static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
880{
881 if (!--packed_refs->referrers) {
882 free_ref_entry(packed_refs->root);
ca919930 883 stat_validity_clear(&packed_refs->validity);
5f5e2a88
MH
884 free(packed_refs);
885 return 1;
886 } else {
887 return 0;
888 }
889}
890
760c4512 891static void clear_packed_ref_cache(struct ref_cache *refs)
e1e22e37 892{
d12229f5 893 if (refs->packed) {
5f5e2a88
MH
894 struct packed_ref_cache *packed_refs = refs->packed;
895
896 if (packed_refs->lock)
9f69d297 897 die("internal error: packed-ref cache cleared while locked");
d12229f5 898 refs->packed = NULL;
5f5e2a88 899 release_packed_ref_cache(packed_refs);
d12229f5 900 }
5e290ff7 901}
e1e22e37 902
760c4512
MH
903static void clear_loose_ref_cache(struct ref_cache *refs)
904{
d12229f5
MH
905 if (refs->loose) {
906 free_ref_entry(refs->loose);
907 refs->loose = NULL;
908 }
760c4512
MH
909}
910
79c7ca54 911static struct ref_cache *create_ref_cache(const char *submodule)
e5dbf605 912{
ce40979c 913 int len;
79c7ca54 914 struct ref_cache *refs;
ce40979c
MH
915 if (!submodule)
916 submodule = "";
917 len = strlen(submodule) + 1;
79c7ca54 918 refs = xcalloc(1, sizeof(struct ref_cache) + len);
ce40979c 919 memcpy(refs->name, submodule, len);
e5dbf605
MH
920 return refs;
921}
922
4349a668 923/*
79c7ca54 924 * Return a pointer to a ref_cache for the specified submodule. For
4349a668
MH
925 * the main repository, use submodule==NULL. The returned structure
926 * will be allocated and initialized but not necessarily populated; it
927 * should not be freed.
928 */
79c7ca54 929static struct ref_cache *get_ref_cache(const char *submodule)
4349a668 930{
9da31cb0
MH
931 struct ref_cache *refs;
932
933 if (!submodule || !*submodule)
934 return &ref_cache;
935
936 for (refs = submodule_ref_caches; refs; refs = refs->next)
0e88c130
MH
937 if (!strcmp(submodule, refs->name))
938 return refs;
0e88c130 939
79c7ca54 940 refs = create_ref_cache(submodule);
9da31cb0
MH
941 refs->next = submodule_ref_caches;
942 submodule_ref_caches = refs;
0e88c130 943 return refs;
4349a668
MH
944}
945
8be8bde7 946void invalidate_ref_cache(const char *submodule)
f130b116 947{
c5f29abd
MH
948 struct ref_cache *refs = get_ref_cache(submodule);
949 clear_packed_ref_cache(refs);
950 clear_loose_ref_cache(refs);
5e290ff7 951}
e1e22e37 952
3feb4f0c
MH
953/* The length of a peeled reference line in packed-refs, including EOL: */
954#define PEELED_LINE_LENGTH 42
955
694b7a19
MH
956/*
957 * The packed-refs header line that we write out. Perhaps other
958 * traits will be added later. The trailing space is required.
959 */
960static const char PACKED_REFS_HEADER[] =
961 "# pack-refs with: peeled fully-peeled \n";
962
bc5fd6d3
MH
963/*
964 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
965 * Return a pointer to the refname within the line (null-terminated),
966 * or NULL if there was a problem.
967 */
968static const char *parse_ref_line(char *line, unsigned char *sha1)
969{
970 /*
971 * 42: the answer to everything.
972 *
973 * In this case, it happens to be the answer to
974 * 40 (length of sha1 hex representation)
975 * +1 (space in between hex and name)
976 * +1 (newline at the end of the line)
977 */
978 int len = strlen(line) - 42;
979
980 if (len <= 0)
981 return NULL;
982 if (get_sha1_hex(line, sha1) < 0)
983 return NULL;
984 if (!isspace(line[40]))
985 return NULL;
986 line += 41;
987 if (isspace(*line))
988 return NULL;
989 if (line[len] != '\n')
990 return NULL;
991 line[len] = 0;
992
993 return line;
994}
995
c29c46fa
MH
996/*
997 * Read f, which is a packed-refs file, into dir.
998 *
999 * A comment line of the form "# pack-refs with: " may contain zero or
1000 * more traits. We interpret the traits as follows:
1001 *
1002 * No traits:
1003 *
1004 * Probably no references are peeled. But if the file contains a
1005 * peeled value for a reference, we will use it.
1006 *
1007 * peeled:
1008 *
1009 * References under "refs/tags/", if they *can* be peeled, *are*
1010 * peeled in this file. References outside of "refs/tags/" are
1011 * probably not peeled even if they could have been, but if we find
1012 * a peeled value for such a reference we will use it.
1013 *
1014 * fully-peeled:
1015 *
1016 * All references in the file that can be peeled are peeled.
1017 * Inversely (and this is more important), any references in the
1018 * file for which no peeled value is recorded is not peelable. This
1019 * trait should typically be written alongside "peeled" for
1020 * compatibility with older clients, but we do not require it
1021 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1022 */
d3177275 1023static void read_packed_refs(FILE *f, struct ref_dir *dir)
f4204ab9 1024{
e9c4c111 1025 struct ref_entry *last = NULL;
f4204ab9 1026 char refline[PATH_MAX];
c29c46fa 1027 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
f4204ab9
JH
1028
1029 while (fgets(refline, sizeof(refline), f)) {
1030 unsigned char sha1[20];
dfefa935 1031 const char *refname;
f4204ab9
JH
1032 static const char header[] = "# pack-refs with:";
1033
1034 if (!strncmp(refline, header, sizeof(header)-1)) {
1035 const char *traits = refline + sizeof(header) - 1;
c29c46fa
MH
1036 if (strstr(traits, " fully-peeled "))
1037 peeled = PEELED_FULLY;
1038 else if (strstr(traits, " peeled "))
1039 peeled = PEELED_TAGS;
f4204ab9
JH
1040 /* perhaps other traits later as well */
1041 continue;
1042 }
1043
dfefa935
MH
1044 refname = parse_ref_line(refline, sha1);
1045 if (refname) {
c29c46fa
MH
1046 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
1047 if (peeled == PEELED_FULLY ||
1048 (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/")))
1049 last->flag |= REF_KNOWS_PEELED;
d3177275 1050 add_ref(dir, last);
f4204ab9
JH
1051 continue;
1052 }
1053 if (last &&
1054 refline[0] == '^' &&
3feb4f0c
MH
1055 strlen(refline) == PEELED_LINE_LENGTH &&
1056 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
c29c46fa 1057 !get_sha1_hex(refline + 1, sha1)) {
593f1bb8 1058 hashcpy(last->u.value.peeled, sha1);
c29c46fa
MH
1059 /*
1060 * Regardless of what the file header said,
1061 * we definitely know the value of *this*
1062 * reference:
1063 */
1064 last->flag |= REF_KNOWS_PEELED;
1065 }
f4204ab9 1066 }
f4204ab9
JH
1067}
1068
2fff7812
MH
1069/*
1070 * Get the packed_ref_cache for the specified ref_cache, creating it
1071 * if necessary.
1072 */
1073static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
5e290ff7 1074{
ca919930
JK
1075 const char *packed_refs_file;
1076
1077 if (*refs->name)
1078 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1079 else
1080 packed_refs_file = git_path("packed-refs");
1081
1082 if (refs->packed &&
1083 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1084 clear_packed_ref_cache(refs);
1085
d12229f5 1086 if (!refs->packed) {
4349a668 1087 FILE *f;
0bad611b 1088
2fff7812 1089 refs->packed = xcalloc(1, sizeof(*refs->packed));
5f5e2a88 1090 acquire_packed_ref_cache(refs->packed);
2fff7812 1091 refs->packed->root = create_dir_entry(refs, "", 0, 0);
4349a668 1092 f = fopen(packed_refs_file, "r");
e1e22e37 1093 if (f) {
ca919930 1094 stat_validity_update(&refs->packed->validity, fileno(f));
2fff7812 1095 read_packed_refs(f, get_ref_dir(refs->packed->root));
e1e22e37 1096 fclose(f);
e1e22e37 1097 }
e1e22e37 1098 }
2fff7812
MH
1099 return refs->packed;
1100}
1101
1102static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1103{
1104 return get_ref_dir(packed_ref_cache->root);
1105}
1106
1107static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1108{
1109 return get_packed_ref_dir(get_packed_ref_cache(refs));
e1e22e37
LT
1110}
1111
30249ee6
MH
1112void add_packed_ref(const char *refname, const unsigned char *sha1)
1113{
9f69d297
MH
1114 struct packed_ref_cache *packed_ref_cache =
1115 get_packed_ref_cache(&ref_cache);
1116
1117 if (!packed_ref_cache->lock)
1118 die("internal error: packed refs not locked");
1119 add_ref(get_packed_ref_dir(packed_ref_cache),
9da31cb0 1120 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
30249ee6
MH
1121}
1122
abc39098 1123/*
28e6a34e
MH
1124 * Read the loose references from the namespace dirname into dir
1125 * (without recursing). dirname must end with '/'. dir must be the
1126 * directory entry corresponding to dirname.
abc39098 1127 */
423a1afc 1128static void read_loose_refs(const char *dirname, struct ref_dir *dir)
e1e22e37 1129{
423a1afc 1130 struct ref_cache *refs = dir->ref_cache;
d3177275 1131 DIR *d;
0bad611b 1132 const char *path;
d5fdae67 1133 struct dirent *de;
abc39098 1134 int dirnamelen = strlen(dirname);
72b64b44 1135 struct strbuf refname;
0bad611b 1136
3b124823 1137 if (*refs->name)
66a3d20b 1138 path = git_path_submodule(refs->name, "%s", dirname);
0bad611b 1139 else
66a3d20b 1140 path = git_path("%s", dirname);
0bad611b 1141
d3177275 1142 d = opendir(path);
d5fdae67
MH
1143 if (!d)
1144 return;
1145
66a3d20b
MH
1146 strbuf_init(&refname, dirnamelen + 257);
1147 strbuf_add(&refname, dirname, dirnamelen);
d5fdae67
MH
1148
1149 while ((de = readdir(d)) != NULL) {
1150 unsigned char sha1[20];
1151 struct stat st;
1152 int flag;
d5fdae67
MH
1153 const char *refdir;
1154
1155 if (de->d_name[0] == '.')
1156 continue;
d5fdae67
MH
1157 if (has_extension(de->d_name, ".lock"))
1158 continue;
72b64b44 1159 strbuf_addstr(&refname, de->d_name);
d5fdae67 1160 refdir = *refs->name
72b64b44
MH
1161 ? git_path_submodule(refs->name, "%s", refname.buf)
1162 : git_path("%s", refname.buf);
1163 if (stat(refdir, &st) < 0) {
1164 ; /* silently ignore */
1165 } else if (S_ISDIR(st.st_mode)) {
abc39098 1166 strbuf_addch(&refname, '/');
28e6a34e 1167 add_entry_to_dir(dir,
b9146f51
RS
1168 create_dir_entry(refs, refname.buf,
1169 refname.len, 1));
72b64b44 1170 } else {
3b124823 1171 if (*refs->name) {
f8948e2f 1172 hashclr(sha1);
0bad611b 1173 flag = 0;
72b64b44 1174 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
0bad611b 1175 hashclr(sha1);
98ac34b2 1176 flag |= REF_ISBROKEN;
0bad611b 1177 }
72b64b44 1178 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
09116a1c
JH
1179 hashclr(sha1);
1180 flag |= REF_ISBROKEN;
1181 }
9f2fb4a3
MH
1182 add_entry_to_dir(dir,
1183 create_ref_entry(refname.buf, sha1, flag, 1));
e1e22e37 1184 }
66a3d20b 1185 strbuf_setlen(&refname, dirnamelen);
e1e22e37 1186 }
72b64b44 1187 strbuf_release(&refname);
d5fdae67 1188 closedir(d);
e1e22e37
LT
1189}
1190
d3177275 1191static struct ref_dir *get_loose_refs(struct ref_cache *refs)
e1e22e37 1192{
d12229f5 1193 if (!refs->loose) {
28e6a34e
MH
1194 /*
1195 * Mark the top-level directory complete because we
1196 * are about to read the only subdirectory that can
1197 * hold references:
1198 */
b9146f51 1199 refs->loose = create_dir_entry(refs, "", 0, 0);
28e6a34e
MH
1200 /*
1201 * Create an incomplete entry for "refs/":
1202 */
1203 add_entry_to_dir(get_ref_dir(refs->loose),
b9146f51 1204 create_dir_entry(refs, "refs/", 5, 1));
e1e22e37 1205 }
d7826d54 1206 return get_ref_dir(refs->loose);
e1e22e37
LT
1207}
1208
ca8db142
LT
1209/* We allow "recursive" symbolic refs. Only within reason, though */
1210#define MAXDEPTH 5
0ebde32c
LT
1211#define MAXREFLEN (1024)
1212
e5fa45c1
JH
1213/*
1214 * Called by resolve_gitlink_ref_recursive() after it failed to read
b0626608
MH
1215 * from the loose refs in ref_cache refs. Find <refname> in the
1216 * packed-refs file for the submodule.
e5fa45c1 1217 */
b0626608 1218static int resolve_gitlink_packed_ref(struct ref_cache *refs,
85be1fe3 1219 const char *refname, unsigned char *sha1)
0ebde32c 1220{
2c5c66be 1221 struct ref_entry *ref;
d3177275 1222 struct ref_dir *dir = get_packed_refs(refs);
0ebde32c 1223
432ad41e 1224 ref = find_ref(dir, refname);
b0626608
MH
1225 if (ref == NULL)
1226 return -1;
1227
593f1bb8 1228 memcpy(sha1, ref->u.value.sha1, 20);
b0626608 1229 return 0;
0ebde32c
LT
1230}
1231
b0626608 1232static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
85be1fe3 1233 const char *refname, unsigned char *sha1,
dfefa935 1234 int recursion)
0ebde32c 1235{
064d51dc 1236 int fd, len;
0ebde32c 1237 char buffer[128], *p;
064d51dc 1238 char *path;
0ebde32c 1239
064d51dc 1240 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
0ebde32c 1241 return -1;
064d51dc
MH
1242 path = *refs->name
1243 ? git_path_submodule(refs->name, "%s", refname)
1244 : git_path("%s", refname);
1245 fd = open(path, O_RDONLY);
0ebde32c 1246 if (fd < 0)
b0626608 1247 return resolve_gitlink_packed_ref(refs, refname, sha1);
0ebde32c
LT
1248
1249 len = read(fd, buffer, sizeof(buffer)-1);
1250 close(fd);
1251 if (len < 0)
1252 return -1;
1253 while (len && isspace(buffer[len-1]))
1254 len--;
1255 buffer[len] = 0;
1256
1257 /* Was it a detached head or an old-fashioned symlink? */
85be1fe3 1258 if (!get_sha1_hex(buffer, sha1))
0ebde32c
LT
1259 return 0;
1260
1261 /* Symref? */
1262 if (strncmp(buffer, "ref:", 4))
1263 return -1;
1264 p = buffer + 4;
1265 while (isspace(*p))
1266 p++;
1267
064d51dc 1268 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
0ebde32c
LT
1269}
1270
85be1fe3 1271int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
0ebde32c
LT
1272{
1273 int len = strlen(path), retval;
064d51dc 1274 char *submodule;
b0626608 1275 struct ref_cache *refs;
0ebde32c
LT
1276
1277 while (len && path[len-1] == '/')
1278 len--;
1279 if (!len)
1280 return -1;
b0626608
MH
1281 submodule = xstrndup(path, len);
1282 refs = get_ref_cache(submodule);
1283 free(submodule);
1284
064d51dc 1285 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
0ebde32c
LT
1286 return retval;
1287}
ca8db142 1288
4886b89f 1289/*
63331581
MH
1290 * Return the ref_entry for the given refname from the packed
1291 * references. If it does not exist, return NULL.
4886b89f 1292 */
63331581 1293static struct ref_entry *get_packed_ref(const char *refname)
c224ca7f 1294{
9da31cb0 1295 return find_ref(get_packed_refs(&ref_cache), refname);
c224ca7f
MH
1296}
1297
47f534bf
MH
1298/*
1299 * A loose ref file doesn't exist; check for a packed ref. The
1300 * options are forwarded from resolve_safe_unsafe().
1301 */
1302static const char *handle_missing_loose_ref(const char *refname,
1303 unsigned char *sha1,
1304 int reading,
1305 int *flag)
1306{
1307 struct ref_entry *entry;
1308
1309 /*
1310 * The loose reference file does not exist; check for a packed
1311 * reference.
1312 */
1313 entry = get_packed_ref(refname);
1314 if (entry) {
1315 hashcpy(sha1, entry->u.value.sha1);
1316 if (flag)
1317 *flag |= REF_ISPACKED;
1318 return refname;
1319 }
1320 /* The reference is not a packed reference, either. */
1321 if (reading) {
1322 return NULL;
1323 } else {
1324 hashclr(sha1);
1325 return refname;
1326 }
1327}
1328
8d68493f 1329const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
8a65ff76 1330{
0104ca09
HO
1331 int depth = MAXDEPTH;
1332 ssize_t len;
a876ed83 1333 char buffer[256];
dfefa935 1334 static char refname_buffer[256];
ca8db142 1335
8da19775
JH
1336 if (flag)
1337 *flag = 0;
1338
dfefa935 1339 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
8384d788
MH
1340 return NULL;
1341
a876ed83 1342 for (;;) {
55956350 1343 char path[PATH_MAX];
a876ed83
JH
1344 struct stat st;
1345 char *buf;
1346 int fd;
8a65ff76 1347
a876ed83
JH
1348 if (--depth < 0)
1349 return NULL;
ca8db142 1350
dfefa935 1351 git_snpath(path, sizeof(path), "%s", refname);
c224ca7f 1352
fcb7c762
MH
1353 /*
1354 * We might have to loop back here to avoid a race
1355 * condition: first we lstat() the file, then we try
1356 * to read it as a link or as a file. But if somebody
1357 * changes the type of the file (file <-> directory
1358 * <-> symlink) between the lstat() and reading, then
1359 * we don't want to report that as an error but rather
1360 * try again starting with the lstat().
1361 */
1362 stat_ref:
a876ed83 1363 if (lstat(path, &st) < 0) {
47f534bf
MH
1364 if (errno == ENOENT)
1365 return handle_missing_loose_ref(refname, sha1,
1366 reading, flag);
1367 else
a876ed83 1368 return NULL;
a876ed83 1369 }
ca8db142 1370
a876ed83
JH
1371 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1372 if (S_ISLNK(st.st_mode)) {
1373 len = readlink(path, buffer, sizeof(buffer)-1);
fcb7c762
MH
1374 if (len < 0) {
1375 if (errno == ENOENT || errno == EINVAL)
1376 /* inconsistent with lstat; retry */
1377 goto stat_ref;
1378 else
1379 return NULL;
1380 }
b54cb795 1381 buffer[len] = 0;
1f58a038
MH
1382 if (!prefixcmp(buffer, "refs/") &&
1383 !check_refname_format(buffer, 0)) {
dfefa935
MH
1384 strcpy(refname_buffer, buffer);
1385 refname = refname_buffer;
8da19775
JH
1386 if (flag)
1387 *flag |= REF_ISSYMREF;
a876ed83
JH
1388 continue;
1389 }
ca8db142 1390 }
a876ed83 1391
7a21632f
DS
1392 /* Is it a directory? */
1393 if (S_ISDIR(st.st_mode)) {
1394 errno = EISDIR;
1395 return NULL;
1396 }
1397
a876ed83
JH
1398 /*
1399 * Anything else, just open it and try to use it as
1400 * a ref
1401 */
1402 fd = open(path, O_RDONLY);
fcb7c762
MH
1403 if (fd < 0) {
1404 if (errno == ENOENT)
1405 /* inconsistent with lstat; retry */
1406 goto stat_ref;
1407 else
1408 return NULL;
1409 }
93d26e4c 1410 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83 1411 close(fd);
28775050
MH
1412 if (len < 0)
1413 return NULL;
1414 while (len && isspace(buffer[len-1]))
1415 len--;
1416 buffer[len] = '\0';
a876ed83
JH
1417
1418 /*
1419 * Is it a symbolic ref?
1420 */
2884c06a
MH
1421 if (prefixcmp(buffer, "ref:")) {
1422 /*
1423 * Please note that FETCH_HEAD has a second
1424 * line containing other data.
1425 */
1426 if (get_sha1_hex(buffer, sha1) ||
1427 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1428 if (flag)
1429 *flag |= REF_ISBROKEN;
1430 return NULL;
1431 }
1432 return refname;
1433 }
55956350
JH
1434 if (flag)
1435 *flag |= REF_ISSYMREF;
a876ed83 1436 buf = buffer + 4;
28775050
MH
1437 while (isspace(*buf))
1438 buf++;
313fb010 1439 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
55956350
JH
1440 if (flag)
1441 *flag |= REF_ISBROKEN;
313fb010
MH
1442 return NULL;
1443 }
dfefa935 1444 refname = strcpy(refname_buffer, buf);
8a65ff76 1445 }
a876ed83
JH
1446}
1447
96ec7b1e
NTND
1448char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1449{
8cad4744 1450 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
96ec7b1e
NTND
1451 return ret ? xstrdup(ret) : NULL;
1452}
1453
d08bae7e
IL
1454/* The argument to filter_refs */
1455struct ref_filter {
1456 const char *pattern;
1457 each_ref_fn *fn;
1458 void *cb_data;
1459};
1460
dfefa935 1461int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
a876ed83 1462{
8d68493f 1463 if (resolve_ref_unsafe(refname, sha1, reading, flags))
a876ed83
JH
1464 return 0;
1465 return -1;
8a65ff76
LT
1466}
1467
dfefa935 1468int read_ref(const char *refname, unsigned char *sha1)
c6893323 1469{
dfefa935 1470 return read_ref_full(refname, sha1, 1, NULL);
c6893323
NTND
1471}
1472
bc5fd6d3 1473int ref_exists(const char *refname)
ef06b918 1474{
bc5fd6d3
MH
1475 unsigned char sha1[20];
1476 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
ef06b918
JH
1477}
1478
85be1fe3 1479static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
dfefa935 1480 void *data)
d08bae7e
IL
1481{
1482 struct ref_filter *filter = (struct ref_filter *)data;
dfefa935 1483 if (fnmatch(filter->pattern, refname, 0))
d08bae7e 1484 return 0;
85be1fe3 1485 return filter->fn(refname, sha1, flags, filter->cb_data);
d08bae7e
IL
1486}
1487
68cf8703
MH
1488enum peel_status {
1489 /* object was peeled successfully: */
1490 PEEL_PEELED = 0,
1491
1492 /*
1493 * object cannot be peeled because the named object (or an
1494 * object referred to by a tag in the peel chain), does not
1495 * exist.
1496 */
1497 PEEL_INVALID = -1,
1498
1499 /* object cannot be peeled because it is not a tag: */
9a489f3c
MH
1500 PEEL_NON_TAG = -2,
1501
1502 /* ref_entry contains no peeled value because it is a symref: */
1503 PEEL_IS_SYMREF = -3,
1504
1505 /*
1506 * ref_entry cannot be peeled because it is broken (i.e., the
1507 * symbolic reference cannot even be resolved to an object
1508 * name):
1509 */
1510 PEEL_BROKEN = -4
68cf8703
MH
1511};
1512
cb2ae1c4
MH
1513/*
1514 * Peel the named object; i.e., if the object is a tag, resolve the
68cf8703
MH
1515 * tag recursively until a non-tag is found. If successful, store the
1516 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1517 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1518 * and leave sha1 unchanged.
cb2ae1c4 1519 */
68cf8703 1520static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
cb2ae1c4
MH
1521{
1522 struct object *o = lookup_unknown_object(name);
1523
1524 if (o->type == OBJ_NONE) {
1525 int type = sha1_object_info(name, NULL);
1526 if (type < 0)
68cf8703 1527 return PEEL_INVALID;
cb2ae1c4
MH
1528 o->type = type;
1529 }
1530
1531 if (o->type != OBJ_TAG)
68cf8703 1532 return PEEL_NON_TAG;
cb2ae1c4
MH
1533
1534 o = deref_tag_noverify(o);
1535 if (!o)
68cf8703 1536 return PEEL_INVALID;
cb2ae1c4
MH
1537
1538 hashcpy(sha1, o->sha1);
68cf8703 1539 return PEEL_PEELED;
cb2ae1c4
MH
1540}
1541
9a489f3c 1542/*
f85354b5
MH
1543 * Peel the entry (if possible) and return its new peel_status. If
1544 * repeel is true, re-peel the entry even if there is an old peeled
1545 * value that is already stored in it.
694b7a19
MH
1546 *
1547 * It is OK to call this function with a packed reference entry that
1548 * might be stale and might even refer to an object that has since
1549 * been garbage-collected. In such a case, if the entry has
1550 * REF_KNOWS_PEELED then leave the status unchanged and return
1551 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
9a489f3c 1552 */
f85354b5 1553static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
9a489f3c
MH
1554{
1555 enum peel_status status;
1556
f85354b5
MH
1557 if (entry->flag & REF_KNOWS_PEELED) {
1558 if (repeel) {
1559 entry->flag &= ~REF_KNOWS_PEELED;
1560 hashclr(entry->u.value.peeled);
1561 } else {
1562 return is_null_sha1(entry->u.value.peeled) ?
1563 PEEL_NON_TAG : PEEL_PEELED;
1564 }
1565 }
9a489f3c
MH
1566 if (entry->flag & REF_ISBROKEN)
1567 return PEEL_BROKEN;
1568 if (entry->flag & REF_ISSYMREF)
1569 return PEEL_IS_SYMREF;
1570
1571 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1572 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1573 entry->flag |= REF_KNOWS_PEELED;
1574 return status;
1575}
1576
dfefa935 1577int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1578{
1579 int flag;
1580 unsigned char base[20];
cf0adba7 1581
dfefa935 1582 if (current_ref && (current_ref->name == refname
9a489f3c 1583 || !strcmp(current_ref->name, refname))) {
f85354b5 1584 if (peel_entry(current_ref, 0))
9a489f3c
MH
1585 return -1;
1586 hashcpy(sha1, current_ref->u.value.peeled);
1587 return 0;
0ae91be0
SP
1588 }
1589
dfefa935 1590 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1591 return -1;
1592
9a489f3c
MH
1593 /*
1594 * If the reference is packed, read its ref_entry from the
1595 * cache in the hope that we already know its peeled value.
1596 * We only try this optimization on packed references because
1597 * (a) forcing the filling of the loose reference cache could
1598 * be expensive and (b) loose references anyway usually do not
1599 * have REF_KNOWS_PEELED.
1600 */
1601 if (flag & REF_ISPACKED) {
f361baeb 1602 struct ref_entry *r = get_packed_ref(refname);
9a489f3c 1603 if (r) {
f85354b5 1604 if (peel_entry(r, 0))
9a489f3c 1605 return -1;
593f1bb8 1606 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1607 return 0;
cf0adba7 1608 }
cf0adba7
JH
1609 }
1610
cb2ae1c4 1611 return peel_object(base, sha1);
cf0adba7
JH
1612}
1613
bc5fd6d3
MH
1614struct warn_if_dangling_data {
1615 FILE *fp;
1616 const char *refname;
1617 const char *msg_fmt;
1618};
1619
1620static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1621 int flags, void *cb_data)
1622{
1623 struct warn_if_dangling_data *d = cb_data;
1624 const char *resolves_to;
1625 unsigned char junk[20];
1626
1627 if (!(flags & REF_ISSYMREF))
1628 return 0;
1629
1630 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1631 if (!resolves_to || strcmp(resolves_to, d->refname))
1632 return 0;
1633
1634 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1635 fputc('\n', d->fp);
bc5fd6d3
MH
1636 return 0;
1637}
1638
1639void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1640{
1641 struct warn_if_dangling_data data;
1642
1643 data.fp = fp;
1644 data.refname = refname;
1645 data.msg_fmt = msg_fmt;
1646 for_each_rawref(warn_if_dangling_symref, &data);
1647}
1648
fcce1703 1649/*
65cf102b 1650 * Call fn for each reference in the specified ref_cache, omitting
624cac35
MH
1651 * references not in the containing_dir of base. fn is called for all
1652 * references, including broken ones. If fn ever returns a non-zero
fcce1703
MH
1653 * value, stop the iteration and return that value; otherwise, return
1654 * 0.
1655 */
65cf102b 1656static int do_for_each_entry(struct ref_cache *refs, const char *base,
624cac35 1657 each_ref_entry_fn fn, void *cb_data)
8a65ff76 1658{
98eeb09e
JK
1659 struct packed_ref_cache *packed_ref_cache;
1660 struct ref_dir *loose_dir;
1661 struct ref_dir *packed_dir;
933ac036
MH
1662 int retval = 0;
1663
98eeb09e
JK
1664 /*
1665 * We must make sure that all loose refs are read before accessing the
1666 * packed-refs file; this avoids a race condition in which loose refs
1667 * are migrated to the packed-refs file by a simultaneous process, but
1668 * our in-memory view is from before the migration. get_packed_ref_cache()
1669 * takes care of making sure our view is up to date with what is on
1670 * disk.
1671 */
1672 loose_dir = get_loose_refs(refs);
933ac036 1673 if (base && *base) {
933ac036
MH
1674 loose_dir = find_containing_dir(loose_dir, base, 0);
1675 }
98eeb09e
JK
1676 if (loose_dir)
1677 prime_ref_dir(loose_dir);
1678
1679 packed_ref_cache = get_packed_ref_cache(refs);
8baf2bb9 1680 acquire_packed_ref_cache(packed_ref_cache);
98eeb09e 1681 packed_dir = get_packed_ref_dir(packed_ref_cache);
933ac036
MH
1682 if (base && *base) {
1683 packed_dir = find_containing_dir(packed_dir, base, 0);
933ac036
MH
1684 }
1685
1686 if (packed_dir && loose_dir) {
1687 sort_ref_dir(packed_dir);
1688 sort_ref_dir(loose_dir);
624cac35
MH
1689 retval = do_for_each_entry_in_dirs(
1690 packed_dir, loose_dir, fn, cb_data);
933ac036
MH
1691 } else if (packed_dir) {
1692 sort_ref_dir(packed_dir);
624cac35
MH
1693 retval = do_for_each_entry_in_dir(
1694 packed_dir, 0, fn, cb_data);
933ac036
MH
1695 } else if (loose_dir) {
1696 sort_ref_dir(loose_dir);
624cac35
MH
1697 retval = do_for_each_entry_in_dir(
1698 loose_dir, 0, fn, cb_data);
933ac036
MH
1699 }
1700
8baf2bb9 1701 release_packed_ref_cache(packed_ref_cache);
933ac036 1702 return retval;
8a65ff76
LT
1703}
1704
624cac35 1705/*
65cf102b 1706 * Call fn for each reference in the specified ref_cache for which the
624cac35
MH
1707 * refname begins with base. If trim is non-zero, then trim that many
1708 * characters off the beginning of each refname before passing the
1709 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1710 * broken references in the iteration. If fn ever returns a non-zero
1711 * value, stop the iteration and return that value; otherwise, return
1712 * 0.
1713 */
65cf102b
MH
1714static int do_for_each_ref(struct ref_cache *refs, const char *base,
1715 each_ref_fn fn, int trim, int flags, void *cb_data)
624cac35
MH
1716{
1717 struct ref_entry_cb data;
1718 data.base = base;
1719 data.trim = trim;
1720 data.flags = flags;
1721 data.fn = fn;
1722 data.cb_data = cb_data;
1723
65cf102b 1724 return do_for_each_entry(refs, base, do_one_ref, &data);
624cac35
MH
1725}
1726
0bad611b 1727static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1728{
1729 unsigned char sha1[20];
8da19775
JH
1730 int flag;
1731
0bad611b
HV
1732 if (submodule) {
1733 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1734 return fn("HEAD", sha1, 0, cb_data);
1735
1736 return 0;
1737 }
1738
c6893323 1739 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1740 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1741
2f34ba32 1742 return 0;
723c31fe
LT
1743}
1744
0bad611b
HV
1745int head_ref(each_ref_fn fn, void *cb_data)
1746{
1747 return do_head_ref(NULL, fn, cb_data);
1748}
1749
9ef6aeb0
HV
1750int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1751{
1752 return do_head_ref(submodule, fn, cb_data);
1753}
1754
cb5d709f 1755int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1756{
9da31cb0 1757 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
a62be77f
SE
1758}
1759
9ef6aeb0
HV
1760int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1761{
65cf102b 1762 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
a62be77f
SE
1763}
1764
2a8177b6
CC
1765int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1766{
9da31cb0 1767 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1768}
1769
9ef6aeb0
HV
1770int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1771 each_ref_fn fn, void *cb_data)
1772{
65cf102b 1773 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1774}
1775
cb5d709f 1776int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1777{
2a8177b6 1778 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1779}
1780
9ef6aeb0
HV
1781int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1782{
1783 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1784}
1785
cb5d709f 1786int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1787{
2a8177b6 1788 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1789}
1790
9ef6aeb0
HV
1791int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1792{
1793 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1794}
1795
cb5d709f 1796int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1797{
2a8177b6 1798 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1799}
1800
9ef6aeb0
HV
1801int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1802{
1803 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1804}
1805
29268700
CC
1806int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1807{
9da31cb0 1808 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1809}
1810
a1bea2c1
JT
1811int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1812{
1813 struct strbuf buf = STRBUF_INIT;
1814 int ret = 0;
1815 unsigned char sha1[20];
1816 int flag;
1817
1818 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1819 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1820 ret = fn(buf.buf, sha1, flag, cb_data);
1821 strbuf_release(&buf);
1822
1823 return ret;
1824}
1825
1826int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1827{
1828 struct strbuf buf = STRBUF_INIT;
1829 int ret;
1830 strbuf_addf(&buf, "%srefs/", get_git_namespace());
9da31cb0 1831 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
a1bea2c1
JT
1832 strbuf_release(&buf);
1833 return ret;
1834}
1835
b09fe971
IL
1836int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1837 const char *prefix, void *cb_data)
d08bae7e
IL
1838{
1839 struct strbuf real_pattern = STRBUF_INIT;
1840 struct ref_filter filter;
d08bae7e
IL
1841 int ret;
1842
b09fe971 1843 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 1844 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1845 else if (prefix)
1846 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1847 strbuf_addstr(&real_pattern, pattern);
1848
894a9d33 1849 if (!has_glob_specials(pattern)) {
9517e6b8 1850 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1851 if (real_pattern.buf[real_pattern.len - 1] != '/')
1852 strbuf_addch(&real_pattern, '/');
1853 /* No need to check for '*', there is none. */
1854 strbuf_addch(&real_pattern, '*');
1855 }
1856
1857 filter.pattern = real_pattern.buf;
1858 filter.fn = fn;
1859 filter.cb_data = cb_data;
1860 ret = for_each_ref(filter_refs, &filter);
1861
1862 strbuf_release(&real_pattern);
1863 return ret;
1864}
1865
b09fe971
IL
1866int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1867{
1868 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1869}
1870
f8948e2f
JH
1871int for_each_rawref(each_ref_fn fn, void *cb_data)
1872{
9da31cb0 1873 return do_for_each_ref(&ref_cache, "", fn, 0,
f8948e2f 1874 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1875}
1876
4577e483 1877const char *prettify_refname(const char *name)
a9c37a72 1878{
a9c37a72
DB
1879 return name + (
1880 !prefixcmp(name, "refs/heads/") ? 11 :
1881 !prefixcmp(name, "refs/tags/") ? 10 :
1882 !prefixcmp(name, "refs/remotes/") ? 13 :
1883 0);
1884}
1885
79803322
SP
1886const char *ref_rev_parse_rules[] = {
1887 "%.*s",
1888 "refs/%.*s",
1889 "refs/tags/%.*s",
1890 "refs/heads/%.*s",
1891 "refs/remotes/%.*s",
1892 "refs/remotes/%.*s/HEAD",
1893 NULL
1894};
1895
1896int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1897{
1898 const char **p;
1899 const int abbrev_name_len = strlen(abbrev_name);
1900
1901 for (p = rules; *p; p++) {
1902 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1903 return 1;
1904 }
1905 }
1906
1907 return 0;
1908}
1909
e5f38ec3 1910static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1911 const unsigned char *old_sha1, int mustexist)
1912{
c6893323 1913 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 1914 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
1915 unlock_ref(lock);
1916 return NULL;
1917 }
a89fccd2 1918 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1919 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1920 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1921 unlock_ref(lock);
1922 return NULL;
1923 }
1924 return lock;
1925}
1926
7155b727 1927static int remove_empty_directories(const char *file)
bc7127ef
JH
1928{
1929 /* we want to create a file but there is a directory there;
1930 * if that is an empty directory (or a directory that contains
1931 * only empty directories), remove them.
1932 */
7155b727
JS
1933 struct strbuf path;
1934 int result;
bc7127ef 1935
7155b727
JS
1936 strbuf_init(&path, 20);
1937 strbuf_addstr(&path, file);
1938
a0f4afbe 1939 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1940
1941 strbuf_release(&path);
1942
1943 return result;
bc7127ef
JH
1944}
1945
ff74f7f1
JH
1946/*
1947 * *string and *len will only be substituted, and *string returned (for
1948 * later free()ing) if the string passed in is a magic short-hand form
1949 * to name a branch.
1950 */
1951static char *substitute_branch_name(const char **string, int *len)
1952{
1953 struct strbuf buf = STRBUF_INIT;
1954 int ret = interpret_branch_name(*string, &buf);
1955
1956 if (ret == *len) {
1957 size_t size;
1958 *string = strbuf_detach(&buf, &size);
1959 *len = size;
1960 return (char *)*string;
1961 }
1962
1963 return NULL;
1964}
1965
1966int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1967{
1968 char *last_branch = substitute_branch_name(&str, &len);
1969 const char **p, *r;
1970 int refs_found = 0;
1971
1972 *ref = NULL;
1973 for (p = ref_rev_parse_rules; *p; p++) {
1974 char fullref[PATH_MAX];
1975 unsigned char sha1_from_ref[20];
1976 unsigned char *this_result;
1977 int flag;
1978
1979 this_result = refs_found ? sha1_from_ref : sha1;
1980 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 1981 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
1982 if (r) {
1983 if (!refs_found++)
1984 *ref = xstrdup(r);
1985 if (!warn_ambiguous_refs)
1986 break;
55956350 1987 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 1988 warning("ignoring dangling symref %s.", fullref);
55956350
JH
1989 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1990 warning("ignoring broken ref %s.", fullref);
1991 }
ff74f7f1
JH
1992 }
1993 free(last_branch);
1994 return refs_found;
1995}
1996
1997int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1998{
1999 char *last_branch = substitute_branch_name(&str, &len);
2000 const char **p;
2001 int logs_found = 0;
2002
2003 *log = NULL;
2004 for (p = ref_rev_parse_rules; *p; p++) {
2005 struct stat st;
2006 unsigned char hash[20];
2007 char path[PATH_MAX];
2008 const char *ref, *it;
2009
2010 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 2011 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
2012 if (!ref)
2013 continue;
2014 if (!stat(git_path("logs/%s", path), &st) &&
2015 S_ISREG(st.st_mode))
2016 it = path;
2017 else if (strcmp(ref, path) &&
2018 !stat(git_path("logs/%s", ref), &st) &&
2019 S_ISREG(st.st_mode))
2020 it = ref;
2021 else
2022 continue;
2023 if (!logs_found++) {
2024 *log = xstrdup(it);
2025 hashcpy(sha1, hash);
2026 }
2027 if (!warn_ambiguous_refs)
2028 break;
2029 }
2030 free(last_branch);
2031 return logs_found;
2032}
2033
dfefa935
MH
2034static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2035 const unsigned char *old_sha1,
2036 int flags, int *type_p)
4bd18c43 2037{
434cd0cd 2038 char *ref_file;
dfefa935 2039 const char *orig_refname = refname;
4bd18c43 2040 struct ref_lock *lock;
5cc3cef9 2041 int last_errno = 0;
acd3b9ec 2042 int type, lflags;
4431fcc4 2043 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 2044 int missing = 0;
4bd18c43
SP
2045
2046 lock = xcalloc(1, sizeof(struct ref_lock));
2047 lock->lock_fd = -1;
2048
8d68493f 2049 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 2050 if (!refname && errno == EISDIR) {
bc7127ef
JH
2051 /* we are trying to lock foo but we used to
2052 * have foo/bar which now does not exist;
2053 * it is normal for the empty directory 'foo'
2054 * to remain.
2055 */
dfefa935 2056 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
2057 if (remove_empty_directories(ref_file)) {
2058 last_errno = errno;
dfefa935 2059 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
2060 goto error_return;
2061 }
8d68493f 2062 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 2063 }
68db31cc
SV
2064 if (type_p)
2065 *type_p = type;
dfefa935 2066 if (!refname) {
5cc3cef9 2067 last_errno = errno;
818f477c 2068 error("unable to resolve reference %s: %s",
dfefa935 2069 orig_refname, strerror(errno));
5cc3cef9 2070 goto error_return;
4bd18c43 2071 }
5bdd8d4a 2072 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
2073 /* When the ref did not exist and we are creating it,
2074 * make sure there is no existing ref that is packed
2075 * whose name begins with our refname, nor a ref whose
2076 * name is a proper prefix of our refname.
2077 */
5bdd8d4a 2078 if (missing &&
9da31cb0 2079 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
f475e08e 2080 last_errno = ENOTDIR;
c976d415 2081 goto error_return;
f475e08e 2082 }
22a3844e 2083
c33d5174 2084 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 2085
acd3b9ec
JH
2086 lflags = LOCK_DIE_ON_ERROR;
2087 if (flags & REF_NODEREF) {
dfefa935 2088 refname = orig_refname;
acd3b9ec
JH
2089 lflags |= LOCK_NODEREF;
2090 }
dfefa935
MH
2091 lock->ref_name = xstrdup(refname);
2092 lock->orig_ref_name = xstrdup(orig_refname);
2093 ref_file = git_path("%s", refname);
5bdd8d4a 2094 if (missing)
68db31cc
SV
2095 lock->force_write = 1;
2096 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2097 lock->force_write = 1;
4bd18c43 2098
5cc3cef9
JH
2099 if (safe_create_leading_directories(ref_file)) {
2100 last_errno = errno;
2101 error("unable to create directory for %s", ref_file);
2102 goto error_return;
2103 }
4bd18c43 2104
acd3b9ec 2105 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 2106 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
2107
2108 error_return:
2109 unlock_ref(lock);
2110 errno = last_errno;
2111 return NULL;
4bd18c43
SP
2112}
2113
dfefa935 2114struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 2115{
53cce84c 2116 char refpath[PATH_MAX];
dfefa935 2117 if (check_refname_format(refname, 0))
4bd18c43 2118 return NULL;
dfefa935 2119 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 2120 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
2121}
2122
dfefa935 2123struct ref_lock *lock_any_ref_for_update(const char *refname,
9bbb0fa1
BK
2124 const unsigned char *old_sha1,
2125 int flags, int *type_p)
4bd18c43 2126{
dfefa935 2127 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 2128 return NULL;
9bbb0fa1 2129 return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);
c0277d15
JH
2130}
2131
fec3137f
MH
2132/*
2133 * Write an entry to the packed-refs file for the specified refname.
2134 * If peeled is non-NULL, write it as the entry's peeled value.
2135 */
2136static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
2137 unsigned char *peeled)
d66da478 2138{
d66da478
MH
2139 char line[PATH_MAX + 100];
2140 int len;
2141
d66da478
MH
2142 len = snprintf(line, sizeof(line), "%s %s\n",
2143 sha1_to_hex(sha1), refname);
2144 /* this should not happen but just being defensive */
2145 if (len > sizeof(line))
2146 die("too long a refname '%s'", refname);
fec3137f
MH
2147 write_or_die(fd, line, len);
2148
2149 if (peeled) {
2150 if (snprintf(line, sizeof(line), "^%s\n",
2151 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
2152 die("internal error");
2153 write_or_die(fd, line, PEELED_LINE_LENGTH);
2154 }
2155}
2156
7b40d396
MH
2157/*
2158 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2159 */
2160static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2161{
2162 int *fd = cb_data;
2163 enum peel_status peel_status = peel_entry(entry, 0);
2164
2165 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2166 error("internal error: %s is not a valid packed reference!",
2167 entry->name);
2168 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2169 peel_status == PEEL_PEELED ?
2170 entry->u.value.peeled : NULL);
2171 return 0;
2172}
2173
9f69d297
MH
2174int lock_packed_refs(int flags)
2175{
2176 struct packed_ref_cache *packed_ref_cache;
2177
9f69d297
MH
2178 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2179 return -1;
5d478f5c
MH
2180 /*
2181 * Get the current packed-refs while holding the lock. If the
2182 * packed-refs file has been modified since we last read it,
2183 * this will automatically invalidate the cache and re-read
2184 * the packed-refs file.
2185 */
9f69d297
MH
2186 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2187 packed_ref_cache->lock = &packlock;
4f6b83e3
MH
2188 /* Increment the reference count to prevent it from being freed: */
2189 acquire_packed_ref_cache(packed_ref_cache);
9f69d297
MH
2190 return 0;
2191}
2192
2193int commit_packed_refs(void)
2194{
2195 struct packed_ref_cache *packed_ref_cache =
2196 get_packed_ref_cache(&ref_cache);
2197 int error = 0;
2198
2199 if (!packed_ref_cache->lock)
2200 die("internal error: packed-refs not locked");
2201 write_or_die(packed_ref_cache->lock->fd,
2202 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2203
2204 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2205 0, write_packed_entry_fn,
2206 &packed_ref_cache->lock->fd);
2207 if (commit_lock_file(packed_ref_cache->lock))
2208 error = -1;
2209 packed_ref_cache->lock = NULL;
4f6b83e3 2210 release_packed_ref_cache(packed_ref_cache);
9f69d297
MH
2211 return error;
2212}
2213
2214void rollback_packed_refs(void)
2215{
2216 struct packed_ref_cache *packed_ref_cache =
2217 get_packed_ref_cache(&ref_cache);
2218
2219 if (!packed_ref_cache->lock)
2220 die("internal error: packed-refs not locked");
2221 rollback_lock_file(packed_ref_cache->lock);
2222 packed_ref_cache->lock = NULL;
4f6b83e3 2223 release_packed_ref_cache(packed_ref_cache);
9f69d297
MH
2224 clear_packed_ref_cache(&ref_cache);
2225}
2226
32d462ce
MH
2227struct ref_to_prune {
2228 struct ref_to_prune *next;
2229 unsigned char sha1[20];
2230 char name[FLEX_ARRAY];
2231};
2232
2233struct pack_refs_cb_data {
2234 unsigned int flags;
267f9a8c 2235 struct ref_dir *packed_refs;
32d462ce 2236 struct ref_to_prune *ref_to_prune;
32d462ce
MH
2237};
2238
267f9a8c
MH
2239/*
2240 * An each_ref_entry_fn that is run over loose references only. If
2241 * the loose reference can be packed, add an entry in the packed ref
2242 * cache. If the reference should be pruned, also add it to
2243 * ref_to_prune in the pack_refs_cb_data.
2244 */
2245static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
32d462ce
MH
2246{
2247 struct pack_refs_cb_data *cb = cb_data;
f85354b5 2248 enum peel_status peel_status;
267f9a8c 2249 struct ref_entry *packed_entry;
b2a8226d 2250 int is_tag_ref = !prefixcmp(entry->name, "refs/tags/");
32d462ce 2251
267f9a8c
MH
2252 /* ALWAYS pack tags */
2253 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
32d462ce
MH
2254 return 0;
2255
b2a8226d
MH
2256 /* Do not pack symbolic or broken refs: */
2257 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2258 return 0;
2259
267f9a8c 2260 /* Add a packed ref cache entry equivalent to the loose entry. */
f85354b5 2261 peel_status = peel_entry(entry, 1);
0f29920f 2262 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
f85354b5
MH
2263 die("internal error peeling reference %s (%s)",
2264 entry->name, sha1_to_hex(entry->u.value.sha1));
267f9a8c
MH
2265 packed_entry = find_ref(cb->packed_refs, entry->name);
2266 if (packed_entry) {
2267 /* Overwrite existing packed entry with info from loose entry */
2268 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2269 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2270 } else {
2271 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2272 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2273 add_ref(cb->packed_refs, packed_entry);
2274 }
2275 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
32d462ce 2276
267f9a8c
MH
2277 /* Schedule the loose reference for pruning if requested. */
2278 if ((cb->flags & PACK_REFS_PRUNE)) {
12e77559 2279 int namelen = strlen(entry->name) + 1;
32d462ce 2280 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
12e77559
MH
2281 hashcpy(n->sha1, entry->u.value.sha1);
2282 strcpy(n->name, entry->name);
32d462ce
MH
2283 n->next = cb->ref_to_prune;
2284 cb->ref_to_prune = n;
2285 }
d66da478
MH
2286 return 0;
2287}
2288
32d462ce
MH
2289/*
2290 * Remove empty parents, but spare refs/ and immediate subdirs.
2291 * Note: munges *name.
2292 */
2293static void try_remove_empty_parents(char *name)
2294{
2295 char *p, *q;
2296 int i;
2297 p = name;
2298 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2299 while (*p && *p != '/')
2300 p++;
2301 /* tolerate duplicate slashes; see check_refname_format() */
2302 while (*p == '/')
2303 p++;
2304 }
2305 for (q = p; *q; q++)
2306 ;
2307 while (1) {
2308 while (q > p && *q != '/')
2309 q--;
2310 while (q > p && *(q-1) == '/')
2311 q--;
2312 if (q == p)
2313 break;
2314 *q = '\0';
2315 if (rmdir(git_path("%s", name)))
2316 break;
2317 }
2318}
2319
2320/* make sure nobody touched the ref, and unlink */
2321static void prune_ref(struct ref_to_prune *r)
2322{
2323 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2324
2325 if (lock) {
2326 unlink_or_warn(git_path("%s", r->name));
2327 unlock_ref(lock);
2328 try_remove_empty_parents(r->name);
2329 }
2330}
2331
2332static void prune_refs(struct ref_to_prune *r)
2333{
2334 while (r) {
2335 prune_ref(r);
2336 r = r->next;
2337 }
2338}
2339
32d462ce
MH
2340int pack_refs(unsigned int flags)
2341{
32d462ce
MH
2342 struct pack_refs_cb_data cbdata;
2343
2344 memset(&cbdata, 0, sizeof(cbdata));
2345 cbdata.flags = flags;
2346
9f69d297 2347 lock_packed_refs(LOCK_DIE_ON_ERROR);
267f9a8c 2348 cbdata.packed_refs = get_packed_refs(&ref_cache);
32d462ce 2349
267f9a8c
MH
2350 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2351 pack_if_possible_fn, &cbdata);
32d462ce 2352
9f69d297 2353 if (commit_packed_refs())
32d462ce 2354 die_errno("unable to overwrite old ref-pack file");
9f69d297 2355
32d462ce
MH
2356 prune_refs(cbdata.ref_to_prune);
2357 return 0;
2358}
2359
7b40d396
MH
2360/*
2361 * If entry is no longer needed in packed-refs, add it to the string
2362 * list pointed to by cb_data. Reasons for deleting entries:
2363 *
2364 * - Entry is broken.
2365 * - Entry is overridden by a loose ref.
2366 * - Entry does not point at a valid object.
2367 *
2368 * In the first and third cases, also emit an error message because these
2369 * are indications of repository corruption.
2370 */
2371static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
c0277d15 2372{
7b40d396 2373 struct string_list *refs_to_delete = cb_data;
fec3137f 2374
ab292bc4
MH
2375 if (entry->flag & REF_ISBROKEN) {
2376 /* This shouldn't happen to packed refs. */
2377 error("%s is broken!", entry->name);
7b40d396 2378 string_list_append(refs_to_delete, entry->name);
c0277d15 2379 return 0;
ab292bc4
MH
2380 }
2381 if (!has_sha1_file(entry->u.value.sha1)) {
2382 unsigned char sha1[20];
2383 int flags;
2384
2385 if (read_ref_full(entry->name, sha1, 0, &flags))
2386 /* We should at least have found the packed ref. */
2387 die("Internal error");
7b40d396 2388 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
ab292bc4
MH
2389 /*
2390 * This packed reference is overridden by a
2391 * loose reference, so it is OK that its value
2392 * is no longer valid; for example, it might
2393 * refer to an object that has been garbage
2394 * collected. For this purpose we don't even
2395 * care whether the loose reference itself is
2396 * invalid, broken, symbolic, etc. Silently
7b40d396 2397 * remove the packed reference.
ab292bc4 2398 */
7b40d396 2399 string_list_append(refs_to_delete, entry->name);
ab292bc4 2400 return 0;
7b40d396 2401 }
ab292bc4
MH
2402 /*
2403 * There is no overriding loose reference, so the fact
2404 * that this reference doesn't refer to a valid object
2405 * indicates some kind of repository corruption.
2406 * Report the problem, then omit the reference from
2407 * the output.
2408 */
2409 error("%s does not point to a valid object!", entry->name);
7b40d396 2410 string_list_append(refs_to_delete, entry->name);
ab292bc4
MH
2411 return 0;
2412 }
2413
d66da478
MH
2414 return 0;
2415}
2416
c0277d15
JH
2417static int repack_without_ref(const char *refname)
2418{
7618fd80 2419 struct ref_dir *packed;
7b40d396
MH
2420 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2421 struct string_list_item *ref_to_delete;
7618fd80
MH
2422
2423 if (!get_packed_ref(refname))
2424 return 0; /* refname does not exist in packed refs */
2425
9f69d297 2426 if (lock_packed_refs(0)) {
1b018fd9 2427 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 2428 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 2429 }
9da31cb0 2430 packed = get_packed_refs(&ref_cache);
7b40d396
MH
2431
2432 /* Remove refname from the cache: */
506a760d
MH
2433 if (remove_entry(packed, refname) == -1) {
2434 /*
2435 * The packed entry disappeared while we were
2436 * acquiring the lock.
2437 */
9f69d297 2438 rollback_packed_refs();
506a760d
MH
2439 return 0;
2440 }
7b40d396
MH
2441
2442 /* Remove any other accumulated cruft: */
2443 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2444 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2445 if (remove_entry(packed, ref_to_delete->string) == -1)
2446 die("internal error");
2447 }
2448
2449 /* Write what remains: */
9f69d297 2450 return commit_packed_refs();
c0277d15
JH
2451}
2452
eca35a25 2453int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
2454{
2455 struct ref_lock *lock;
eca35a25 2456 int err, i = 0, ret = 0, flag = 0;
c0277d15 2457
547d058f 2458 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
2459 if (!lock)
2460 return 1;
045a476f 2461 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 2462 /* loose */
547d058f
RS
2463 i = strlen(lock->lk->filename) - 5; /* .lock */
2464 lock->lk->filename[i] = 0;
2465 err = unlink_or_warn(lock->lk->filename);
691f1a28 2466 if (err && errno != ENOENT)
c0277d15 2467 ret = 1;
691f1a28 2468
547d058f 2469 lock->lk->filename[i] = '.';
c0277d15
JH
2470 }
2471 /* removing the loose one could have resurrected an earlier
2472 * packed one. Also, if it was not loose we need to repack
2473 * without it.
2474 */
b274a714 2475 ret |= repack_without_ref(lock->ref_name);
c0277d15 2476
691f1a28 2477 unlink_or_warn(git_path("logs/%s", lock->ref_name));
9da31cb0 2478 clear_loose_ref_cache(&ref_cache);
c0277d15
JH
2479 unlock_ref(lock);
2480 return ret;
4bd18c43
SP
2481}
2482
765c2258
PH
2483/*
2484 * People using contrib's git-new-workdir have .git/logs/refs ->
2485 * /some/other/path/.git/logs/refs, and that may live on another device.
2486 *
2487 * IOW, to avoid cross device rename errors, the temporary renamed log must
2488 * live into logs/refs.
2489 */
2490#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2491
dfefa935 2492int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 2493{
c976d415
LH
2494 unsigned char sha1[20], orig_sha1[20];
2495 int flag = 0, logmoved = 0;
2496 struct ref_lock *lock;
c976d415 2497 struct stat loginfo;
dfefa935 2498 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 2499 const char *symref = NULL;
c976d415 2500
450d4c0f 2501 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 2502 return error("reflog for %s is a symlink", oldrefname);
c976d415 2503
8d68493f 2504 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 2505 if (flag & REF_ISSYMREF)
fa58186c 2506 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 2507 oldrefname);
eca35a25 2508 if (!symref)
dfefa935 2509 return error("refname %s not found", oldrefname);
c976d415 2510
9da31cb0 2511 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
c976d415
LH
2512 return 1;
2513
9da31cb0 2514 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
c976d415
LH
2515 return 1;
2516
dfefa935 2517 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 2518 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 2519 oldrefname, strerror(errno));
c976d415 2520
dfefa935
MH
2521 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2522 error("unable to delete old %s", oldrefname);
c976d415
LH
2523 goto rollback;
2524 }
2525
dfefa935
MH
2526 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2527 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 2528 if (errno==EISDIR) {
dfefa935
MH
2529 if (remove_empty_directories(git_path("%s", newrefname))) {
2530 error("Directory not empty: %s", newrefname);
c976d415
LH
2531 goto rollback;
2532 }
2533 } else {
dfefa935 2534 error("unable to delete existing %s", newrefname);
c976d415
LH
2535 goto rollback;
2536 }
2537 }
2538
dfefa935
MH
2539 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2540 error("unable to create directory for %s", newrefname);
c976d415
LH
2541 goto rollback;
2542 }
2543
2544 retry:
dfefa935 2545 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
d9e74d57
JR
2546 if (errno==EISDIR || errno==ENOTDIR) {
2547 /*
2548 * rename(a, b) when b is an existing
2549 * directory ought to result in ISDIR, but
2550 * Solaris 5.8 gives ENOTDIR. Sheesh.
2551 */
dfefa935
MH
2552 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2553 error("Directory not empty: logs/%s", newrefname);
c976d415
LH
2554 goto rollback;
2555 }
2556 goto retry;
2557 } else {
765c2258 2558 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
dfefa935 2559 newrefname, strerror(errno));
c976d415
LH
2560 goto rollback;
2561 }
2562 }
2563 logmoved = log;
2564
dfefa935 2565 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 2566 if (!lock) {
dfefa935 2567 error("unable to lock %s for update", newrefname);
c976d415
LH
2568 goto rollback;
2569 }
c976d415
LH
2570 lock->force_write = 1;
2571 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 2572 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 2573 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
2574 goto rollback;
2575 }
2576
2577 return 0;
2578
2579 rollback:
dfefa935 2580 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 2581 if (!lock) {
dfefa935 2582 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
2583 goto rollbacklog;
2584 }
2585
2586 lock->force_write = 1;
2587 flag = log_all_ref_updates;
2588 log_all_ref_updates = 0;
2589 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2590 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2591 log_all_ref_updates = flag;
2592
2593 rollbacklog:
dfefa935 2594 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2595 error("unable to restore logfile %s from %s: %s",
dfefa935 2596 oldrefname, newrefname, strerror(errno));
c976d415 2597 if (!logmoved && log &&
dfefa935 2598 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2599 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2600 oldrefname, strerror(errno));
c976d415
LH
2601
2602 return 1;
2603}
2604
435fc852 2605int close_ref(struct ref_lock *lock)
b531394d
BC
2606{
2607 if (close_lock_file(lock->lk))
2608 return -1;
2609 lock->lock_fd = -1;
2610 return 0;
2611}
2612
435fc852 2613int commit_ref(struct ref_lock *lock)
b531394d
BC
2614{
2615 if (commit_lock_file(lock->lk))
2616 return -1;
2617 lock->lock_fd = -1;
2618 return 0;
2619}
2620
e5f38ec3 2621void unlock_ref(struct ref_lock *lock)
4bd18c43 2622{
4ed7cd3a
BC
2623 /* Do not free lock->lk -- atexit() still looks at them */
2624 if (lock->lk)
2625 rollback_lock_file(lock->lk);
434cd0cd 2626 free(lock->ref_name);
1655707c 2627 free(lock->orig_ref_name);
4bd18c43
SP
2628 free(lock);
2629}
2630
0ec29a47
JH
2631/*
2632 * copy the reflog message msg to buf, which has been allocated sufficiently
2633 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2634 * because reflog file is one line per entry.
2635 */
2636static int copy_msg(char *buf, const char *msg)
2637{
2638 char *cp = buf;
2639 char c;
2640 int wasspace = 1;
2641
2642 *cp++ = '\t';
2643 while ((c = *msg++)) {
2644 if (wasspace && isspace(c))
2645 continue;
2646 wasspace = isspace(c);
2647 if (wasspace)
2648 c = ' ';
2649 *cp++ = c;
2650 }
2651 while (buf < cp && isspace(cp[-1]))
2652 cp--;
2653 *cp++ = '\n';
2654 return cp - buf;
2655}
2656
dfefa935 2657int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2658{
859c3017 2659 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2660
dfefa935 2661 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2662 if (log_all_ref_updates &&
dfefa935
MH
2663 (!prefixcmp(refname, "refs/heads/") ||
2664 !prefixcmp(refname, "refs/remotes/") ||
2665 !prefixcmp(refname, "refs/notes/") ||
2666 !strcmp(refname, "HEAD"))) {
157aaea5 2667 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 2668 return error("unable to create directory for %s",
157aaea5 2669 logfile);
6de08ae6
SP
2670 oflags |= O_CREAT;
2671 }
2672
157aaea5 2673 logfd = open(logfile, oflags, 0666);
6de08ae6 2674 if (logfd < 0) {
1974bf62 2675 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2676 return 0;
3b463c3f
JH
2677
2678 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2679 if (remove_empty_directories(logfile)) {
3b463c3f 2680 return error("There are still logs under '%s'",
157aaea5 2681 logfile);
3b463c3f 2682 }
157aaea5 2683 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2684 }
2685
2686 if (logfd < 0)
2687 return error("Unable to append to %s: %s",
157aaea5 2688 logfile, strerror(errno));
6de08ae6
SP
2689 }
2690
157aaea5 2691 adjust_shared_perm(logfile);
859c3017
EM
2692 close(logfd);
2693 return 0;
2694}
443b92b6 2695
dfefa935 2696static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2697 const unsigned char *new_sha1, const char *msg)
2698{
2699 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2700 unsigned maxlen, len;
2701 int msglen;
157aaea5 2702 char log_file[PATH_MAX];
859c3017
EM
2703 char *logrec;
2704 const char *committer;
2705
2706 if (log_all_ref_updates < 0)
2707 log_all_ref_updates = !is_bare_repository();
2708
dfefa935 2709 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2710 if (result)
2711 return result;
2712
2713 logfd = open(log_file, oflags);
2714 if (logfd < 0)
2715 return 0;
0ec29a47 2716 msglen = msg ? strlen(msg) : 0;
774751a8 2717 committer = git_committer_info(0);
8ac65937
JH
2718 maxlen = strlen(committer) + msglen + 100;
2719 logrec = xmalloc(maxlen);
2720 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2721 sha1_to_hex(old_sha1),
2722 sha1_to_hex(new_sha1),
8ac65937
JH
2723 committer);
2724 if (msglen)
0ec29a47 2725 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2726 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2727 free(logrec);
91c8d590 2728 if (close(logfd) != 0 || written != len)
9a13f0b7 2729 return error("Unable to append to %s", log_file);
6de08ae6
SP
2730 return 0;
2731}
2732
c3b0dec5
LT
2733static int is_branch(const char *refname)
2734{
2735 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2736}
2737
4bd18c43
SP
2738int write_ref_sha1(struct ref_lock *lock,
2739 const unsigned char *sha1, const char *logmsg)
2740{
2741 static char term = '\n';
c3b0dec5 2742 struct object *o;
4bd18c43
SP
2743
2744 if (!lock)
95fc7512 2745 return -1;
a89fccd2 2746 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2747 unlock_ref(lock);
2748 return 0;
95fc7512 2749 }
c3b0dec5
LT
2750 o = parse_object(sha1);
2751 if (!o) {
7be8b3ba 2752 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2753 lock->ref_name, sha1_to_hex(sha1));
2754 unlock_ref(lock);
2755 return -1;
2756 }
2757 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2758 error("Trying to write non-commit object %s to branch %s",
2759 sha1_to_hex(sha1), lock->ref_name);
2760 unlock_ref(lock);
2761 return -1;
2762 }
93822c22
AW
2763 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2764 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 2765 || close_ref(lock) < 0) {
c33d5174 2766 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
2767 unlock_ref(lock);
2768 return -1;
2769 }
9da31cb0 2770 clear_loose_ref_cache(&ref_cache);
bd104db1
NP
2771 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2772 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2773 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2774 unlock_ref(lock);
2775 return -1;
2776 }
605fac8b
NP
2777 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2778 /*
2779 * Special hack: If a branch is updated directly and HEAD
2780 * points to it (may happen on the remote side of a push
2781 * for example) then logically the HEAD reflog should be
2782 * updated too.
2783 * A generic solution implies reverse symref information,
2784 * but finding all symrefs pointing to the given branch
2785 * would be rather costly for this rare event (the direct
2786 * update of a branch) to be worth it. So let's cheat and
2787 * check with HEAD only which should cover 99% of all usage
2788 * scenarios (even 100% of the default ones).
2789 */
2790 unsigned char head_sha1[20];
2791 int head_flag;
2792 const char *head_ref;
8cad4744 2793 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2794 if (head_ref && (head_flag & REF_ISSYMREF) &&
2795 !strcmp(head_ref, lock->ref_name))
2796 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2797 }
b531394d 2798 if (commit_ref(lock)) {
434cd0cd 2799 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2800 unlock_ref(lock);
2801 return -1;
2802 }
4bd18c43
SP
2803 unlock_ref(lock);
2804 return 0;
95fc7512 2805}
d556fae2 2806
8b5157e4
NP
2807int create_symref(const char *ref_target, const char *refs_heads_master,
2808 const char *logmsg)
41b625b0
NP
2809{
2810 const char *lockpath;
2811 char ref[1000];
2812 int fd, len, written;
a4f34cbb 2813 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2814 unsigned char old_sha1[20], new_sha1[20];
2815
2816 if (logmsg && read_ref(ref_target, old_sha1))
2817 hashclr(old_sha1);
41b625b0 2818
d48744d1
JH
2819 if (safe_create_leading_directories(git_HEAD) < 0)
2820 return error("unable to create directory for %s", git_HEAD);
2821
41b625b0
NP
2822#ifndef NO_SYMLINK_HEAD
2823 if (prefer_symlink_refs) {
2824 unlink(git_HEAD);
2825 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2826 goto done;
41b625b0
NP
2827 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2828 }
2829#endif
2830
2831 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2832 if (sizeof(ref) <= len) {
2833 error("refname too long: %s", refs_heads_master);
47fc52e2 2834 goto error_free_return;
41b625b0
NP
2835 }
2836 lockpath = mkpath("%s.lock", git_HEAD);
2837 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2838 if (fd < 0) {
2839 error("Unable to open %s for writing", lockpath);
47fc52e2 2840 goto error_free_return;
41b625b0
NP
2841 }
2842 written = write_in_full(fd, ref, len);
91c8d590 2843 if (close(fd) != 0 || written != len) {
41b625b0 2844 error("Unable to write to %s", lockpath);
47fc52e2 2845 goto error_unlink_return;
41b625b0
NP
2846 }
2847 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 2848 error("Unable to create %s", git_HEAD);
47fc52e2 2849 goto error_unlink_return;
41b625b0
NP
2850 }
2851 if (adjust_shared_perm(git_HEAD)) {
41b625b0 2852 error("Unable to fix permissions on %s", lockpath);
47fc52e2 2853 error_unlink_return:
691f1a28 2854 unlink_or_warn(lockpath);
47fc52e2
JH
2855 error_free_return:
2856 free(git_HEAD);
2857 return -1;
41b625b0 2858 }
8b5157e4 2859
ee96d11b 2860#ifndef NO_SYMLINK_HEAD
8b5157e4 2861 done:
ee96d11b 2862#endif
8b5157e4
NP
2863 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2864 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2865
47fc52e2 2866 free(git_HEAD);
41b625b0
NP
2867 return 0;
2868}
2869
16d7cc90
JH
2870static char *ref_msg(const char *line, const char *endp)
2871{
2872 const char *ep;
16d7cc90 2873 line += 82;
182af834
PH
2874 ep = memchr(line, '\n', endp - line);
2875 if (!ep)
2876 ep = endp;
2877 return xmemdupz(line, ep - line);
16d7cc90
JH
2878}
2879
dfefa935
MH
2880int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2881 unsigned char *sha1, char **msg,
2882 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 2883{
e5229042 2884 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 2885 char *tz_c;
e29cb53a 2886 int logfd, tz, reccnt = 0;
d556fae2
SP
2887 struct stat st;
2888 unsigned long date;
e5229042 2889 unsigned char logged_sha1[20];
cb48cb58 2890 void *log_mapped;
dc49cd76 2891 size_t mapsz;
d556fae2 2892
dfefa935 2893 logfile = git_path("logs/%s", refname);
d556fae2
SP
2894 logfd = open(logfile, O_RDONLY, 0);
2895 if (logfd < 0)
d824cbba 2896 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
2897 fstat(logfd, &st);
2898 if (!st.st_size)
2899 die("Log %s is empty.", logfile);
dc49cd76
SP
2900 mapsz = xsize_t(st.st_size);
2901 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 2902 logdata = log_mapped;
d556fae2
SP
2903 close(logfd);
2904
e5229042 2905 lastrec = NULL;
d556fae2
SP
2906 rec = logend = logdata + st.st_size;
2907 while (logdata < rec) {
e29cb53a 2908 reccnt++;
d556fae2
SP
2909 if (logdata < rec && *(rec-1) == '\n')
2910 rec--;
e5229042
SP
2911 lastgt = NULL;
2912 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 2913 rec--;
e5229042
SP
2914 if (*rec == '>')
2915 lastgt = rec;
2916 }
2917 if (!lastgt)
d556fae2 2918 die("Log %s is corrupt.", logfile);
e5229042 2919 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 2920 if (date <= at_time || cnt == 0) {
76a44c5c 2921 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
2922 if (msg)
2923 *msg = ref_msg(rec, logend);
2924 if (cutoff_time)
2925 *cutoff_time = date;
2926 if (cutoff_tz)
2927 *cutoff_tz = tz;
2928 if (cutoff_cnt)
76a44c5c 2929 *cutoff_cnt = reccnt - 1;
e5229042
SP
2930 if (lastrec) {
2931 if (get_sha1_hex(lastrec, logged_sha1))
2932 die("Log %s is corrupt.", logfile);
2933 if (get_sha1_hex(rec + 41, sha1))
2934 die("Log %s is corrupt.", logfile);
a89fccd2 2935 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2936 warning("Log %s has gap after %s.",
73013afd 2937 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 2938 }
e5f38ec3
JH
2939 }
2940 else if (date == at_time) {
e5229042
SP
2941 if (get_sha1_hex(rec + 41, sha1))
2942 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
2943 }
2944 else {
e5229042
SP
2945 if (get_sha1_hex(rec + 41, logged_sha1))
2946 die("Log %s is corrupt.", logfile);
a89fccd2 2947 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2948 warning("Log %s unexpectedly ended on %s.",
73013afd 2949 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
2950 }
2951 }
dc49cd76 2952 munmap(log_mapped, mapsz);
d556fae2
SP
2953 return 0;
2954 }
e5229042 2955 lastrec = rec;
ab2a1a32
JH
2956 if (cnt > 0)
2957 cnt--;
d556fae2
SP
2958 }
2959
e5229042
SP
2960 rec = logdata;
2961 while (rec < logend && *rec != '>' && *rec != '\n')
2962 rec++;
2963 if (rec == logend || *rec == '\n')
d556fae2 2964 die("Log %s is corrupt.", logfile);
e5229042 2965 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
2966 tz = strtoul(tz_c, NULL, 10);
2967 if (get_sha1_hex(logdata, sha1))
2968 die("Log %s is corrupt.", logfile);
d1a4489a
JK
2969 if (is_null_sha1(sha1)) {
2970 if (get_sha1_hex(logdata + 41, sha1))
2971 die("Log %s is corrupt.", logfile);
2972 }
16d7cc90
JH
2973 if (msg)
2974 *msg = ref_msg(logdata, logend);
dc49cd76 2975 munmap(log_mapped, mapsz);
16d7cc90
JH
2976
2977 if (cutoff_time)
2978 *cutoff_time = date;
2979 if (cutoff_tz)
2980 *cutoff_tz = tz;
2981 if (cutoff_cnt)
2982 *cutoff_cnt = reccnt;
2983 return 1;
d556fae2 2984}
2ff81662 2985
9a7a183b
JH
2986static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
2987{
2988 unsigned char osha1[20], nsha1[20];
2989 char *email_end, *message;
2990 unsigned long timestamp;
2991 int tz;
2992
2993 /* old SP new SP name <email> SP time TAB msg LF */
2994 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
2995 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
2996 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
2997 !(email_end = strchr(sb->buf + 82, '>')) ||
2998 email_end[1] != ' ' ||
2999 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3000 !message || message[0] != ' ' ||
3001 (message[1] != '+' && message[1] != '-') ||
3002 !isdigit(message[2]) || !isdigit(message[3]) ||
3003 !isdigit(message[4]) || !isdigit(message[5]))
3004 return 0; /* corrupt? */
3005 email_end[1] = '\0';
3006 tz = strtol(message + 1, NULL, 10);
3007 if (message[6] != '\t')
3008 message += 6;
3009 else
3010 message += 7;
3011 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3012}
3013
98f85ff4
JH
3014static char *find_beginning_of_line(char *bob, char *scan)
3015{
3016 while (bob < scan && *(--scan) != '\n')
3017 ; /* keep scanning backwards */
3018 /*
3019 * Return either beginning of the buffer, or LF at the end of
3020 * the previous line.
3021 */
3022 return scan;
3023}
3024
3025int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
2ff81662 3026{
8ca78803 3027 struct strbuf sb = STRBUF_INIT;
98f85ff4
JH
3028 FILE *logfp;
3029 long pos;
3030 int ret = 0, at_tail = 1;
2ff81662 3031
7ae07c1b 3032 logfp = fopen(git_path("logs/%s", refname), "r");
2ff81662 3033 if (!logfp)
883d60fa 3034 return -1;
101d15e0 3035
98f85ff4
JH
3036 /* Jump to the end */
3037 if (fseek(logfp, 0, SEEK_END) < 0)
3038 return error("cannot seek back reflog for %s: %s",
3039 refname, strerror(errno));
3040 pos = ftell(logfp);
3041 while (!ret && 0 < pos) {
3042 int cnt;
3043 size_t nread;
3044 char buf[BUFSIZ];
3045 char *endp, *scanp;
3046
3047 /* Fill next block from the end */
3048 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3049 if (fseek(logfp, pos - cnt, SEEK_SET))
3050 return error("cannot seek back reflog for %s: %s",
3051 refname, strerror(errno));
3052 nread = fread(buf, cnt, 1, logfp);
e4ca819a 3053 if (nread != 1)
98f85ff4
JH
3054 return error("cannot read %d bytes from reflog for %s: %s",
3055 cnt, refname, strerror(errno));
3056 pos -= cnt;
3057
3058 scanp = endp = buf + cnt;
3059 if (at_tail && scanp[-1] == '\n')
3060 /* Looking at the final LF at the end of the file */
3061 scanp--;
3062 at_tail = 0;
3063
3064 while (buf < scanp) {
3065 /*
3066 * terminating LF of the previous line, or the beginning
3067 * of the buffer.
3068 */
3069 char *bp;
3070
3071 bp = find_beginning_of_line(buf, scanp);
3072
3073 if (*bp != '\n') {
3074 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3075 if (pos)
3076 break; /* need to fill another block */
3077 scanp = buf - 1; /* leave loop */
3078 } else {
3079 /*
3080 * (bp + 1) thru endp is the beginning of the
3081 * current line we have in sb
3082 */
3083 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3084 scanp = bp;
3085 endp = bp + 1;
3086 }
3087 ret = show_one_reflog_ent(&sb, fn, cb_data);
3088 strbuf_reset(&sb);
3089 if (ret)
3090 break;
9d33f7c2 3091 }
101d15e0 3092
2ff81662 3093 }
98f85ff4 3094 if (!ret && sb.len)
9a7a183b 3095 ret = show_one_reflog_ent(&sb, fn, cb_data);
98f85ff4 3096
2ff81662 3097 fclose(logfp);
8ca78803 3098 strbuf_release(&sb);
2266bf27 3099 return ret;
2ff81662 3100}
e29cb53a 3101
dfefa935 3102int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 3103{
98f85ff4
JH
3104 FILE *logfp;
3105 struct strbuf sb = STRBUF_INIT;
3106 int ret = 0;
3107
3108 logfp = fopen(git_path("logs/%s", refname), "r");
3109 if (!logfp)
3110 return -1;
101d15e0 3111
98f85ff4
JH
3112 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3113 ret = show_one_reflog_ent(&sb, fn, cb_data);
3114 fclose(logfp);
3115 strbuf_release(&sb);
3116 return ret;
3117}
989c0e5d
MH
3118/*
3119 * Call fn for each reflog in the namespace indicated by name. name
3120 * must be empty or end with '/'. Name will be used as a scratch
3121 * space, but its contents will be restored before return.
3122 */
3123static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 3124{
989c0e5d 3125 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 3126 int retval = 0;
93c603fc 3127 struct dirent *de;
989c0e5d 3128 int oldlen = name->len;
eb8381c8 3129
93c603fc 3130 if (!d)
989c0e5d 3131 return name->len ? errno : 0;
eb8381c8 3132
93c603fc
MH
3133 while ((de = readdir(d)) != NULL) {
3134 struct stat st;
eb8381c8 3135
93c603fc
MH
3136 if (de->d_name[0] == '.')
3137 continue;
93c603fc
MH
3138 if (has_extension(de->d_name, ".lock"))
3139 continue;
989c0e5d
MH
3140 strbuf_addstr(name, de->d_name);
3141 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3142 ; /* silently ignore */
93c603fc 3143 } else {
eb8381c8 3144 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
3145 strbuf_addch(name, '/');
3146 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
3147 } else {
3148 unsigned char sha1[20];
989c0e5d
MH
3149 if (read_ref_full(name->buf, sha1, 0, NULL))
3150 retval = error("bad ref for %s", name->buf);
eb8381c8 3151 else
989c0e5d 3152 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
3153 }
3154 if (retval)
3155 break;
3156 }
989c0e5d 3157 strbuf_setlen(name, oldlen);
eb8381c8 3158 }
93c603fc 3159 closedir(d);
eb8381c8
NP
3160 return retval;
3161}
3162
3163int for_each_reflog(each_ref_fn fn, void *cb_data)
3164{
989c0e5d
MH
3165 int retval;
3166 struct strbuf name;
3167 strbuf_init(&name, PATH_MAX);
3168 retval = do_for_each_reflog(&name, fn, cb_data);
3169 strbuf_release(&name);
3170 return retval;
eb8381c8 3171}
3d9f037c 3172
4738a333
BK
3173static struct ref_lock *update_ref_lock(const char *refname,
3174 const unsigned char *oldval,
3175 int flags, int *type_p,
3176 enum action_on_err onerr)
3d9f037c 3177{
4738a333
BK
3178 struct ref_lock *lock;
3179 lock = lock_any_ref_for_update(refname, oldval, flags, type_p);
3d9f037c
CR
3180 if (!lock) {
3181 const char *str = "Cannot lock the ref '%s'.";
3182 switch (onerr) {
3183 case MSG_ON_ERR: error(str, refname); break;
3184 case DIE_ON_ERR: die(str, refname); break;
3185 case QUIET_ON_ERR: break;
3186 }
3d9f037c 3187 }
4738a333
BK
3188 return lock;
3189}
3190
3191static int update_ref_write(const char *action, const char *refname,
3192 const unsigned char *sha1, struct ref_lock *lock,
3193 enum action_on_err onerr)
3194{
3d9f037c
CR
3195 if (write_ref_sha1(lock, sha1, action) < 0) {
3196 const char *str = "Cannot update the ref '%s'.";
3197 switch (onerr) {
3198 case MSG_ON_ERR: error(str, refname); break;
3199 case DIE_ON_ERR: die(str, refname); break;
3200 case QUIET_ON_ERR: break;
3201 }
3202 return 1;
3203 }
3204 return 0;
3205}
cda69f48 3206
4738a333
BK
3207int update_ref(const char *action, const char *refname,
3208 const unsigned char *sha1, const unsigned char *oldval,
3209 int flags, enum action_on_err onerr)
3210{
3211 struct ref_lock *lock;
3212 lock = update_ref_lock(refname, oldval, flags, 0, onerr);
3213 if (!lock)
3214 return 1;
3215 return update_ref_write(action, refname, sha1, lock, onerr);
3216}
3217
5483f799 3218struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
3219{
3220 for ( ; list; list = list->next)
3221 if (!strcmp(list->name, name))
5483f799 3222 return (struct ref *)list;
cda69f48
JK
3223 return NULL;
3224}
7c2b3029
JK
3225
3226/*
3227 * generate a format suitable for scanf from a ref_rev_parse_rules
3228 * rule, that is replace the "%.*s" spec with a "%s" spec
3229 */
3230static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
3231{
3232 char *spec;
3233
3234 spec = strstr(rule, "%.*s");
3235 if (!spec || strstr(spec + 4, "%.*s"))
3236 die("invalid rule in ref_rev_parse_rules: %s", rule);
3237
3238 /* copy all until spec */
3239 strncpy(scanf_fmt, rule, spec - rule);
3240 scanf_fmt[spec - rule] = '\0';
3241 /* copy new spec */
3242 strcat(scanf_fmt, "%s");
3243 /* copy remaining rule */
3244 strcat(scanf_fmt, spec + 4);
3245
3246 return;
3247}
3248
dfefa935 3249char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
3250{
3251 int i;
3252 static char **scanf_fmts;
3253 static int nr_rules;
3254 char *short_name;
3255
3256 /* pre generate scanf formats from ref_rev_parse_rules[] */
3257 if (!nr_rules) {
3258 size_t total_len = 0;
3259
3260 /* the rule list is NULL terminated, count them first */
3261 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
3262 /* no +1 because strlen("%s") < strlen("%.*s") */
3263 total_len += strlen(ref_rev_parse_rules[nr_rules]);
3264
3265 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3266
3267 total_len = 0;
3268 for (i = 0; i < nr_rules; i++) {
3269 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
3270 + total_len;
3271 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
3272 total_len += strlen(ref_rev_parse_rules[i]);
3273 }
3274 }
3275
3276 /* bail out if there are no rules */
3277 if (!nr_rules)
dfefa935 3278 return xstrdup(refname);
7c2b3029 3279
dfefa935
MH
3280 /* buffer for scanf result, at most refname must fit */
3281 short_name = xstrdup(refname);
7c2b3029
JK
3282
3283 /* skip first rule, it will always match */
3284 for (i = nr_rules - 1; i > 0 ; --i) {
3285 int j;
6e7b3309 3286 int rules_to_fail = i;
7c2b3029
JK
3287 int short_name_len;
3288
dfefa935 3289 if (1 != sscanf(refname, scanf_fmts[i], short_name))
7c2b3029
JK
3290 continue;
3291
3292 short_name_len = strlen(short_name);
3293
6e7b3309
BW
3294 /*
3295 * in strict mode, all (except the matched one) rules
3296 * must fail to resolve to a valid non-ambiguous ref
3297 */
3298 if (strict)
3299 rules_to_fail = nr_rules;
3300
7c2b3029
JK
3301 /*
3302 * check if the short name resolves to a valid ref,
3303 * but use only rules prior to the matched one
3304 */
6e7b3309 3305 for (j = 0; j < rules_to_fail; j++) {
7c2b3029 3306 const char *rule = ref_rev_parse_rules[j];
7c2b3029
JK
3307 char refname[PATH_MAX];
3308
6e7b3309
BW
3309 /* skip matched rule */
3310 if (i == j)
3311 continue;
3312
7c2b3029
JK
3313 /*
3314 * the short name is ambiguous, if it resolves
3315 * (with this previous rule) to a valid ref
3316 * read_ref() returns 0 on success
3317 */
3318 mksnpath(refname, sizeof(refname),
3319 rule, short_name_len, short_name);
c6893323 3320 if (ref_exists(refname))
7c2b3029
JK
3321 break;
3322 }
3323
3324 /*
3325 * short name is non-ambiguous if all previous rules
3326 * haven't resolved to a valid ref
3327 */
6e7b3309 3328 if (j == rules_to_fail)
7c2b3029
JK
3329 return short_name;
3330 }
3331
3332 free(short_name);
dfefa935 3333 return xstrdup(refname);
7c2b3029 3334}
daebaa78
JH
3335
3336static struct string_list *hide_refs;
3337
3338int parse_hide_refs_config(const char *var, const char *value, const char *section)
3339{
3340 if (!strcmp("transfer.hiderefs", var) ||
3341 /* NEEDSWORK: use parse_config_key() once both are merged */
3342 (!prefixcmp(var, section) && var[strlen(section)] == '.' &&
3343 !strcmp(var + strlen(section), ".hiderefs"))) {
3344 char *ref;
3345 int len;
3346
3347 if (!value)
3348 return config_error_nonbool(var);
3349 ref = xstrdup(value);
3350 len = strlen(ref);
3351 while (len && ref[len - 1] == '/')
3352 ref[--len] = '\0';
3353 if (!hide_refs) {
3354 hide_refs = xcalloc(1, sizeof(*hide_refs));
3355 hide_refs->strdup_strings = 1;
3356 }
3357 string_list_append(hide_refs, ref);
3358 }
3359 return 0;
3360}
3361
3362int ref_is_hidden(const char *refname)
3363{
3364 struct string_list_item *item;
3365
3366 if (!hide_refs)
3367 return 0;
3368 for_each_string_list_item(item, hide_refs) {
3369 int len;
3370 if (prefixcmp(refname, item->string))
3371 continue;
3372 len = strlen(item->string);
3373 if (!refname[len] || refname[len] == '/')
3374 return 1;
3375 }
3376 return 0;
3377}