refs.c: make ref_transaction_begin take an err argument
[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 8/*
dde8a902
DT
9 * How to handle various characters in refnames:
10 * 0: An acceptable character for refs
11 * 1: End-of-component
12 * 2: ., look for a preceding . to reject .. in refs
13 * 3: {, look for a preceding @ to reject @{ in refs
14 * 4: A bad character: ASCII control characters, "~", "^", ":" or SP
15 */
16static unsigned char refname_disposition[256] = {
17 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
18 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
19 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1,
20 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
21 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
22 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
23 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
24 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
25};
26
27/*
28 * Try to read one refname component from the front of refname.
29 * Return the length of the component found, or -1 if the component is
30 * not legal. It is legal if it is something reasonable to have under
31 * ".git/refs/"; We do not like it if:
bc5fd6d3
MH
32 *
33 * - any path component of it begins with ".", or
34 * - it has double dots "..", or
35 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
36 * - it ends with a "/".
37 * - it ends with ".lock"
38 * - it contains a "\" (backslash)
39 */
bc5fd6d3
MH
40static int check_refname_component(const char *refname, int flags)
41{
42 const char *cp;
43 char last = '\0';
44
45 for (cp = refname; ; cp++) {
dde8a902
DT
46 int ch = *cp & 255;
47 unsigned char disp = refname_disposition[ch];
48 switch (disp) {
49 case 1:
50 goto out;
51 case 2:
52 if (last == '.')
53 return -1; /* Refname contains "..". */
54 break;
55 case 3:
56 if (last == '@')
57 return -1; /* Refname contains "@{". */
bc5fd6d3 58 break;
dde8a902
DT
59 case 4:
60 return -1;
61 }
bc5fd6d3
MH
62 last = ch;
63 }
dde8a902 64out:
bc5fd6d3 65 if (cp == refname)
dac529e4 66 return 0; /* Component has zero length. */
bc5fd6d3
MH
67 if (refname[0] == '.') {
68 if (!(flags & REFNAME_DOT_COMPONENT))
69 return -1; /* Component starts with '.'. */
70 /*
71 * Even if leading dots are allowed, don't allow "."
72 * as a component (".." is prevented by a rule above).
73 */
74 if (refname[1] == '\0')
75 return -1; /* Component equals ".". */
76 }
77 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
78 return -1; /* Refname ends with ".lock". */
79 return cp - refname;
80}
81
82int check_refname_format(const char *refname, int flags)
83{
84 int component_len, component_count = 0;
85
9ba89f48
FC
86 if (!strcmp(refname, "@"))
87 /* Refname is a single character '@'. */
88 return -1;
89
bc5fd6d3
MH
90 while (1) {
91 /* We are at the start of a path component. */
92 component_len = check_refname_component(refname, flags);
dac529e4 93 if (component_len <= 0) {
bc5fd6d3
MH
94 if ((flags & REFNAME_REFSPEC_PATTERN) &&
95 refname[0] == '*' &&
96 (refname[1] == '\0' || refname[1] == '/')) {
97 /* Accept one wildcard as a full refname component. */
98 flags &= ~REFNAME_REFSPEC_PATTERN;
99 component_len = 1;
100 } else {
101 return -1;
102 }
103 }
104 component_count++;
105 if (refname[component_len] == '\0')
106 break;
107 /* Skip to next component. */
108 refname += component_len + 1;
109 }
110
111 if (refname[component_len - 1] == '.')
112 return -1; /* Refname ends with '.'. */
113 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
114 return -1; /* Refname has only one component. */
115 return 0;
116}
117
118struct ref_entry;
e1e22e37 119
28e6a34e
MH
120/*
121 * Information used (along with the information in ref_entry) to
122 * describe a single cached reference. This data structure only
123 * occurs embedded in a union in struct ref_entry, and only when
124 * (ref_entry->flag & REF_DIR) is zero.
125 */
593f1bb8 126struct ref_value {
6c6f58df
MH
127 /*
128 * The name of the object to which this reference resolves
129 * (which may be a tag object). If REF_ISBROKEN, this is
130 * null. If REF_ISSYMREF, then this is the name of the object
131 * referred to by the last reference in the symlink chain.
132 */
593f1bb8 133 unsigned char sha1[20];
6c6f58df
MH
134
135 /*
136 * If REF_KNOWS_PEELED, then this field holds the peeled value
137 * of this reference, or null if the reference is known not to
2312a793
MH
138 * be peelable. See the documentation for peel_ref() for an
139 * exact definition of "peelable".
6c6f58df 140 */
593f1bb8
MH
141 unsigned char peeled[20];
142};
143
f006c42a
MH
144struct ref_cache;
145
28e6a34e
MH
146/*
147 * Information used (along with the information in ref_entry) to
148 * describe a level in the hierarchy of references. This data
149 * structure only occurs embedded in a union in struct ref_entry, and
150 * only when (ref_entry.flag & REF_DIR) is set. In that case,
151 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
152 * in the directory have already been read:
153 *
154 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
155 * or packed references, already read.
156 *
157 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
158 * references that hasn't been read yet (nor has any of its
159 * subdirectories).
160 *
161 * Entries within a directory are stored within a growable array of
162 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
163 * sorted are sorted by their component name in strcmp() order and the
164 * remaining entries are unsorted.
165 *
166 * Loose references are read lazily, one directory at a time. When a
167 * directory of loose references is read, then all of the references
168 * in that directory are stored, and REF_INCOMPLETE stubs are created
169 * for any subdirectories, but the subdirectories themselves are not
170 * read. The reading is triggered by get_ref_dir().
171 */
d3177275 172struct ref_dir {
e9c4c111 173 int nr, alloc;
e6ed3ca6
MH
174
175 /*
176 * Entries with index 0 <= i < sorted are sorted by name. New
177 * entries are appended to the list unsorted, and are sorted
178 * only when required; thus we avoid the need to sort the list
179 * after the addition of every reference.
180 */
181 int sorted;
182
f006c42a
MH
183 /* A pointer to the ref_cache that contains this ref_dir. */
184 struct ref_cache *ref_cache;
185
d3177275 186 struct ref_entry **entries;
e9c4c111
JP
187};
188
89df9c84
MH
189/*
190 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
191 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
192 * refs.h.
193 */
194
195/*
196 * The field ref_entry->u.value.peeled of this value entry contains
197 * the correct peeled value for the reference, which might be
198 * null_sha1 if the reference is not a tag or if it is broken.
199 */
432ad41e 200#define REF_KNOWS_PEELED 0x08
28e6a34e
MH
201
202/* ref_entry represents a directory of references */
432ad41e 203#define REF_DIR 0x10
cf0adba7 204
28e6a34e
MH
205/*
206 * Entry has not yet been read from disk (used only for REF_DIR
207 * entries representing loose references)
208 */
209#define REF_INCOMPLETE 0x20
210
432ad41e
MH
211/*
212 * A ref_entry represents either a reference or a "subdirectory" of
28e6a34e
MH
213 * references.
214 *
215 * Each directory in the reference namespace is represented by a
216 * ref_entry with (flags & REF_DIR) set and containing a subdir member
217 * that holds the entries in that directory that have been read so
218 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
219 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
220 * used for loose reference directories.
221 *
222 * References are represented by a ref_entry with (flags & REF_DIR)
223 * unset and a value member that describes the reference's value. The
224 * flag member is at the ref_entry level, but it is also needed to
225 * interpret the contents of the value field (in other words, a
226 * ref_value object is not very much use without the enclosing
227 * ref_entry).
432ad41e
MH
228 *
229 * Reference names cannot end with slash and directories' names are
230 * always stored with a trailing slash (except for the top-level
231 * directory, which is always denoted by ""). This has two nice
232 * consequences: (1) when the entries in each subdir are sorted
233 * lexicographically by name (as they usually are), the references in
234 * a whole tree can be generated in lexicographic order by traversing
235 * the tree in left-to-right, depth-first order; (2) the names of
236 * references and subdirectories cannot conflict, and therefore the
237 * presence of an empty subdirectory does not block the creation of a
238 * similarly-named reference. (The fact that reference names with the
239 * same leading components can conflict *with each other* is a
240 * separate issue that is regulated by is_refname_available().)
241 *
242 * Please note that the name field contains the fully-qualified
243 * reference (or subdirectory) name. Space could be saved by only
244 * storing the relative names. But that would require the full names
245 * to be generated on the fly when iterating in do_for_each_ref(), and
246 * would break callback functions, who have always been able to assume
247 * that the name strings that they are passed will not be freed during
248 * the iteration.
249 */
bc5fd6d3
MH
250struct ref_entry {
251 unsigned char flag; /* ISSYMREF? ISPACKED? */
593f1bb8 252 union {
432ad41e
MH
253 struct ref_value value; /* if not (flags&REF_DIR) */
254 struct ref_dir subdir; /* if (flags&REF_DIR) */
593f1bb8 255 } u;
432ad41e
MH
256 /*
257 * The full name of the reference (e.g., "refs/heads/master")
258 * or the full name of the directory with a trailing slash
259 * (e.g., "refs/heads/"):
260 */
bc5fd6d3
MH
261 char name[FLEX_ARRAY];
262};
e1e22e37 263
28e6a34e
MH
264static void read_loose_refs(const char *dirname, struct ref_dir *dir);
265
d7826d54
MH
266static struct ref_dir *get_ref_dir(struct ref_entry *entry)
267{
28e6a34e 268 struct ref_dir *dir;
d7826d54 269 assert(entry->flag & REF_DIR);
28e6a34e
MH
270 dir = &entry->u.subdir;
271 if (entry->flag & REF_INCOMPLETE) {
272 read_loose_refs(entry->name, dir);
273 entry->flag &= ~REF_INCOMPLETE;
274 }
275 return dir;
d7826d54
MH
276}
277
cddc4258
MH
278static struct ref_entry *create_ref_entry(const char *refname,
279 const unsigned char *sha1, int flag,
280 int check_name)
e1e22e37
LT
281{
282 int len;
cddc4258 283 struct ref_entry *ref;
e1e22e37 284
09116a1c 285 if (check_name &&
dfefa935
MH
286 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
287 die("Reference has invalid format: '%s'", refname);
cddc4258
MH
288 len = strlen(refname) + 1;
289 ref = xmalloc(sizeof(struct ref_entry) + len);
593f1bb8
MH
290 hashcpy(ref->u.value.sha1, sha1);
291 hashclr(ref->u.value.peeled);
cddc4258
MH
292 memcpy(ref->name, refname, len);
293 ref->flag = flag;
294 return ref;
295}
296
432ad41e
MH
297static void clear_ref_dir(struct ref_dir *dir);
298
732134ed
MH
299static void free_ref_entry(struct ref_entry *entry)
300{
27b5587c
MH
301 if (entry->flag & REF_DIR) {
302 /*
303 * Do not use get_ref_dir() here, as that might
304 * trigger the reading of loose refs.
305 */
306 clear_ref_dir(&entry->u.subdir);
307 }
732134ed
MH
308 free(entry);
309}
310
432ad41e
MH
311/*
312 * Add a ref_entry to the end of dir (unsorted). Entry is always
313 * stored directly in dir; no recursion into subdirectories is
314 * done.
315 */
316static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
cddc4258 317{
432ad41e
MH
318 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
319 dir->entries[dir->nr++] = entry;
654ad400
MH
320 /* optimize for the case that entries are added in order */
321 if (dir->nr == 1 ||
322 (dir->nr == dir->sorted + 1 &&
323 strcmp(dir->entries[dir->nr - 2]->name,
324 dir->entries[dir->nr - 1]->name) < 0))
325 dir->sorted = dir->nr;
c774aab9
JP
326}
327
432ad41e
MH
328/*
329 * Clear and free all entries in dir, recursively.
330 */
d3177275 331static void clear_ref_dir(struct ref_dir *dir)
bc5fd6d3
MH
332{
333 int i;
d3177275
MH
334 for (i = 0; i < dir->nr; i++)
335 free_ref_entry(dir->entries[i]);
336 free(dir->entries);
337 dir->sorted = dir->nr = dir->alloc = 0;
338 dir->entries = NULL;
bc5fd6d3
MH
339}
340
432ad41e
MH
341/*
342 * Create a struct ref_entry object for the specified dirname.
343 * dirname is the name of the directory with a trailing slash (e.g.,
344 * "refs/heads/") or "" for the top-level directory.
345 */
f006c42a 346static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
b9146f51
RS
347 const char *dirname, size_t len,
348 int incomplete)
432ad41e
MH
349{
350 struct ref_entry *direntry;
432ad41e 351 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
b9146f51
RS
352 memcpy(direntry->name, dirname, len);
353 direntry->name[len] = '\0';
f006c42a 354 direntry->u.subdir.ref_cache = ref_cache;
28e6a34e 355 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
432ad41e
MH
356 return direntry;
357}
358
e9c4c111 359static int ref_entry_cmp(const void *a, const void *b)
c774aab9 360{
e9c4c111
JP
361 struct ref_entry *one = *(struct ref_entry **)a;
362 struct ref_entry *two = *(struct ref_entry **)b;
363 return strcmp(one->name, two->name);
364}
c774aab9 365
d3177275 366static void sort_ref_dir(struct ref_dir *dir);
bc5fd6d3 367
e1980c9d
JH
368struct string_slice {
369 size_t len;
370 const char *str;
371};
372
373static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
374{
c971ddfd
RS
375 const struct string_slice *key = key_;
376 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
377 int cmp = strncmp(key->str, ent->name, key->len);
e1980c9d
JH
378 if (cmp)
379 return cmp;
c971ddfd 380 return '\0' - (unsigned char)ent->name[key->len];
e1980c9d
JH
381}
382
432ad41e 383/*
9fc0a648
MH
384 * Return the index of the entry with the given refname from the
385 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
386 * no such entry is found. dir must already be complete.
432ad41e 387 */
9fc0a648 388static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
bc5fd6d3 389{
e1980c9d
JH
390 struct ref_entry **r;
391 struct string_slice key;
bc5fd6d3 392
432ad41e 393 if (refname == NULL || !dir->nr)
9fc0a648 394 return -1;
bc5fd6d3 395
d3177275 396 sort_ref_dir(dir);
e1980c9d
JH
397 key.len = len;
398 key.str = refname;
399 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
400 ref_entry_cmp_sslice);
bc5fd6d3
MH
401
402 if (r == NULL)
9fc0a648 403 return -1;
bc5fd6d3 404
9fc0a648 405 return r - dir->entries;
bc5fd6d3
MH
406}
407
f348ac92
MH
408/*
409 * Search for a directory entry directly within dir (without
410 * recursing). Sort dir if necessary. subdirname must be a directory
411 * name (i.e., end in '/'). If mkdir is set, then create the
412 * directory if it is missing; otherwise, return NULL if the desired
28e6a34e 413 * directory cannot be found. dir must already be complete.
f348ac92 414 */
3f3aa1bc 415static struct ref_dir *search_for_subdir(struct ref_dir *dir,
dd02e728
RS
416 const char *subdirname, size_t len,
417 int mkdir)
f348ac92 418{
9fc0a648
MH
419 int entry_index = search_ref_dir(dir, subdirname, len);
420 struct ref_entry *entry;
421 if (entry_index == -1) {
f348ac92
MH
422 if (!mkdir)
423 return NULL;
28e6a34e
MH
424 /*
425 * Since dir is complete, the absence of a subdir
426 * means that the subdir really doesn't exist;
427 * therefore, create an empty record for it but mark
428 * the record complete.
429 */
b9146f51 430 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
f348ac92 431 add_entry_to_dir(dir, entry);
9fc0a648
MH
432 } else {
433 entry = dir->entries[entry_index];
f348ac92 434 }
3f3aa1bc 435 return get_ref_dir(entry);
f348ac92
MH
436}
437
432ad41e
MH
438/*
439 * If refname is a reference name, find the ref_dir within the dir
440 * tree that should hold refname. If refname is a directory name
441 * (i.e., ends in '/'), then return that ref_dir itself. dir must
28e6a34e
MH
442 * represent the top-level directory and must already be complete.
443 * Sort ref_dirs and recurse into subdirectories as necessary. If
444 * mkdir is set, then create any missing directories; otherwise,
445 * return NULL if the desired directory cannot be found.
432ad41e
MH
446 */
447static struct ref_dir *find_containing_dir(struct ref_dir *dir,
448 const char *refname, int mkdir)
449{
5fa04418 450 const char *slash;
5fa04418 451 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
dd02e728 452 size_t dirnamelen = slash - refname + 1;
3f3aa1bc 453 struct ref_dir *subdir;
dd02e728 454 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
663c1295
JH
455 if (!subdir) {
456 dir = NULL;
f348ac92 457 break;
432ad41e 458 }
3f3aa1bc 459 dir = subdir;
432ad41e
MH
460 }
461
432ad41e
MH
462 return dir;
463}
464
465/*
466 * Find the value entry with the given name in dir, sorting ref_dirs
467 * and recursing into subdirectories as necessary. If the name is not
468 * found or it corresponds to a directory entry, return NULL.
469 */
470static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
471{
9fc0a648 472 int entry_index;
432ad41e
MH
473 struct ref_entry *entry;
474 dir = find_containing_dir(dir, refname, 0);
475 if (!dir)
476 return NULL;
9fc0a648
MH
477 entry_index = search_ref_dir(dir, refname, strlen(refname));
478 if (entry_index == -1)
479 return NULL;
480 entry = dir->entries[entry_index];
481 return (entry->flag & REF_DIR) ? NULL : entry;
432ad41e
MH
482}
483
506a760d
MH
484/*
485 * Remove the entry with the given name from dir, recursing into
486 * subdirectories as necessary. If refname is the name of a directory
487 * (i.e., ends with '/'), then remove the directory and its contents.
488 * If the removal was successful, return the number of entries
489 * remaining in the directory entry that contained the deleted entry.
490 * If the name was not found, return -1. Please note that this
491 * function only deletes the entry from the cache; it does not delete
492 * it from the filesystem or ensure that other cache entries (which
493 * might be symbolic references to the removed entry) are updated.
494 * Nor does it remove any containing dir entries that might be made
495 * empty by the removal. dir must represent the top-level directory
496 * and must already be complete.
497 */
498static int remove_entry(struct ref_dir *dir, const char *refname)
499{
500 int refname_len = strlen(refname);
501 int entry_index;
502 struct ref_entry *entry;
503 int is_dir = refname[refname_len - 1] == '/';
504 if (is_dir) {
505 /*
506 * refname represents a reference directory. Remove
507 * the trailing slash; otherwise we will get the
508 * directory *representing* refname rather than the
509 * one *containing* it.
510 */
511 char *dirname = xmemdupz(refname, refname_len - 1);
512 dir = find_containing_dir(dir, dirname, 0);
513 free(dirname);
514 } else {
515 dir = find_containing_dir(dir, refname, 0);
516 }
517 if (!dir)
518 return -1;
519 entry_index = search_ref_dir(dir, refname, refname_len);
520 if (entry_index == -1)
521 return -1;
522 entry = dir->entries[entry_index];
523
524 memmove(&dir->entries[entry_index],
525 &dir->entries[entry_index + 1],
526 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
527 );
528 dir->nr--;
529 if (dir->sorted > entry_index)
530 dir->sorted--;
531 free_ref_entry(entry);
532 return dir->nr;
432ad41e
MH
533}
534
535/*
536 * Add a ref_entry to the ref_dir (unsorted), recursing into
537 * subdirectories as necessary. dir must represent the top-level
538 * directory. Return 0 on success.
539 */
540static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
541{
542 dir = find_containing_dir(dir, ref->name, 1);
543 if (!dir)
544 return -1;
545 add_entry_to_dir(dir, ref);
546 return 0;
547}
548
202a56a9
MH
549/*
550 * Emit a warning and return true iff ref1 and ref2 have the same name
551 * and the same sha1. Die if they have the same name but different
552 * sha1s.
553 */
554static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
555{
432ad41e 556 if (strcmp(ref1->name, ref2->name))
202a56a9 557 return 0;
432ad41e
MH
558
559 /* Duplicate name; make sure that they don't conflict: */
560
561 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
562 /* This is impossible by construction */
563 die("Reference directory conflict: %s", ref1->name);
564
565 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
566 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
567
568 warning("Duplicated ref: %s", ref1->name);
569 return 1;
202a56a9
MH
570}
571
e6ed3ca6 572/*
432ad41e
MH
573 * Sort the entries in dir non-recursively (if they are not already
574 * sorted) and remove any duplicate entries.
e6ed3ca6 575 */
d3177275 576static void sort_ref_dir(struct ref_dir *dir)
e9c4c111 577{
202a56a9 578 int i, j;
81a79d8e 579 struct ref_entry *last = NULL;
c774aab9 580
e6ed3ca6
MH
581 /*
582 * This check also prevents passing a zero-length array to qsort(),
583 * which is a problem on some platforms.
584 */
d3177275 585 if (dir->sorted == dir->nr)
e9c4c111 586 return;
c774aab9 587
d3177275 588 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
c774aab9 589
81a79d8e
MH
590 /* Remove any duplicates: */
591 for (i = 0, j = 0; j < dir->nr; j++) {
592 struct ref_entry *entry = dir->entries[j];
593 if (last && is_dup_ref(last, entry))
594 free_ref_entry(entry);
595 else
596 last = dir->entries[i++] = entry;
e9c4c111 597 }
81a79d8e 598 dir->sorted = dir->nr = i;
e9c4c111 599}
c774aab9 600
fcce1703
MH
601/* Include broken references in a do_for_each_ref*() iteration: */
602#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
c774aab9 603
662428f4
MH
604/*
605 * Return true iff the reference described by entry can be resolved to
606 * an object in the database. Emit a warning if the referred-to
607 * object does not exist.
608 */
609static int ref_resolves_to_object(struct ref_entry *entry)
610{
611 if (entry->flag & REF_ISBROKEN)
612 return 0;
613 if (!has_sha1_file(entry->u.value.sha1)) {
614 error("%s does not point to a valid object!", entry->name);
615 return 0;
616 }
617 return 1;
618}
c774aab9 619
7d76fdc8
MH
620/*
621 * current_ref is a performance hack: when iterating over references
622 * using the for_each_ref*() functions, current_ref is set to the
623 * current reference's entry before calling the callback function. If
624 * the callback function calls peel_ref(), then peel_ref() first
625 * checks whether the reference to be peeled is the current reference
626 * (it usually is) and if so, returns that reference's peeled version
627 * if it is available. This avoids a refname lookup in a common case.
628 */
bc5fd6d3 629static struct ref_entry *current_ref;
c774aab9 630
624cac35
MH
631typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
632
633struct ref_entry_cb {
634 const char *base;
635 int trim;
636 int flags;
637 each_ref_fn *fn;
638 void *cb_data;
639};
640
fcce1703 641/*
624cac35
MH
642 * Handle one reference in a do_for_each_ref*()-style iteration,
643 * calling an each_ref_fn for each entry.
fcce1703 644 */
624cac35 645static int do_one_ref(struct ref_entry *entry, void *cb_data)
bc5fd6d3 646{
624cac35 647 struct ref_entry_cb *data = cb_data;
d0cf51e9 648 struct ref_entry *old_current_ref;
429213e4 649 int retval;
d0cf51e9 650
59556548 651 if (!starts_with(entry->name, data->base))
bc5fd6d3 652 return 0;
c774aab9 653
624cac35 654 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
662428f4 655 !ref_resolves_to_object(entry))
bc5fd6d3 656 return 0;
c774aab9 657
d0cf51e9
MH
658 /* Store the old value, in case this is a recursive call: */
659 old_current_ref = current_ref;
bc5fd6d3 660 current_ref = entry;
624cac35
MH
661 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
662 entry->flag, data->cb_data);
d0cf51e9 663 current_ref = old_current_ref;
429213e4 664 return retval;
bc5fd6d3 665}
c774aab9 666
c36b5bc2 667/*
d3177275 668 * Call fn for each reference in dir that has index in the range
432ad41e
MH
669 * offset <= index < dir->nr. Recurse into subdirectories that are in
670 * that index range, sorting them before iterating. This function
624cac35
MH
671 * does not sort dir itself; it should be sorted beforehand. fn is
672 * called for all references, including broken ones.
c36b5bc2 673 */
624cac35
MH
674static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
675 each_ref_entry_fn fn, void *cb_data)
c36b5bc2
MH
676{
677 int i;
d3177275
MH
678 assert(dir->sorted == dir->nr);
679 for (i = offset; i < dir->nr; i++) {
432ad41e
MH
680 struct ref_entry *entry = dir->entries[i];
681 int retval;
682 if (entry->flag & REF_DIR) {
d7826d54
MH
683 struct ref_dir *subdir = get_ref_dir(entry);
684 sort_ref_dir(subdir);
624cac35 685 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
432ad41e 686 } else {
624cac35 687 retval = fn(entry, cb_data);
432ad41e 688 }
c36b5bc2
MH
689 if (retval)
690 return retval;
691 }
692 return 0;
693}
694
b3fd060f 695/*
d3177275 696 * Call fn for each reference in the union of dir1 and dir2, in order
432ad41e
MH
697 * by refname. Recurse into subdirectories. If a value entry appears
698 * in both dir1 and dir2, then only process the version that is in
699 * dir2. The input dirs must already be sorted, but subdirs will be
624cac35
MH
700 * sorted as needed. fn is called for all references, including
701 * broken ones.
b3fd060f 702 */
624cac35
MH
703static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
704 struct ref_dir *dir2,
705 each_ref_entry_fn fn, void *cb_data)
b3fd060f
MH
706{
707 int retval;
708 int i1 = 0, i2 = 0;
709
d3177275
MH
710 assert(dir1->sorted == dir1->nr);
711 assert(dir2->sorted == dir2->nr);
432ad41e
MH
712 while (1) {
713 struct ref_entry *e1, *e2;
714 int cmp;
715 if (i1 == dir1->nr) {
624cac35 716 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
432ad41e
MH
717 }
718 if (i2 == dir2->nr) {
624cac35 719 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
432ad41e
MH
720 }
721 e1 = dir1->entries[i1];
722 e2 = dir2->entries[i2];
723 cmp = strcmp(e1->name, e2->name);
724 if (cmp == 0) {
725 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
726 /* Both are directories; descend them in parallel. */
d7826d54
MH
727 struct ref_dir *subdir1 = get_ref_dir(e1);
728 struct ref_dir *subdir2 = get_ref_dir(e2);
729 sort_ref_dir(subdir1);
730 sort_ref_dir(subdir2);
624cac35
MH
731 retval = do_for_each_entry_in_dirs(
732 subdir1, subdir2, fn, cb_data);
432ad41e
MH
733 i1++;
734 i2++;
735 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
736 /* Both are references; ignore the one from dir1. */
624cac35 737 retval = fn(e2, cb_data);
432ad41e
MH
738 i1++;
739 i2++;
740 } else {
741 die("conflict between reference and directory: %s",
742 e1->name);
743 }
b3fd060f 744 } else {
432ad41e
MH
745 struct ref_entry *e;
746 if (cmp < 0) {
747 e = e1;
b3fd060f 748 i1++;
432ad41e
MH
749 } else {
750 e = e2;
751 i2++;
752 }
753 if (e->flag & REF_DIR) {
d7826d54
MH
754 struct ref_dir *subdir = get_ref_dir(e);
755 sort_ref_dir(subdir);
624cac35
MH
756 retval = do_for_each_entry_in_dir(
757 subdir, 0, fn, cb_data);
432ad41e 758 } else {
624cac35 759 retval = fn(e, cb_data);
b3fd060f
MH
760 }
761 }
762 if (retval)
763 return retval;
764 }
b3fd060f
MH
765}
766
98eeb09e
JK
767/*
768 * Load all of the refs from the dir into our in-memory cache. The hard work
769 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
770 * through all of the sub-directories. We do not even need to care about
771 * sorting, as traversal order does not matter to us.
772 */
773static void prime_ref_dir(struct ref_dir *dir)
774{
775 int i;
776 for (i = 0; i < dir->nr; i++) {
777 struct ref_entry *entry = dir->entries[i];
778 if (entry->flag & REF_DIR)
779 prime_ref_dir(get_ref_dir(entry));
780 }
781}
d66da478
MH
782/*
783 * Return true iff refname1 and refname2 conflict with each other.
784 * Two reference names conflict if one of them exactly matches the
785 * leading components of the other; e.g., "foo/bar" conflicts with
786 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
787 * "foo/barbados".
788 */
789static int names_conflict(const char *refname1, const char *refname2)
790{
5a4d4947
MH
791 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
792 ;
793 return (*refname1 == '\0' && *refname2 == '/')
794 || (*refname1 == '/' && *refname2 == '\0');
795}
796
797struct name_conflict_cb {
798 const char *refname;
799 const char *oldrefname;
800 const char *conflicting_refname;
801};
802
624cac35 803static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
5a4d4947
MH
804{
805 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
624cac35 806 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
5a4d4947 807 return 0;
624cac35
MH
808 if (names_conflict(data->refname, entry->name)) {
809 data->conflicting_refname = entry->name;
5a4d4947 810 return 1;
d66da478 811 }
5a4d4947 812 return 0;
d66da478
MH
813}
814
bc5fd6d3
MH
815/*
816 * Return true iff a reference named refname could be created without
624cac35 817 * conflicting with the name of an existing reference in dir. If
5a4d4947
MH
818 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
819 * (e.g., because oldrefname is scheduled for deletion in the same
bc5fd6d3
MH
820 * operation).
821 */
822static int is_refname_available(const char *refname, const char *oldrefname,
d3177275 823 struct ref_dir *dir)
bc5fd6d3 824{
5a4d4947
MH
825 struct name_conflict_cb data;
826 data.refname = refname;
827 data.oldrefname = oldrefname;
828 data.conflicting_refname = NULL;
829
d3177275 830 sort_ref_dir(dir);
624cac35 831 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
5a4d4947
MH
832 error("'%s' exists; cannot create '%s'",
833 data.conflicting_refname, refname);
834 return 0;
bc5fd6d3
MH
835 }
836 return 1;
e1e22e37
LT
837}
838
2fff7812
MH
839struct packed_ref_cache {
840 struct ref_entry *root;
9f69d297 841
5f5e2a88
MH
842 /*
843 * Count of references to the data structure in this instance,
844 * including the pointer from ref_cache::packed if any. The
845 * data will not be freed as long as the reference count is
846 * nonzero.
847 */
848 unsigned int referrers;
849
9f69d297
MH
850 /*
851 * Iff the packed-refs file associated with this instance is
852 * currently locked for writing, this points at the associated
4f6b83e3
MH
853 * lock (which is owned by somebody else). The referrer count
854 * is also incremented when the file is locked and decremented
855 * when it is unlocked.
9f69d297
MH
856 */
857 struct lock_file *lock;
ca919930
JK
858
859 /* The metadata from when this packed-refs cache was read */
860 struct stat_validity validity;
2fff7812
MH
861};
862
5e290ff7
JH
863/*
864 * Future: need to be in "struct repository"
865 * when doing a full libification.
866 */
79c7ca54
MH
867static struct ref_cache {
868 struct ref_cache *next;
d12229f5 869 struct ref_entry *loose;
2fff7812 870 struct packed_ref_cache *packed;
9da31cb0
MH
871 /*
872 * The submodule name, or "" for the main repo. We allocate
873 * length 1 rather than FLEX_ARRAY so that the main ref_cache
874 * is initialized correctly.
875 */
876 char name[1];
877} ref_cache, *submodule_ref_caches;
0e88c130 878
9f69d297
MH
879/* Lock used for the main packed-refs file: */
880static struct lock_file packlock;
881
5f5e2a88
MH
882/*
883 * Increment the reference count of *packed_refs.
884 */
885static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
886{
887 packed_refs->referrers++;
888}
889
890/*
891 * Decrease the reference count of *packed_refs. If it goes to zero,
892 * free *packed_refs and return true; otherwise return false.
893 */
894static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
895{
896 if (!--packed_refs->referrers) {
897 free_ref_entry(packed_refs->root);
ca919930 898 stat_validity_clear(&packed_refs->validity);
5f5e2a88
MH
899 free(packed_refs);
900 return 1;
901 } else {
902 return 0;
903 }
904}
905
760c4512 906static void clear_packed_ref_cache(struct ref_cache *refs)
e1e22e37 907{
d12229f5 908 if (refs->packed) {
5f5e2a88
MH
909 struct packed_ref_cache *packed_refs = refs->packed;
910
911 if (packed_refs->lock)
9f69d297 912 die("internal error: packed-ref cache cleared while locked");
d12229f5 913 refs->packed = NULL;
5f5e2a88 914 release_packed_ref_cache(packed_refs);
d12229f5 915 }
5e290ff7 916}
e1e22e37 917
760c4512
MH
918static void clear_loose_ref_cache(struct ref_cache *refs)
919{
d12229f5
MH
920 if (refs->loose) {
921 free_ref_entry(refs->loose);
922 refs->loose = NULL;
923 }
760c4512
MH
924}
925
79c7ca54 926static struct ref_cache *create_ref_cache(const char *submodule)
e5dbf605 927{
ce40979c 928 int len;
79c7ca54 929 struct ref_cache *refs;
ce40979c
MH
930 if (!submodule)
931 submodule = "";
932 len = strlen(submodule) + 1;
79c7ca54 933 refs = xcalloc(1, sizeof(struct ref_cache) + len);
ce40979c 934 memcpy(refs->name, submodule, len);
e5dbf605
MH
935 return refs;
936}
937
4349a668 938/*
79c7ca54 939 * Return a pointer to a ref_cache for the specified submodule. For
4349a668
MH
940 * the main repository, use submodule==NULL. The returned structure
941 * will be allocated and initialized but not necessarily populated; it
942 * should not be freed.
943 */
79c7ca54 944static struct ref_cache *get_ref_cache(const char *submodule)
4349a668 945{
9da31cb0
MH
946 struct ref_cache *refs;
947
948 if (!submodule || !*submodule)
949 return &ref_cache;
950
951 for (refs = submodule_ref_caches; refs; refs = refs->next)
0e88c130
MH
952 if (!strcmp(submodule, refs->name))
953 return refs;
0e88c130 954
79c7ca54 955 refs = create_ref_cache(submodule);
9da31cb0
MH
956 refs->next = submodule_ref_caches;
957 submodule_ref_caches = refs;
0e88c130 958 return refs;
4349a668
MH
959}
960
3feb4f0c
MH
961/* The length of a peeled reference line in packed-refs, including EOL: */
962#define PEELED_LINE_LENGTH 42
963
694b7a19
MH
964/*
965 * The packed-refs header line that we write out. Perhaps other
966 * traits will be added later. The trailing space is required.
967 */
968static const char PACKED_REFS_HEADER[] =
969 "# pack-refs with: peeled fully-peeled \n";
970
bc5fd6d3
MH
971/*
972 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
973 * Return a pointer to the refname within the line (null-terminated),
974 * or NULL if there was a problem.
975 */
976static const char *parse_ref_line(char *line, unsigned char *sha1)
977{
978 /*
979 * 42: the answer to everything.
980 *
981 * In this case, it happens to be the answer to
982 * 40 (length of sha1 hex representation)
983 * +1 (space in between hex and name)
984 * +1 (newline at the end of the line)
985 */
986 int len = strlen(line) - 42;
987
988 if (len <= 0)
989 return NULL;
990 if (get_sha1_hex(line, sha1) < 0)
991 return NULL;
992 if (!isspace(line[40]))
993 return NULL;
994 line += 41;
995 if (isspace(*line))
996 return NULL;
997 if (line[len] != '\n')
998 return NULL;
999 line[len] = 0;
1000
1001 return line;
1002}
1003
c29c46fa
MH
1004/*
1005 * Read f, which is a packed-refs file, into dir.
1006 *
1007 * A comment line of the form "# pack-refs with: " may contain zero or
1008 * more traits. We interpret the traits as follows:
1009 *
1010 * No traits:
1011 *
1012 * Probably no references are peeled. But if the file contains a
1013 * peeled value for a reference, we will use it.
1014 *
1015 * peeled:
1016 *
1017 * References under "refs/tags/", if they *can* be peeled, *are*
1018 * peeled in this file. References outside of "refs/tags/" are
1019 * probably not peeled even if they could have been, but if we find
1020 * a peeled value for such a reference we will use it.
1021 *
1022 * fully-peeled:
1023 *
1024 * All references in the file that can be peeled are peeled.
1025 * Inversely (and this is more important), any references in the
1026 * file for which no peeled value is recorded is not peelable. This
1027 * trait should typically be written alongside "peeled" for
1028 * compatibility with older clients, but we do not require it
1029 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1030 */
d3177275 1031static void read_packed_refs(FILE *f, struct ref_dir *dir)
f4204ab9 1032{
e9c4c111 1033 struct ref_entry *last = NULL;
f4204ab9 1034 char refline[PATH_MAX];
c29c46fa 1035 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
f4204ab9
JH
1036
1037 while (fgets(refline, sizeof(refline), f)) {
1038 unsigned char sha1[20];
dfefa935 1039 const char *refname;
f4204ab9
JH
1040 static const char header[] = "# pack-refs with:";
1041
1042 if (!strncmp(refline, header, sizeof(header)-1)) {
1043 const char *traits = refline + sizeof(header) - 1;
c29c46fa
MH
1044 if (strstr(traits, " fully-peeled "))
1045 peeled = PEELED_FULLY;
1046 else if (strstr(traits, " peeled "))
1047 peeled = PEELED_TAGS;
f4204ab9
JH
1048 /* perhaps other traits later as well */
1049 continue;
1050 }
1051
dfefa935
MH
1052 refname = parse_ref_line(refline, sha1);
1053 if (refname) {
c29c46fa
MH
1054 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
1055 if (peeled == PEELED_FULLY ||
59556548 1056 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
c29c46fa 1057 last->flag |= REF_KNOWS_PEELED;
d3177275 1058 add_ref(dir, last);
f4204ab9
JH
1059 continue;
1060 }
1061 if (last &&
1062 refline[0] == '^' &&
3feb4f0c
MH
1063 strlen(refline) == PEELED_LINE_LENGTH &&
1064 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
c29c46fa 1065 !get_sha1_hex(refline + 1, sha1)) {
593f1bb8 1066 hashcpy(last->u.value.peeled, sha1);
c29c46fa
MH
1067 /*
1068 * Regardless of what the file header said,
1069 * we definitely know the value of *this*
1070 * reference:
1071 */
1072 last->flag |= REF_KNOWS_PEELED;
1073 }
f4204ab9 1074 }
f4204ab9
JH
1075}
1076
2fff7812
MH
1077/*
1078 * Get the packed_ref_cache for the specified ref_cache, creating it
1079 * if necessary.
1080 */
1081static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
5e290ff7 1082{
ca919930
JK
1083 const char *packed_refs_file;
1084
1085 if (*refs->name)
1086 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1087 else
1088 packed_refs_file = git_path("packed-refs");
1089
1090 if (refs->packed &&
1091 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1092 clear_packed_ref_cache(refs);
1093
d12229f5 1094 if (!refs->packed) {
4349a668 1095 FILE *f;
0bad611b 1096
2fff7812 1097 refs->packed = xcalloc(1, sizeof(*refs->packed));
5f5e2a88 1098 acquire_packed_ref_cache(refs->packed);
2fff7812 1099 refs->packed->root = create_dir_entry(refs, "", 0, 0);
4349a668 1100 f = fopen(packed_refs_file, "r");
e1e22e37 1101 if (f) {
ca919930 1102 stat_validity_update(&refs->packed->validity, fileno(f));
2fff7812 1103 read_packed_refs(f, get_ref_dir(refs->packed->root));
e1e22e37 1104 fclose(f);
e1e22e37 1105 }
e1e22e37 1106 }
2fff7812
MH
1107 return refs->packed;
1108}
1109
1110static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1111{
1112 return get_ref_dir(packed_ref_cache->root);
1113}
1114
1115static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1116{
1117 return get_packed_ref_dir(get_packed_ref_cache(refs));
e1e22e37
LT
1118}
1119
30249ee6
MH
1120void add_packed_ref(const char *refname, const unsigned char *sha1)
1121{
9f69d297
MH
1122 struct packed_ref_cache *packed_ref_cache =
1123 get_packed_ref_cache(&ref_cache);
1124
1125 if (!packed_ref_cache->lock)
1126 die("internal error: packed refs not locked");
1127 add_ref(get_packed_ref_dir(packed_ref_cache),
9da31cb0 1128 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
30249ee6
MH
1129}
1130
abc39098 1131/*
28e6a34e
MH
1132 * Read the loose references from the namespace dirname into dir
1133 * (without recursing). dirname must end with '/'. dir must be the
1134 * directory entry corresponding to dirname.
abc39098 1135 */
423a1afc 1136static void read_loose_refs(const char *dirname, struct ref_dir *dir)
e1e22e37 1137{
423a1afc 1138 struct ref_cache *refs = dir->ref_cache;
d3177275 1139 DIR *d;
0bad611b 1140 const char *path;
d5fdae67 1141 struct dirent *de;
abc39098 1142 int dirnamelen = strlen(dirname);
72b64b44 1143 struct strbuf refname;
0bad611b 1144
3b124823 1145 if (*refs->name)
66a3d20b 1146 path = git_path_submodule(refs->name, "%s", dirname);
0bad611b 1147 else
66a3d20b 1148 path = git_path("%s", dirname);
0bad611b 1149
d3177275 1150 d = opendir(path);
d5fdae67
MH
1151 if (!d)
1152 return;
1153
66a3d20b
MH
1154 strbuf_init(&refname, dirnamelen + 257);
1155 strbuf_add(&refname, dirname, dirnamelen);
d5fdae67
MH
1156
1157 while ((de = readdir(d)) != NULL) {
1158 unsigned char sha1[20];
1159 struct stat st;
1160 int flag;
d5fdae67
MH
1161 const char *refdir;
1162
1163 if (de->d_name[0] == '.')
1164 continue;
d5fdae67
MH
1165 if (has_extension(de->d_name, ".lock"))
1166 continue;
72b64b44 1167 strbuf_addstr(&refname, de->d_name);
d5fdae67 1168 refdir = *refs->name
72b64b44
MH
1169 ? git_path_submodule(refs->name, "%s", refname.buf)
1170 : git_path("%s", refname.buf);
1171 if (stat(refdir, &st) < 0) {
1172 ; /* silently ignore */
1173 } else if (S_ISDIR(st.st_mode)) {
abc39098 1174 strbuf_addch(&refname, '/');
28e6a34e 1175 add_entry_to_dir(dir,
b9146f51
RS
1176 create_dir_entry(refs, refname.buf,
1177 refname.len, 1));
72b64b44 1178 } else {
3b124823 1179 if (*refs->name) {
f8948e2f 1180 hashclr(sha1);
0bad611b 1181 flag = 0;
72b64b44 1182 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
0bad611b 1183 hashclr(sha1);
98ac34b2 1184 flag |= REF_ISBROKEN;
0bad611b 1185 }
72b64b44 1186 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
09116a1c
JH
1187 hashclr(sha1);
1188 flag |= REF_ISBROKEN;
1189 }
9f2fb4a3
MH
1190 add_entry_to_dir(dir,
1191 create_ref_entry(refname.buf, sha1, flag, 1));
e1e22e37 1192 }
66a3d20b 1193 strbuf_setlen(&refname, dirnamelen);
e1e22e37 1194 }
72b64b44 1195 strbuf_release(&refname);
d5fdae67 1196 closedir(d);
e1e22e37
LT
1197}
1198
d3177275 1199static struct ref_dir *get_loose_refs(struct ref_cache *refs)
e1e22e37 1200{
d12229f5 1201 if (!refs->loose) {
28e6a34e
MH
1202 /*
1203 * Mark the top-level directory complete because we
1204 * are about to read the only subdirectory that can
1205 * hold references:
1206 */
b9146f51 1207 refs->loose = create_dir_entry(refs, "", 0, 0);
28e6a34e
MH
1208 /*
1209 * Create an incomplete entry for "refs/":
1210 */
1211 add_entry_to_dir(get_ref_dir(refs->loose),
b9146f51 1212 create_dir_entry(refs, "refs/", 5, 1));
e1e22e37 1213 }
d7826d54 1214 return get_ref_dir(refs->loose);
e1e22e37
LT
1215}
1216
ca8db142
LT
1217/* We allow "recursive" symbolic refs. Only within reason, though */
1218#define MAXDEPTH 5
0ebde32c
LT
1219#define MAXREFLEN (1024)
1220
e5fa45c1
JH
1221/*
1222 * Called by resolve_gitlink_ref_recursive() after it failed to read
b0626608
MH
1223 * from the loose refs in ref_cache refs. Find <refname> in the
1224 * packed-refs file for the submodule.
e5fa45c1 1225 */
b0626608 1226static int resolve_gitlink_packed_ref(struct ref_cache *refs,
85be1fe3 1227 const char *refname, unsigned char *sha1)
0ebde32c 1228{
2c5c66be 1229 struct ref_entry *ref;
d3177275 1230 struct ref_dir *dir = get_packed_refs(refs);
0ebde32c 1231
432ad41e 1232 ref = find_ref(dir, refname);
b0626608
MH
1233 if (ref == NULL)
1234 return -1;
1235
50546b15 1236 hashcpy(sha1, ref->u.value.sha1);
b0626608 1237 return 0;
0ebde32c
LT
1238}
1239
b0626608 1240static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
85be1fe3 1241 const char *refname, unsigned char *sha1,
dfefa935 1242 int recursion)
0ebde32c 1243{
064d51dc 1244 int fd, len;
0ebde32c 1245 char buffer[128], *p;
064d51dc 1246 char *path;
0ebde32c 1247
064d51dc 1248 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
0ebde32c 1249 return -1;
064d51dc
MH
1250 path = *refs->name
1251 ? git_path_submodule(refs->name, "%s", refname)
1252 : git_path("%s", refname);
1253 fd = open(path, O_RDONLY);
0ebde32c 1254 if (fd < 0)
b0626608 1255 return resolve_gitlink_packed_ref(refs, refname, sha1);
0ebde32c
LT
1256
1257 len = read(fd, buffer, sizeof(buffer)-1);
1258 close(fd);
1259 if (len < 0)
1260 return -1;
1261 while (len && isspace(buffer[len-1]))
1262 len--;
1263 buffer[len] = 0;
1264
1265 /* Was it a detached head or an old-fashioned symlink? */
85be1fe3 1266 if (!get_sha1_hex(buffer, sha1))
0ebde32c
LT
1267 return 0;
1268
1269 /* Symref? */
1270 if (strncmp(buffer, "ref:", 4))
1271 return -1;
1272 p = buffer + 4;
1273 while (isspace(*p))
1274 p++;
1275
064d51dc 1276 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
0ebde32c
LT
1277}
1278
85be1fe3 1279int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
0ebde32c
LT
1280{
1281 int len = strlen(path), retval;
064d51dc 1282 char *submodule;
b0626608 1283 struct ref_cache *refs;
0ebde32c
LT
1284
1285 while (len && path[len-1] == '/')
1286 len--;
1287 if (!len)
1288 return -1;
b0626608
MH
1289 submodule = xstrndup(path, len);
1290 refs = get_ref_cache(submodule);
1291 free(submodule);
1292
064d51dc 1293 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
0ebde32c
LT
1294 return retval;
1295}
ca8db142 1296
4886b89f 1297/*
63331581
MH
1298 * Return the ref_entry for the given refname from the packed
1299 * references. If it does not exist, return NULL.
4886b89f 1300 */
63331581 1301static struct ref_entry *get_packed_ref(const char *refname)
c224ca7f 1302{
9da31cb0 1303 return find_ref(get_packed_refs(&ref_cache), refname);
c224ca7f
MH
1304}
1305
47f534bf
MH
1306/*
1307 * A loose ref file doesn't exist; check for a packed ref. The
1308 * options are forwarded from resolve_safe_unsafe().
1309 */
1310static const char *handle_missing_loose_ref(const char *refname,
1311 unsigned char *sha1,
1312 int reading,
1313 int *flag)
1314{
1315 struct ref_entry *entry;
1316
1317 /*
1318 * The loose reference file does not exist; check for a packed
1319 * reference.
1320 */
1321 entry = get_packed_ref(refname);
1322 if (entry) {
1323 hashcpy(sha1, entry->u.value.sha1);
1324 if (flag)
1325 *flag |= REF_ISPACKED;
1326 return refname;
1327 }
1328 /* The reference is not a packed reference, either. */
1329 if (reading) {
1330 return NULL;
1331 } else {
1332 hashclr(sha1);
1333 return refname;
1334 }
1335}
1336
76d70dc0 1337/* This function needs to return a meaningful errno on failure */
8d68493f 1338const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
8a65ff76 1339{
0104ca09
HO
1340 int depth = MAXDEPTH;
1341 ssize_t len;
a876ed83 1342 char buffer[256];
dfefa935 1343 static char refname_buffer[256];
ca8db142 1344
8da19775
JH
1345 if (flag)
1346 *flag = 0;
1347
76d70dc0
RS
1348 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1349 errno = EINVAL;
8384d788 1350 return NULL;
76d70dc0 1351 }
8384d788 1352
a876ed83 1353 for (;;) {
55956350 1354 char path[PATH_MAX];
a876ed83
JH
1355 struct stat st;
1356 char *buf;
1357 int fd;
8a65ff76 1358
76d70dc0
RS
1359 if (--depth < 0) {
1360 errno = ELOOP;
a876ed83 1361 return NULL;
76d70dc0 1362 }
ca8db142 1363
dfefa935 1364 git_snpath(path, sizeof(path), "%s", refname);
c224ca7f 1365
fcb7c762
MH
1366 /*
1367 * We might have to loop back here to avoid a race
1368 * condition: first we lstat() the file, then we try
1369 * to read it as a link or as a file. But if somebody
1370 * changes the type of the file (file <-> directory
1371 * <-> symlink) between the lstat() and reading, then
1372 * we don't want to report that as an error but rather
1373 * try again starting with the lstat().
1374 */
1375 stat_ref:
a876ed83 1376 if (lstat(path, &st) < 0) {
47f534bf
MH
1377 if (errno == ENOENT)
1378 return handle_missing_loose_ref(refname, sha1,
1379 reading, flag);
1380 else
a876ed83 1381 return NULL;
a876ed83 1382 }
ca8db142 1383
a876ed83
JH
1384 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1385 if (S_ISLNK(st.st_mode)) {
1386 len = readlink(path, buffer, sizeof(buffer)-1);
fcb7c762
MH
1387 if (len < 0) {
1388 if (errno == ENOENT || errno == EINVAL)
1389 /* inconsistent with lstat; retry */
1390 goto stat_ref;
1391 else
1392 return NULL;
1393 }
b54cb795 1394 buffer[len] = 0;
59556548 1395 if (starts_with(buffer, "refs/") &&
1f58a038 1396 !check_refname_format(buffer, 0)) {
dfefa935
MH
1397 strcpy(refname_buffer, buffer);
1398 refname = refname_buffer;
8da19775
JH
1399 if (flag)
1400 *flag |= REF_ISSYMREF;
a876ed83
JH
1401 continue;
1402 }
ca8db142 1403 }
a876ed83 1404
7a21632f
DS
1405 /* Is it a directory? */
1406 if (S_ISDIR(st.st_mode)) {
1407 errno = EISDIR;
1408 return NULL;
1409 }
1410
a876ed83
JH
1411 /*
1412 * Anything else, just open it and try to use it as
1413 * a ref
1414 */
1415 fd = open(path, O_RDONLY);
fcb7c762
MH
1416 if (fd < 0) {
1417 if (errno == ENOENT)
1418 /* inconsistent with lstat; retry */
1419 goto stat_ref;
1420 else
1421 return NULL;
1422 }
93d26e4c 1423 len = read_in_full(fd, buffer, sizeof(buffer)-1);
76d70dc0
RS
1424 if (len < 0) {
1425 int save_errno = errno;
1426 close(fd);
1427 errno = save_errno;
28775050 1428 return NULL;
76d70dc0
RS
1429 }
1430 close(fd);
28775050
MH
1431 while (len && isspace(buffer[len-1]))
1432 len--;
1433 buffer[len] = '\0';
a876ed83
JH
1434
1435 /*
1436 * Is it a symbolic ref?
1437 */
59556548 1438 if (!starts_with(buffer, "ref:")) {
2884c06a
MH
1439 /*
1440 * Please note that FETCH_HEAD has a second
1441 * line containing other data.
1442 */
1443 if (get_sha1_hex(buffer, sha1) ||
1444 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1445 if (flag)
1446 *flag |= REF_ISBROKEN;
76d70dc0 1447 errno = EINVAL;
2884c06a
MH
1448 return NULL;
1449 }
1450 return refname;
1451 }
55956350
JH
1452 if (flag)
1453 *flag |= REF_ISSYMREF;
a876ed83 1454 buf = buffer + 4;
28775050
MH
1455 while (isspace(*buf))
1456 buf++;
313fb010 1457 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
55956350
JH
1458 if (flag)
1459 *flag |= REF_ISBROKEN;
76d70dc0 1460 errno = EINVAL;
313fb010
MH
1461 return NULL;
1462 }
dfefa935 1463 refname = strcpy(refname_buffer, buf);
8a65ff76 1464 }
a876ed83
JH
1465}
1466
96ec7b1e
NTND
1467char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1468{
8cad4744 1469 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
96ec7b1e
NTND
1470 return ret ? xstrdup(ret) : NULL;
1471}
1472
d08bae7e
IL
1473/* The argument to filter_refs */
1474struct ref_filter {
1475 const char *pattern;
1476 each_ref_fn *fn;
1477 void *cb_data;
1478};
1479
dfefa935 1480int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
a876ed83 1481{
8d68493f 1482 if (resolve_ref_unsafe(refname, sha1, reading, flags))
a876ed83
JH
1483 return 0;
1484 return -1;
8a65ff76
LT
1485}
1486
dfefa935 1487int read_ref(const char *refname, unsigned char *sha1)
c6893323 1488{
dfefa935 1489 return read_ref_full(refname, sha1, 1, NULL);
c6893323
NTND
1490}
1491
bc5fd6d3 1492int ref_exists(const char *refname)
ef06b918 1493{
bc5fd6d3
MH
1494 unsigned char sha1[20];
1495 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
ef06b918
JH
1496}
1497
85be1fe3 1498static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
dfefa935 1499 void *data)
d08bae7e
IL
1500{
1501 struct ref_filter *filter = (struct ref_filter *)data;
eb07894f 1502 if (wildmatch(filter->pattern, refname, 0, NULL))
d08bae7e 1503 return 0;
85be1fe3 1504 return filter->fn(refname, sha1, flags, filter->cb_data);
d08bae7e
IL
1505}
1506
68cf8703
MH
1507enum peel_status {
1508 /* object was peeled successfully: */
1509 PEEL_PEELED = 0,
1510
1511 /*
1512 * object cannot be peeled because the named object (or an
1513 * object referred to by a tag in the peel chain), does not
1514 * exist.
1515 */
1516 PEEL_INVALID = -1,
1517
1518 /* object cannot be peeled because it is not a tag: */
9a489f3c
MH
1519 PEEL_NON_TAG = -2,
1520
1521 /* ref_entry contains no peeled value because it is a symref: */
1522 PEEL_IS_SYMREF = -3,
1523
1524 /*
1525 * ref_entry cannot be peeled because it is broken (i.e., the
1526 * symbolic reference cannot even be resolved to an object
1527 * name):
1528 */
1529 PEEL_BROKEN = -4
68cf8703
MH
1530};
1531
cb2ae1c4
MH
1532/*
1533 * Peel the named object; i.e., if the object is a tag, resolve the
68cf8703
MH
1534 * tag recursively until a non-tag is found. If successful, store the
1535 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1536 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1537 * and leave sha1 unchanged.
cb2ae1c4 1538 */
68cf8703 1539static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
cb2ae1c4
MH
1540{
1541 struct object *o = lookup_unknown_object(name);
1542
1543 if (o->type == OBJ_NONE) {
1544 int type = sha1_object_info(name, NULL);
1545 if (type < 0)
68cf8703 1546 return PEEL_INVALID;
cb2ae1c4
MH
1547 o->type = type;
1548 }
1549
1550 if (o->type != OBJ_TAG)
68cf8703 1551 return PEEL_NON_TAG;
cb2ae1c4
MH
1552
1553 o = deref_tag_noverify(o);
1554 if (!o)
68cf8703 1555 return PEEL_INVALID;
cb2ae1c4
MH
1556
1557 hashcpy(sha1, o->sha1);
68cf8703 1558 return PEEL_PEELED;
cb2ae1c4
MH
1559}
1560
9a489f3c 1561/*
f85354b5
MH
1562 * Peel the entry (if possible) and return its new peel_status. If
1563 * repeel is true, re-peel the entry even if there is an old peeled
1564 * value that is already stored in it.
694b7a19
MH
1565 *
1566 * It is OK to call this function with a packed reference entry that
1567 * might be stale and might even refer to an object that has since
1568 * been garbage-collected. In such a case, if the entry has
1569 * REF_KNOWS_PEELED then leave the status unchanged and return
1570 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
9a489f3c 1571 */
f85354b5 1572static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
9a489f3c
MH
1573{
1574 enum peel_status status;
1575
f85354b5
MH
1576 if (entry->flag & REF_KNOWS_PEELED) {
1577 if (repeel) {
1578 entry->flag &= ~REF_KNOWS_PEELED;
1579 hashclr(entry->u.value.peeled);
1580 } else {
1581 return is_null_sha1(entry->u.value.peeled) ?
1582 PEEL_NON_TAG : PEEL_PEELED;
1583 }
1584 }
9a489f3c
MH
1585 if (entry->flag & REF_ISBROKEN)
1586 return PEEL_BROKEN;
1587 if (entry->flag & REF_ISSYMREF)
1588 return PEEL_IS_SYMREF;
1589
1590 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1591 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1592 entry->flag |= REF_KNOWS_PEELED;
1593 return status;
1594}
1595
dfefa935 1596int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1597{
1598 int flag;
1599 unsigned char base[20];
cf0adba7 1600
dfefa935 1601 if (current_ref && (current_ref->name == refname
9a489f3c 1602 || !strcmp(current_ref->name, refname))) {
f85354b5 1603 if (peel_entry(current_ref, 0))
9a489f3c
MH
1604 return -1;
1605 hashcpy(sha1, current_ref->u.value.peeled);
1606 return 0;
0ae91be0
SP
1607 }
1608
dfefa935 1609 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1610 return -1;
1611
9a489f3c
MH
1612 /*
1613 * If the reference is packed, read its ref_entry from the
1614 * cache in the hope that we already know its peeled value.
1615 * We only try this optimization on packed references because
1616 * (a) forcing the filling of the loose reference cache could
1617 * be expensive and (b) loose references anyway usually do not
1618 * have REF_KNOWS_PEELED.
1619 */
1620 if (flag & REF_ISPACKED) {
f361baeb 1621 struct ref_entry *r = get_packed_ref(refname);
9a489f3c 1622 if (r) {
f85354b5 1623 if (peel_entry(r, 0))
9a489f3c 1624 return -1;
593f1bb8 1625 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1626 return 0;
cf0adba7 1627 }
cf0adba7
JH
1628 }
1629
cb2ae1c4 1630 return peel_object(base, sha1);
cf0adba7
JH
1631}
1632
bc5fd6d3
MH
1633struct warn_if_dangling_data {
1634 FILE *fp;
1635 const char *refname;
e6bea66d 1636 const struct string_list *refnames;
bc5fd6d3
MH
1637 const char *msg_fmt;
1638};
1639
1640static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1641 int flags, void *cb_data)
1642{
1643 struct warn_if_dangling_data *d = cb_data;
1644 const char *resolves_to;
1645 unsigned char junk[20];
1646
1647 if (!(flags & REF_ISSYMREF))
1648 return 0;
1649
1650 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
e6bea66d
JL
1651 if (!resolves_to
1652 || (d->refname
1653 ? strcmp(resolves_to, d->refname)
1654 : !string_list_has_string(d->refnames, resolves_to))) {
bc5fd6d3 1655 return 0;
e6bea66d 1656 }
bc5fd6d3
MH
1657
1658 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1659 fputc('\n', d->fp);
bc5fd6d3
MH
1660 return 0;
1661}
1662
1663void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1664{
1665 struct warn_if_dangling_data data;
1666
1667 data.fp = fp;
1668 data.refname = refname;
e6bea66d
JL
1669 data.refnames = NULL;
1670 data.msg_fmt = msg_fmt;
1671 for_each_rawref(warn_if_dangling_symref, &data);
1672}
1673
1674void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
1675{
1676 struct warn_if_dangling_data data;
1677
1678 data.fp = fp;
1679 data.refname = NULL;
1680 data.refnames = refnames;
bc5fd6d3
MH
1681 data.msg_fmt = msg_fmt;
1682 for_each_rawref(warn_if_dangling_symref, &data);
1683}
1684
fcce1703 1685/*
65cf102b 1686 * Call fn for each reference in the specified ref_cache, omitting
624cac35
MH
1687 * references not in the containing_dir of base. fn is called for all
1688 * references, including broken ones. If fn ever returns a non-zero
fcce1703
MH
1689 * value, stop the iteration and return that value; otherwise, return
1690 * 0.
1691 */
65cf102b 1692static int do_for_each_entry(struct ref_cache *refs, const char *base,
624cac35 1693 each_ref_entry_fn fn, void *cb_data)
8a65ff76 1694{
98eeb09e
JK
1695 struct packed_ref_cache *packed_ref_cache;
1696 struct ref_dir *loose_dir;
1697 struct ref_dir *packed_dir;
933ac036
MH
1698 int retval = 0;
1699
98eeb09e
JK
1700 /*
1701 * We must make sure that all loose refs are read before accessing the
1702 * packed-refs file; this avoids a race condition in which loose refs
1703 * are migrated to the packed-refs file by a simultaneous process, but
1704 * our in-memory view is from before the migration. get_packed_ref_cache()
1705 * takes care of making sure our view is up to date with what is on
1706 * disk.
1707 */
1708 loose_dir = get_loose_refs(refs);
933ac036 1709 if (base && *base) {
933ac036
MH
1710 loose_dir = find_containing_dir(loose_dir, base, 0);
1711 }
98eeb09e
JK
1712 if (loose_dir)
1713 prime_ref_dir(loose_dir);
1714
1715 packed_ref_cache = get_packed_ref_cache(refs);
8baf2bb9 1716 acquire_packed_ref_cache(packed_ref_cache);
98eeb09e 1717 packed_dir = get_packed_ref_dir(packed_ref_cache);
933ac036
MH
1718 if (base && *base) {
1719 packed_dir = find_containing_dir(packed_dir, base, 0);
933ac036
MH
1720 }
1721
1722 if (packed_dir && loose_dir) {
1723 sort_ref_dir(packed_dir);
1724 sort_ref_dir(loose_dir);
624cac35
MH
1725 retval = do_for_each_entry_in_dirs(
1726 packed_dir, loose_dir, fn, cb_data);
933ac036
MH
1727 } else if (packed_dir) {
1728 sort_ref_dir(packed_dir);
624cac35
MH
1729 retval = do_for_each_entry_in_dir(
1730 packed_dir, 0, fn, cb_data);
933ac036
MH
1731 } else if (loose_dir) {
1732 sort_ref_dir(loose_dir);
624cac35
MH
1733 retval = do_for_each_entry_in_dir(
1734 loose_dir, 0, fn, cb_data);
933ac036
MH
1735 }
1736
8baf2bb9 1737 release_packed_ref_cache(packed_ref_cache);
933ac036 1738 return retval;
8a65ff76
LT
1739}
1740
624cac35 1741/*
65cf102b 1742 * Call fn for each reference in the specified ref_cache for which the
624cac35
MH
1743 * refname begins with base. If trim is non-zero, then trim that many
1744 * characters off the beginning of each refname before passing the
1745 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1746 * broken references in the iteration. If fn ever returns a non-zero
1747 * value, stop the iteration and return that value; otherwise, return
1748 * 0.
1749 */
65cf102b
MH
1750static int do_for_each_ref(struct ref_cache *refs, const char *base,
1751 each_ref_fn fn, int trim, int flags, void *cb_data)
624cac35
MH
1752{
1753 struct ref_entry_cb data;
1754 data.base = base;
1755 data.trim = trim;
1756 data.flags = flags;
1757 data.fn = fn;
1758 data.cb_data = cb_data;
1759
65cf102b 1760 return do_for_each_entry(refs, base, do_one_ref, &data);
624cac35
MH
1761}
1762
0bad611b 1763static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1764{
1765 unsigned char sha1[20];
8da19775
JH
1766 int flag;
1767
0bad611b
HV
1768 if (submodule) {
1769 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1770 return fn("HEAD", sha1, 0, cb_data);
1771
1772 return 0;
1773 }
1774
c6893323 1775 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1776 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1777
2f34ba32 1778 return 0;
723c31fe
LT
1779}
1780
0bad611b
HV
1781int head_ref(each_ref_fn fn, void *cb_data)
1782{
1783 return do_head_ref(NULL, fn, cb_data);
1784}
1785
9ef6aeb0
HV
1786int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1787{
1788 return do_head_ref(submodule, fn, cb_data);
1789}
1790
cb5d709f 1791int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1792{
9da31cb0 1793 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
a62be77f
SE
1794}
1795
9ef6aeb0
HV
1796int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1797{
65cf102b 1798 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
a62be77f
SE
1799}
1800
2a8177b6
CC
1801int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1802{
9da31cb0 1803 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1804}
1805
9ef6aeb0
HV
1806int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1807 each_ref_fn fn, void *cb_data)
1808{
65cf102b 1809 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1810}
1811
cb5d709f 1812int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1813{
2a8177b6 1814 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1815}
1816
9ef6aeb0
HV
1817int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1818{
1819 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1820}
1821
cb5d709f 1822int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1823{
2a8177b6 1824 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1825}
1826
9ef6aeb0
HV
1827int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1828{
1829 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1830}
1831
cb5d709f 1832int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1833{
2a8177b6 1834 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1835}
1836
9ef6aeb0
HV
1837int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1838{
1839 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1840}
1841
29268700
CC
1842int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1843{
9da31cb0 1844 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1845}
1846
a1bea2c1
JT
1847int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1848{
1849 struct strbuf buf = STRBUF_INIT;
1850 int ret = 0;
1851 unsigned char sha1[20];
1852 int flag;
1853
1854 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1855 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1856 ret = fn(buf.buf, sha1, flag, cb_data);
1857 strbuf_release(&buf);
1858
1859 return ret;
1860}
1861
1862int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1863{
1864 struct strbuf buf = STRBUF_INIT;
1865 int ret;
1866 strbuf_addf(&buf, "%srefs/", get_git_namespace());
9da31cb0 1867 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
a1bea2c1
JT
1868 strbuf_release(&buf);
1869 return ret;
1870}
1871
b09fe971
IL
1872int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1873 const char *prefix, void *cb_data)
d08bae7e
IL
1874{
1875 struct strbuf real_pattern = STRBUF_INIT;
1876 struct ref_filter filter;
d08bae7e
IL
1877 int ret;
1878
59556548 1879 if (!prefix && !starts_with(pattern, "refs/"))
d08bae7e 1880 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1881 else if (prefix)
1882 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1883 strbuf_addstr(&real_pattern, pattern);
1884
894a9d33 1885 if (!has_glob_specials(pattern)) {
9517e6b8 1886 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1887 if (real_pattern.buf[real_pattern.len - 1] != '/')
1888 strbuf_addch(&real_pattern, '/');
1889 /* No need to check for '*', there is none. */
1890 strbuf_addch(&real_pattern, '*');
1891 }
1892
1893 filter.pattern = real_pattern.buf;
1894 filter.fn = fn;
1895 filter.cb_data = cb_data;
1896 ret = for_each_ref(filter_refs, &filter);
1897
1898 strbuf_release(&real_pattern);
1899 return ret;
1900}
1901
b09fe971
IL
1902int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1903{
1904 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1905}
1906
f8948e2f
JH
1907int for_each_rawref(each_ref_fn fn, void *cb_data)
1908{
9da31cb0 1909 return do_for_each_ref(&ref_cache, "", fn, 0,
f8948e2f 1910 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1911}
1912
4577e483 1913const char *prettify_refname(const char *name)
a9c37a72 1914{
a9c37a72 1915 return name + (
59556548
CC
1916 starts_with(name, "refs/heads/") ? 11 :
1917 starts_with(name, "refs/tags/") ? 10 :
1918 starts_with(name, "refs/remotes/") ? 13 :
a9c37a72
DB
1919 0);
1920}
1921
54457fe5 1922static const char *ref_rev_parse_rules[] = {
79803322
SP
1923 "%.*s",
1924 "refs/%.*s",
1925 "refs/tags/%.*s",
1926 "refs/heads/%.*s",
1927 "refs/remotes/%.*s",
1928 "refs/remotes/%.*s/HEAD",
1929 NULL
1930};
1931
54457fe5 1932int refname_match(const char *abbrev_name, const char *full_name)
79803322
SP
1933{
1934 const char **p;
1935 const int abbrev_name_len = strlen(abbrev_name);
1936
54457fe5 1937 for (p = ref_rev_parse_rules; *p; p++) {
79803322
SP
1938 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1939 return 1;
1940 }
1941 }
1942
1943 return 0;
1944}
1945
835e3c99 1946/* This function should make sure errno is meaningful on error */
e5f38ec3 1947static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1948 const unsigned char *old_sha1, int mustexist)
1949{
c6893323 1950 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
835e3c99 1951 int save_errno = errno;
434cd0cd 1952 error("Can't verify ref %s", lock->ref_name);
4bd18c43 1953 unlock_ref(lock);
835e3c99 1954 errno = save_errno;
4bd18c43
SP
1955 return NULL;
1956 }
a89fccd2 1957 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1958 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1959 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1960 unlock_ref(lock);
835e3c99 1961 errno = EBUSY;
4bd18c43
SP
1962 return NULL;
1963 }
1964 return lock;
1965}
1966
7155b727 1967static int remove_empty_directories(const char *file)
bc7127ef
JH
1968{
1969 /* we want to create a file but there is a directory there;
1970 * if that is an empty directory (or a directory that contains
1971 * only empty directories), remove them.
1972 */
7155b727 1973 struct strbuf path;
470a91ef 1974 int result, save_errno;
bc7127ef 1975
7155b727
JS
1976 strbuf_init(&path, 20);
1977 strbuf_addstr(&path, file);
1978
a0f4afbe 1979 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
470a91ef 1980 save_errno = errno;
7155b727
JS
1981
1982 strbuf_release(&path);
470a91ef 1983 errno = save_errno;
7155b727
JS
1984
1985 return result;
bc7127ef
JH
1986}
1987
ff74f7f1
JH
1988/*
1989 * *string and *len will only be substituted, and *string returned (for
1990 * later free()ing) if the string passed in is a magic short-hand form
1991 * to name a branch.
1992 */
1993static char *substitute_branch_name(const char **string, int *len)
1994{
1995 struct strbuf buf = STRBUF_INIT;
cf99a761 1996 int ret = interpret_branch_name(*string, *len, &buf);
ff74f7f1
JH
1997
1998 if (ret == *len) {
1999 size_t size;
2000 *string = strbuf_detach(&buf, &size);
2001 *len = size;
2002 return (char *)*string;
2003 }
2004
2005 return NULL;
2006}
2007
2008int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
2009{
2010 char *last_branch = substitute_branch_name(&str, &len);
2011 const char **p, *r;
2012 int refs_found = 0;
2013
2014 *ref = NULL;
2015 for (p = ref_rev_parse_rules; *p; p++) {
2016 char fullref[PATH_MAX];
2017 unsigned char sha1_from_ref[20];
2018 unsigned char *this_result;
2019 int flag;
2020
2021 this_result = refs_found ? sha1_from_ref : sha1;
2022 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 2023 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
2024 if (r) {
2025 if (!refs_found++)
2026 *ref = xstrdup(r);
2027 if (!warn_ambiguous_refs)
2028 break;
55956350 2029 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 2030 warning("ignoring dangling symref %s.", fullref);
55956350
JH
2031 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
2032 warning("ignoring broken ref %s.", fullref);
2033 }
ff74f7f1
JH
2034 }
2035 free(last_branch);
2036 return refs_found;
2037}
2038
2039int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
2040{
2041 char *last_branch = substitute_branch_name(&str, &len);
2042 const char **p;
2043 int logs_found = 0;
2044
2045 *log = NULL;
2046 for (p = ref_rev_parse_rules; *p; p++) {
ff74f7f1
JH
2047 unsigned char hash[20];
2048 char path[PATH_MAX];
2049 const char *ref, *it;
2050
2051 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 2052 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
2053 if (!ref)
2054 continue;
4da58835 2055 if (reflog_exists(path))
ff74f7f1 2056 it = path;
4da58835 2057 else if (strcmp(ref, path) && reflog_exists(ref))
ff74f7f1
JH
2058 it = ref;
2059 else
2060 continue;
2061 if (!logs_found++) {
2062 *log = xstrdup(it);
2063 hashcpy(sha1, hash);
2064 }
2065 if (!warn_ambiguous_refs)
2066 break;
2067 }
2068 free(last_branch);
2069 return logs_found;
2070}
2071
470a91ef 2072/* This function should make sure errno is meaningful on error */
dfefa935
MH
2073static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2074 const unsigned char *old_sha1,
2075 int flags, int *type_p)
4bd18c43 2076{
434cd0cd 2077 char *ref_file;
dfefa935 2078 const char *orig_refname = refname;
4bd18c43 2079 struct ref_lock *lock;
5cc3cef9 2080 int last_errno = 0;
acd3b9ec 2081 int type, lflags;
4431fcc4 2082 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 2083 int missing = 0;
c4c61c76 2084 int attempts_remaining = 3;
4bd18c43
SP
2085
2086 lock = xcalloc(1, sizeof(struct ref_lock));
2087 lock->lock_fd = -1;
2088
8d68493f 2089 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 2090 if (!refname && errno == EISDIR) {
bc7127ef
JH
2091 /* we are trying to lock foo but we used to
2092 * have foo/bar which now does not exist;
2093 * it is normal for the empty directory 'foo'
2094 * to remain.
2095 */
dfefa935 2096 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
2097 if (remove_empty_directories(ref_file)) {
2098 last_errno = errno;
dfefa935 2099 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
2100 goto error_return;
2101 }
8d68493f 2102 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 2103 }
68db31cc
SV
2104 if (type_p)
2105 *type_p = type;
dfefa935 2106 if (!refname) {
5cc3cef9 2107 last_errno = errno;
818f477c 2108 error("unable to resolve reference %s: %s",
dfefa935 2109 orig_refname, strerror(errno));
5cc3cef9 2110 goto error_return;
4bd18c43 2111 }
5bdd8d4a 2112 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
2113 /* When the ref did not exist and we are creating it,
2114 * make sure there is no existing ref that is packed
2115 * whose name begins with our refname, nor a ref whose
2116 * name is a proper prefix of our refname.
2117 */
5bdd8d4a 2118 if (missing &&
9da31cb0 2119 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
f475e08e 2120 last_errno = ENOTDIR;
c976d415 2121 goto error_return;
f475e08e 2122 }
22a3844e 2123
c33d5174 2124 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 2125
e5c223e9 2126 lflags = 0;
acd3b9ec 2127 if (flags & REF_NODEREF) {
dfefa935 2128 refname = orig_refname;
acd3b9ec
JH
2129 lflags |= LOCK_NODEREF;
2130 }
dfefa935
MH
2131 lock->ref_name = xstrdup(refname);
2132 lock->orig_ref_name = xstrdup(orig_refname);
2133 ref_file = git_path("%s", refname);
5bdd8d4a 2134 if (missing)
68db31cc
SV
2135 lock->force_write = 1;
2136 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2137 lock->force_write = 1;
4bd18c43 2138
c4c61c76
MH
2139 retry:
2140 switch (safe_create_leading_directories(ref_file)) {
2141 case SCLD_OK:
2142 break; /* success */
2143 case SCLD_VANISHED:
2144 if (--attempts_remaining > 0)
2145 goto retry;
2146 /* fall through */
2147 default:
5cc3cef9
JH
2148 last_errno = errno;
2149 error("unable to create directory for %s", ref_file);
2150 goto error_return;
2151 }
4bd18c43 2152
acd3b9ec 2153 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
e5c223e9
MH
2154 if (lock->lock_fd < 0) {
2155 if (errno == ENOENT && --attempts_remaining > 0)
2156 /*
2157 * Maybe somebody just deleted one of the
2158 * directories leading to ref_file. Try
2159 * again:
2160 */
2161 goto retry;
2162 else
2163 unable_to_lock_index_die(ref_file, errno);
2164 }
4bd18c43 2165 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
2166
2167 error_return:
2168 unlock_ref(lock);
2169 errno = last_errno;
2170 return NULL;
4bd18c43
SP
2171}
2172
dfefa935 2173struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 2174{
53cce84c 2175 char refpath[PATH_MAX];
dfefa935 2176 if (check_refname_format(refname, 0))
4bd18c43 2177 return NULL;
dfefa935 2178 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 2179 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
2180}
2181
dfefa935 2182struct ref_lock *lock_any_ref_for_update(const char *refname,
9bbb0fa1
BK
2183 const unsigned char *old_sha1,
2184 int flags, int *type_p)
4bd18c43 2185{
dfefa935 2186 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 2187 return NULL;
9bbb0fa1 2188 return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);
c0277d15
JH
2189}
2190
fec3137f
MH
2191/*
2192 * Write an entry to the packed-refs file for the specified refname.
2193 * If peeled is non-NULL, write it as the entry's peeled value.
2194 */
2195static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
2196 unsigned char *peeled)
d66da478 2197{
d66da478
MH
2198 char line[PATH_MAX + 100];
2199 int len;
2200
d66da478
MH
2201 len = snprintf(line, sizeof(line), "%s %s\n",
2202 sha1_to_hex(sha1), refname);
2203 /* this should not happen but just being defensive */
2204 if (len > sizeof(line))
2205 die("too long a refname '%s'", refname);
fec3137f
MH
2206 write_or_die(fd, line, len);
2207
2208 if (peeled) {
2209 if (snprintf(line, sizeof(line), "^%s\n",
2210 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
2211 die("internal error");
2212 write_or_die(fd, line, PEELED_LINE_LENGTH);
2213 }
2214}
2215
7b40d396
MH
2216/*
2217 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2218 */
2219static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2220{
2221 int *fd = cb_data;
2222 enum peel_status peel_status = peel_entry(entry, 0);
2223
2224 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2225 error("internal error: %s is not a valid packed reference!",
2226 entry->name);
2227 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2228 peel_status == PEEL_PEELED ?
2229 entry->u.value.peeled : NULL);
2230 return 0;
2231}
2232
447ff1bf 2233/* This should return a meaningful errno on failure */
9f69d297
MH
2234int lock_packed_refs(int flags)
2235{
2236 struct packed_ref_cache *packed_ref_cache;
2237
9f69d297
MH
2238 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2239 return -1;
5d478f5c
MH
2240 /*
2241 * Get the current packed-refs while holding the lock. If the
2242 * packed-refs file has been modified since we last read it,
2243 * this will automatically invalidate the cache and re-read
2244 * the packed-refs file.
2245 */
9f69d297
MH
2246 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2247 packed_ref_cache->lock = &packlock;
4f6b83e3
MH
2248 /* Increment the reference count to prevent it from being freed: */
2249 acquire_packed_ref_cache(packed_ref_cache);
9f69d297
MH
2250 return 0;
2251}
2252
d3f66555
RS
2253/*
2254 * Commit the packed refs changes.
2255 * On error we must make sure that errno contains a meaningful value.
2256 */
9f69d297
MH
2257int commit_packed_refs(void)
2258{
2259 struct packed_ref_cache *packed_ref_cache =
2260 get_packed_ref_cache(&ref_cache);
2261 int error = 0;
d3f66555 2262 int save_errno = 0;
9f69d297
MH
2263
2264 if (!packed_ref_cache->lock)
2265 die("internal error: packed-refs not locked");
2266 write_or_die(packed_ref_cache->lock->fd,
2267 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2268
2269 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2270 0, write_packed_entry_fn,
2271 &packed_ref_cache->lock->fd);
d3f66555
RS
2272 if (commit_lock_file(packed_ref_cache->lock)) {
2273 save_errno = errno;
9f69d297 2274 error = -1;
d3f66555 2275 }
9f69d297 2276 packed_ref_cache->lock = NULL;
4f6b83e3 2277 release_packed_ref_cache(packed_ref_cache);
d3f66555 2278 errno = save_errno;
9f69d297
MH
2279 return error;
2280}
2281
2282void rollback_packed_refs(void)
2283{
2284 struct packed_ref_cache *packed_ref_cache =
2285 get_packed_ref_cache(&ref_cache);
2286
2287 if (!packed_ref_cache->lock)
2288 die("internal error: packed-refs not locked");
2289 rollback_lock_file(packed_ref_cache->lock);
2290 packed_ref_cache->lock = NULL;
4f6b83e3 2291 release_packed_ref_cache(packed_ref_cache);
9f69d297
MH
2292 clear_packed_ref_cache(&ref_cache);
2293}
2294
32d462ce
MH
2295struct ref_to_prune {
2296 struct ref_to_prune *next;
2297 unsigned char sha1[20];
2298 char name[FLEX_ARRAY];
2299};
2300
2301struct pack_refs_cb_data {
2302 unsigned int flags;
267f9a8c 2303 struct ref_dir *packed_refs;
32d462ce 2304 struct ref_to_prune *ref_to_prune;
32d462ce
MH
2305};
2306
267f9a8c
MH
2307/*
2308 * An each_ref_entry_fn that is run over loose references only. If
2309 * the loose reference can be packed, add an entry in the packed ref
2310 * cache. If the reference should be pruned, also add it to
2311 * ref_to_prune in the pack_refs_cb_data.
2312 */
2313static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
32d462ce
MH
2314{
2315 struct pack_refs_cb_data *cb = cb_data;
f85354b5 2316 enum peel_status peel_status;
267f9a8c 2317 struct ref_entry *packed_entry;
59556548 2318 int is_tag_ref = starts_with(entry->name, "refs/tags/");
32d462ce 2319
267f9a8c
MH
2320 /* ALWAYS pack tags */
2321 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
32d462ce
MH
2322 return 0;
2323
b2a8226d
MH
2324 /* Do not pack symbolic or broken refs: */
2325 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2326 return 0;
2327
267f9a8c 2328 /* Add a packed ref cache entry equivalent to the loose entry. */
f85354b5 2329 peel_status = peel_entry(entry, 1);
0f29920f 2330 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
f85354b5
MH
2331 die("internal error peeling reference %s (%s)",
2332 entry->name, sha1_to_hex(entry->u.value.sha1));
267f9a8c
MH
2333 packed_entry = find_ref(cb->packed_refs, entry->name);
2334 if (packed_entry) {
2335 /* Overwrite existing packed entry with info from loose entry */
2336 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2337 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2338 } else {
2339 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2340 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2341 add_ref(cb->packed_refs, packed_entry);
2342 }
2343 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
32d462ce 2344
267f9a8c
MH
2345 /* Schedule the loose reference for pruning if requested. */
2346 if ((cb->flags & PACK_REFS_PRUNE)) {
12e77559 2347 int namelen = strlen(entry->name) + 1;
32d462ce 2348 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
12e77559
MH
2349 hashcpy(n->sha1, entry->u.value.sha1);
2350 strcpy(n->name, entry->name);
32d462ce
MH
2351 n->next = cb->ref_to_prune;
2352 cb->ref_to_prune = n;
2353 }
d66da478
MH
2354 return 0;
2355}
2356
32d462ce
MH
2357/*
2358 * Remove empty parents, but spare refs/ and immediate subdirs.
2359 * Note: munges *name.
2360 */
2361static void try_remove_empty_parents(char *name)
2362{
2363 char *p, *q;
2364 int i;
2365 p = name;
2366 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2367 while (*p && *p != '/')
2368 p++;
2369 /* tolerate duplicate slashes; see check_refname_format() */
2370 while (*p == '/')
2371 p++;
2372 }
2373 for (q = p; *q; q++)
2374 ;
2375 while (1) {
2376 while (q > p && *q != '/')
2377 q--;
2378 while (q > p && *(q-1) == '/')
2379 q--;
2380 if (q == p)
2381 break;
2382 *q = '\0';
2383 if (rmdir(git_path("%s", name)))
2384 break;
2385 }
2386}
2387
2388/* make sure nobody touched the ref, and unlink */
2389static void prune_ref(struct ref_to_prune *r)
2390{
2391 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2392
2393 if (lock) {
2394 unlink_or_warn(git_path("%s", r->name));
2395 unlock_ref(lock);
2396 try_remove_empty_parents(r->name);
2397 }
2398}
2399
2400static void prune_refs(struct ref_to_prune *r)
2401{
2402 while (r) {
2403 prune_ref(r);
2404 r = r->next;
2405 }
2406}
2407
32d462ce
MH
2408int pack_refs(unsigned int flags)
2409{
32d462ce
MH
2410 struct pack_refs_cb_data cbdata;
2411
2412 memset(&cbdata, 0, sizeof(cbdata));
2413 cbdata.flags = flags;
2414
9f69d297 2415 lock_packed_refs(LOCK_DIE_ON_ERROR);
267f9a8c 2416 cbdata.packed_refs = get_packed_refs(&ref_cache);
32d462ce 2417
267f9a8c
MH
2418 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2419 pack_if_possible_fn, &cbdata);
32d462ce 2420
9f69d297 2421 if (commit_packed_refs())
32d462ce 2422 die_errno("unable to overwrite old ref-pack file");
9f69d297 2423
32d462ce
MH
2424 prune_refs(cbdata.ref_to_prune);
2425 return 0;
2426}
2427
7b40d396
MH
2428/*
2429 * If entry is no longer needed in packed-refs, add it to the string
2430 * list pointed to by cb_data. Reasons for deleting entries:
2431 *
2432 * - Entry is broken.
2433 * - Entry is overridden by a loose ref.
2434 * - Entry does not point at a valid object.
2435 *
2436 * In the first and third cases, also emit an error message because these
2437 * are indications of repository corruption.
2438 */
2439static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
c0277d15 2440{
7b40d396 2441 struct string_list *refs_to_delete = cb_data;
fec3137f 2442
ab292bc4
MH
2443 if (entry->flag & REF_ISBROKEN) {
2444 /* This shouldn't happen to packed refs. */
2445 error("%s is broken!", entry->name);
7b40d396 2446 string_list_append(refs_to_delete, entry->name);
c0277d15 2447 return 0;
ab292bc4
MH
2448 }
2449 if (!has_sha1_file(entry->u.value.sha1)) {
2450 unsigned char sha1[20];
2451 int flags;
2452
2453 if (read_ref_full(entry->name, sha1, 0, &flags))
2454 /* We should at least have found the packed ref. */
2455 die("Internal error");
7b40d396 2456 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
ab292bc4
MH
2457 /*
2458 * This packed reference is overridden by a
2459 * loose reference, so it is OK that its value
2460 * is no longer valid; for example, it might
2461 * refer to an object that has been garbage
2462 * collected. For this purpose we don't even
2463 * care whether the loose reference itself is
2464 * invalid, broken, symbolic, etc. Silently
7b40d396 2465 * remove the packed reference.
ab292bc4 2466 */
7b40d396 2467 string_list_append(refs_to_delete, entry->name);
ab292bc4 2468 return 0;
7b40d396 2469 }
ab292bc4
MH
2470 /*
2471 * There is no overriding loose reference, so the fact
2472 * that this reference doesn't refer to a valid object
2473 * indicates some kind of repository corruption.
2474 * Report the problem, then omit the reference from
2475 * the output.
2476 */
2477 error("%s does not point to a valid object!", entry->name);
7b40d396 2478 string_list_append(refs_to_delete, entry->name);
ab292bc4
MH
2479 return 0;
2480 }
2481
d66da478
MH
2482 return 0;
2483}
2484
60bca085 2485int repack_without_refs(const char **refnames, int n, struct strbuf *err)
c0277d15 2486{
7618fd80 2487 struct ref_dir *packed;
7b40d396
MH
2488 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2489 struct string_list_item *ref_to_delete;
60bca085 2490 int i, ret, removed = 0;
61cee0db
BK
2491
2492 /* Look for a packed ref */
2493 for (i = 0; i < n; i++)
2494 if (get_packed_ref(refnames[i]))
2495 break;
7618fd80 2496
61cee0db
BK
2497 /* Avoid locking if we have nothing to do */
2498 if (i == n)
2499 return 0; /* no refname exists in packed refs */
7618fd80 2500
9f69d297 2501 if (lock_packed_refs(0)) {
60bca085
RS
2502 if (err) {
2503 unable_to_lock_message(git_path("packed-refs"), errno,
2504 err);
2505 return -1;
2506 }
1b018fd9 2507 unable_to_lock_error(git_path("packed-refs"), errno);
61cee0db 2508 return error("cannot delete '%s' from packed refs", refnames[i]);
1b018fd9 2509 }
9da31cb0 2510 packed = get_packed_refs(&ref_cache);
7b40d396 2511
61cee0db
BK
2512 /* Remove refnames from the cache */
2513 for (i = 0; i < n; i++)
2514 if (remove_entry(packed, refnames[i]) != -1)
2515 removed = 1;
2516 if (!removed) {
506a760d 2517 /*
61cee0db 2518 * All packed entries disappeared while we were
506a760d
MH
2519 * acquiring the lock.
2520 */
9f69d297 2521 rollback_packed_refs();
506a760d
MH
2522 return 0;
2523 }
7b40d396 2524
61cee0db 2525 /* Remove any other accumulated cruft */
7b40d396
MH
2526 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2527 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2528 if (remove_entry(packed, ref_to_delete->string) == -1)
2529 die("internal error");
2530 }
2531
61cee0db 2532 /* Write what remains */
60bca085
RS
2533 ret = commit_packed_refs();
2534 if (ret && err)
2535 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",
2536 strerror(errno));
2537 return ret;
c0277d15
JH
2538}
2539
61cee0db 2540static int repack_without_ref(const char *refname)
c0277d15 2541{
60bca085 2542 return repack_without_refs(&refname, 1, NULL);
61cee0db 2543}
c0277d15 2544
2ddb5d17
BK
2545static int delete_ref_loose(struct ref_lock *lock, int flag)
2546{
045a476f 2547 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 2548 /* loose */
2ddb5d17
BK
2549 int err, i = strlen(lock->lk->filename) - 5; /* .lock */
2550
547d058f
RS
2551 lock->lk->filename[i] = 0;
2552 err = unlink_or_warn(lock->lk->filename);
547d058f 2553 lock->lk->filename[i] = '.';
2ddb5d17
BK
2554 if (err && errno != ENOENT)
2555 return 1;
c0277d15 2556 }
2ddb5d17
BK
2557 return 0;
2558}
2559
eca35a25 2560int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
2561{
2562 struct ref_lock *lock;
2ddb5d17 2563 int ret = 0, flag = 0;
c0277d15 2564
547d058f 2565 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
2566 if (!lock)
2567 return 1;
2ddb5d17 2568 ret |= delete_ref_loose(lock, flag);
691f1a28 2569
c0277d15
JH
2570 /* removing the loose one could have resurrected an earlier
2571 * packed one. Also, if it was not loose we need to repack
2572 * without it.
2573 */
b274a714 2574 ret |= repack_without_ref(lock->ref_name);
c0277d15 2575
691f1a28 2576 unlink_or_warn(git_path("logs/%s", lock->ref_name));
9da31cb0 2577 clear_loose_ref_cache(&ref_cache);
c0277d15
JH
2578 unlock_ref(lock);
2579 return ret;
4bd18c43
SP
2580}
2581
765c2258
PH
2582/*
2583 * People using contrib's git-new-workdir have .git/logs/refs ->
2584 * /some/other/path/.git/logs/refs, and that may live on another device.
2585 *
2586 * IOW, to avoid cross device rename errors, the temporary renamed log must
2587 * live into logs/refs.
2588 */
2589#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2590
fa59ae79
MH
2591static int rename_tmp_log(const char *newrefname)
2592{
f1e9e9a4 2593 int attempts_remaining = 4;
ae4a283e
MH
2594
2595 retry:
08f555cb
MH
2596 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2597 case SCLD_OK:
2598 break; /* success */
2599 case SCLD_VANISHED:
2600 if (--attempts_remaining > 0)
2601 goto retry;
2602 /* fall through */
2603 default:
fa59ae79
MH
2604 error("unable to create directory for %s", newrefname);
2605 return -1;
2606 }
2607
fa59ae79 2608 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
f1e9e9a4 2609 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
fa59ae79
MH
2610 /*
2611 * rename(a, b) when b is an existing
2612 * directory ought to result in ISDIR, but
2613 * Solaris 5.8 gives ENOTDIR. Sheesh.
2614 */
2615 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2616 error("Directory not empty: logs/%s", newrefname);
2617 return -1;
2618 }
2619 goto retry;
ae4a283e
MH
2620 } else if (errno == ENOENT && --attempts_remaining > 0) {
2621 /*
2622 * Maybe another process just deleted one of
2623 * the directories in the path to newrefname.
2624 * Try again from the beginning.
2625 */
2626 goto retry;
fa59ae79
MH
2627 } else {
2628 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2629 newrefname, strerror(errno));
2630 return -1;
2631 }
2632 }
2633 return 0;
2634}
2635
dfefa935 2636int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 2637{
c976d415
LH
2638 unsigned char sha1[20], orig_sha1[20];
2639 int flag = 0, logmoved = 0;
2640 struct ref_lock *lock;
c976d415 2641 struct stat loginfo;
dfefa935 2642 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 2643 const char *symref = NULL;
c976d415 2644
450d4c0f 2645 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 2646 return error("reflog for %s is a symlink", oldrefname);
c976d415 2647
8d68493f 2648 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 2649 if (flag & REF_ISSYMREF)
fa58186c 2650 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 2651 oldrefname);
eca35a25 2652 if (!symref)
dfefa935 2653 return error("refname %s not found", oldrefname);
c976d415 2654
9da31cb0 2655 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
c976d415
LH
2656 return 1;
2657
9da31cb0 2658 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
c976d415
LH
2659 return 1;
2660
dfefa935 2661 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 2662 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 2663 oldrefname, strerror(errno));
c976d415 2664
dfefa935
MH
2665 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2666 error("unable to delete old %s", oldrefname);
c976d415
LH
2667 goto rollback;
2668 }
2669
dfefa935
MH
2670 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2671 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 2672 if (errno==EISDIR) {
dfefa935
MH
2673 if (remove_empty_directories(git_path("%s", newrefname))) {
2674 error("Directory not empty: %s", newrefname);
c976d415
LH
2675 goto rollback;
2676 }
2677 } else {
dfefa935 2678 error("unable to delete existing %s", newrefname);
c976d415
LH
2679 goto rollback;
2680 }
2681 }
2682
fa59ae79 2683 if (log && rename_tmp_log(newrefname))
c976d415 2684 goto rollback;
c976d415 2685
c976d415
LH
2686 logmoved = log;
2687
dfefa935 2688 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 2689 if (!lock) {
dfefa935 2690 error("unable to lock %s for update", newrefname);
c976d415
LH
2691 goto rollback;
2692 }
c976d415
LH
2693 lock->force_write = 1;
2694 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 2695 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 2696 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
2697 goto rollback;
2698 }
2699
2700 return 0;
2701
2702 rollback:
dfefa935 2703 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 2704 if (!lock) {
dfefa935 2705 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
2706 goto rollbacklog;
2707 }
2708
2709 lock->force_write = 1;
2710 flag = log_all_ref_updates;
2711 log_all_ref_updates = 0;
2712 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2713 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2714 log_all_ref_updates = flag;
2715
2716 rollbacklog:
dfefa935 2717 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2718 error("unable to restore logfile %s from %s: %s",
dfefa935 2719 oldrefname, newrefname, strerror(errno));
c976d415 2720 if (!logmoved && log &&
dfefa935 2721 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2722 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2723 oldrefname, strerror(errno));
c976d415
LH
2724
2725 return 1;
2726}
2727
435fc852 2728int close_ref(struct ref_lock *lock)
b531394d
BC
2729{
2730 if (close_lock_file(lock->lk))
2731 return -1;
2732 lock->lock_fd = -1;
2733 return 0;
2734}
2735
435fc852 2736int commit_ref(struct ref_lock *lock)
b531394d
BC
2737{
2738 if (commit_lock_file(lock->lk))
2739 return -1;
2740 lock->lock_fd = -1;
2741 return 0;
2742}
2743
e5f38ec3 2744void unlock_ref(struct ref_lock *lock)
4bd18c43 2745{
4ed7cd3a
BC
2746 /* Do not free lock->lk -- atexit() still looks at them */
2747 if (lock->lk)
2748 rollback_lock_file(lock->lk);
434cd0cd 2749 free(lock->ref_name);
1655707c 2750 free(lock->orig_ref_name);
4bd18c43
SP
2751 free(lock);
2752}
2753
0ec29a47
JH
2754/*
2755 * copy the reflog message msg to buf, which has been allocated sufficiently
2756 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2757 * because reflog file is one line per entry.
2758 */
2759static int copy_msg(char *buf, const char *msg)
2760{
2761 char *cp = buf;
2762 char c;
2763 int wasspace = 1;
2764
2765 *cp++ = '\t';
2766 while ((c = *msg++)) {
2767 if (wasspace && isspace(c))
2768 continue;
2769 wasspace = isspace(c);
2770 if (wasspace)
2771 c = ' ';
2772 *cp++ = c;
2773 }
2774 while (buf < cp && isspace(cp[-1]))
2775 cp--;
2776 *cp++ = '\n';
2777 return cp - buf;
2778}
2779
bd3b02da 2780/* This function must set a meaningful errno on failure */
dfefa935 2781int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2782{
859c3017 2783 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2784
dfefa935 2785 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2786 if (log_all_ref_updates &&
59556548
CC
2787 (starts_with(refname, "refs/heads/") ||
2788 starts_with(refname, "refs/remotes/") ||
2789 starts_with(refname, "refs/notes/") ||
dfefa935 2790 !strcmp(refname, "HEAD"))) {
bd3b02da
RS
2791 if (safe_create_leading_directories(logfile) < 0) {
2792 int save_errno = errno;
2793 error("unable to create directory for %s", logfile);
2794 errno = save_errno;
2795 return -1;
2796 }
6de08ae6
SP
2797 oflags |= O_CREAT;
2798 }
2799
157aaea5 2800 logfd = open(logfile, oflags, 0666);
6de08ae6 2801 if (logfd < 0) {
1974bf62 2802 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2803 return 0;
3b463c3f
JH
2804
2805 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2806 if (remove_empty_directories(logfile)) {
bd3b02da
RS
2807 int save_errno = errno;
2808 error("There are still logs under '%s'",
2809 logfile);
2810 errno = save_errno;
2811 return -1;
3b463c3f 2812 }
157aaea5 2813 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2814 }
2815
bd3b02da
RS
2816 if (logfd < 0) {
2817 int save_errno = errno;
2818 error("Unable to append to %s: %s", logfile,
2819 strerror(errno));
2820 errno = save_errno;
2821 return -1;
2822 }
6de08ae6
SP
2823 }
2824
157aaea5 2825 adjust_shared_perm(logfile);
859c3017
EM
2826 close(logfd);
2827 return 0;
2828}
443b92b6 2829
dfefa935 2830static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2831 const unsigned char *new_sha1, const char *msg)
2832{
2833 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2834 unsigned maxlen, len;
2835 int msglen;
157aaea5 2836 char log_file[PATH_MAX];
859c3017
EM
2837 char *logrec;
2838 const char *committer;
2839
2840 if (log_all_ref_updates < 0)
2841 log_all_ref_updates = !is_bare_repository();
2842
dfefa935 2843 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2844 if (result)
2845 return result;
2846
2847 logfd = open(log_file, oflags);
2848 if (logfd < 0)
2849 return 0;
0ec29a47 2850 msglen = msg ? strlen(msg) : 0;
774751a8 2851 committer = git_committer_info(0);
8ac65937
JH
2852 maxlen = strlen(committer) + msglen + 100;
2853 logrec = xmalloc(maxlen);
2854 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2855 sha1_to_hex(old_sha1),
2856 sha1_to_hex(new_sha1),
8ac65937
JH
2857 committer);
2858 if (msglen)
0ec29a47 2859 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2860 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2861 free(logrec);
dc615de8
RS
2862 if (written != len) {
2863 int save_errno = errno;
2864 close(logfd);
2865 error("Unable to append to %s", log_file);
2866 errno = save_errno;
2867 return -1;
2868 }
2869 if (close(logfd)) {
2870 int save_errno = errno;
2871 error("Unable to append to %s", log_file);
2872 errno = save_errno;
2873 return -1;
2874 }
6de08ae6
SP
2875 return 0;
2876}
2877
c3b0dec5
LT
2878static int is_branch(const char *refname)
2879{
59556548 2880 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
c3b0dec5
LT
2881}
2882
dc615de8 2883/* This function must return a meaningful errno */
4bd18c43
SP
2884int write_ref_sha1(struct ref_lock *lock,
2885 const unsigned char *sha1, const char *logmsg)
2886{
2887 static char term = '\n';
c3b0dec5 2888 struct object *o;
4bd18c43 2889
dc615de8
RS
2890 if (!lock) {
2891 errno = EINVAL;
95fc7512 2892 return -1;
dc615de8 2893 }
a89fccd2 2894 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2895 unlock_ref(lock);
2896 return 0;
95fc7512 2897 }
c3b0dec5
LT
2898 o = parse_object(sha1);
2899 if (!o) {
7be8b3ba 2900 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2901 lock->ref_name, sha1_to_hex(sha1));
2902 unlock_ref(lock);
dc615de8 2903 errno = EINVAL;
c3b0dec5
LT
2904 return -1;
2905 }
2906 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2907 error("Trying to write non-commit object %s to branch %s",
2908 sha1_to_hex(sha1), lock->ref_name);
2909 unlock_ref(lock);
dc615de8 2910 errno = EINVAL;
c3b0dec5
LT
2911 return -1;
2912 }
93822c22 2913 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
dc615de8
RS
2914 write_in_full(lock->lock_fd, &term, 1) != 1 ||
2915 close_ref(lock) < 0) {
2916 int save_errno = errno;
c33d5174 2917 error("Couldn't write %s", lock->lk->filename);
4bd18c43 2918 unlock_ref(lock);
dc615de8 2919 errno = save_errno;
4bd18c43
SP
2920 return -1;
2921 }
9da31cb0 2922 clear_loose_ref_cache(&ref_cache);
bd104db1
NP
2923 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2924 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2925 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2926 unlock_ref(lock);
2927 return -1;
2928 }
605fac8b
NP
2929 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2930 /*
2931 * Special hack: If a branch is updated directly and HEAD
2932 * points to it (may happen on the remote side of a push
2933 * for example) then logically the HEAD reflog should be
2934 * updated too.
2935 * A generic solution implies reverse symref information,
2936 * but finding all symrefs pointing to the given branch
2937 * would be rather costly for this rare event (the direct
2938 * update of a branch) to be worth it. So let's cheat and
2939 * check with HEAD only which should cover 99% of all usage
2940 * scenarios (even 100% of the default ones).
2941 */
2942 unsigned char head_sha1[20];
2943 int head_flag;
2944 const char *head_ref;
8cad4744 2945 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2946 if (head_ref && (head_flag & REF_ISSYMREF) &&
2947 !strcmp(head_ref, lock->ref_name))
2948 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2949 }
b531394d 2950 if (commit_ref(lock)) {
434cd0cd 2951 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2952 unlock_ref(lock);
2953 return -1;
2954 }
4bd18c43
SP
2955 unlock_ref(lock);
2956 return 0;
95fc7512 2957}
d556fae2 2958
8b5157e4
NP
2959int create_symref(const char *ref_target, const char *refs_heads_master,
2960 const char *logmsg)
41b625b0
NP
2961{
2962 const char *lockpath;
2963 char ref[1000];
2964 int fd, len, written;
a4f34cbb 2965 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2966 unsigned char old_sha1[20], new_sha1[20];
2967
2968 if (logmsg && read_ref(ref_target, old_sha1))
2969 hashclr(old_sha1);
41b625b0 2970
d48744d1
JH
2971 if (safe_create_leading_directories(git_HEAD) < 0)
2972 return error("unable to create directory for %s", git_HEAD);
2973
41b625b0
NP
2974#ifndef NO_SYMLINK_HEAD
2975 if (prefer_symlink_refs) {
2976 unlink(git_HEAD);
2977 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2978 goto done;
41b625b0
NP
2979 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2980 }
2981#endif
2982
2983 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2984 if (sizeof(ref) <= len) {
2985 error("refname too long: %s", refs_heads_master);
47fc52e2 2986 goto error_free_return;
41b625b0
NP
2987 }
2988 lockpath = mkpath("%s.lock", git_HEAD);
2989 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2990 if (fd < 0) {
2991 error("Unable to open %s for writing", lockpath);
47fc52e2 2992 goto error_free_return;
41b625b0
NP
2993 }
2994 written = write_in_full(fd, ref, len);
91c8d590 2995 if (close(fd) != 0 || written != len) {
41b625b0 2996 error("Unable to write to %s", lockpath);
47fc52e2 2997 goto error_unlink_return;
41b625b0
NP
2998 }
2999 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 3000 error("Unable to create %s", git_HEAD);
47fc52e2 3001 goto error_unlink_return;
41b625b0
NP
3002 }
3003 if (adjust_shared_perm(git_HEAD)) {
41b625b0 3004 error("Unable to fix permissions on %s", lockpath);
47fc52e2 3005 error_unlink_return:
691f1a28 3006 unlink_or_warn(lockpath);
47fc52e2
JH
3007 error_free_return:
3008 free(git_HEAD);
3009 return -1;
41b625b0 3010 }
8b5157e4 3011
ee96d11b 3012#ifndef NO_SYMLINK_HEAD
8b5157e4 3013 done:
ee96d11b 3014#endif
8b5157e4
NP
3015 if (logmsg && !read_ref(refs_heads_master, new_sha1))
3016 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
3017
47fc52e2 3018 free(git_HEAD);
41b625b0
NP
3019 return 0;
3020}
3021
4207ed28
RS
3022struct read_ref_at_cb {
3023 const char *refname;
3024 unsigned long at_time;
3025 int cnt;
3026 int reccnt;
3027 unsigned char *sha1;
3028 int found_it;
3029
3030 unsigned char osha1[20];
3031 unsigned char nsha1[20];
3032 int tz;
3033 unsigned long date;
3034 char **msg;
3035 unsigned long *cutoff_time;
3036 int *cutoff_tz;
3037 int *cutoff_cnt;
3038};
3039
3040static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,
3041 const char *email, unsigned long timestamp, int tz,
3042 const char *message, void *cb_data)
3043{
3044 struct read_ref_at_cb *cb = cb_data;
3045
3046 cb->reccnt++;
3047 cb->tz = tz;
3048 cb->date = timestamp;
3049
3050 if (timestamp <= cb->at_time || cb->cnt == 0) {
3051 if (cb->msg)
3052 *cb->msg = xstrdup(message);
3053 if (cb->cutoff_time)
3054 *cb->cutoff_time = timestamp;
3055 if (cb->cutoff_tz)
3056 *cb->cutoff_tz = tz;
3057 if (cb->cutoff_cnt)
3058 *cb->cutoff_cnt = cb->reccnt - 1;
3059 /*
3060 * we have not yet updated cb->[n|o]sha1 so they still
3061 * hold the values for the previous record.
3062 */
3063 if (!is_null_sha1(cb->osha1)) {
3064 hashcpy(cb->sha1, nsha1);
3065 if (hashcmp(cb->osha1, nsha1))
3066 warning("Log for ref %s has gap after %s.",
3067 cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));
3068 }
3069 else if (cb->date == cb->at_time)
3070 hashcpy(cb->sha1, nsha1);
3071 else if (hashcmp(nsha1, cb->sha1))
3072 warning("Log for ref %s unexpectedly ended on %s.",
3073 cb->refname, show_date(cb->date, cb->tz,
3074 DATE_RFC2822));
3075 hashcpy(cb->osha1, osha1);
3076 hashcpy(cb->nsha1, nsha1);
3077 cb->found_it = 1;
3078 return 1;
3079 }
3080 hashcpy(cb->osha1, osha1);
3081 hashcpy(cb->nsha1, nsha1);
3082 if (cb->cnt > 0)
3083 cb->cnt--;
3084 return 0;
3085}
3086
3087static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,
3088 const char *email, unsigned long timestamp,
3089 int tz, const char *message, void *cb_data)
3090{
3091 struct read_ref_at_cb *cb = cb_data;
3092
3093 if (cb->msg)
3094 *cb->msg = xstrdup(message);
3095 if (cb->cutoff_time)
3096 *cb->cutoff_time = timestamp;
3097 if (cb->cutoff_tz)
3098 *cb->cutoff_tz = tz;
3099 if (cb->cutoff_cnt)
3100 *cb->cutoff_cnt = cb->reccnt;
3101 hashcpy(cb->sha1, osha1);
3102 if (is_null_sha1(cb->sha1))
3103 hashcpy(cb->sha1, nsha1);
3104 /* We just want the first entry */
3105 return 1;
16d7cc90
JH
3106}
3107
dfefa935
MH
3108int read_ref_at(const char *refname, unsigned long at_time, int cnt,
3109 unsigned char *sha1, char **msg,
3110 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 3111{
4207ed28 3112 struct read_ref_at_cb cb;
d556fae2 3113
4207ed28
RS
3114 memset(&cb, 0, sizeof(cb));
3115 cb.refname = refname;
3116 cb.at_time = at_time;
3117 cb.cnt = cnt;
3118 cb.msg = msg;
3119 cb.cutoff_time = cutoff_time;
3120 cb.cutoff_tz = cutoff_tz;
3121 cb.cutoff_cnt = cutoff_cnt;
3122 cb.sha1 = sha1;
3123
3124 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
3125
3126 if (!cb.reccnt)
3127 die("Log for %s is empty.", refname);
3128 if (cb.found_it)
3129 return 0;
3130
3131 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
d556fae2 3132
16d7cc90 3133 return 1;
d556fae2 3134}
2ff81662 3135
4da58835
RS
3136int reflog_exists(const char *refname)
3137{
3138 struct stat st;
3139
3140 return !lstat(git_path("logs/%s", refname), &st) &&
3141 S_ISREG(st.st_mode);
3142}
3143
3144int delete_reflog(const char *refname)
3145{
3146 return remove_path(git_path("logs/%s", refname));
3147}
3148
9a7a183b
JH
3149static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3150{
3151 unsigned char osha1[20], nsha1[20];
3152 char *email_end, *message;
3153 unsigned long timestamp;
3154 int tz;
3155
3156 /* old SP new SP name <email> SP time TAB msg LF */
3157 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
3158 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
3159 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3160 !(email_end = strchr(sb->buf + 82, '>')) ||
3161 email_end[1] != ' ' ||
3162 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3163 !message || message[0] != ' ' ||
3164 (message[1] != '+' && message[1] != '-') ||
3165 !isdigit(message[2]) || !isdigit(message[3]) ||
3166 !isdigit(message[4]) || !isdigit(message[5]))
3167 return 0; /* corrupt? */
3168 email_end[1] = '\0';
3169 tz = strtol(message + 1, NULL, 10);
3170 if (message[6] != '\t')
3171 message += 6;
3172 else
3173 message += 7;
3174 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3175}
3176
98f85ff4
JH
3177static char *find_beginning_of_line(char *bob, char *scan)
3178{
3179 while (bob < scan && *(--scan) != '\n')
3180 ; /* keep scanning backwards */
3181 /*
3182 * Return either beginning of the buffer, or LF at the end of
3183 * the previous line.
3184 */
3185 return scan;
3186}
3187
3188int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
2ff81662 3189{
8ca78803 3190 struct strbuf sb = STRBUF_INIT;
98f85ff4
JH
3191 FILE *logfp;
3192 long pos;
3193 int ret = 0, at_tail = 1;
2ff81662 3194
7ae07c1b 3195 logfp = fopen(git_path("logs/%s", refname), "r");
2ff81662 3196 if (!logfp)
883d60fa 3197 return -1;
101d15e0 3198
98f85ff4
JH
3199 /* Jump to the end */
3200 if (fseek(logfp, 0, SEEK_END) < 0)
3201 return error("cannot seek back reflog for %s: %s",
3202 refname, strerror(errno));
3203 pos = ftell(logfp);
3204 while (!ret && 0 < pos) {
3205 int cnt;
3206 size_t nread;
3207 char buf[BUFSIZ];
3208 char *endp, *scanp;
3209
3210 /* Fill next block from the end */
3211 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3212 if (fseek(logfp, pos - cnt, SEEK_SET))
3213 return error("cannot seek back reflog for %s: %s",
3214 refname, strerror(errno));
3215 nread = fread(buf, cnt, 1, logfp);
e4ca819a 3216 if (nread != 1)
98f85ff4
JH
3217 return error("cannot read %d bytes from reflog for %s: %s",
3218 cnt, refname, strerror(errno));
3219 pos -= cnt;
3220
3221 scanp = endp = buf + cnt;
3222 if (at_tail && scanp[-1] == '\n')
3223 /* Looking at the final LF at the end of the file */
3224 scanp--;
3225 at_tail = 0;
3226
3227 while (buf < scanp) {
3228 /*
3229 * terminating LF of the previous line, or the beginning
3230 * of the buffer.
3231 */
3232 char *bp;
3233
3234 bp = find_beginning_of_line(buf, scanp);
3235
3236 if (*bp != '\n') {
3237 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3238 if (pos)
3239 break; /* need to fill another block */
3240 scanp = buf - 1; /* leave loop */
3241 } else {
3242 /*
3243 * (bp + 1) thru endp is the beginning of the
3244 * current line we have in sb
3245 */
3246 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3247 scanp = bp;
3248 endp = bp + 1;
3249 }
3250 ret = show_one_reflog_ent(&sb, fn, cb_data);
3251 strbuf_reset(&sb);
3252 if (ret)
3253 break;
9d33f7c2 3254 }
101d15e0 3255
2ff81662 3256 }
98f85ff4 3257 if (!ret && sb.len)
9a7a183b 3258 ret = show_one_reflog_ent(&sb, fn, cb_data);
98f85ff4 3259
2ff81662 3260 fclose(logfp);
8ca78803 3261 strbuf_release(&sb);
2266bf27 3262 return ret;
2ff81662 3263}
e29cb53a 3264
dfefa935 3265int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 3266{
98f85ff4
JH
3267 FILE *logfp;
3268 struct strbuf sb = STRBUF_INIT;
3269 int ret = 0;
3270
3271 logfp = fopen(git_path("logs/%s", refname), "r");
3272 if (!logfp)
3273 return -1;
101d15e0 3274
98f85ff4
JH
3275 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3276 ret = show_one_reflog_ent(&sb, fn, cb_data);
3277 fclose(logfp);
3278 strbuf_release(&sb);
3279 return ret;
3280}
989c0e5d
MH
3281/*
3282 * Call fn for each reflog in the namespace indicated by name. name
3283 * must be empty or end with '/'. Name will be used as a scratch
3284 * space, but its contents will be restored before return.
3285 */
3286static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 3287{
989c0e5d 3288 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 3289 int retval = 0;
93c603fc 3290 struct dirent *de;
989c0e5d 3291 int oldlen = name->len;
eb8381c8 3292
93c603fc 3293 if (!d)
989c0e5d 3294 return name->len ? errno : 0;
eb8381c8 3295
93c603fc
MH
3296 while ((de = readdir(d)) != NULL) {
3297 struct stat st;
eb8381c8 3298
93c603fc
MH
3299 if (de->d_name[0] == '.')
3300 continue;
93c603fc
MH
3301 if (has_extension(de->d_name, ".lock"))
3302 continue;
989c0e5d
MH
3303 strbuf_addstr(name, de->d_name);
3304 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3305 ; /* silently ignore */
93c603fc 3306 } else {
eb8381c8 3307 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
3308 strbuf_addch(name, '/');
3309 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
3310 } else {
3311 unsigned char sha1[20];
989c0e5d
MH
3312 if (read_ref_full(name->buf, sha1, 0, NULL))
3313 retval = error("bad ref for %s", name->buf);
eb8381c8 3314 else
989c0e5d 3315 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
3316 }
3317 if (retval)
3318 break;
3319 }
989c0e5d 3320 strbuf_setlen(name, oldlen);
eb8381c8 3321 }
93c603fc 3322 closedir(d);
eb8381c8
NP
3323 return retval;
3324}
3325
3326int for_each_reflog(each_ref_fn fn, void *cb_data)
3327{
989c0e5d
MH
3328 int retval;
3329 struct strbuf name;
3330 strbuf_init(&name, PATH_MAX);
3331 retval = do_for_each_reflog(&name, fn, cb_data);
3332 strbuf_release(&name);
3333 return retval;
eb8381c8 3334}
3d9f037c 3335
4738a333
BK
3336static struct ref_lock *update_ref_lock(const char *refname,
3337 const unsigned char *oldval,
3338 int flags, int *type_p,
3339 enum action_on_err onerr)
3d9f037c 3340{
4738a333
BK
3341 struct ref_lock *lock;
3342 lock = lock_any_ref_for_update(refname, oldval, flags, type_p);
3d9f037c
CR
3343 if (!lock) {
3344 const char *str = "Cannot lock the ref '%s'.";
3345 switch (onerr) {
f4124112
MH
3346 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
3347 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
3348 case UPDATE_REFS_QUIET_ON_ERR: break;
3d9f037c 3349 }
3d9f037c 3350 }
4738a333
BK
3351 return lock;
3352}
3353
3354static int update_ref_write(const char *action, const char *refname,
3355 const unsigned char *sha1, struct ref_lock *lock,
c1703d76 3356 struct strbuf *err, enum action_on_err onerr)
4738a333 3357{
3d9f037c
CR
3358 if (write_ref_sha1(lock, sha1, action) < 0) {
3359 const char *str = "Cannot update the ref '%s'.";
c1703d76
RS
3360 if (err)
3361 strbuf_addf(err, str, refname);
3362
3d9f037c 3363 switch (onerr) {
f4124112
MH
3364 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
3365 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
3366 case UPDATE_REFS_QUIET_ON_ERR: break;
3d9f037c
CR
3367 }
3368 return 1;
3369 }
3370 return 0;
3371}
cda69f48 3372
b5c8ea2a
MH
3373/**
3374 * Information needed for a single ref update. Set new_sha1 to the
3375 * new value or to zero to delete the ref. To check the old value
3376 * while locking the ref, set have_old to 1 and set old_sha1 to the
3377 * value or to zero to ensure the ref does not exist before update.
3378 */
3379struct ref_update {
b5c8ea2a
MH
3380 unsigned char new_sha1[20];
3381 unsigned char old_sha1[20];
3382 int flags; /* REF_NODEREF? */
3383 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */
81c960e4 3384 struct ref_lock *lock;
84178db7 3385 int type;
88615910 3386 const char refname[FLEX_ARRAY];
b5c8ea2a
MH
3387};
3388
caa4046c
MH
3389/*
3390 * Data structure for holding a reference transaction, which can
3391 * consist of checks and updates to multiple references, carried out
3392 * as atomically as possible. This structure is opaque to callers.
3393 */
3394struct ref_transaction {
3395 struct ref_update **updates;
3396 size_t alloc;
3397 size_t nr;
3398};
3399
93a644ea 3400struct ref_transaction *ref_transaction_begin(struct strbuf *err)
caa4046c
MH
3401{
3402 return xcalloc(1, sizeof(struct ref_transaction));
3403}
3404
026bd1d3 3405void ref_transaction_free(struct ref_transaction *transaction)
caa4046c
MH
3406{
3407 int i;
3408
1b07255c
RS
3409 if (!transaction)
3410 return;
3411
88615910
MH
3412 for (i = 0; i < transaction->nr; i++)
3413 free(transaction->updates[i]);
caa4046c
MH
3414
3415 free(transaction->updates);
3416 free(transaction);
3417}
3418
caa4046c
MH
3419static struct ref_update *add_update(struct ref_transaction *transaction,
3420 const char *refname)
3421{
88615910
MH
3422 size_t len = strlen(refname);
3423 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
caa4046c 3424
88615910 3425 strcpy((char *)update->refname, refname);
caa4046c
MH
3426 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
3427 transaction->updates[transaction->nr++] = update;
3428 return update;
3429}
3430
8e34800e
RS
3431int ref_transaction_update(struct ref_transaction *transaction,
3432 const char *refname,
3433 const unsigned char *new_sha1,
3434 const unsigned char *old_sha1,
3435 int flags, int have_old,
3436 struct strbuf *err)
caa4046c 3437{
8e34800e
RS
3438 struct ref_update *update;
3439
3440 if (have_old && !old_sha1)
3441 die("BUG: have_old is true but old_sha1 is NULL");
caa4046c 3442
8e34800e 3443 update = add_update(transaction, refname);
caa4046c
MH
3444 hashcpy(update->new_sha1, new_sha1);
3445 update->flags = flags;
3446 update->have_old = have_old;
3447 if (have_old)
3448 hashcpy(update->old_sha1, old_sha1);
8e34800e 3449 return 0;
caa4046c
MH
3450}
3451
b416af5b
RS
3452int ref_transaction_create(struct ref_transaction *transaction,
3453 const char *refname,
3454 const unsigned char *new_sha1,
3455 int flags,
3456 struct strbuf *err)
caa4046c 3457{
b416af5b
RS
3458 struct ref_update *update;
3459
3460 if (!new_sha1 || is_null_sha1(new_sha1))
3461 die("BUG: create ref with null new_sha1");
3462
3463 update = add_update(transaction, refname);
caa4046c 3464
caa4046c
MH
3465 hashcpy(update->new_sha1, new_sha1);
3466 hashclr(update->old_sha1);
3467 update->flags = flags;
3468 update->have_old = 1;
b416af5b 3469 return 0;
caa4046c
MH
3470}
3471
8c8bdc0d
RS
3472int ref_transaction_delete(struct ref_transaction *transaction,
3473 const char *refname,
3474 const unsigned char *old_sha1,
3475 int flags, int have_old,
3476 struct strbuf *err)
caa4046c 3477{
8c8bdc0d 3478 struct ref_update *update;
caa4046c 3479
8c8bdc0d
RS
3480 if (have_old && !old_sha1)
3481 die("BUG: have_old is true but old_sha1 is NULL");
3482
3483 update = add_update(transaction, refname);
caa4046c
MH
3484 update->flags = flags;
3485 update->have_old = have_old;
3486 if (have_old) {
3487 assert(!is_null_sha1(old_sha1));
3488 hashcpy(update->old_sha1, old_sha1);
3489 }
8c8bdc0d 3490 return 0;
caa4046c
MH
3491}
3492
4738a333
BK
3493int update_ref(const char *action, const char *refname,
3494 const unsigned char *sha1, const unsigned char *oldval,
3495 int flags, enum action_on_err onerr)
3496{
3497 struct ref_lock *lock;
ce1e8462 3498 lock = update_ref_lock(refname, oldval, flags, NULL, onerr);
4738a333
BK
3499 if (!lock)
3500 return 1;
c1703d76 3501 return update_ref_write(action, refname, sha1, lock, NULL, onerr);
4738a333
BK
3502}
3503
98aee92d
BK
3504static int ref_update_compare(const void *r1, const void *r2)
3505{
3506 const struct ref_update * const *u1 = r1;
3507 const struct ref_update * const *u2 = r2;
5524e241 3508 return strcmp((*u1)->refname, (*u2)->refname);
98aee92d
BK
3509}
3510
3511static int ref_update_reject_duplicates(struct ref_update **updates, int n,
01319837 3512 struct strbuf *err)
98aee92d
BK
3513{
3514 int i;
3515 for (i = 1; i < n; i++)
5524e241 3516 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
98aee92d
BK
3517 const char *str =
3518 "Multiple updates for ref '%s' not allowed.";
038d0051
RS
3519 if (err)
3520 strbuf_addf(err, str, updates[i]->refname);
3521
98aee92d
BK
3522 return 1;
3523 }
3524 return 0;
3525}
3526
b5c8ea2a 3527int ref_transaction_commit(struct ref_transaction *transaction,
01319837 3528 const char *msg, struct strbuf *err)
98aee92d
BK
3529{
3530 int ret = 0, delnum = 0, i;
98aee92d 3531 const char **delnames;
b5c8ea2a 3532 int n = transaction->nr;
6a402338 3533 struct ref_update **updates = transaction->updates;
98aee92d 3534
b5c8ea2a 3535 if (!n)
98aee92d
BK
3536 return 0;
3537
3538 /* Allocate work space */
98aee92d
BK
3539 delnames = xmalloc(sizeof(*delnames) * n);
3540
3541 /* Copy, sort, and reject duplicate refs */
98aee92d 3542 qsort(updates, n, sizeof(*updates), ref_update_compare);
01319837 3543 ret = ref_update_reject_duplicates(updates, n, err);
98aee92d
BK
3544 if (ret)
3545 goto cleanup;
3546
3547 /* Acquire all locks while verifying old values */
3548 for (i = 0; i < n; i++) {
cb198d21
MH
3549 struct ref_update *update = updates[i];
3550
81c960e4
MH
3551 update->lock = update_ref_lock(update->refname,
3552 (update->have_old ?
3553 update->old_sha1 : NULL),
3554 update->flags,
01319837
RS
3555 &update->type,
3556 UPDATE_REFS_QUIET_ON_ERR);
81c960e4 3557 if (!update->lock) {
995f8746
RS
3558 if (err)
3559 strbuf_addf(err, "Cannot lock the ref '%s'.",
3560 update->refname);
98aee92d
BK
3561 ret = 1;
3562 goto cleanup;
3563 }
3564 }
3565
3566 /* Perform updates first so live commits remain referenced */
cb198d21
MH
3567 for (i = 0; i < n; i++) {
3568 struct ref_update *update = updates[i];
3569
3570 if (!is_null_sha1(update->new_sha1)) {
b5c8ea2a 3571 ret = update_ref_write(msg,
cb198d21
MH
3572 update->refname,
3573 update->new_sha1,
01319837
RS
3574 update->lock, err,
3575 UPDATE_REFS_QUIET_ON_ERR);
81c960e4 3576 update->lock = NULL; /* freed by update_ref_write */
98aee92d
BK
3577 if (ret)
3578 goto cleanup;
3579 }
cb198d21 3580 }
98aee92d
BK
3581
3582 /* Perform deletes now that updates are safely completed */
81c960e4
MH
3583 for (i = 0; i < n; i++) {
3584 struct ref_update *update = updates[i];
3585
3586 if (update->lock) {
3587 delnames[delnum++] = update->lock->ref_name;
84178db7 3588 ret |= delete_ref_loose(update->lock, update->type);
98aee92d 3589 }
81c960e4
MH
3590 }
3591
60bca085 3592 ret |= repack_without_refs(delnames, delnum, err);
98aee92d
BK
3593 for (i = 0; i < delnum; i++)
3594 unlink_or_warn(git_path("logs/%s", delnames[i]));
3595 clear_loose_ref_cache(&ref_cache);
3596
3597cleanup:
3598 for (i = 0; i < n; i++)
81c960e4
MH
3599 if (updates[i]->lock)
3600 unlock_ref(updates[i]->lock);
98aee92d 3601 free(delnames);
caa4046c
MH
3602 return ret;
3603}
3604
dfefa935 3605char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
3606{
3607 int i;
3608 static char **scanf_fmts;
3609 static int nr_rules;
3610 char *short_name;
3611
7c2b3029 3612 if (!nr_rules) {
4346663a
MH
3613 /*
3614 * Pre-generate scanf formats from ref_rev_parse_rules[].
3615 * Generate a format suitable for scanf from a
3616 * ref_rev_parse_rules rule by interpolating "%s" at the