refs: extract a function peel_entry()
[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"
95fc7512 6
bc5fd6d3
MH
7/*
8 * Make sure "ref" is something reasonable to have under ".git/refs/";
9 * We do not like it if:
10 *
11 * - any path component of it begins with ".", or
12 * - it has double dots "..", or
13 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
14 * - it ends with a "/".
15 * - it ends with ".lock"
16 * - it contains a "\" (backslash)
17 */
f4204ab9 18
bc5fd6d3
MH
19/* Return true iff ch is not allowed in reference names. */
20static inline int bad_ref_char(int ch)
21{
22 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
23 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
24 return 1;
25 /* 2.13 Pattern Matching Notation */
26 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
27 return 1;
28 return 0;
29}
30
31/*
32 * Try to read one refname component from the front of refname. Return
33 * the length of the component found, or -1 if the component is not
34 * legal.
35 */
36static int check_refname_component(const char *refname, int flags)
37{
38 const char *cp;
39 char last = '\0';
40
41 for (cp = refname; ; cp++) {
42 char ch = *cp;
43 if (ch == '\0' || ch == '/')
44 break;
45 if (bad_ref_char(ch))
46 return -1; /* Illegal character in refname. */
47 if (last == '.' && ch == '.')
48 return -1; /* Refname contains "..". */
49 if (last == '@' && ch == '{')
50 return -1; /* Refname contains "@{". */
51 last = ch;
52 }
53 if (cp == refname)
dac529e4 54 return 0; /* Component has zero length. */
bc5fd6d3
MH
55 if (refname[0] == '.') {
56 if (!(flags & REFNAME_DOT_COMPONENT))
57 return -1; /* Component starts with '.'. */
58 /*
59 * Even if leading dots are allowed, don't allow "."
60 * as a component (".." is prevented by a rule above).
61 */
62 if (refname[1] == '\0')
63 return -1; /* Component equals ".". */
64 }
65 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
66 return -1; /* Refname ends with ".lock". */
67 return cp - refname;
68}
69
70int check_refname_format(const char *refname, int flags)
71{
72 int component_len, component_count = 0;
73
74 while (1) {
75 /* We are at the start of a path component. */
76 component_len = check_refname_component(refname, flags);
dac529e4 77 if (component_len <= 0) {
bc5fd6d3
MH
78 if ((flags & REFNAME_REFSPEC_PATTERN) &&
79 refname[0] == '*' &&
80 (refname[1] == '\0' || refname[1] == '/')) {
81 /* Accept one wildcard as a full refname component. */
82 flags &= ~REFNAME_REFSPEC_PATTERN;
83 component_len = 1;
84 } else {
85 return -1;
86 }
87 }
88 component_count++;
89 if (refname[component_len] == '\0')
90 break;
91 /* Skip to next component. */
92 refname += component_len + 1;
93 }
94
95 if (refname[component_len - 1] == '.')
96 return -1; /* Refname ends with '.'. */
97 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
98 return -1; /* Refname has only one component. */
99 return 0;
100}
101
102struct ref_entry;
e1e22e37 103
28e6a34e
MH
104/*
105 * Information used (along with the information in ref_entry) to
106 * describe a single cached reference. This data structure only
107 * occurs embedded in a union in struct ref_entry, and only when
108 * (ref_entry->flag & REF_DIR) is zero.
109 */
593f1bb8 110struct ref_value {
6c6f58df
MH
111 /*
112 * The name of the object to which this reference resolves
113 * (which may be a tag object). If REF_ISBROKEN, this is
114 * null. If REF_ISSYMREF, then this is the name of the object
115 * referred to by the last reference in the symlink chain.
116 */
593f1bb8 117 unsigned char sha1[20];
6c6f58df
MH
118
119 /*
120 * If REF_KNOWS_PEELED, then this field holds the peeled value
121 * of this reference, or null if the reference is known not to
2312a793
MH
122 * be peelable. See the documentation for peel_ref() for an
123 * exact definition of "peelable".
6c6f58df 124 */
593f1bb8
MH
125 unsigned char peeled[20];
126};
127
f006c42a
MH
128struct ref_cache;
129
28e6a34e
MH
130/*
131 * Information used (along with the information in ref_entry) to
132 * describe a level in the hierarchy of references. This data
133 * structure only occurs embedded in a union in struct ref_entry, and
134 * only when (ref_entry.flag & REF_DIR) is set. In that case,
135 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
136 * in the directory have already been read:
137 *
138 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
139 * or packed references, already read.
140 *
141 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
142 * references that hasn't been read yet (nor has any of its
143 * subdirectories).
144 *
145 * Entries within a directory are stored within a growable array of
146 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
147 * sorted are sorted by their component name in strcmp() order and the
148 * remaining entries are unsorted.
149 *
150 * Loose references are read lazily, one directory at a time. When a
151 * directory of loose references is read, then all of the references
152 * in that directory are stored, and REF_INCOMPLETE stubs are created
153 * for any subdirectories, but the subdirectories themselves are not
154 * read. The reading is triggered by get_ref_dir().
155 */
d3177275 156struct ref_dir {
e9c4c111 157 int nr, alloc;
e6ed3ca6
MH
158
159 /*
160 * Entries with index 0 <= i < sorted are sorted by name. New
161 * entries are appended to the list unsorted, and are sorted
162 * only when required; thus we avoid the need to sort the list
163 * after the addition of every reference.
164 */
165 int sorted;
166
f006c42a
MH
167 /* A pointer to the ref_cache that contains this ref_dir. */
168 struct ref_cache *ref_cache;
169
d3177275 170 struct ref_entry **entries;
e9c4c111
JP
171};
172
89df9c84
MH
173/*
174 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
175 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
176 * refs.h.
177 */
178
179/*
180 * The field ref_entry->u.value.peeled of this value entry contains
181 * the correct peeled value for the reference, which might be
182 * null_sha1 if the reference is not a tag or if it is broken.
183 */
432ad41e 184#define REF_KNOWS_PEELED 0x08
28e6a34e
MH
185
186/* ref_entry represents a directory of references */
432ad41e 187#define REF_DIR 0x10
cf0adba7 188
28e6a34e
MH
189/*
190 * Entry has not yet been read from disk (used only for REF_DIR
191 * entries representing loose references)
192 */
193#define REF_INCOMPLETE 0x20
194
432ad41e
MH
195/*
196 * A ref_entry represents either a reference or a "subdirectory" of
28e6a34e
MH
197 * references.
198 *
199 * Each directory in the reference namespace is represented by a
200 * ref_entry with (flags & REF_DIR) set and containing a subdir member
201 * that holds the entries in that directory that have been read so
202 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
203 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
204 * used for loose reference directories.
205 *
206 * References are represented by a ref_entry with (flags & REF_DIR)
207 * unset and a value member that describes the reference's value. The
208 * flag member is at the ref_entry level, but it is also needed to
209 * interpret the contents of the value field (in other words, a
210 * ref_value object is not very much use without the enclosing
211 * ref_entry).
432ad41e
MH
212 *
213 * Reference names cannot end with slash and directories' names are
214 * always stored with a trailing slash (except for the top-level
215 * directory, which is always denoted by ""). This has two nice
216 * consequences: (1) when the entries in each subdir are sorted
217 * lexicographically by name (as they usually are), the references in
218 * a whole tree can be generated in lexicographic order by traversing
219 * the tree in left-to-right, depth-first order; (2) the names of
220 * references and subdirectories cannot conflict, and therefore the
221 * presence of an empty subdirectory does not block the creation of a
222 * similarly-named reference. (The fact that reference names with the
223 * same leading components can conflict *with each other* is a
224 * separate issue that is regulated by is_refname_available().)
225 *
226 * Please note that the name field contains the fully-qualified
227 * reference (or subdirectory) name. Space could be saved by only
228 * storing the relative names. But that would require the full names
229 * to be generated on the fly when iterating in do_for_each_ref(), and
230 * would break callback functions, who have always been able to assume
231 * that the name strings that they are passed will not be freed during
232 * the iteration.
233 */
bc5fd6d3
MH
234struct ref_entry {
235 unsigned char flag; /* ISSYMREF? ISPACKED? */
593f1bb8 236 union {
432ad41e
MH
237 struct ref_value value; /* if not (flags&REF_DIR) */
238 struct ref_dir subdir; /* if (flags&REF_DIR) */
593f1bb8 239 } u;
432ad41e
MH
240 /*
241 * The full name of the reference (e.g., "refs/heads/master")
242 * or the full name of the directory with a trailing slash
243 * (e.g., "refs/heads/"):
244 */
bc5fd6d3
MH
245 char name[FLEX_ARRAY];
246};
e1e22e37 247
28e6a34e
MH
248static void read_loose_refs(const char *dirname, struct ref_dir *dir);
249
d7826d54
MH
250static struct ref_dir *get_ref_dir(struct ref_entry *entry)
251{
28e6a34e 252 struct ref_dir *dir;
d7826d54 253 assert(entry->flag & REF_DIR);
28e6a34e
MH
254 dir = &entry->u.subdir;
255 if (entry->flag & REF_INCOMPLETE) {
256 read_loose_refs(entry->name, dir);
257 entry->flag &= ~REF_INCOMPLETE;
258 }
259 return dir;
d7826d54
MH
260}
261
cddc4258
MH
262static struct ref_entry *create_ref_entry(const char *refname,
263 const unsigned char *sha1, int flag,
264 int check_name)
e1e22e37
LT
265{
266 int len;
cddc4258 267 struct ref_entry *ref;
e1e22e37 268
09116a1c 269 if (check_name &&
dfefa935
MH
270 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
271 die("Reference has invalid format: '%s'", refname);
cddc4258
MH
272 len = strlen(refname) + 1;
273 ref = xmalloc(sizeof(struct ref_entry) + len);
593f1bb8
MH
274 hashcpy(ref->u.value.sha1, sha1);
275 hashclr(ref->u.value.peeled);
cddc4258
MH
276 memcpy(ref->name, refname, len);
277 ref->flag = flag;
278 return ref;
279}
280
432ad41e
MH
281static void clear_ref_dir(struct ref_dir *dir);
282
732134ed
MH
283static void free_ref_entry(struct ref_entry *entry)
284{
27b5587c
MH
285 if (entry->flag & REF_DIR) {
286 /*
287 * Do not use get_ref_dir() here, as that might
288 * trigger the reading of loose refs.
289 */
290 clear_ref_dir(&entry->u.subdir);
291 }
732134ed
MH
292 free(entry);
293}
294
432ad41e
MH
295/*
296 * Add a ref_entry to the end of dir (unsorted). Entry is always
297 * stored directly in dir; no recursion into subdirectories is
298 * done.
299 */
300static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
cddc4258 301{
432ad41e
MH
302 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
303 dir->entries[dir->nr++] = entry;
654ad400
MH
304 /* optimize for the case that entries are added in order */
305 if (dir->nr == 1 ||
306 (dir->nr == dir->sorted + 1 &&
307 strcmp(dir->entries[dir->nr - 2]->name,
308 dir->entries[dir->nr - 1]->name) < 0))
309 dir->sorted = dir->nr;
c774aab9
JP
310}
311
432ad41e
MH
312/*
313 * Clear and free all entries in dir, recursively.
314 */
d3177275 315static void clear_ref_dir(struct ref_dir *dir)
bc5fd6d3
MH
316{
317 int i;
d3177275
MH
318 for (i = 0; i < dir->nr; i++)
319 free_ref_entry(dir->entries[i]);
320 free(dir->entries);
321 dir->sorted = dir->nr = dir->alloc = 0;
322 dir->entries = NULL;
bc5fd6d3
MH
323}
324
432ad41e
MH
325/*
326 * Create a struct ref_entry object for the specified dirname.
327 * dirname is the name of the directory with a trailing slash (e.g.,
328 * "refs/heads/") or "" for the top-level directory.
329 */
f006c42a 330static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
b9146f51
RS
331 const char *dirname, size_t len,
332 int incomplete)
432ad41e
MH
333{
334 struct ref_entry *direntry;
432ad41e 335 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
b9146f51
RS
336 memcpy(direntry->name, dirname, len);
337 direntry->name[len] = '\0';
f006c42a 338 direntry->u.subdir.ref_cache = ref_cache;
28e6a34e 339 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
432ad41e
MH
340 return direntry;
341}
342
e9c4c111 343static int ref_entry_cmp(const void *a, const void *b)
c774aab9 344{
e9c4c111
JP
345 struct ref_entry *one = *(struct ref_entry **)a;
346 struct ref_entry *two = *(struct ref_entry **)b;
347 return strcmp(one->name, two->name);
348}
c774aab9 349
d3177275 350static void sort_ref_dir(struct ref_dir *dir);
bc5fd6d3 351
e1980c9d
JH
352struct string_slice {
353 size_t len;
354 const char *str;
355};
356
357static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
358{
359 struct string_slice *key = (struct string_slice *)key_;
360 struct ref_entry *ent = *(struct ref_entry **)ent_;
361 int entlen = strlen(ent->name);
362 int cmplen = key->len < entlen ? key->len : entlen;
363 int cmp = memcmp(key->str, ent->name, cmplen);
364 if (cmp)
365 return cmp;
366 return key->len - entlen;
367}
368
432ad41e
MH
369/*
370 * Return the entry with the given refname from the ref_dir
371 * (non-recursively), sorting dir if necessary. Return NULL if no
28e6a34e 372 * such entry is found. dir must already be complete.
432ad41e 373 */
40ad937d
RS
374static struct ref_entry *search_ref_dir(struct ref_dir *dir,
375 const char *refname, size_t len)
bc5fd6d3 376{
e1980c9d
JH
377 struct ref_entry **r;
378 struct string_slice key;
bc5fd6d3 379
432ad41e 380 if (refname == NULL || !dir->nr)
bc5fd6d3
MH
381 return NULL;
382
d3177275 383 sort_ref_dir(dir);
e1980c9d
JH
384 key.len = len;
385 key.str = refname;
386 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
387 ref_entry_cmp_sslice);
bc5fd6d3
MH
388
389 if (r == NULL)
390 return NULL;
391
392 return *r;
393}
394
f348ac92
MH
395/*
396 * Search for a directory entry directly within dir (without
397 * recursing). Sort dir if necessary. subdirname must be a directory
398 * name (i.e., end in '/'). If mkdir is set, then create the
399 * directory if it is missing; otherwise, return NULL if the desired
28e6a34e 400 * directory cannot be found. dir must already be complete.
f348ac92 401 */
3f3aa1bc 402static struct ref_dir *search_for_subdir(struct ref_dir *dir,
dd02e728
RS
403 const char *subdirname, size_t len,
404 int mkdir)
f348ac92 405{
40ad937d 406 struct ref_entry *entry = search_ref_dir(dir, subdirname, len);
f348ac92
MH
407 if (!entry) {
408 if (!mkdir)
409 return NULL;
28e6a34e
MH
410 /*
411 * Since dir is complete, the absence of a subdir
412 * means that the subdir really doesn't exist;
413 * therefore, create an empty record for it but mark
414 * the record complete.
415 */
b9146f51 416 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
f348ac92
MH
417 add_entry_to_dir(dir, entry);
418 }
3f3aa1bc 419 return get_ref_dir(entry);
f348ac92
MH
420}
421
432ad41e
MH
422/*
423 * If refname is a reference name, find the ref_dir within the dir
424 * tree that should hold refname. If refname is a directory name
425 * (i.e., ends in '/'), then return that ref_dir itself. dir must
28e6a34e
MH
426 * represent the top-level directory and must already be complete.
427 * Sort ref_dirs and recurse into subdirectories as necessary. If
428 * mkdir is set, then create any missing directories; otherwise,
429 * return NULL if the desired directory cannot be found.
432ad41e
MH
430 */
431static struct ref_dir *find_containing_dir(struct ref_dir *dir,
432 const char *refname, int mkdir)
433{
5fa04418 434 const char *slash;
5fa04418 435 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
dd02e728 436 size_t dirnamelen = slash - refname + 1;
3f3aa1bc 437 struct ref_dir *subdir;
dd02e728 438 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
663c1295
JH
439 if (!subdir) {
440 dir = NULL;
f348ac92 441 break;
432ad41e 442 }
3f3aa1bc 443 dir = subdir;
432ad41e
MH
444 }
445
432ad41e
MH
446 return dir;
447}
448
449/*
450 * Find the value entry with the given name in dir, sorting ref_dirs
451 * and recursing into subdirectories as necessary. If the name is not
452 * found or it corresponds to a directory entry, return NULL.
453 */
454static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
455{
456 struct ref_entry *entry;
457 dir = find_containing_dir(dir, refname, 0);
458 if (!dir)
459 return NULL;
40ad937d 460 entry = search_ref_dir(dir, refname, strlen(refname));
432ad41e
MH
461 return (entry && !(entry->flag & REF_DIR)) ? entry : NULL;
462}
463
464/*
465 * Add a ref_entry to the ref_dir (unsorted), recursing into
466 * subdirectories as necessary. dir must represent the top-level
467 * directory. Return 0 on success.
468 */
469static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
470{
471 dir = find_containing_dir(dir, ref->name, 1);
472 if (!dir)
473 return -1;
474 add_entry_to_dir(dir, ref);
475 return 0;
476}
477
202a56a9
MH
478/*
479 * Emit a warning and return true iff ref1 and ref2 have the same name
480 * and the same sha1. Die if they have the same name but different
481 * sha1s.
482 */
483static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
484{
432ad41e 485 if (strcmp(ref1->name, ref2->name))
202a56a9 486 return 0;
432ad41e
MH
487
488 /* Duplicate name; make sure that they don't conflict: */
489
490 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
491 /* This is impossible by construction */
492 die("Reference directory conflict: %s", ref1->name);
493
494 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
495 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
496
497 warning("Duplicated ref: %s", ref1->name);
498 return 1;
202a56a9
MH
499}
500
e6ed3ca6 501/*
432ad41e
MH
502 * Sort the entries in dir non-recursively (if they are not already
503 * sorted) and remove any duplicate entries.
e6ed3ca6 504 */
d3177275 505static void sort_ref_dir(struct ref_dir *dir)
e9c4c111 506{
202a56a9 507 int i, j;
81a79d8e 508 struct ref_entry *last = NULL;
c774aab9 509
e6ed3ca6
MH
510 /*
511 * This check also prevents passing a zero-length array to qsort(),
512 * which is a problem on some platforms.
513 */
d3177275 514 if (dir->sorted == dir->nr)
e9c4c111 515 return;
c774aab9 516
d3177275 517 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
c774aab9 518
81a79d8e
MH
519 /* Remove any duplicates: */
520 for (i = 0, j = 0; j < dir->nr; j++) {
521 struct ref_entry *entry = dir->entries[j];
522 if (last && is_dup_ref(last, entry))
523 free_ref_entry(entry);
524 else
525 last = dir->entries[i++] = entry;
e9c4c111 526 }
81a79d8e 527 dir->sorted = dir->nr = i;
e9c4c111 528}
c774aab9 529
fcce1703
MH
530/* Include broken references in a do_for_each_ref*() iteration: */
531#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
c774aab9 532
662428f4
MH
533/*
534 * Return true iff the reference described by entry can be resolved to
535 * an object in the database. Emit a warning if the referred-to
536 * object does not exist.
537 */
538static int ref_resolves_to_object(struct ref_entry *entry)
539{
540 if (entry->flag & REF_ISBROKEN)
541 return 0;
542 if (!has_sha1_file(entry->u.value.sha1)) {
543 error("%s does not point to a valid object!", entry->name);
544 return 0;
545 }
546 return 1;
547}
548
7d76fdc8
MH
549/*
550 * current_ref is a performance hack: when iterating over references
551 * using the for_each_ref*() functions, current_ref is set to the
552 * current reference's entry before calling the callback function. If
553 * the callback function calls peel_ref(), then peel_ref() first
554 * checks whether the reference to be peeled is the current reference
555 * (it usually is) and if so, returns that reference's peeled version
556 * if it is available. This avoids a refname lookup in a common case.
557 */
bc5fd6d3 558static struct ref_entry *current_ref;
c774aab9 559
fcce1703
MH
560/*
561 * Handle one reference in a do_for_each_ref*()-style iteration.
562 */
bc5fd6d3
MH
563static int do_one_ref(const char *base, each_ref_fn fn, int trim,
564 int flags, void *cb_data, struct ref_entry *entry)
565{
429213e4 566 int retval;
bc5fd6d3
MH
567 if (prefixcmp(entry->name, base))
568 return 0;
c774aab9 569
662428f4
MH
570 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
571 !ref_resolves_to_object(entry))
572 return 0;
573
bc5fd6d3 574 current_ref = entry;
593f1bb8 575 retval = fn(entry->name + trim, entry->u.value.sha1, entry->flag, cb_data);
429213e4
MH
576 current_ref = NULL;
577 return retval;
bc5fd6d3 578}
c774aab9 579
c36b5bc2 580/*
d3177275 581 * Call fn for each reference in dir that has index in the range
432ad41e
MH
582 * offset <= index < dir->nr. Recurse into subdirectories that are in
583 * that index range, sorting them before iterating. This function
584 * does not sort dir itself; it should be sorted beforehand.
c36b5bc2 585 */
d3177275
MH
586static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
587 const char *base,
588 each_ref_fn fn, int trim, int flags, void *cb_data)
c36b5bc2
MH
589{
590 int i;
d3177275
MH
591 assert(dir->sorted == dir->nr);
592 for (i = offset; i < dir->nr; i++) {
432ad41e
MH
593 struct ref_entry *entry = dir->entries[i];
594 int retval;
595 if (entry->flag & REF_DIR) {
d7826d54
MH
596 struct ref_dir *subdir = get_ref_dir(entry);
597 sort_ref_dir(subdir);
598 retval = do_for_each_ref_in_dir(subdir, 0,
432ad41e
MH
599 base, fn, trim, flags, cb_data);
600 } else {
601 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
602 }
c36b5bc2
MH
603 if (retval)
604 return retval;
605 }
606 return 0;
607}
608
b3fd060f 609/*
d3177275 610 * Call fn for each reference in the union of dir1 and dir2, in order
432ad41e
MH
611 * by refname. Recurse into subdirectories. If a value entry appears
612 * in both dir1 and dir2, then only process the version that is in
613 * dir2. The input dirs must already be sorted, but subdirs will be
614 * sorted as needed.
b3fd060f 615 */
d3177275
MH
616static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
617 struct ref_dir *dir2,
618 const char *base, each_ref_fn fn, int trim,
619 int flags, void *cb_data)
b3fd060f
MH
620{
621 int retval;
622 int i1 = 0, i2 = 0;
623
d3177275
MH
624 assert(dir1->sorted == dir1->nr);
625 assert(dir2->sorted == dir2->nr);
432ad41e
MH
626 while (1) {
627 struct ref_entry *e1, *e2;
628 int cmp;
629 if (i1 == dir1->nr) {
630 return do_for_each_ref_in_dir(dir2, i2,
631 base, fn, trim, flags, cb_data);
632 }
633 if (i2 == dir2->nr) {
634 return do_for_each_ref_in_dir(dir1, i1,
635 base, fn, trim, flags, cb_data);
636 }
637 e1 = dir1->entries[i1];
638 e2 = dir2->entries[i2];
639 cmp = strcmp(e1->name, e2->name);
640 if (cmp == 0) {
641 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
642 /* Both are directories; descend them in parallel. */
d7826d54
MH
643 struct ref_dir *subdir1 = get_ref_dir(e1);
644 struct ref_dir *subdir2 = get_ref_dir(e2);
645 sort_ref_dir(subdir1);
646 sort_ref_dir(subdir2);
432ad41e 647 retval = do_for_each_ref_in_dirs(
d7826d54 648 subdir1, subdir2,
432ad41e
MH
649 base, fn, trim, flags, cb_data);
650 i1++;
651 i2++;
652 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
653 /* Both are references; ignore the one from dir1. */
654 retval = do_one_ref(base, fn, trim, flags, cb_data, e2);
655 i1++;
656 i2++;
657 } else {
658 die("conflict between reference and directory: %s",
659 e1->name);
660 }
b3fd060f 661 } else {
432ad41e
MH
662 struct ref_entry *e;
663 if (cmp < 0) {
664 e = e1;
b3fd060f 665 i1++;
432ad41e
MH
666 } else {
667 e = e2;
668 i2++;
669 }
670 if (e->flag & REF_DIR) {
d7826d54
MH
671 struct ref_dir *subdir = get_ref_dir(e);
672 sort_ref_dir(subdir);
432ad41e 673 retval = do_for_each_ref_in_dir(
d7826d54 674 subdir, 0,
432ad41e
MH
675 base, fn, trim, flags, cb_data);
676 } else {
677 retval = do_one_ref(base, fn, trim, flags, cb_data, e);
b3fd060f
MH
678 }
679 }
680 if (retval)
681 return retval;
682 }
b3fd060f
MH
683}
684
d66da478
MH
685/*
686 * Return true iff refname1 and refname2 conflict with each other.
687 * Two reference names conflict if one of them exactly matches the
688 * leading components of the other; e.g., "foo/bar" conflicts with
689 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
690 * "foo/barbados".
691 */
692static int names_conflict(const char *refname1, const char *refname2)
693{
5a4d4947
MH
694 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
695 ;
696 return (*refname1 == '\0' && *refname2 == '/')
697 || (*refname1 == '/' && *refname2 == '\0');
698}
699
700struct name_conflict_cb {
701 const char *refname;
702 const char *oldrefname;
703 const char *conflicting_refname;
704};
705
706static int name_conflict_fn(const char *existingrefname, const unsigned char *sha1,
707 int flags, void *cb_data)
708{
709 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
710 if (data->oldrefname && !strcmp(data->oldrefname, existingrefname))
711 return 0;
712 if (names_conflict(data->refname, existingrefname)) {
713 data->conflicting_refname = existingrefname;
714 return 1;
d66da478 715 }
5a4d4947 716 return 0;
d66da478
MH
717}
718
bc5fd6d3
MH
719/*
720 * Return true iff a reference named refname could be created without
5a4d4947
MH
721 * conflicting with the name of an existing reference in array. If
722 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
723 * (e.g., because oldrefname is scheduled for deletion in the same
bc5fd6d3
MH
724 * operation).
725 */
726static int is_refname_available(const char *refname, const char *oldrefname,
d3177275 727 struct ref_dir *dir)
bc5fd6d3 728{
5a4d4947
MH
729 struct name_conflict_cb data;
730 data.refname = refname;
731 data.oldrefname = oldrefname;
732 data.conflicting_refname = NULL;
733
d3177275
MH
734 sort_ref_dir(dir);
735 if (do_for_each_ref_in_dir(dir, 0, "", name_conflict_fn,
736 0, DO_FOR_EACH_INCLUDE_BROKEN,
737 &data)) {
5a4d4947
MH
738 error("'%s' exists; cannot create '%s'",
739 data.conflicting_refname, refname);
740 return 0;
bc5fd6d3
MH
741 }
742 return 1;
e1e22e37
LT
743}
744
5e290ff7
JH
745/*
746 * Future: need to be in "struct repository"
747 * when doing a full libification.
748 */
79c7ca54
MH
749static struct ref_cache {
750 struct ref_cache *next;
d12229f5
MH
751 struct ref_entry *loose;
752 struct ref_entry *packed;
ce40979c
MH
753 /* The submodule name, or "" for the main repo. */
754 char name[FLEX_ARRAY];
79c7ca54 755} *ref_cache;
0e88c130 756
760c4512 757static void clear_packed_ref_cache(struct ref_cache *refs)
e1e22e37 758{
d12229f5
MH
759 if (refs->packed) {
760 free_ref_entry(refs->packed);
761 refs->packed = NULL;
762 }
5e290ff7 763}
e1e22e37 764
760c4512
MH
765static void clear_loose_ref_cache(struct ref_cache *refs)
766{
d12229f5
MH
767 if (refs->loose) {
768 free_ref_entry(refs->loose);
769 refs->loose = NULL;
770 }
760c4512
MH
771}
772
79c7ca54 773static struct ref_cache *create_ref_cache(const char *submodule)
e5dbf605 774{
ce40979c 775 int len;
79c7ca54 776 struct ref_cache *refs;
ce40979c
MH
777 if (!submodule)
778 submodule = "";
779 len = strlen(submodule) + 1;
79c7ca54 780 refs = xcalloc(1, sizeof(struct ref_cache) + len);
ce40979c 781 memcpy(refs->name, submodule, len);
e5dbf605
MH
782 return refs;
783}
784
4349a668 785/*
79c7ca54 786 * Return a pointer to a ref_cache for the specified submodule. For
4349a668
MH
787 * the main repository, use submodule==NULL. The returned structure
788 * will be allocated and initialized but not necessarily populated; it
789 * should not be freed.
790 */
79c7ca54 791static struct ref_cache *get_ref_cache(const char *submodule)
4349a668 792{
79c7ca54 793 struct ref_cache *refs = ref_cache;
0e88c130
MH
794 if (!submodule)
795 submodule = "";
796 while (refs) {
797 if (!strcmp(submodule, refs->name))
798 return refs;
799 refs = refs->next;
4349a668 800 }
0e88c130 801
79c7ca54
MH
802 refs = create_ref_cache(submodule);
803 refs->next = ref_cache;
804 ref_cache = refs;
0e88c130 805 return refs;
4349a668
MH
806}
807
8be8bde7 808void invalidate_ref_cache(const char *submodule)
f130b116 809{
c5f29abd
MH
810 struct ref_cache *refs = get_ref_cache(submodule);
811 clear_packed_ref_cache(refs);
812 clear_loose_ref_cache(refs);
5e290ff7 813}
e1e22e37 814
3feb4f0c
MH
815/* The length of a peeled reference line in packed-refs, including EOL: */
816#define PEELED_LINE_LENGTH 42
817
bc5fd6d3
MH
818/*
819 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
820 * Return a pointer to the refname within the line (null-terminated),
821 * or NULL if there was a problem.
822 */
823static const char *parse_ref_line(char *line, unsigned char *sha1)
824{
825 /*
826 * 42: the answer to everything.
827 *
828 * In this case, it happens to be the answer to
829 * 40 (length of sha1 hex representation)
830 * +1 (space in between hex and name)
831 * +1 (newline at the end of the line)
832 */
833 int len = strlen(line) - 42;
834
835 if (len <= 0)
836 return NULL;
837 if (get_sha1_hex(line, sha1) < 0)
838 return NULL;
839 if (!isspace(line[40]))
840 return NULL;
841 line += 41;
842 if (isspace(*line))
843 return NULL;
844 if (line[len] != '\n')
845 return NULL;
846 line[len] = 0;
847
848 return line;
849}
850
c29c46fa
MH
851/*
852 * Read f, which is a packed-refs file, into dir.
853 *
854 * A comment line of the form "# pack-refs with: " may contain zero or
855 * more traits. We interpret the traits as follows:
856 *
857 * No traits:
858 *
859 * Probably no references are peeled. But if the file contains a
860 * peeled value for a reference, we will use it.
861 *
862 * peeled:
863 *
864 * References under "refs/tags/", if they *can* be peeled, *are*
865 * peeled in this file. References outside of "refs/tags/" are
866 * probably not peeled even if they could have been, but if we find
867 * a peeled value for such a reference we will use it.
868 *
869 * fully-peeled:
870 *
871 * All references in the file that can be peeled are peeled.
872 * Inversely (and this is more important), any references in the
873 * file for which no peeled value is recorded is not peelable. This
874 * trait should typically be written alongside "peeled" for
875 * compatibility with older clients, but we do not require it
876 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
877 */
d3177275 878static void read_packed_refs(FILE *f, struct ref_dir *dir)
f4204ab9 879{
e9c4c111 880 struct ref_entry *last = NULL;
f4204ab9 881 char refline[PATH_MAX];
c29c46fa 882 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
f4204ab9
JH
883
884 while (fgets(refline, sizeof(refline), f)) {
885 unsigned char sha1[20];
dfefa935 886 const char *refname;
f4204ab9
JH
887 static const char header[] = "# pack-refs with:";
888
889 if (!strncmp(refline, header, sizeof(header)-1)) {
890 const char *traits = refline + sizeof(header) - 1;
c29c46fa
MH
891 if (strstr(traits, " fully-peeled "))
892 peeled = PEELED_FULLY;
893 else if (strstr(traits, " peeled "))
894 peeled = PEELED_TAGS;
f4204ab9
JH
895 /* perhaps other traits later as well */
896 continue;
897 }
898
dfefa935
MH
899 refname = parse_ref_line(refline, sha1);
900 if (refname) {
c29c46fa
MH
901 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
902 if (peeled == PEELED_FULLY ||
903 (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/")))
904 last->flag |= REF_KNOWS_PEELED;
d3177275 905 add_ref(dir, last);
f4204ab9
JH
906 continue;
907 }
908 if (last &&
909 refline[0] == '^' &&
3feb4f0c
MH
910 strlen(refline) == PEELED_LINE_LENGTH &&
911 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
c29c46fa 912 !get_sha1_hex(refline + 1, sha1)) {
593f1bb8 913 hashcpy(last->u.value.peeled, sha1);
c29c46fa
MH
914 /*
915 * Regardless of what the file header said,
916 * we definitely know the value of *this*
917 * reference:
918 */
919 last->flag |= REF_KNOWS_PEELED;
920 }
f4204ab9 921 }
f4204ab9
JH
922}
923
d3177275 924static struct ref_dir *get_packed_refs(struct ref_cache *refs)
5e290ff7 925{
d12229f5 926 if (!refs->packed) {
4349a668
MH
927 const char *packed_refs_file;
928 FILE *f;
0bad611b 929
b9146f51 930 refs->packed = create_dir_entry(refs, "", 0, 0);
316b097a
MH
931 if (*refs->name)
932 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
4349a668
MH
933 else
934 packed_refs_file = git_path("packed-refs");
935 f = fopen(packed_refs_file, "r");
e1e22e37 936 if (f) {
d7826d54 937 read_packed_refs(f, get_ref_dir(refs->packed));
e1e22e37 938 fclose(f);
e1e22e37 939 }
e1e22e37 940 }
d7826d54 941 return get_ref_dir(refs->packed);
e1e22e37
LT
942}
943
30249ee6
MH
944void add_packed_ref(const char *refname, const unsigned char *sha1)
945{
946 add_ref(get_packed_refs(get_ref_cache(NULL)),
947 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
948}
949
abc39098 950/*
28e6a34e
MH
951 * Read the loose references from the namespace dirname into dir
952 * (without recursing). dirname must end with '/'. dir must be the
953 * directory entry corresponding to dirname.
abc39098 954 */
423a1afc 955static void read_loose_refs(const char *dirname, struct ref_dir *dir)
e1e22e37 956{
423a1afc 957 struct ref_cache *refs = dir->ref_cache;
d3177275 958 DIR *d;
0bad611b 959 const char *path;
d5fdae67 960 struct dirent *de;
abc39098 961 int dirnamelen = strlen(dirname);
72b64b44 962 struct strbuf refname;
0bad611b 963
3b124823 964 if (*refs->name)
66a3d20b 965 path = git_path_submodule(refs->name, "%s", dirname);
0bad611b 966 else
66a3d20b 967 path = git_path("%s", dirname);
0bad611b 968
d3177275 969 d = opendir(path);
d5fdae67
MH
970 if (!d)
971 return;
972
66a3d20b
MH
973 strbuf_init(&refname, dirnamelen + 257);
974 strbuf_add(&refname, dirname, dirnamelen);
d5fdae67
MH
975
976 while ((de = readdir(d)) != NULL) {
977 unsigned char sha1[20];
978 struct stat st;
979 int flag;
d5fdae67
MH
980 const char *refdir;
981
982 if (de->d_name[0] == '.')
983 continue;
d5fdae67
MH
984 if (has_extension(de->d_name, ".lock"))
985 continue;
72b64b44 986 strbuf_addstr(&refname, de->d_name);
d5fdae67 987 refdir = *refs->name
72b64b44
MH
988 ? git_path_submodule(refs->name, "%s", refname.buf)
989 : git_path("%s", refname.buf);
990 if (stat(refdir, &st) < 0) {
991 ; /* silently ignore */
992 } else if (S_ISDIR(st.st_mode)) {
abc39098 993 strbuf_addch(&refname, '/');
28e6a34e 994 add_entry_to_dir(dir,
b9146f51
RS
995 create_dir_entry(refs, refname.buf,
996 refname.len, 1));
72b64b44 997 } else {
3b124823 998 if (*refs->name) {
f8948e2f 999 hashclr(sha1);
0bad611b 1000 flag = 0;
72b64b44 1001 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
0bad611b 1002 hashclr(sha1);
98ac34b2 1003 flag |= REF_ISBROKEN;
0bad611b 1004 }
72b64b44 1005 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
09116a1c
JH
1006 hashclr(sha1);
1007 flag |= REF_ISBROKEN;
1008 }
9f2fb4a3
MH
1009 add_entry_to_dir(dir,
1010 create_ref_entry(refname.buf, sha1, flag, 1));
e1e22e37 1011 }
66a3d20b 1012 strbuf_setlen(&refname, dirnamelen);
e1e22e37 1013 }
72b64b44 1014 strbuf_release(&refname);
d5fdae67 1015 closedir(d);
e1e22e37
LT
1016}
1017
d3177275 1018static struct ref_dir *get_loose_refs(struct ref_cache *refs)
e1e22e37 1019{
d12229f5 1020 if (!refs->loose) {
28e6a34e
MH
1021 /*
1022 * Mark the top-level directory complete because we
1023 * are about to read the only subdirectory that can
1024 * hold references:
1025 */
b9146f51 1026 refs->loose = create_dir_entry(refs, "", 0, 0);
28e6a34e
MH
1027 /*
1028 * Create an incomplete entry for "refs/":
1029 */
1030 add_entry_to_dir(get_ref_dir(refs->loose),
b9146f51 1031 create_dir_entry(refs, "refs/", 5, 1));
e1e22e37 1032 }
d7826d54 1033 return get_ref_dir(refs->loose);
e1e22e37
LT
1034}
1035
ca8db142
LT
1036/* We allow "recursive" symbolic refs. Only within reason, though */
1037#define MAXDEPTH 5
0ebde32c
LT
1038#define MAXREFLEN (1024)
1039
e5fa45c1
JH
1040/*
1041 * Called by resolve_gitlink_ref_recursive() after it failed to read
b0626608
MH
1042 * from the loose refs in ref_cache refs. Find <refname> in the
1043 * packed-refs file for the submodule.
e5fa45c1 1044 */
b0626608 1045static int resolve_gitlink_packed_ref(struct ref_cache *refs,
85be1fe3 1046 const char *refname, unsigned char *sha1)
0ebde32c 1047{
2c5c66be 1048 struct ref_entry *ref;
d3177275 1049 struct ref_dir *dir = get_packed_refs(refs);
0ebde32c 1050
432ad41e 1051 ref = find_ref(dir, refname);
b0626608
MH
1052 if (ref == NULL)
1053 return -1;
1054
593f1bb8 1055 memcpy(sha1, ref->u.value.sha1, 20);
b0626608 1056 return 0;
0ebde32c
LT
1057}
1058
b0626608 1059static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
85be1fe3 1060 const char *refname, unsigned char *sha1,
dfefa935 1061 int recursion)
0ebde32c 1062{
064d51dc 1063 int fd, len;
0ebde32c 1064 char buffer[128], *p;
064d51dc 1065 char *path;
0ebde32c 1066
064d51dc 1067 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
0ebde32c 1068 return -1;
064d51dc
MH
1069 path = *refs->name
1070 ? git_path_submodule(refs->name, "%s", refname)
1071 : git_path("%s", refname);
1072 fd = open(path, O_RDONLY);
0ebde32c 1073 if (fd < 0)
b0626608 1074 return resolve_gitlink_packed_ref(refs, refname, sha1);
0ebde32c
LT
1075
1076 len = read(fd, buffer, sizeof(buffer)-1);
1077 close(fd);
1078 if (len < 0)
1079 return -1;
1080 while (len && isspace(buffer[len-1]))
1081 len--;
1082 buffer[len] = 0;
1083
1084 /* Was it a detached head or an old-fashioned symlink? */
85be1fe3 1085 if (!get_sha1_hex(buffer, sha1))
0ebde32c
LT
1086 return 0;
1087
1088 /* Symref? */
1089 if (strncmp(buffer, "ref:", 4))
1090 return -1;
1091 p = buffer + 4;
1092 while (isspace(*p))
1093 p++;
1094
064d51dc 1095 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
0ebde32c
LT
1096}
1097
85be1fe3 1098int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
0ebde32c
LT
1099{
1100 int len = strlen(path), retval;
064d51dc 1101 char *submodule;
b0626608 1102 struct ref_cache *refs;
0ebde32c
LT
1103
1104 while (len && path[len-1] == '/')
1105 len--;
1106 if (!len)
1107 return -1;
b0626608
MH
1108 submodule = xstrndup(path, len);
1109 refs = get_ref_cache(submodule);
1110 free(submodule);
1111
064d51dc 1112 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
0ebde32c
LT
1113 return retval;
1114}
ca8db142 1115
4886b89f 1116/*
63331581
MH
1117 * Return the ref_entry for the given refname from the packed
1118 * references. If it does not exist, return NULL.
4886b89f 1119 */
63331581 1120static struct ref_entry *get_packed_ref(const char *refname)
c224ca7f 1121{
63331581 1122 return find_ref(get_packed_refs(get_ref_cache(NULL)), refname);
c224ca7f
MH
1123}
1124
8d68493f 1125const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
8a65ff76 1126{
0104ca09
HO
1127 int depth = MAXDEPTH;
1128 ssize_t len;
a876ed83 1129 char buffer[256];
dfefa935 1130 static char refname_buffer[256];
ca8db142 1131
8da19775
JH
1132 if (flag)
1133 *flag = 0;
1134
dfefa935 1135 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
8384d788
MH
1136 return NULL;
1137
a876ed83 1138 for (;;) {
55956350 1139 char path[PATH_MAX];
a876ed83
JH
1140 struct stat st;
1141 char *buf;
1142 int fd;
8a65ff76 1143
a876ed83
JH
1144 if (--depth < 0)
1145 return NULL;
ca8db142 1146
dfefa935 1147 git_snpath(path, sizeof(path), "%s", refname);
c224ca7f 1148
a876ed83 1149 if (lstat(path, &st) < 0) {
63331581
MH
1150 struct ref_entry *entry;
1151
c224ca7f
MH
1152 if (errno != ENOENT)
1153 return NULL;
1154 /*
1155 * The loose reference file does not exist;
1156 * check for a packed reference.
1157 */
63331581
MH
1158 entry = get_packed_ref(refname);
1159 if (entry) {
1160 hashcpy(sha1, entry->u.value.sha1);
c224ca7f
MH
1161 if (flag)
1162 *flag |= REF_ISPACKED;
dfefa935 1163 return refname;
434cd0cd 1164 }
c224ca7f
MH
1165 /* The reference is not a packed reference, either. */
1166 if (reading) {
a876ed83 1167 return NULL;
c224ca7f
MH
1168 } else {
1169 hashclr(sha1);
dfefa935 1170 return refname;
c224ca7f 1171 }
a876ed83 1172 }
ca8db142 1173
a876ed83
JH
1174 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1175 if (S_ISLNK(st.st_mode)) {
1176 len = readlink(path, buffer, sizeof(buffer)-1);
7bb2bf8e
MH
1177 if (len < 0)
1178 return NULL;
b54cb795 1179 buffer[len] = 0;
1f58a038
MH
1180 if (!prefixcmp(buffer, "refs/") &&
1181 !check_refname_format(buffer, 0)) {
dfefa935
MH
1182 strcpy(refname_buffer, buffer);
1183 refname = refname_buffer;
8da19775
JH
1184 if (flag)
1185 *flag |= REF_ISSYMREF;
a876ed83
JH
1186 continue;
1187 }
ca8db142 1188 }
a876ed83 1189
7a21632f
DS
1190 /* Is it a directory? */
1191 if (S_ISDIR(st.st_mode)) {
1192 errno = EISDIR;
1193 return NULL;
1194 }
1195
a876ed83
JH
1196 /*
1197 * Anything else, just open it and try to use it as
1198 * a ref
1199 */
1200 fd = open(path, O_RDONLY);
1201 if (fd < 0)
1202 return NULL;
93d26e4c 1203 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83 1204 close(fd);
28775050
MH
1205 if (len < 0)
1206 return NULL;
1207 while (len && isspace(buffer[len-1]))
1208 len--;
1209 buffer[len] = '\0';
a876ed83
JH
1210
1211 /*
1212 * Is it a symbolic ref?
1213 */
28775050 1214 if (prefixcmp(buffer, "ref:"))
a876ed83 1215 break;
55956350
JH
1216 if (flag)
1217 *flag |= REF_ISSYMREF;
a876ed83 1218 buf = buffer + 4;
28775050
MH
1219 while (isspace(*buf))
1220 buf++;
313fb010 1221 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
55956350
JH
1222 if (flag)
1223 *flag |= REF_ISBROKEN;
313fb010
MH
1224 return NULL;
1225 }
dfefa935 1226 refname = strcpy(refname_buffer, buf);
8a65ff76 1227 }
f989fea0
MH
1228 /* Please note that FETCH_HEAD has a second line containing other data. */
1229 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
55956350
JH
1230 if (flag)
1231 *flag |= REF_ISBROKEN;
a876ed83 1232 return NULL;
629cd3ac 1233 }
dfefa935 1234 return refname;
a876ed83
JH
1235}
1236
96ec7b1e
NTND
1237char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1238{
8cad4744 1239 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
96ec7b1e
NTND
1240 return ret ? xstrdup(ret) : NULL;
1241}
1242
d08bae7e
IL
1243/* The argument to filter_refs */
1244struct ref_filter {
1245 const char *pattern;
1246 each_ref_fn *fn;
1247 void *cb_data;
1248};
1249
dfefa935 1250int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
a876ed83 1251{
8d68493f 1252 if (resolve_ref_unsafe(refname, sha1, reading, flags))
a876ed83
JH
1253 return 0;
1254 return -1;
8a65ff76
LT
1255}
1256
dfefa935 1257int read_ref(const char *refname, unsigned char *sha1)
c6893323 1258{
dfefa935 1259 return read_ref_full(refname, sha1, 1, NULL);
c6893323
NTND
1260}
1261
bc5fd6d3 1262int ref_exists(const char *refname)
ef06b918 1263{
bc5fd6d3
MH
1264 unsigned char sha1[20];
1265 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
ef06b918
JH
1266}
1267
85be1fe3 1268static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
dfefa935 1269 void *data)
d08bae7e
IL
1270{
1271 struct ref_filter *filter = (struct ref_filter *)data;
dfefa935 1272 if (fnmatch(filter->pattern, refname, 0))
d08bae7e 1273 return 0;
85be1fe3 1274 return filter->fn(refname, sha1, flags, filter->cb_data);
d08bae7e
IL
1275}
1276
68cf8703
MH
1277enum peel_status {
1278 /* object was peeled successfully: */
1279 PEEL_PEELED = 0,
1280
1281 /*
1282 * object cannot be peeled because the named object (or an
1283 * object referred to by a tag in the peel chain), does not
1284 * exist.
1285 */
1286 PEEL_INVALID = -1,
1287
1288 /* object cannot be peeled because it is not a tag: */
9a489f3c
MH
1289 PEEL_NON_TAG = -2,
1290
1291 /* ref_entry contains no peeled value because it is a symref: */
1292 PEEL_IS_SYMREF = -3,
1293
1294 /*
1295 * ref_entry cannot be peeled because it is broken (i.e., the
1296 * symbolic reference cannot even be resolved to an object
1297 * name):
1298 */
1299 PEEL_BROKEN = -4
68cf8703
MH
1300};
1301
cb2ae1c4
MH
1302/*
1303 * Peel the named object; i.e., if the object is a tag, resolve the
68cf8703
MH
1304 * tag recursively until a non-tag is found. If successful, store the
1305 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1306 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1307 * and leave sha1 unchanged.
cb2ae1c4 1308 */
68cf8703 1309static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
cb2ae1c4
MH
1310{
1311 struct object *o = lookup_unknown_object(name);
1312
1313 if (o->type == OBJ_NONE) {
1314 int type = sha1_object_info(name, NULL);
1315 if (type < 0)
68cf8703 1316 return PEEL_INVALID;
cb2ae1c4
MH
1317 o->type = type;
1318 }
1319
1320 if (o->type != OBJ_TAG)
68cf8703 1321 return PEEL_NON_TAG;
cb2ae1c4
MH
1322
1323 o = deref_tag_noverify(o);
1324 if (!o)
68cf8703 1325 return PEEL_INVALID;
cb2ae1c4
MH
1326
1327 hashcpy(sha1, o->sha1);
68cf8703 1328 return PEEL_PEELED;
cb2ae1c4
MH
1329}
1330
9a489f3c
MH
1331/*
1332 * Peel the entry (if possible) and return its new peel_status.
1333 */
1334static enum peel_status peel_entry(struct ref_entry *entry)
1335{
1336 enum peel_status status;
1337
1338 if (entry->flag & REF_KNOWS_PEELED)
1339 return is_null_sha1(entry->u.value.peeled) ?
1340 PEEL_NON_TAG : PEEL_PEELED;
1341 if (entry->flag & REF_ISBROKEN)
1342 return PEEL_BROKEN;
1343 if (entry->flag & REF_ISSYMREF)
1344 return PEEL_IS_SYMREF;
1345
1346 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1347 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1348 entry->flag |= REF_KNOWS_PEELED;
1349 return status;
1350}
1351
dfefa935 1352int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1353{
1354 int flag;
1355 unsigned char base[20];
cf0adba7 1356
dfefa935 1357 if (current_ref && (current_ref->name == refname
9a489f3c
MH
1358 || !strcmp(current_ref->name, refname))) {
1359 if (peel_entry(current_ref))
1360 return -1;
1361 hashcpy(sha1, current_ref->u.value.peeled);
1362 return 0;
0ae91be0
SP
1363 }
1364
dfefa935 1365 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1366 return -1;
1367
9a489f3c
MH
1368 /*
1369 * If the reference is packed, read its ref_entry from the
1370 * cache in the hope that we already know its peeled value.
1371 * We only try this optimization on packed references because
1372 * (a) forcing the filling of the loose reference cache could
1373 * be expensive and (b) loose references anyway usually do not
1374 * have REF_KNOWS_PEELED.
1375 */
1376 if (flag & REF_ISPACKED) {
f361baeb 1377 struct ref_entry *r = get_packed_ref(refname);
9a489f3c
MH
1378 if (r) {
1379 if (peel_entry(r))
1380 return -1;
593f1bb8 1381 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1382 return 0;
cf0adba7 1383 }
cf0adba7
JH
1384 }
1385
cb2ae1c4 1386 return peel_object(base, sha1);
cf0adba7
JH
1387}
1388
bc5fd6d3
MH
1389struct warn_if_dangling_data {
1390 FILE *fp;
1391 const char *refname;
1392 const char *msg_fmt;
1393};
1394
1395static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1396 int flags, void *cb_data)
1397{
1398 struct warn_if_dangling_data *d = cb_data;
1399 const char *resolves_to;
1400 unsigned char junk[20];
1401
1402 if (!(flags & REF_ISSYMREF))
1403 return 0;
1404
1405 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1406 if (!resolves_to || strcmp(resolves_to, d->refname))
1407 return 0;
1408
1409 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1410 fputc('\n', d->fp);
bc5fd6d3
MH
1411 return 0;
1412}
1413
1414void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1415{
1416 struct warn_if_dangling_data data;
1417
1418 data.fp = fp;
1419 data.refname = refname;
1420 data.msg_fmt = msg_fmt;
1421 for_each_rawref(warn_if_dangling_symref, &data);
1422}
1423
fcce1703
MH
1424/*
1425 * Call fn for each reference in the specified submodule for which the
1426 * refname begins with base. If trim is non-zero, then trim that many
1427 * characters off the beginning of each refname before passing the
1428 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1429 * broken references in the iteration. If fn ever returns a non-zero
1430 * value, stop the iteration and return that value; otherwise, return
1431 * 0.
1432 */
0bad611b
HV
1433static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
1434 int trim, int flags, void *cb_data)
8a65ff76 1435{
316b097a 1436 struct ref_cache *refs = get_ref_cache(submodule);
933ac036
MH
1437 struct ref_dir *packed_dir = get_packed_refs(refs);
1438 struct ref_dir *loose_dir = get_loose_refs(refs);
1439 int retval = 0;
1440
1441 if (base && *base) {
1442 packed_dir = find_containing_dir(packed_dir, base, 0);
1443 loose_dir = find_containing_dir(loose_dir, base, 0);
1444 }
1445
1446 if (packed_dir && loose_dir) {
1447 sort_ref_dir(packed_dir);
1448 sort_ref_dir(loose_dir);
1449 retval = do_for_each_ref_in_dirs(
1450 packed_dir, loose_dir,
1451 base, fn, trim, flags, cb_data);
1452 } else if (packed_dir) {
1453 sort_ref_dir(packed_dir);
1454 retval = do_for_each_ref_in_dir(
1455 packed_dir, 0,
1456 base, fn, trim, flags, cb_data);
1457 } else if (loose_dir) {
1458 sort_ref_dir(loose_dir);
1459 retval = do_for_each_ref_in_dir(
1460 loose_dir, 0,
1461 base, fn, trim, flags, cb_data);
1462 }
1463
1464 return retval;
8a65ff76
LT
1465}
1466
0bad611b 1467static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1468{
1469 unsigned char sha1[20];
8da19775
JH
1470 int flag;
1471
0bad611b
HV
1472 if (submodule) {
1473 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1474 return fn("HEAD", sha1, 0, cb_data);
1475
1476 return 0;
1477 }
1478
c6893323 1479 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1480 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1481
2f34ba32 1482 return 0;
723c31fe
LT
1483}
1484
0bad611b
HV
1485int head_ref(each_ref_fn fn, void *cb_data)
1486{
1487 return do_head_ref(NULL, fn, cb_data);
1488}
1489
9ef6aeb0
HV
1490int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1491{
1492 return do_head_ref(submodule, fn, cb_data);
1493}
1494
cb5d709f 1495int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1496{
b3cfc406 1497 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
a62be77f
SE
1498}
1499
9ef6aeb0
HV
1500int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1501{
b3cfc406 1502 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
a62be77f
SE
1503}
1504
2a8177b6
CC
1505int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1506{
0bad611b 1507 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1508}
1509
9ef6aeb0
HV
1510int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1511 each_ref_fn fn, void *cb_data)
1512{
1513 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1514}
1515
cb5d709f 1516int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1517{
2a8177b6 1518 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1519}
1520
9ef6aeb0
HV
1521int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1522{
1523 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1524}
1525
cb5d709f 1526int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1527{
2a8177b6 1528 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1529}
1530
9ef6aeb0
HV
1531int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1532{
1533 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1534}
1535
cb5d709f 1536int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1537{
2a8177b6 1538 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1539}
1540
9ef6aeb0
HV
1541int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1542{
1543 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1544}
1545
29268700
CC
1546int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1547{
0bad611b 1548 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1549}
1550
a1bea2c1
JT
1551int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1552{
1553 struct strbuf buf = STRBUF_INIT;
1554 int ret = 0;
1555 unsigned char sha1[20];
1556 int flag;
1557
1558 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1559 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1560 ret = fn(buf.buf, sha1, flag, cb_data);
1561 strbuf_release(&buf);
1562
1563 return ret;
1564}
1565
1566int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1567{
1568 struct strbuf buf = STRBUF_INIT;
1569 int ret;
1570 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1571 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
1572 strbuf_release(&buf);
1573 return ret;
1574}
1575
b09fe971
IL
1576int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1577 const char *prefix, void *cb_data)
d08bae7e
IL
1578{
1579 struct strbuf real_pattern = STRBUF_INIT;
1580 struct ref_filter filter;
d08bae7e
IL
1581 int ret;
1582
b09fe971 1583 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 1584 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1585 else if (prefix)
1586 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1587 strbuf_addstr(&real_pattern, pattern);
1588
894a9d33 1589 if (!has_glob_specials(pattern)) {
9517e6b8 1590 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1591 if (real_pattern.buf[real_pattern.len - 1] != '/')
1592 strbuf_addch(&real_pattern, '/');
1593 /* No need to check for '*', there is none. */
1594 strbuf_addch(&real_pattern, '*');
1595 }
1596
1597 filter.pattern = real_pattern.buf;
1598 filter.fn = fn;
1599 filter.cb_data = cb_data;
1600 ret = for_each_ref(filter_refs, &filter);
1601
1602 strbuf_release(&real_pattern);
1603 return ret;
1604}
1605
b09fe971
IL
1606int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1607{
1608 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1609}
1610
f8948e2f
JH
1611int for_each_rawref(each_ref_fn fn, void *cb_data)
1612{
b3cfc406 1613 return do_for_each_ref(NULL, "", fn, 0,
f8948e2f 1614 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1615}
1616
4577e483 1617const char *prettify_refname(const char *name)
a9c37a72 1618{
a9c37a72
DB
1619 return name + (
1620 !prefixcmp(name, "refs/heads/") ? 11 :
1621 !prefixcmp(name, "refs/tags/") ? 10 :
1622 !prefixcmp(name, "refs/remotes/") ? 13 :
1623 0);
1624}
1625
79803322
SP
1626const char *ref_rev_parse_rules[] = {
1627 "%.*s",
1628 "refs/%.*s",
1629 "refs/tags/%.*s",
1630 "refs/heads/%.*s",
1631 "refs/remotes/%.*s",
1632 "refs/remotes/%.*s/HEAD",
1633 NULL
1634};
1635
1636int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1637{
1638 const char **p;
1639 const int abbrev_name_len = strlen(abbrev_name);
1640
1641 for (p = rules; *p; p++) {
1642 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1643 return 1;
1644 }
1645 }
1646
1647 return 0;
1648}
1649
e5f38ec3 1650static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1651 const unsigned char *old_sha1, int mustexist)
1652{
c6893323 1653 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 1654 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
1655 unlock_ref(lock);
1656 return NULL;
1657 }
a89fccd2 1658 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1659 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1660 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1661 unlock_ref(lock);
1662 return NULL;
1663 }
1664 return lock;
1665}
1666
7155b727 1667static int remove_empty_directories(const char *file)
bc7127ef
JH
1668{
1669 /* we want to create a file but there is a directory there;
1670 * if that is an empty directory (or a directory that contains
1671 * only empty directories), remove them.
1672 */
7155b727
JS
1673 struct strbuf path;
1674 int result;
bc7127ef 1675
7155b727
JS
1676 strbuf_init(&path, 20);
1677 strbuf_addstr(&path, file);
1678
a0f4afbe 1679 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1680
1681 strbuf_release(&path);
1682
1683 return result;
bc7127ef
JH
1684}
1685
ff74f7f1
JH
1686/*
1687 * *string and *len will only be substituted, and *string returned (for
1688 * later free()ing) if the string passed in is a magic short-hand form
1689 * to name a branch.
1690 */
1691static char *substitute_branch_name(const char **string, int *len)
1692{
1693 struct strbuf buf = STRBUF_INIT;
1694 int ret = interpret_branch_name(*string, &buf);
1695
1696 if (ret == *len) {
1697 size_t size;
1698 *string = strbuf_detach(&buf, &size);
1699 *len = size;
1700 return (char *)*string;
1701 }
1702
1703 return NULL;
1704}
1705
1706int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1707{
1708 char *last_branch = substitute_branch_name(&str, &len);
1709 const char **p, *r;
1710 int refs_found = 0;
1711
1712 *ref = NULL;
1713 for (p = ref_rev_parse_rules; *p; p++) {
1714 char fullref[PATH_MAX];
1715 unsigned char sha1_from_ref[20];
1716 unsigned char *this_result;
1717 int flag;
1718
1719 this_result = refs_found ? sha1_from_ref : sha1;
1720 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 1721 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
1722 if (r) {
1723 if (!refs_found++)
1724 *ref = xstrdup(r);
1725 if (!warn_ambiguous_refs)
1726 break;
55956350 1727 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 1728 warning("ignoring dangling symref %s.", fullref);
55956350
JH
1729 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1730 warning("ignoring broken ref %s.", fullref);
1731 }
ff74f7f1
JH
1732 }
1733 free(last_branch);
1734 return refs_found;
1735}
1736
1737int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1738{
1739 char *last_branch = substitute_branch_name(&str, &len);
1740 const char **p;
1741 int logs_found = 0;
1742
1743 *log = NULL;
1744 for (p = ref_rev_parse_rules; *p; p++) {
1745 struct stat st;
1746 unsigned char hash[20];
1747 char path[PATH_MAX];
1748 const char *ref, *it;
1749
1750 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 1751 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
1752 if (!ref)
1753 continue;
1754 if (!stat(git_path("logs/%s", path), &st) &&
1755 S_ISREG(st.st_mode))
1756 it = path;
1757 else if (strcmp(ref, path) &&
1758 !stat(git_path("logs/%s", ref), &st) &&
1759 S_ISREG(st.st_mode))
1760 it = ref;
1761 else
1762 continue;
1763 if (!logs_found++) {
1764 *log = xstrdup(it);
1765 hashcpy(sha1, hash);
1766 }
1767 if (!warn_ambiguous_refs)
1768 break;
1769 }
1770 free(last_branch);
1771 return logs_found;
1772}
1773
dfefa935
MH
1774static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1775 const unsigned char *old_sha1,
1776 int flags, int *type_p)
4bd18c43 1777{
434cd0cd 1778 char *ref_file;
dfefa935 1779 const char *orig_refname = refname;
4bd18c43 1780 struct ref_lock *lock;
5cc3cef9 1781 int last_errno = 0;
acd3b9ec 1782 int type, lflags;
4431fcc4 1783 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1784 int missing = 0;
4bd18c43
SP
1785
1786 lock = xcalloc(1, sizeof(struct ref_lock));
1787 lock->lock_fd = -1;
1788
8d68493f 1789 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 1790 if (!refname && errno == EISDIR) {
bc7127ef
JH
1791 /* we are trying to lock foo but we used to
1792 * have foo/bar which now does not exist;
1793 * it is normal for the empty directory 'foo'
1794 * to remain.
1795 */
dfefa935 1796 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
1797 if (remove_empty_directories(ref_file)) {
1798 last_errno = errno;
dfefa935 1799 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
1800 goto error_return;
1801 }
8d68493f 1802 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 1803 }
68db31cc
SV
1804 if (type_p)
1805 *type_p = type;
dfefa935 1806 if (!refname) {
5cc3cef9 1807 last_errno = errno;
818f477c 1808 error("unable to resolve reference %s: %s",
dfefa935 1809 orig_refname, strerror(errno));
5cc3cef9 1810 goto error_return;
4bd18c43 1811 }
5bdd8d4a 1812 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1813 /* When the ref did not exist and we are creating it,
1814 * make sure there is no existing ref that is packed
1815 * whose name begins with our refname, nor a ref whose
1816 * name is a proper prefix of our refname.
1817 */
5bdd8d4a 1818 if (missing &&
316b097a 1819 !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
f475e08e 1820 last_errno = ENOTDIR;
c976d415 1821 goto error_return;
f475e08e 1822 }
22a3844e 1823
c33d5174 1824 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1825
acd3b9ec
JH
1826 lflags = LOCK_DIE_ON_ERROR;
1827 if (flags & REF_NODEREF) {
dfefa935 1828 refname = orig_refname;
acd3b9ec
JH
1829 lflags |= LOCK_NODEREF;
1830 }
dfefa935
MH
1831 lock->ref_name = xstrdup(refname);
1832 lock->orig_ref_name = xstrdup(orig_refname);
1833 ref_file = git_path("%s", refname);
5bdd8d4a 1834 if (missing)
68db31cc
SV
1835 lock->force_write = 1;
1836 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1837 lock->force_write = 1;
4bd18c43 1838
5cc3cef9
JH
1839 if (safe_create_leading_directories(ref_file)) {
1840 last_errno = errno;
1841 error("unable to create directory for %s", ref_file);
1842 goto error_return;
1843 }
4bd18c43 1844
acd3b9ec 1845 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1846 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1847
1848 error_return:
1849 unlock_ref(lock);
1850 errno = last_errno;
1851 return NULL;
4bd18c43
SP
1852}
1853
dfefa935 1854struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 1855{
53cce84c 1856 char refpath[PATH_MAX];
dfefa935 1857 if (check_refname_format(refname, 0))
4bd18c43 1858 return NULL;
dfefa935 1859 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 1860 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1861}
1862
dfefa935
MH
1863struct ref_lock *lock_any_ref_for_update(const char *refname,
1864 const unsigned char *old_sha1, int flags)
4bd18c43 1865{
dfefa935 1866 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 1867 return NULL;
dfefa935 1868 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
c0277d15
JH
1869}
1870
d66da478
MH
1871struct repack_without_ref_sb {
1872 const char *refname;
1873 int fd;
1874};
1875
1876static int repack_without_ref_fn(const char *refname, const unsigned char *sha1,
1877 int flags, void *cb_data)
1878{
1879 struct repack_without_ref_sb *data = cb_data;
1880 char line[PATH_MAX + 100];
1881 int len;
1882
1883 if (!strcmp(data->refname, refname))
1884 return 0;
1885 len = snprintf(line, sizeof(line), "%s %s\n",
1886 sha1_to_hex(sha1), refname);
1887 /* this should not happen but just being defensive */
1888 if (len > sizeof(line))
1889 die("too long a refname '%s'", refname);
1890 write_or_die(data->fd, line, len);
1891 return 0;
1892}
1893
26a063a1
JH
1894static struct lock_file packlock;
1895
c0277d15
JH
1896static int repack_without_ref(const char *refname)
1897{
d66da478 1898 struct repack_without_ref_sb data;
b3f1280e 1899 struct ref_cache *refs = get_ref_cache(NULL);
7618fd80
MH
1900 struct ref_dir *packed;
1901
1902 if (!get_packed_ref(refname))
1903 return 0; /* refname does not exist in packed refs */
1904
d66da478
MH
1905 data.refname = refname;
1906 data.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1907 if (data.fd < 0) {
1b018fd9 1908 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 1909 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 1910 }
b3f1280e
JK
1911 clear_packed_ref_cache(refs);
1912 packed = get_packed_refs(refs);
d3177275 1913 do_for_each_ref_in_dir(packed, 0, "", repack_without_ref_fn, 0, 0, &data);
c0277d15
JH
1914 return commit_lock_file(&packlock);
1915}
1916
eca35a25 1917int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
1918{
1919 struct ref_lock *lock;
eca35a25 1920 int err, i = 0, ret = 0, flag = 0;
c0277d15 1921
547d058f 1922 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
1923 if (!lock)
1924 return 1;
045a476f 1925 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 1926 /* loose */
547d058f
RS
1927 i = strlen(lock->lk->filename) - 5; /* .lock */
1928 lock->lk->filename[i] = 0;
1929 err = unlink_or_warn(lock->lk->filename);
691f1a28 1930 if (err && errno != ENOENT)
c0277d15 1931 ret = 1;
691f1a28 1932
547d058f 1933 lock->lk->filename[i] = '.';
c0277d15
JH
1934 }
1935 /* removing the loose one could have resurrected an earlier
1936 * packed one. Also, if it was not loose we need to repack
1937 * without it.
1938 */
b274a714 1939 ret |= repack_without_ref(lock->ref_name);
c0277d15 1940
691f1a28 1941 unlink_or_warn(git_path("logs/%s", lock->ref_name));
3870a0d1 1942 invalidate_ref_cache(NULL);
c0277d15
JH
1943 unlock_ref(lock);
1944 return ret;
4bd18c43
SP
1945}
1946
765c2258
PH
1947/*
1948 * People using contrib's git-new-workdir have .git/logs/refs ->
1949 * /some/other/path/.git/logs/refs, and that may live on another device.
1950 *
1951 * IOW, to avoid cross device rename errors, the temporary renamed log must
1952 * live into logs/refs.
1953 */
1954#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1955
dfefa935 1956int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 1957{
c976d415
LH
1958 unsigned char sha1[20], orig_sha1[20];
1959 int flag = 0, logmoved = 0;
1960 struct ref_lock *lock;
c976d415 1961 struct stat loginfo;
dfefa935 1962 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 1963 const char *symref = NULL;
316b097a 1964 struct ref_cache *refs = get_ref_cache(NULL);
c976d415 1965
450d4c0f 1966 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 1967 return error("reflog for %s is a symlink", oldrefname);
c976d415 1968
8d68493f 1969 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 1970 if (flag & REF_ISSYMREF)
fa58186c 1971 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 1972 oldrefname);
eca35a25 1973 if (!symref)
dfefa935 1974 return error("refname %s not found", oldrefname);
c976d415 1975
316b097a 1976 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
c976d415
LH
1977 return 1;
1978
316b097a 1979 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
c976d415
LH
1980 return 1;
1981
dfefa935 1982 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 1983 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 1984 oldrefname, strerror(errno));
c976d415 1985
dfefa935
MH
1986 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
1987 error("unable to delete old %s", oldrefname);
c976d415
LH
1988 goto rollback;
1989 }
1990
dfefa935
MH
1991 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
1992 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 1993 if (errno==EISDIR) {
dfefa935
MH
1994 if (remove_empty_directories(git_path("%s", newrefname))) {
1995 error("Directory not empty: %s", newrefname);
c976d415
LH
1996 goto rollback;
1997 }
1998 } else {
dfefa935 1999 error("unable to delete existing %s", newrefname);
c976d415
LH
2000 goto rollback;
2001 }
2002 }
2003
dfefa935
MH
2004 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2005 error("unable to create directory for %s", newrefname);
c976d415
LH
2006 goto rollback;
2007 }
2008
2009 retry:
dfefa935 2010 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
d9e74d57
JR
2011 if (errno==EISDIR || errno==ENOTDIR) {
2012 /*
2013 * rename(a, b) when b is an existing
2014 * directory ought to result in ISDIR, but
2015 * Solaris 5.8 gives ENOTDIR. Sheesh.
2016 */
dfefa935
MH
2017 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2018 error("Directory not empty: logs/%s", newrefname);
c976d415
LH
2019 goto rollback;
2020 }
2021 goto retry;
2022 } else {
765c2258 2023 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
dfefa935 2024 newrefname, strerror(errno));
c976d415
LH
2025 goto rollback;
2026 }
2027 }
2028 logmoved = log;
2029
dfefa935 2030 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 2031 if (!lock) {
dfefa935 2032 error("unable to lock %s for update", newrefname);
c976d415
LH
2033 goto rollback;
2034 }
c976d415
LH
2035 lock->force_write = 1;
2036 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 2037 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 2038 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
2039 goto rollback;
2040 }
2041
2042 return 0;
2043
2044 rollback:
dfefa935 2045 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 2046 if (!lock) {
dfefa935 2047 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
2048 goto rollbacklog;
2049 }
2050
2051 lock->force_write = 1;
2052 flag = log_all_ref_updates;
2053 log_all_ref_updates = 0;
2054 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2055 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2056 log_all_ref_updates = flag;
2057
2058 rollbacklog:
dfefa935 2059 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2060 error("unable to restore logfile %s from %s: %s",
dfefa935 2061 oldrefname, newrefname, strerror(errno));
c976d415 2062 if (!logmoved && log &&
dfefa935 2063 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2064 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2065 oldrefname, strerror(errno));
c976d415
LH
2066
2067 return 1;
2068}
2069
435fc852 2070int close_ref(struct ref_lock *lock)
b531394d
BC
2071{
2072 if (close_lock_file(lock->lk))
2073 return -1;
2074 lock->lock_fd = -1;
2075 return 0;
2076}
2077
435fc852 2078int commit_ref(struct ref_lock *lock)
b531394d
BC
2079{
2080 if (commit_lock_file(lock->lk))
2081 return -1;
2082 lock->lock_fd = -1;
2083 return 0;
2084}
2085
e5f38ec3 2086void unlock_ref(struct ref_lock *lock)
4bd18c43 2087{
4ed7cd3a
BC
2088 /* Do not free lock->lk -- atexit() still looks at them */
2089 if (lock->lk)
2090 rollback_lock_file(lock->lk);
434cd0cd 2091 free(lock->ref_name);
1655707c 2092 free(lock->orig_ref_name);
4bd18c43
SP
2093 free(lock);
2094}
2095
0ec29a47
JH
2096/*
2097 * copy the reflog message msg to buf, which has been allocated sufficiently
2098 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2099 * because reflog file is one line per entry.
2100 */
2101static int copy_msg(char *buf, const char *msg)
2102{
2103 char *cp = buf;
2104 char c;
2105 int wasspace = 1;
2106
2107 *cp++ = '\t';
2108 while ((c = *msg++)) {
2109 if (wasspace && isspace(c))
2110 continue;
2111 wasspace = isspace(c);
2112 if (wasspace)
2113 c = ' ';
2114 *cp++ = c;
2115 }
2116 while (buf < cp && isspace(cp[-1]))
2117 cp--;
2118 *cp++ = '\n';
2119 return cp - buf;
2120}
2121
dfefa935 2122int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2123{
859c3017 2124 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2125
dfefa935 2126 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2127 if (log_all_ref_updates &&
dfefa935
MH
2128 (!prefixcmp(refname, "refs/heads/") ||
2129 !prefixcmp(refname, "refs/remotes/") ||
2130 !prefixcmp(refname, "refs/notes/") ||
2131 !strcmp(refname, "HEAD"))) {
157aaea5 2132 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 2133 return error("unable to create directory for %s",
157aaea5 2134 logfile);
6de08ae6
SP
2135 oflags |= O_CREAT;
2136 }
2137
157aaea5 2138 logfd = open(logfile, oflags, 0666);
6de08ae6 2139 if (logfd < 0) {
1974bf62 2140 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2141 return 0;
3b463c3f
JH
2142
2143 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2144 if (remove_empty_directories(logfile)) {
3b463c3f 2145 return error("There are still logs under '%s'",
157aaea5 2146 logfile);
3b463c3f 2147 }
157aaea5 2148 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2149 }
2150
2151 if (logfd < 0)
2152 return error("Unable to append to %s: %s",
157aaea5 2153 logfile, strerror(errno));
6de08ae6
SP
2154 }
2155
157aaea5 2156 adjust_shared_perm(logfile);
859c3017
EM
2157 close(logfd);
2158 return 0;
2159}
443b92b6 2160
dfefa935 2161static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2162 const unsigned char *new_sha1, const char *msg)
2163{
2164 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2165 unsigned maxlen, len;
2166 int msglen;
157aaea5 2167 char log_file[PATH_MAX];
859c3017
EM
2168 char *logrec;
2169 const char *committer;
2170
2171 if (log_all_ref_updates < 0)
2172 log_all_ref_updates = !is_bare_repository();
2173
dfefa935 2174 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2175 if (result)
2176 return result;
2177
2178 logfd = open(log_file, oflags);
2179 if (logfd < 0)
2180 return 0;
0ec29a47 2181 msglen = msg ? strlen(msg) : 0;
774751a8 2182 committer = git_committer_info(0);
8ac65937
JH
2183 maxlen = strlen(committer) + msglen + 100;
2184 logrec = xmalloc(maxlen);
2185 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2186 sha1_to_hex(old_sha1),
2187 sha1_to_hex(new_sha1),
8ac65937
JH
2188 committer);
2189 if (msglen)
0ec29a47 2190 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2191 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2192 free(logrec);
91c8d590 2193 if (close(logfd) != 0 || written != len)
9a13f0b7 2194 return error("Unable to append to %s", log_file);
6de08ae6
SP
2195 return 0;
2196}
2197
c3b0dec5
LT
2198static int is_branch(const char *refname)
2199{
2200 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2201}
2202
4bd18c43
SP
2203int write_ref_sha1(struct ref_lock *lock,
2204 const unsigned char *sha1, const char *logmsg)
2205{
2206 static char term = '\n';
c3b0dec5 2207 struct object *o;
4bd18c43
SP
2208
2209 if (!lock)
95fc7512 2210 return -1;
a89fccd2 2211 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2212 unlock_ref(lock);
2213 return 0;
95fc7512 2214 }
c3b0dec5
LT
2215 o = parse_object(sha1);
2216 if (!o) {
7be8b3ba 2217 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2218 lock->ref_name, sha1_to_hex(sha1));
2219 unlock_ref(lock);
2220 return -1;
2221 }
2222 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2223 error("Trying to write non-commit object %s to branch %s",
2224 sha1_to_hex(sha1), lock->ref_name);
2225 unlock_ref(lock);
2226 return -1;
2227 }
93822c22
AW
2228 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2229 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 2230 || close_ref(lock) < 0) {
c33d5174 2231 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
2232 unlock_ref(lock);
2233 return -1;
2234 }
8bf90dc9 2235 clear_loose_ref_cache(get_ref_cache(NULL));
bd104db1
NP
2236 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2237 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2238 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2239 unlock_ref(lock);
2240 return -1;
2241 }
605fac8b
NP
2242 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2243 /*
2244 * Special hack: If a branch is updated directly and HEAD
2245 * points to it (may happen on the remote side of a push
2246 * for example) then logically the HEAD reflog should be
2247 * updated too.
2248 * A generic solution implies reverse symref information,
2249 * but finding all symrefs pointing to the given branch
2250 * would be rather costly for this rare event (the direct
2251 * update of a branch) to be worth it. So let's cheat and
2252 * check with HEAD only which should cover 99% of all usage
2253 * scenarios (even 100% of the default ones).
2254 */
2255 unsigned char head_sha1[20];
2256 int head_flag;
2257 const char *head_ref;
8cad4744 2258 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2259 if (head_ref && (head_flag & REF_ISSYMREF) &&
2260 !strcmp(head_ref, lock->ref_name))
2261 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2262 }
b531394d 2263 if (commit_ref(lock)) {
434cd0cd 2264 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2265 unlock_ref(lock);
2266 return -1;
2267 }
4bd18c43
SP
2268 unlock_ref(lock);
2269 return 0;
95fc7512 2270}
d556fae2 2271
8b5157e4
NP
2272int create_symref(const char *ref_target, const char *refs_heads_master,
2273 const char *logmsg)
41b625b0
NP
2274{
2275 const char *lockpath;
2276 char ref[1000];
2277 int fd, len, written;
a4f34cbb 2278 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2279 unsigned char old_sha1[20], new_sha1[20];
2280
2281 if (logmsg && read_ref(ref_target, old_sha1))
2282 hashclr(old_sha1);
41b625b0 2283
d48744d1
JH
2284 if (safe_create_leading_directories(git_HEAD) < 0)
2285 return error("unable to create directory for %s", git_HEAD);
2286
41b625b0
NP
2287#ifndef NO_SYMLINK_HEAD
2288 if (prefer_symlink_refs) {
2289 unlink(git_HEAD);
2290 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2291 goto done;
41b625b0
NP
2292 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2293 }
2294#endif
2295
2296 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2297 if (sizeof(ref) <= len) {
2298 error("refname too long: %s", refs_heads_master);
47fc52e2 2299 goto error_free_return;
41b625b0
NP
2300 }
2301 lockpath = mkpath("%s.lock", git_HEAD);
2302 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2303 if (fd < 0) {
2304 error("Unable to open %s for writing", lockpath);
47fc52e2 2305 goto error_free_return;
41b625b0
NP
2306 }
2307 written = write_in_full(fd, ref, len);
91c8d590 2308 if (close(fd) != 0 || written != len) {
41b625b0 2309 error("Unable to write to %s", lockpath);
47fc52e2 2310 goto error_unlink_return;
41b625b0
NP
2311 }
2312 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 2313 error("Unable to create %s", git_HEAD);
47fc52e2 2314 goto error_unlink_return;
41b625b0
NP
2315 }
2316 if (adjust_shared_perm(git_HEAD)) {
41b625b0 2317 error("Unable to fix permissions on %s", lockpath);
47fc52e2 2318 error_unlink_return:
691f1a28 2319 unlink_or_warn(lockpath);
47fc52e2
JH
2320 error_free_return:
2321 free(git_HEAD);
2322 return -1;
41b625b0 2323 }
8b5157e4 2324
ee96d11b 2325#ifndef NO_SYMLINK_HEAD
8b5157e4 2326 done:
ee96d11b 2327#endif
8b5157e4
NP
2328 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2329 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2330
47fc52e2 2331 free(git_HEAD);
41b625b0
NP
2332 return 0;
2333}
2334
16d7cc90
JH
2335static char *ref_msg(const char *line, const char *endp)
2336{
2337 const char *ep;
16d7cc90 2338 line += 82;
182af834
PH
2339 ep = memchr(line, '\n', endp - line);
2340 if (!ep)
2341 ep = endp;
2342 return xmemdupz(line, ep - line);
16d7cc90
JH
2343}
2344
dfefa935
MH
2345int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2346 unsigned char *sha1, char **msg,
2347 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 2348{
e5229042 2349 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 2350 char *tz_c;
e29cb53a 2351 int logfd, tz, reccnt = 0;
d556fae2
SP
2352 struct stat st;
2353 unsigned long date;
e5229042 2354 unsigned char logged_sha1[20];
cb48cb58 2355 void *log_mapped;
dc49cd76 2356 size_t mapsz;
d556fae2 2357
dfefa935 2358 logfile = git_path("logs/%s", refname);
d556fae2
SP
2359 logfd = open(logfile, O_RDONLY, 0);
2360 if (logfd < 0)
d824cbba 2361 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
2362 fstat(logfd, &st);
2363 if (!st.st_size)
2364 die("Log %s is empty.", logfile);
dc49cd76
SP
2365 mapsz = xsize_t(st.st_size);
2366 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 2367 logdata = log_mapped;
d556fae2
SP
2368 close(logfd);
2369
e5229042 2370 lastrec = NULL;
d556fae2
SP
2371 rec = logend = logdata + st.st_size;
2372 while (logdata < rec) {
e29cb53a 2373 reccnt++;
d556fae2
SP
2374 if (logdata < rec && *(rec-1) == '\n')
2375 rec--;
e5229042
SP
2376 lastgt = NULL;
2377 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 2378 rec--;
e5229042
SP
2379 if (*rec == '>')
2380 lastgt = rec;
2381 }
2382 if (!lastgt)
d556fae2 2383 die("Log %s is corrupt.", logfile);
e5229042 2384 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 2385 if (date <= at_time || cnt == 0) {
76a44c5c 2386 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
2387 if (msg)
2388 *msg = ref_msg(rec, logend);
2389 if (cutoff_time)
2390 *cutoff_time = date;
2391 if (cutoff_tz)
2392 *cutoff_tz = tz;
2393 if (cutoff_cnt)
76a44c5c 2394 *cutoff_cnt = reccnt - 1;
e5229042
SP
2395 if (lastrec) {
2396 if (get_sha1_hex(lastrec, logged_sha1))
2397 die("Log %s is corrupt.", logfile);
2398 if (get_sha1_hex(rec + 41, sha1))
2399 die("Log %s is corrupt.", logfile);
a89fccd2 2400 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2401 warning("Log %s has gap after %s.",
73013afd 2402 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 2403 }
e5f38ec3
JH
2404 }
2405 else if (date == at_time) {
e5229042
SP
2406 if (get_sha1_hex(rec + 41, sha1))
2407 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
2408 }
2409 else {
e5229042
SP
2410 if (get_sha1_hex(rec + 41, logged_sha1))
2411 die("Log %s is corrupt.", logfile);
a89fccd2 2412 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2413 warning("Log %s unexpectedly ended on %s.",
73013afd 2414 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
2415 }
2416 }
dc49cd76 2417 munmap(log_mapped, mapsz);
d556fae2
SP
2418 return 0;
2419 }
e5229042 2420 lastrec = rec;
ab2a1a32
JH
2421 if (cnt > 0)
2422 cnt--;
d556fae2
SP
2423 }
2424
e5229042
SP
2425 rec = logdata;
2426 while (rec < logend && *rec != '>' && *rec != '\n')
2427 rec++;
2428 if (rec == logend || *rec == '\n')
d556fae2 2429 die("Log %s is corrupt.", logfile);
e5229042 2430 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
2431 tz = strtoul(tz_c, NULL, 10);
2432 if (get_sha1_hex(logdata, sha1))
2433 die("Log %s is corrupt.", logfile);
d1a4489a
JK
2434 if (is_null_sha1(sha1)) {
2435 if (get_sha1_hex(logdata + 41, sha1))
2436 die("Log %s is corrupt.", logfile);
2437 }
16d7cc90
JH
2438 if (msg)
2439 *msg = ref_msg(logdata, logend);
dc49cd76 2440 munmap(log_mapped, mapsz);
16d7cc90
JH
2441
2442 if (cutoff_time)
2443 *cutoff_time = date;
2444 if (cutoff_tz)
2445 *cutoff_tz = tz;
2446 if (cutoff_cnt)
2447 *cutoff_cnt = reccnt;
2448 return 1;
d556fae2 2449}
2ff81662 2450
dfefa935 2451int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)
2ff81662
JH
2452{
2453 const char *logfile;
2454 FILE *logfp;
8ca78803 2455 struct strbuf sb = STRBUF_INIT;
2266bf27 2456 int ret = 0;
2ff81662 2457
dfefa935 2458 logfile = git_path("logs/%s", refname);
2ff81662
JH
2459 logfp = fopen(logfile, "r");
2460 if (!logfp)
883d60fa 2461 return -1;
101d15e0
JH
2462
2463 if (ofs) {
2464 struct stat statbuf;
2465 if (fstat(fileno(logfp), &statbuf) ||
2466 statbuf.st_size < ofs ||
2467 fseek(logfp, -ofs, SEEK_END) ||
8ca78803 2468 strbuf_getwholeline(&sb, logfp, '\n')) {
9d33f7c2 2469 fclose(logfp);
8ca78803 2470 strbuf_release(&sb);
101d15e0 2471 return -1;
9d33f7c2 2472 }
101d15e0
JH
2473 }
2474
8ca78803 2475 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2ff81662 2476 unsigned char osha1[20], nsha1[20];
883d60fa
JS
2477 char *email_end, *message;
2478 unsigned long timestamp;
8ca78803 2479 int tz;
2ff81662
JH
2480
2481 /* old SP new SP name <email> SP time TAB msg LF */
8ca78803
RS
2482 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
2483 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
2484 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
2485 !(email_end = strchr(sb.buf + 82, '>')) ||
883d60fa
JS
2486 email_end[1] != ' ' ||
2487 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2488 !message || message[0] != ' ' ||
2489 (message[1] != '+' && message[1] != '-') ||
2490 !isdigit(message[2]) || !isdigit(message[3]) ||
b4dd4856 2491 !isdigit(message[4]) || !isdigit(message[5]))
2ff81662 2492 continue; /* corrupt? */
883d60fa
JS
2493 email_end[1] = '\0';
2494 tz = strtol(message + 1, NULL, 10);
b4dd4856
JS
2495 if (message[6] != '\t')
2496 message += 6;
2497 else
2498 message += 7;
8ca78803
RS
2499 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
2500 cb_data);
883d60fa 2501 if (ret)
2266bf27 2502 break;
2ff81662
JH
2503 }
2504 fclose(logfp);
8ca78803 2505 strbuf_release(&sb);
2266bf27 2506 return ret;
2ff81662 2507}
e29cb53a 2508
dfefa935 2509int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 2510{
dfefa935 2511 return for_each_recent_reflog_ent(refname, fn, 0, cb_data);
101d15e0
JH
2512}
2513
989c0e5d
MH
2514/*
2515 * Call fn for each reflog in the namespace indicated by name. name
2516 * must be empty or end with '/'. Name will be used as a scratch
2517 * space, but its contents will be restored before return.
2518 */
2519static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 2520{
989c0e5d 2521 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 2522 int retval = 0;
93c603fc 2523 struct dirent *de;
989c0e5d 2524 int oldlen = name->len;
eb8381c8 2525
93c603fc 2526 if (!d)
989c0e5d 2527 return name->len ? errno : 0;
eb8381c8 2528
93c603fc
MH
2529 while ((de = readdir(d)) != NULL) {
2530 struct stat st;
eb8381c8 2531
93c603fc
MH
2532 if (de->d_name[0] == '.')
2533 continue;
93c603fc
MH
2534 if (has_extension(de->d_name, ".lock"))
2535 continue;
989c0e5d
MH
2536 strbuf_addstr(name, de->d_name);
2537 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
2538 ; /* silently ignore */
93c603fc 2539 } else {
eb8381c8 2540 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
2541 strbuf_addch(name, '/');
2542 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
2543 } else {
2544 unsigned char sha1[20];
989c0e5d
MH
2545 if (read_ref_full(name->buf, sha1, 0, NULL))
2546 retval = error("bad ref for %s", name->buf);
eb8381c8 2547 else
989c0e5d 2548 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
2549 }
2550 if (retval)
2551 break;
2552 }
989c0e5d 2553 strbuf_setlen(name, oldlen);
eb8381c8 2554 }
93c603fc 2555 closedir(d);
eb8381c8
NP
2556 return retval;
2557}
2558
2559int for_each_reflog(each_ref_fn fn, void *cb_data)
2560{
989c0e5d
MH
2561 int retval;
2562 struct strbuf name;
2563 strbuf_init(&name, PATH_MAX);
2564 retval = do_for_each_reflog(&name, fn, cb_data);
2565 strbuf_release(&name);
2566 return retval;
eb8381c8 2567}
3d9f037c
CR
2568
2569int update_ref(const char *action, const char *refname,
2570 const unsigned char *sha1, const unsigned char *oldval,
2571 int flags, enum action_on_err onerr)
2572{
2573 static struct ref_lock *lock;
2574 lock = lock_any_ref_for_update(refname, oldval, flags);
2575 if (!lock) {
2576 const char *str = "Cannot lock the ref '%s'.";
2577 switch (onerr) {
2578 case MSG_ON_ERR: error(str, refname); break;
2579 case DIE_ON_ERR: die(str, refname); break;
2580 case QUIET_ON_ERR: break;
2581 }
2582 return 1;
2583 }
2584 if (write_ref_sha1(lock, sha1, action) < 0) {
2585 const char *str = "Cannot update the ref '%s'.";
2586 switch (onerr) {
2587 case MSG_ON_ERR: error(str, refname); break;
2588 case DIE_ON_ERR: die(str, refname); break;
2589 case QUIET_ON_ERR: break;
2590 }
2591 return 1;
2592 }
2593 return 0;
2594}
cda69f48 2595
5483f799 2596struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
2597{
2598 for ( ; list; list = list->next)
2599 if (!strcmp(list->name, name))
5483f799 2600 return (struct ref *)list;
cda69f48
JK
2601 return NULL;
2602}
7c2b3029
JK
2603
2604/*
2605 * generate a format suitable for scanf from a ref_rev_parse_rules
2606 * rule, that is replace the "%.*s" spec with a "%s" spec
2607 */
2608static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
2609{
2610 char *spec;
2611
2612 spec = strstr(rule, "%.*s");
2613 if (!spec || strstr(spec + 4, "%.*s"))
2614 die("invalid rule in ref_rev_parse_rules: %s", rule);
2615
2616 /* copy all until spec */
2617 strncpy(scanf_fmt, rule, spec - rule);
2618 scanf_fmt[spec - rule] = '\0';
2619 /* copy new spec */
2620 strcat(scanf_fmt, "%s");
2621 /* copy remaining rule */
2622 strcat(scanf_fmt, spec + 4);
2623
2624 return;
2625}
2626
dfefa935 2627char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
2628{
2629 int i;
2630 static char **scanf_fmts;
2631 static int nr_rules;
2632 char *short_name;
2633
2634 /* pre generate scanf formats from ref_rev_parse_rules[] */
2635 if (!nr_rules) {
2636 size_t total_len = 0;
2637
2638 /* the rule list is NULL terminated, count them first */
2639 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2640 /* no +1 because strlen("%s") < strlen("%.*s") */
2641 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2642
2643 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2644
2645 total_len = 0;
2646 for (i = 0; i < nr_rules; i++) {
2647 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2648 + total_len;
2649 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2650 total_len += strlen(ref_rev_parse_rules[i]);
2651 }
2652 }
2653
2654 /* bail out if there are no rules */
2655 if (!nr_rules)
dfefa935 2656 return xstrdup(refname);
7c2b3029 2657
dfefa935
MH
2658 /* buffer for scanf result, at most refname must fit */
2659 short_name = xstrdup(refname);
7c2b3029
JK
2660
2661 /* skip first rule, it will always match */
2662 for (i = nr_rules - 1; i > 0 ; --i) {
2663 int j;
6e7b3309 2664 int rules_to_fail = i;
7c2b3029
JK
2665 int short_name_len;
2666
dfefa935 2667 if (1 != sscanf(refname, scanf_fmts[i], short_name))
7c2b3029
JK
2668 continue;
2669
2670 short_name_len = strlen(short_name);
2671
6e7b3309
BW
2672 /*
2673 * in strict mode, all (except the matched one) rules
2674 * must fail to resolve to a valid non-ambiguous ref
2675 */
2676 if (strict)
2677 rules_to_fail = nr_rules;
2678
7c2b3029
JK
2679 /*
2680 * check if the short name resolves to a valid ref,
2681 * but use only rules prior to the matched one
2682 */
6e7b3309 2683 for (j = 0; j < rules_to_fail; j++) {
7c2b3029 2684 const char *rule = ref_rev_parse_rules[j];
7c2b3029
JK
2685 char refname[PATH_MAX];
2686
6e7b3309
BW
2687 /* skip matched rule */
2688 if (i == j)
2689 continue;
2690
7c2b3029
JK
2691 /*
2692 * the short name is ambiguous, if it resolves
2693 * (with this previous rule) to a valid ref
2694 * read_ref() returns 0 on success
2695 */
2696 mksnpath(refname, sizeof(refname),
2697 rule, short_name_len, short_name);
c6893323 2698 if (ref_exists(refname))
7c2b3029
JK
2699 break;
2700 }
2701
2702 /*
2703 * short name is non-ambiguous if all previous rules
2704 * haven't resolved to a valid ref
2705 */
6e7b3309 2706 if (j == rules_to_fail)
7c2b3029
JK
2707 return short_name;
2708 }
2709
2710 free(short_name);
dfefa935 2711 return xstrdup(refname);
7c2b3029 2712}