search_ref_dir(): return an index rather than a pointer
[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 369/*
9fc0a648
MH
370 * Return the index of the entry with the given refname from the
371 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
372 * no such entry is found. dir must already be complete.
432ad41e 373 */
9fc0a648 374static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
bc5fd6d3 375{
e1980c9d
JH
376 struct ref_entry **r;
377 struct string_slice key;
bc5fd6d3 378
432ad41e 379 if (refname == NULL || !dir->nr)
9fc0a648 380 return -1;
bc5fd6d3 381
d3177275 382 sort_ref_dir(dir);
e1980c9d
JH
383 key.len = len;
384 key.str = refname;
385 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
386 ref_entry_cmp_sslice);
bc5fd6d3
MH
387
388 if (r == NULL)
9fc0a648 389 return -1;
bc5fd6d3 390
9fc0a648 391 return r - dir->entries;
bc5fd6d3
MH
392}
393
f348ac92
MH
394/*
395 * Search for a directory entry directly within dir (without
396 * recursing). Sort dir if necessary. subdirname must be a directory
397 * name (i.e., end in '/'). If mkdir is set, then create the
398 * directory if it is missing; otherwise, return NULL if the desired
28e6a34e 399 * directory cannot be found. dir must already be complete.
f348ac92 400 */
3f3aa1bc 401static struct ref_dir *search_for_subdir(struct ref_dir *dir,
dd02e728
RS
402 const char *subdirname, size_t len,
403 int mkdir)
f348ac92 404{
9fc0a648
MH
405 int entry_index = search_ref_dir(dir, subdirname, len);
406 struct ref_entry *entry;
407 if (entry_index == -1) {
f348ac92
MH
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 417 add_entry_to_dir(dir, entry);
9fc0a648
MH
418 } else {
419 entry = dir->entries[entry_index];
f348ac92 420 }
3f3aa1bc 421 return get_ref_dir(entry);
f348ac92
MH
422}
423
432ad41e
MH
424/*
425 * If refname is a reference name, find the ref_dir within the dir
426 * tree that should hold refname. If refname is a directory name
427 * (i.e., ends in '/'), then return that ref_dir itself. dir must
28e6a34e
MH
428 * represent the top-level directory and must already be complete.
429 * Sort ref_dirs and recurse into subdirectories as necessary. If
430 * mkdir is set, then create any missing directories; otherwise,
431 * return NULL if the desired directory cannot be found.
432ad41e
MH
432 */
433static struct ref_dir *find_containing_dir(struct ref_dir *dir,
434 const char *refname, int mkdir)
435{
5fa04418 436 const char *slash;
5fa04418 437 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
dd02e728 438 size_t dirnamelen = slash - refname + 1;
3f3aa1bc 439 struct ref_dir *subdir;
dd02e728 440 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
663c1295
JH
441 if (!subdir) {
442 dir = NULL;
f348ac92 443 break;
432ad41e 444 }
3f3aa1bc 445 dir = subdir;
432ad41e
MH
446 }
447
432ad41e
MH
448 return dir;
449}
450
451/*
452 * Find the value entry with the given name in dir, sorting ref_dirs
453 * and recursing into subdirectories as necessary. If the name is not
454 * found or it corresponds to a directory entry, return NULL.
455 */
456static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
457{
9fc0a648 458 int entry_index;
432ad41e
MH
459 struct ref_entry *entry;
460 dir = find_containing_dir(dir, refname, 0);
461 if (!dir)
462 return NULL;
9fc0a648
MH
463 entry_index = search_ref_dir(dir, refname, strlen(refname));
464 if (entry_index == -1)
465 return NULL;
466 entry = dir->entries[entry_index];
467 return (entry->flag & REF_DIR) ? NULL : entry;
432ad41e
MH
468}
469
470/*
471 * Add a ref_entry to the ref_dir (unsorted), recursing into
472 * subdirectories as necessary. dir must represent the top-level
473 * directory. Return 0 on success.
474 */
475static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
476{
477 dir = find_containing_dir(dir, ref->name, 1);
478 if (!dir)
479 return -1;
480 add_entry_to_dir(dir, ref);
481 return 0;
482}
483
202a56a9
MH
484/*
485 * Emit a warning and return true iff ref1 and ref2 have the same name
486 * and the same sha1. Die if they have the same name but different
487 * sha1s.
488 */
489static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
490{
432ad41e 491 if (strcmp(ref1->name, ref2->name))
202a56a9 492 return 0;
432ad41e
MH
493
494 /* Duplicate name; make sure that they don't conflict: */
495
496 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
497 /* This is impossible by construction */
498 die("Reference directory conflict: %s", ref1->name);
499
500 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
501 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
502
503 warning("Duplicated ref: %s", ref1->name);
504 return 1;
202a56a9
MH
505}
506
e6ed3ca6 507/*
432ad41e
MH
508 * Sort the entries in dir non-recursively (if they are not already
509 * sorted) and remove any duplicate entries.
e6ed3ca6 510 */
d3177275 511static void sort_ref_dir(struct ref_dir *dir)
e9c4c111 512{
202a56a9 513 int i, j;
81a79d8e 514 struct ref_entry *last = NULL;
c774aab9 515
e6ed3ca6
MH
516 /*
517 * This check also prevents passing a zero-length array to qsort(),
518 * which is a problem on some platforms.
519 */
d3177275 520 if (dir->sorted == dir->nr)
e9c4c111 521 return;
c774aab9 522
d3177275 523 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
c774aab9 524
81a79d8e
MH
525 /* Remove any duplicates: */
526 for (i = 0, j = 0; j < dir->nr; j++) {
527 struct ref_entry *entry = dir->entries[j];
528 if (last && is_dup_ref(last, entry))
529 free_ref_entry(entry);
530 else
531 last = dir->entries[i++] = entry;
e9c4c111 532 }
81a79d8e 533 dir->sorted = dir->nr = i;
e9c4c111 534}
c774aab9 535
fcce1703
MH
536/* Include broken references in a do_for_each_ref*() iteration: */
537#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
c774aab9 538
662428f4
MH
539/*
540 * Return true iff the reference described by entry can be resolved to
541 * an object in the database. Emit a warning if the referred-to
542 * object does not exist.
543 */
544static int ref_resolves_to_object(struct ref_entry *entry)
545{
546 if (entry->flag & REF_ISBROKEN)
547 return 0;
548 if (!has_sha1_file(entry->u.value.sha1)) {
549 error("%s does not point to a valid object!", entry->name);
550 return 0;
551 }
552 return 1;
553}
554
7d76fdc8
MH
555/*
556 * current_ref is a performance hack: when iterating over references
557 * using the for_each_ref*() functions, current_ref is set to the
558 * current reference's entry before calling the callback function. If
559 * the callback function calls peel_ref(), then peel_ref() first
560 * checks whether the reference to be peeled is the current reference
561 * (it usually is) and if so, returns that reference's peeled version
562 * if it is available. This avoids a refname lookup in a common case.
563 */
bc5fd6d3 564static struct ref_entry *current_ref;
c774aab9 565
624cac35
MH
566typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
567
568struct ref_entry_cb {
569 const char *base;
570 int trim;
571 int flags;
572 each_ref_fn *fn;
573 void *cb_data;
574};
575
fcce1703 576/*
624cac35
MH
577 * Handle one reference in a do_for_each_ref*()-style iteration,
578 * calling an each_ref_fn for each entry.
fcce1703 579 */
624cac35 580static int do_one_ref(struct ref_entry *entry, void *cb_data)
bc5fd6d3 581{
624cac35 582 struct ref_entry_cb *data = cb_data;
429213e4 583 int retval;
624cac35 584 if (prefixcmp(entry->name, data->base))
bc5fd6d3 585 return 0;
c774aab9 586
624cac35 587 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
662428f4
MH
588 !ref_resolves_to_object(entry))
589 return 0;
590
bc5fd6d3 591 current_ref = entry;
624cac35
MH
592 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
593 entry->flag, data->cb_data);
429213e4
MH
594 current_ref = NULL;
595 return retval;
bc5fd6d3 596}
c774aab9 597
c36b5bc2 598/*
d3177275 599 * Call fn for each reference in dir that has index in the range
432ad41e
MH
600 * offset <= index < dir->nr. Recurse into subdirectories that are in
601 * that index range, sorting them before iterating. This function
624cac35
MH
602 * does not sort dir itself; it should be sorted beforehand. fn is
603 * called for all references, including broken ones.
c36b5bc2 604 */
624cac35
MH
605static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
606 each_ref_entry_fn fn, void *cb_data)
c36b5bc2
MH
607{
608 int i;
d3177275
MH
609 assert(dir->sorted == dir->nr);
610 for (i = offset; i < dir->nr; i++) {
432ad41e
MH
611 struct ref_entry *entry = dir->entries[i];
612 int retval;
613 if (entry->flag & REF_DIR) {
d7826d54
MH
614 struct ref_dir *subdir = get_ref_dir(entry);
615 sort_ref_dir(subdir);
624cac35 616 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
432ad41e 617 } else {
624cac35 618 retval = fn(entry, cb_data);
432ad41e 619 }
c36b5bc2
MH
620 if (retval)
621 return retval;
622 }
623 return 0;
624}
625
b3fd060f 626/*
d3177275 627 * Call fn for each reference in the union of dir1 and dir2, in order
432ad41e
MH
628 * by refname. Recurse into subdirectories. If a value entry appears
629 * in both dir1 and dir2, then only process the version that is in
630 * dir2. The input dirs must already be sorted, but subdirs will be
624cac35
MH
631 * sorted as needed. fn is called for all references, including
632 * broken ones.
b3fd060f 633 */
624cac35
MH
634static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
635 struct ref_dir *dir2,
636 each_ref_entry_fn fn, void *cb_data)
b3fd060f
MH
637{
638 int retval;
639 int i1 = 0, i2 = 0;
640
d3177275
MH
641 assert(dir1->sorted == dir1->nr);
642 assert(dir2->sorted == dir2->nr);
432ad41e
MH
643 while (1) {
644 struct ref_entry *e1, *e2;
645 int cmp;
646 if (i1 == dir1->nr) {
624cac35 647 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
432ad41e
MH
648 }
649 if (i2 == dir2->nr) {
624cac35 650 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
432ad41e
MH
651 }
652 e1 = dir1->entries[i1];
653 e2 = dir2->entries[i2];
654 cmp = strcmp(e1->name, e2->name);
655 if (cmp == 0) {
656 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
657 /* Both are directories; descend them in parallel. */
d7826d54
MH
658 struct ref_dir *subdir1 = get_ref_dir(e1);
659 struct ref_dir *subdir2 = get_ref_dir(e2);
660 sort_ref_dir(subdir1);
661 sort_ref_dir(subdir2);
624cac35
MH
662 retval = do_for_each_entry_in_dirs(
663 subdir1, subdir2, fn, cb_data);
432ad41e
MH
664 i1++;
665 i2++;
666 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
667 /* Both are references; ignore the one from dir1. */
624cac35 668 retval = fn(e2, cb_data);
432ad41e
MH
669 i1++;
670 i2++;
671 } else {
672 die("conflict between reference and directory: %s",
673 e1->name);
674 }
b3fd060f 675 } else {
432ad41e
MH
676 struct ref_entry *e;
677 if (cmp < 0) {
678 e = e1;
b3fd060f 679 i1++;
432ad41e
MH
680 } else {
681 e = e2;
682 i2++;
683 }
684 if (e->flag & REF_DIR) {
d7826d54
MH
685 struct ref_dir *subdir = get_ref_dir(e);
686 sort_ref_dir(subdir);
624cac35
MH
687 retval = do_for_each_entry_in_dir(
688 subdir, 0, fn, cb_data);
432ad41e 689 } else {
624cac35 690 retval = fn(e, cb_data);
b3fd060f
MH
691 }
692 }
693 if (retval)
694 return retval;
695 }
b3fd060f
MH
696}
697
d66da478
MH
698/*
699 * Return true iff refname1 and refname2 conflict with each other.
700 * Two reference names conflict if one of them exactly matches the
701 * leading components of the other; e.g., "foo/bar" conflicts with
702 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
703 * "foo/barbados".
704 */
705static int names_conflict(const char *refname1, const char *refname2)
706{
5a4d4947
MH
707 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
708 ;
709 return (*refname1 == '\0' && *refname2 == '/')
710 || (*refname1 == '/' && *refname2 == '\0');
711}
712
713struct name_conflict_cb {
714 const char *refname;
715 const char *oldrefname;
716 const char *conflicting_refname;
717};
718
624cac35 719static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
5a4d4947
MH
720{
721 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
624cac35 722 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
5a4d4947 723 return 0;
624cac35
MH
724 if (names_conflict(data->refname, entry->name)) {
725 data->conflicting_refname = entry->name;
5a4d4947 726 return 1;
d66da478 727 }
5a4d4947 728 return 0;
d66da478
MH
729}
730
bc5fd6d3
MH
731/*
732 * Return true iff a reference named refname could be created without
624cac35 733 * conflicting with the name of an existing reference in dir. If
5a4d4947
MH
734 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
735 * (e.g., because oldrefname is scheduled for deletion in the same
bc5fd6d3
MH
736 * operation).
737 */
738static int is_refname_available(const char *refname, const char *oldrefname,
d3177275 739 struct ref_dir *dir)
bc5fd6d3 740{
5a4d4947
MH
741 struct name_conflict_cb data;
742 data.refname = refname;
743 data.oldrefname = oldrefname;
744 data.conflicting_refname = NULL;
745
d3177275 746 sort_ref_dir(dir);
624cac35 747 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
5a4d4947
MH
748 error("'%s' exists; cannot create '%s'",
749 data.conflicting_refname, refname);
750 return 0;
bc5fd6d3
MH
751 }
752 return 1;
e1e22e37
LT
753}
754
5e290ff7
JH
755/*
756 * Future: need to be in "struct repository"
757 * when doing a full libification.
758 */
79c7ca54
MH
759static struct ref_cache {
760 struct ref_cache *next;
d12229f5
MH
761 struct ref_entry *loose;
762 struct ref_entry *packed;
ce40979c
MH
763 /* The submodule name, or "" for the main repo. */
764 char name[FLEX_ARRAY];
79c7ca54 765} *ref_cache;
0e88c130 766
760c4512 767static void clear_packed_ref_cache(struct ref_cache *refs)
e1e22e37 768{
d12229f5
MH
769 if (refs->packed) {
770 free_ref_entry(refs->packed);
771 refs->packed = NULL;
772 }
5e290ff7 773}
e1e22e37 774
760c4512
MH
775static void clear_loose_ref_cache(struct ref_cache *refs)
776{
d12229f5
MH
777 if (refs->loose) {
778 free_ref_entry(refs->loose);
779 refs->loose = NULL;
780 }
760c4512
MH
781}
782
79c7ca54 783static struct ref_cache *create_ref_cache(const char *submodule)
e5dbf605 784{
ce40979c 785 int len;
79c7ca54 786 struct ref_cache *refs;
ce40979c
MH
787 if (!submodule)
788 submodule = "";
789 len = strlen(submodule) + 1;
79c7ca54 790 refs = xcalloc(1, sizeof(struct ref_cache) + len);
ce40979c 791 memcpy(refs->name, submodule, len);
e5dbf605
MH
792 return refs;
793}
794
4349a668 795/*
79c7ca54 796 * Return a pointer to a ref_cache for the specified submodule. For
4349a668
MH
797 * the main repository, use submodule==NULL. The returned structure
798 * will be allocated and initialized but not necessarily populated; it
799 * should not be freed.
800 */
79c7ca54 801static struct ref_cache *get_ref_cache(const char *submodule)
4349a668 802{
79c7ca54 803 struct ref_cache *refs = ref_cache;
0e88c130
MH
804 if (!submodule)
805 submodule = "";
806 while (refs) {
807 if (!strcmp(submodule, refs->name))
808 return refs;
809 refs = refs->next;
4349a668 810 }
0e88c130 811
79c7ca54
MH
812 refs = create_ref_cache(submodule);
813 refs->next = ref_cache;
814 ref_cache = refs;
0e88c130 815 return refs;
4349a668
MH
816}
817
8be8bde7 818void invalidate_ref_cache(const char *submodule)
f130b116 819{
c5f29abd
MH
820 struct ref_cache *refs = get_ref_cache(submodule);
821 clear_packed_ref_cache(refs);
822 clear_loose_ref_cache(refs);
5e290ff7 823}
e1e22e37 824
3feb4f0c
MH
825/* The length of a peeled reference line in packed-refs, including EOL: */
826#define PEELED_LINE_LENGTH 42
827
bc5fd6d3
MH
828/*
829 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
830 * Return a pointer to the refname within the line (null-terminated),
831 * or NULL if there was a problem.
832 */
833static const char *parse_ref_line(char *line, unsigned char *sha1)
834{
835 /*
836 * 42: the answer to everything.
837 *
838 * In this case, it happens to be the answer to
839 * 40 (length of sha1 hex representation)
840 * +1 (space in between hex and name)
841 * +1 (newline at the end of the line)
842 */
843 int len = strlen(line) - 42;
844
845 if (len <= 0)
846 return NULL;
847 if (get_sha1_hex(line, sha1) < 0)
848 return NULL;
849 if (!isspace(line[40]))
850 return NULL;
851 line += 41;
852 if (isspace(*line))
853 return NULL;
854 if (line[len] != '\n')
855 return NULL;
856 line[len] = 0;
857
858 return line;
859}
860
c29c46fa
MH
861/*
862 * Read f, which is a packed-refs file, into dir.
863 *
864 * A comment line of the form "# pack-refs with: " may contain zero or
865 * more traits. We interpret the traits as follows:
866 *
867 * No traits:
868 *
869 * Probably no references are peeled. But if the file contains a
870 * peeled value for a reference, we will use it.
871 *
872 * peeled:
873 *
874 * References under "refs/tags/", if they *can* be peeled, *are*
875 * peeled in this file. References outside of "refs/tags/" are
876 * probably not peeled even if they could have been, but if we find
877 * a peeled value for such a reference we will use it.
878 *
879 * fully-peeled:
880 *
881 * All references in the file that can be peeled are peeled.
882 * Inversely (and this is more important), any references in the
883 * file for which no peeled value is recorded is not peelable. This
884 * trait should typically be written alongside "peeled" for
885 * compatibility with older clients, but we do not require it
886 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
887 */
d3177275 888static void read_packed_refs(FILE *f, struct ref_dir *dir)
f4204ab9 889{
e9c4c111 890 struct ref_entry *last = NULL;
f4204ab9 891 char refline[PATH_MAX];
c29c46fa 892 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
f4204ab9
JH
893
894 while (fgets(refline, sizeof(refline), f)) {
895 unsigned char sha1[20];
dfefa935 896 const char *refname;
f4204ab9
JH
897 static const char header[] = "# pack-refs with:";
898
899 if (!strncmp(refline, header, sizeof(header)-1)) {
900 const char *traits = refline + sizeof(header) - 1;
c29c46fa
MH
901 if (strstr(traits, " fully-peeled "))
902 peeled = PEELED_FULLY;
903 else if (strstr(traits, " peeled "))
904 peeled = PEELED_TAGS;
f4204ab9
JH
905 /* perhaps other traits later as well */
906 continue;
907 }
908
dfefa935
MH
909 refname = parse_ref_line(refline, sha1);
910 if (refname) {
c29c46fa
MH
911 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
912 if (peeled == PEELED_FULLY ||
913 (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/")))
914 last->flag |= REF_KNOWS_PEELED;
d3177275 915 add_ref(dir, last);
f4204ab9
JH
916 continue;
917 }
918 if (last &&
919 refline[0] == '^' &&
3feb4f0c
MH
920 strlen(refline) == PEELED_LINE_LENGTH &&
921 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
c29c46fa 922 !get_sha1_hex(refline + 1, sha1)) {
593f1bb8 923 hashcpy(last->u.value.peeled, sha1);
c29c46fa
MH
924 /*
925 * Regardless of what the file header said,
926 * we definitely know the value of *this*
927 * reference:
928 */
929 last->flag |= REF_KNOWS_PEELED;
930 }
f4204ab9 931 }
f4204ab9
JH
932}
933
d3177275 934static struct ref_dir *get_packed_refs(struct ref_cache *refs)
5e290ff7 935{
d12229f5 936 if (!refs->packed) {
4349a668
MH
937 const char *packed_refs_file;
938 FILE *f;
0bad611b 939
b9146f51 940 refs->packed = create_dir_entry(refs, "", 0, 0);
316b097a
MH
941 if (*refs->name)
942 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
4349a668
MH
943 else
944 packed_refs_file = git_path("packed-refs");
945 f = fopen(packed_refs_file, "r");
e1e22e37 946 if (f) {
d7826d54 947 read_packed_refs(f, get_ref_dir(refs->packed));
e1e22e37 948 fclose(f);
e1e22e37 949 }
e1e22e37 950 }
d7826d54 951 return get_ref_dir(refs->packed);
e1e22e37
LT
952}
953
30249ee6
MH
954void add_packed_ref(const char *refname, const unsigned char *sha1)
955{
956 add_ref(get_packed_refs(get_ref_cache(NULL)),
957 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
958}
959
abc39098 960/*
28e6a34e
MH
961 * Read the loose references from the namespace dirname into dir
962 * (without recursing). dirname must end with '/'. dir must be the
963 * directory entry corresponding to dirname.
abc39098 964 */
423a1afc 965static void read_loose_refs(const char *dirname, struct ref_dir *dir)
e1e22e37 966{
423a1afc 967 struct ref_cache *refs = dir->ref_cache;
d3177275 968 DIR *d;
0bad611b 969 const char *path;
d5fdae67 970 struct dirent *de;
abc39098 971 int dirnamelen = strlen(dirname);
72b64b44 972 struct strbuf refname;
0bad611b 973
3b124823 974 if (*refs->name)
66a3d20b 975 path = git_path_submodule(refs->name, "%s", dirname);
0bad611b 976 else
66a3d20b 977 path = git_path("%s", dirname);
0bad611b 978
d3177275 979 d = opendir(path);
d5fdae67
MH
980 if (!d)
981 return;
982
66a3d20b
MH
983 strbuf_init(&refname, dirnamelen + 257);
984 strbuf_add(&refname, dirname, dirnamelen);
d5fdae67
MH
985
986 while ((de = readdir(d)) != NULL) {
987 unsigned char sha1[20];
988 struct stat st;
989 int flag;
d5fdae67
MH
990 const char *refdir;
991
992 if (de->d_name[0] == '.')
993 continue;
d5fdae67
MH
994 if (has_extension(de->d_name, ".lock"))
995 continue;
72b64b44 996 strbuf_addstr(&refname, de->d_name);
d5fdae67 997 refdir = *refs->name
72b64b44
MH
998 ? git_path_submodule(refs->name, "%s", refname.buf)
999 : git_path("%s", refname.buf);
1000 if (stat(refdir, &st) < 0) {
1001 ; /* silently ignore */
1002 } else if (S_ISDIR(st.st_mode)) {
abc39098 1003 strbuf_addch(&refname, '/');
28e6a34e 1004 add_entry_to_dir(dir,
b9146f51
RS
1005 create_dir_entry(refs, refname.buf,
1006 refname.len, 1));
72b64b44 1007 } else {
3b124823 1008 if (*refs->name) {
f8948e2f 1009 hashclr(sha1);
0bad611b 1010 flag = 0;
72b64b44 1011 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
0bad611b 1012 hashclr(sha1);
98ac34b2 1013 flag |= REF_ISBROKEN;
0bad611b 1014 }
72b64b44 1015 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
09116a1c
JH
1016 hashclr(sha1);
1017 flag |= REF_ISBROKEN;
1018 }
9f2fb4a3
MH
1019 add_entry_to_dir(dir,
1020 create_ref_entry(refname.buf, sha1, flag, 1));
e1e22e37 1021 }
66a3d20b 1022 strbuf_setlen(&refname, dirnamelen);
e1e22e37 1023 }
72b64b44 1024 strbuf_release(&refname);
d5fdae67 1025 closedir(d);
e1e22e37
LT
1026}
1027
d3177275 1028static struct ref_dir *get_loose_refs(struct ref_cache *refs)
e1e22e37 1029{
d12229f5 1030 if (!refs->loose) {
28e6a34e
MH
1031 /*
1032 * Mark the top-level directory complete because we
1033 * are about to read the only subdirectory that can
1034 * hold references:
1035 */
b9146f51 1036 refs->loose = create_dir_entry(refs, "", 0, 0);
28e6a34e
MH
1037 /*
1038 * Create an incomplete entry for "refs/":
1039 */
1040 add_entry_to_dir(get_ref_dir(refs->loose),
b9146f51 1041 create_dir_entry(refs, "refs/", 5, 1));
e1e22e37 1042 }
d7826d54 1043 return get_ref_dir(refs->loose);
e1e22e37
LT
1044}
1045
ca8db142
LT
1046/* We allow "recursive" symbolic refs. Only within reason, though */
1047#define MAXDEPTH 5
0ebde32c
LT
1048#define MAXREFLEN (1024)
1049
e5fa45c1
JH
1050/*
1051 * Called by resolve_gitlink_ref_recursive() after it failed to read
b0626608
MH
1052 * from the loose refs in ref_cache refs. Find <refname> in the
1053 * packed-refs file for the submodule.
e5fa45c1 1054 */
b0626608 1055static int resolve_gitlink_packed_ref(struct ref_cache *refs,
85be1fe3 1056 const char *refname, unsigned char *sha1)
0ebde32c 1057{
2c5c66be 1058 struct ref_entry *ref;
d3177275 1059 struct ref_dir *dir = get_packed_refs(refs);
0ebde32c 1060
432ad41e 1061 ref = find_ref(dir, refname);
b0626608
MH
1062 if (ref == NULL)
1063 return -1;
1064
593f1bb8 1065 memcpy(sha1, ref->u.value.sha1, 20);
b0626608 1066 return 0;
0ebde32c
LT
1067}
1068
b0626608 1069static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
85be1fe3 1070 const char *refname, unsigned char *sha1,
dfefa935 1071 int recursion)
0ebde32c 1072{
064d51dc 1073 int fd, len;
0ebde32c 1074 char buffer[128], *p;
064d51dc 1075 char *path;
0ebde32c 1076
064d51dc 1077 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
0ebde32c 1078 return -1;
064d51dc
MH
1079 path = *refs->name
1080 ? git_path_submodule(refs->name, "%s", refname)
1081 : git_path("%s", refname);
1082 fd = open(path, O_RDONLY);
0ebde32c 1083 if (fd < 0)
b0626608 1084 return resolve_gitlink_packed_ref(refs, refname, sha1);
0ebde32c
LT
1085
1086 len = read(fd, buffer, sizeof(buffer)-1);
1087 close(fd);
1088 if (len < 0)
1089 return -1;
1090 while (len && isspace(buffer[len-1]))
1091 len--;
1092 buffer[len] = 0;
1093
1094 /* Was it a detached head or an old-fashioned symlink? */
85be1fe3 1095 if (!get_sha1_hex(buffer, sha1))
0ebde32c
LT
1096 return 0;
1097
1098 /* Symref? */
1099 if (strncmp(buffer, "ref:", 4))
1100 return -1;
1101 p = buffer + 4;
1102 while (isspace(*p))
1103 p++;
1104
064d51dc 1105 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
0ebde32c
LT
1106}
1107
85be1fe3 1108int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
0ebde32c
LT
1109{
1110 int len = strlen(path), retval;
064d51dc 1111 char *submodule;
b0626608 1112 struct ref_cache *refs;
0ebde32c
LT
1113
1114 while (len && path[len-1] == '/')
1115 len--;
1116 if (!len)
1117 return -1;
b0626608
MH
1118 submodule = xstrndup(path, len);
1119 refs = get_ref_cache(submodule);
1120 free(submodule);
1121
064d51dc 1122 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
0ebde32c
LT
1123 return retval;
1124}
ca8db142 1125
4886b89f 1126/*
63331581
MH
1127 * Return the ref_entry for the given refname from the packed
1128 * references. If it does not exist, return NULL.
4886b89f 1129 */
63331581 1130static struct ref_entry *get_packed_ref(const char *refname)
c224ca7f 1131{
63331581 1132 return find_ref(get_packed_refs(get_ref_cache(NULL)), refname);
c224ca7f
MH
1133}
1134
8d68493f 1135const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
8a65ff76 1136{
0104ca09
HO
1137 int depth = MAXDEPTH;
1138 ssize_t len;
a876ed83 1139 char buffer[256];
dfefa935 1140 static char refname_buffer[256];
ca8db142 1141
8da19775
JH
1142 if (flag)
1143 *flag = 0;
1144
dfefa935 1145 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
8384d788
MH
1146 return NULL;
1147
a876ed83 1148 for (;;) {
55956350 1149 char path[PATH_MAX];
a876ed83
JH
1150 struct stat st;
1151 char *buf;
1152 int fd;
8a65ff76 1153
a876ed83
JH
1154 if (--depth < 0)
1155 return NULL;
ca8db142 1156
dfefa935 1157 git_snpath(path, sizeof(path), "%s", refname);
c224ca7f 1158
a876ed83 1159 if (lstat(path, &st) < 0) {
63331581
MH
1160 struct ref_entry *entry;
1161
c224ca7f
MH
1162 if (errno != ENOENT)
1163 return NULL;
1164 /*
1165 * The loose reference file does not exist;
1166 * check for a packed reference.
1167 */
63331581
MH
1168 entry = get_packed_ref(refname);
1169 if (entry) {
1170 hashcpy(sha1, entry->u.value.sha1);
c224ca7f
MH
1171 if (flag)
1172 *flag |= REF_ISPACKED;
dfefa935 1173 return refname;
434cd0cd 1174 }
c224ca7f
MH
1175 /* The reference is not a packed reference, either. */
1176 if (reading) {
a876ed83 1177 return NULL;
c224ca7f
MH
1178 } else {
1179 hashclr(sha1);
dfefa935 1180 return refname;
c224ca7f 1181 }
a876ed83 1182 }
ca8db142 1183
a876ed83
JH
1184 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1185 if (S_ISLNK(st.st_mode)) {
1186 len = readlink(path, buffer, sizeof(buffer)-1);
7bb2bf8e
MH
1187 if (len < 0)
1188 return NULL;
b54cb795 1189 buffer[len] = 0;
1f58a038
MH
1190 if (!prefixcmp(buffer, "refs/") &&
1191 !check_refname_format(buffer, 0)) {
dfefa935
MH
1192 strcpy(refname_buffer, buffer);
1193 refname = refname_buffer;
8da19775
JH
1194 if (flag)
1195 *flag |= REF_ISSYMREF;
a876ed83
JH
1196 continue;
1197 }
ca8db142 1198 }
a876ed83 1199
7a21632f
DS
1200 /* Is it a directory? */
1201 if (S_ISDIR(st.st_mode)) {
1202 errno = EISDIR;
1203 return NULL;
1204 }
1205
a876ed83
JH
1206 /*
1207 * Anything else, just open it and try to use it as
1208 * a ref
1209 */
1210 fd = open(path, O_RDONLY);
1211 if (fd < 0)
1212 return NULL;
93d26e4c 1213 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83 1214 close(fd);
28775050
MH
1215 if (len < 0)
1216 return NULL;
1217 while (len && isspace(buffer[len-1]))
1218 len--;
1219 buffer[len] = '\0';
a876ed83
JH
1220
1221 /*
1222 * Is it a symbolic ref?
1223 */
28775050 1224 if (prefixcmp(buffer, "ref:"))
a876ed83 1225 break;
55956350
JH
1226 if (flag)
1227 *flag |= REF_ISSYMREF;
a876ed83 1228 buf = buffer + 4;
28775050
MH
1229 while (isspace(*buf))
1230 buf++;
313fb010 1231 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
55956350
JH
1232 if (flag)
1233 *flag |= REF_ISBROKEN;
313fb010
MH
1234 return NULL;
1235 }
dfefa935 1236 refname = strcpy(refname_buffer, buf);
8a65ff76 1237 }
f989fea0
MH
1238 /* Please note that FETCH_HEAD has a second line containing other data. */
1239 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
55956350
JH
1240 if (flag)
1241 *flag |= REF_ISBROKEN;
a876ed83 1242 return NULL;
629cd3ac 1243 }
dfefa935 1244 return refname;
a876ed83
JH
1245}
1246
96ec7b1e
NTND
1247char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1248{
8cad4744 1249 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
96ec7b1e
NTND
1250 return ret ? xstrdup(ret) : NULL;
1251}
1252
d08bae7e
IL
1253/* The argument to filter_refs */
1254struct ref_filter {
1255 const char *pattern;
1256 each_ref_fn *fn;
1257 void *cb_data;
1258};
1259
dfefa935 1260int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
a876ed83 1261{
8d68493f 1262 if (resolve_ref_unsafe(refname, sha1, reading, flags))
a876ed83
JH
1263 return 0;
1264 return -1;
8a65ff76
LT
1265}
1266
dfefa935 1267int read_ref(const char *refname, unsigned char *sha1)
c6893323 1268{
dfefa935 1269 return read_ref_full(refname, sha1, 1, NULL);
c6893323
NTND
1270}
1271
bc5fd6d3 1272int ref_exists(const char *refname)
ef06b918 1273{
bc5fd6d3
MH
1274 unsigned char sha1[20];
1275 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
ef06b918
JH
1276}
1277
85be1fe3 1278static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
dfefa935 1279 void *data)
d08bae7e
IL
1280{
1281 struct ref_filter *filter = (struct ref_filter *)data;
dfefa935 1282 if (fnmatch(filter->pattern, refname, 0))
d08bae7e 1283 return 0;
85be1fe3 1284 return filter->fn(refname, sha1, flags, filter->cb_data);
d08bae7e
IL
1285}
1286
68cf8703
MH
1287enum peel_status {
1288 /* object was peeled successfully: */
1289 PEEL_PEELED = 0,
1290
1291 /*
1292 * object cannot be peeled because the named object (or an
1293 * object referred to by a tag in the peel chain), does not
1294 * exist.
1295 */
1296 PEEL_INVALID = -1,
1297
1298 /* object cannot be peeled because it is not a tag: */
9a489f3c
MH
1299 PEEL_NON_TAG = -2,
1300
1301 /* ref_entry contains no peeled value because it is a symref: */
1302 PEEL_IS_SYMREF = -3,
1303
1304 /*
1305 * ref_entry cannot be peeled because it is broken (i.e., the
1306 * symbolic reference cannot even be resolved to an object
1307 * name):
1308 */
1309 PEEL_BROKEN = -4
68cf8703
MH
1310};
1311
cb2ae1c4
MH
1312/*
1313 * Peel the named object; i.e., if the object is a tag, resolve the
68cf8703
MH
1314 * tag recursively until a non-tag is found. If successful, store the
1315 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1316 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1317 * and leave sha1 unchanged.
cb2ae1c4 1318 */
68cf8703 1319static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
cb2ae1c4
MH
1320{
1321 struct object *o = lookup_unknown_object(name);
1322
1323 if (o->type == OBJ_NONE) {
1324 int type = sha1_object_info(name, NULL);
1325 if (type < 0)
68cf8703 1326 return PEEL_INVALID;
cb2ae1c4
MH
1327 o->type = type;
1328 }
1329
1330 if (o->type != OBJ_TAG)
68cf8703 1331 return PEEL_NON_TAG;
cb2ae1c4
MH
1332
1333 o = deref_tag_noverify(o);
1334 if (!o)
68cf8703 1335 return PEEL_INVALID;
cb2ae1c4
MH
1336
1337 hashcpy(sha1, o->sha1);
68cf8703 1338 return PEEL_PEELED;
cb2ae1c4
MH
1339}
1340
9a489f3c
MH
1341/*
1342 * Peel the entry (if possible) and return its new peel_status.
1343 */
1344static enum peel_status peel_entry(struct ref_entry *entry)
1345{
1346 enum peel_status status;
1347
1348 if (entry->flag & REF_KNOWS_PEELED)
1349 return is_null_sha1(entry->u.value.peeled) ?
1350 PEEL_NON_TAG : PEEL_PEELED;
1351 if (entry->flag & REF_ISBROKEN)
1352 return PEEL_BROKEN;
1353 if (entry->flag & REF_ISSYMREF)
1354 return PEEL_IS_SYMREF;
1355
1356 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1357 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1358 entry->flag |= REF_KNOWS_PEELED;
1359 return status;
1360}
1361
dfefa935 1362int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1363{
1364 int flag;
1365 unsigned char base[20];
cf0adba7 1366
dfefa935 1367 if (current_ref && (current_ref->name == refname
9a489f3c
MH
1368 || !strcmp(current_ref->name, refname))) {
1369 if (peel_entry(current_ref))
1370 return -1;
1371 hashcpy(sha1, current_ref->u.value.peeled);
1372 return 0;
0ae91be0
SP
1373 }
1374
dfefa935 1375 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1376 return -1;
1377
9a489f3c
MH
1378 /*
1379 * If the reference is packed, read its ref_entry from the
1380 * cache in the hope that we already know its peeled value.
1381 * We only try this optimization on packed references because
1382 * (a) forcing the filling of the loose reference cache could
1383 * be expensive and (b) loose references anyway usually do not
1384 * have REF_KNOWS_PEELED.
1385 */
1386 if (flag & REF_ISPACKED) {
f361baeb 1387 struct ref_entry *r = get_packed_ref(refname);
9a489f3c
MH
1388 if (r) {
1389 if (peel_entry(r))
1390 return -1;
593f1bb8 1391 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1392 return 0;
cf0adba7 1393 }
cf0adba7
JH
1394 }
1395
cb2ae1c4 1396 return peel_object(base, sha1);
cf0adba7
JH
1397}
1398
bc5fd6d3
MH
1399struct warn_if_dangling_data {
1400 FILE *fp;
1401 const char *refname;
1402 const char *msg_fmt;
1403};
1404
1405static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1406 int flags, void *cb_data)
1407{
1408 struct warn_if_dangling_data *d = cb_data;
1409 const char *resolves_to;
1410 unsigned char junk[20];
1411
1412 if (!(flags & REF_ISSYMREF))
1413 return 0;
1414
1415 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1416 if (!resolves_to || strcmp(resolves_to, d->refname))
1417 return 0;
1418
1419 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1420 fputc('\n', d->fp);
bc5fd6d3
MH
1421 return 0;
1422}
1423
1424void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1425{
1426 struct warn_if_dangling_data data;
1427
1428 data.fp = fp;
1429 data.refname = refname;
1430 data.msg_fmt = msg_fmt;
1431 for_each_rawref(warn_if_dangling_symref, &data);
1432}
1433
fcce1703 1434/*
624cac35
MH
1435 * Call fn for each reference in the specified submodule, omitting
1436 * references not in the containing_dir of base. fn is called for all
1437 * references, including broken ones. If fn ever returns a non-zero
fcce1703
MH
1438 * value, stop the iteration and return that value; otherwise, return
1439 * 0.
1440 */
624cac35
MH
1441static int do_for_each_entry(const char *submodule, const char *base,
1442 each_ref_entry_fn fn, void *cb_data)
8a65ff76 1443{
316b097a 1444 struct ref_cache *refs = get_ref_cache(submodule);
933ac036
MH
1445 struct ref_dir *packed_dir = get_packed_refs(refs);
1446 struct ref_dir *loose_dir = get_loose_refs(refs);
1447 int retval = 0;
1448
1449 if (base && *base) {
1450 packed_dir = find_containing_dir(packed_dir, base, 0);
1451 loose_dir = find_containing_dir(loose_dir, base, 0);
1452 }
1453
1454 if (packed_dir && loose_dir) {
1455 sort_ref_dir(packed_dir);
1456 sort_ref_dir(loose_dir);
624cac35
MH
1457 retval = do_for_each_entry_in_dirs(
1458 packed_dir, loose_dir, fn, cb_data);
933ac036
MH
1459 } else if (packed_dir) {
1460 sort_ref_dir(packed_dir);
624cac35
MH
1461 retval = do_for_each_entry_in_dir(
1462 packed_dir, 0, fn, cb_data);
933ac036
MH
1463 } else if (loose_dir) {
1464 sort_ref_dir(loose_dir);
624cac35
MH
1465 retval = do_for_each_entry_in_dir(
1466 loose_dir, 0, fn, cb_data);
933ac036
MH
1467 }
1468
1469 return retval;
8a65ff76
LT
1470}
1471
624cac35
MH
1472/*
1473 * Call fn for each reference in the specified submodule for which the
1474 * refname begins with base. If trim is non-zero, then trim that many
1475 * characters off the beginning of each refname before passing the
1476 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1477 * broken references in the iteration. If fn ever returns a non-zero
1478 * value, stop the iteration and return that value; otherwise, return
1479 * 0.
1480 */
1481static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
1482 int trim, int flags, void *cb_data)
1483{
1484 struct ref_entry_cb data;
1485 data.base = base;
1486 data.trim = trim;
1487 data.flags = flags;
1488 data.fn = fn;
1489 data.cb_data = cb_data;
1490
1491 return do_for_each_entry(submodule, base, do_one_ref, &data);
1492}
1493
0bad611b 1494static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1495{
1496 unsigned char sha1[20];
8da19775
JH
1497 int flag;
1498
0bad611b
HV
1499 if (submodule) {
1500 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1501 return fn("HEAD", sha1, 0, cb_data);
1502
1503 return 0;
1504 }
1505
c6893323 1506 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1507 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1508
2f34ba32 1509 return 0;
723c31fe
LT
1510}
1511
0bad611b
HV
1512int head_ref(each_ref_fn fn, void *cb_data)
1513{
1514 return do_head_ref(NULL, fn, cb_data);
1515}
1516
9ef6aeb0
HV
1517int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1518{
1519 return do_head_ref(submodule, fn, cb_data);
1520}
1521
cb5d709f 1522int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1523{
b3cfc406 1524 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
a62be77f
SE
1525}
1526
9ef6aeb0
HV
1527int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1528{
b3cfc406 1529 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
a62be77f
SE
1530}
1531
2a8177b6
CC
1532int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1533{
0bad611b 1534 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1535}
1536
9ef6aeb0
HV
1537int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1538 each_ref_fn fn, void *cb_data)
1539{
1540 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1541}
1542
cb5d709f 1543int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1544{
2a8177b6 1545 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1546}
1547
9ef6aeb0
HV
1548int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1549{
1550 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1551}
1552
cb5d709f 1553int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1554{
2a8177b6 1555 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1556}
1557
9ef6aeb0
HV
1558int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1559{
1560 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1561}
1562
cb5d709f 1563int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1564{
2a8177b6 1565 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1566}
1567
9ef6aeb0
HV
1568int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1569{
1570 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1571}
1572
29268700
CC
1573int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1574{
0bad611b 1575 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1576}
1577
a1bea2c1
JT
1578int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1579{
1580 struct strbuf buf = STRBUF_INIT;
1581 int ret = 0;
1582 unsigned char sha1[20];
1583 int flag;
1584
1585 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1586 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1587 ret = fn(buf.buf, sha1, flag, cb_data);
1588 strbuf_release(&buf);
1589
1590 return ret;
1591}
1592
1593int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1594{
1595 struct strbuf buf = STRBUF_INIT;
1596 int ret;
1597 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1598 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
1599 strbuf_release(&buf);
1600 return ret;
1601}
1602
b09fe971
IL
1603int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1604 const char *prefix, void *cb_data)
d08bae7e
IL
1605{
1606 struct strbuf real_pattern = STRBUF_INIT;
1607 struct ref_filter filter;
d08bae7e
IL
1608 int ret;
1609
b09fe971 1610 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 1611 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1612 else if (prefix)
1613 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1614 strbuf_addstr(&real_pattern, pattern);
1615
894a9d33 1616 if (!has_glob_specials(pattern)) {
9517e6b8 1617 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1618 if (real_pattern.buf[real_pattern.len - 1] != '/')
1619 strbuf_addch(&real_pattern, '/');
1620 /* No need to check for '*', there is none. */
1621 strbuf_addch(&real_pattern, '*');
1622 }
1623
1624 filter.pattern = real_pattern.buf;
1625 filter.fn = fn;
1626 filter.cb_data = cb_data;
1627 ret = for_each_ref(filter_refs, &filter);
1628
1629 strbuf_release(&real_pattern);
1630 return ret;
1631}
1632
b09fe971
IL
1633int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1634{
1635 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1636}
1637
f8948e2f
JH
1638int for_each_rawref(each_ref_fn fn, void *cb_data)
1639{
b3cfc406 1640 return do_for_each_ref(NULL, "", fn, 0,
f8948e2f 1641 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1642}
1643
4577e483 1644const char *prettify_refname(const char *name)
a9c37a72 1645{
a9c37a72
DB
1646 return name + (
1647 !prefixcmp(name, "refs/heads/") ? 11 :
1648 !prefixcmp(name, "refs/tags/") ? 10 :
1649 !prefixcmp(name, "refs/remotes/") ? 13 :
1650 0);
1651}
1652
79803322
SP
1653const char *ref_rev_parse_rules[] = {
1654 "%.*s",
1655 "refs/%.*s",
1656 "refs/tags/%.*s",
1657 "refs/heads/%.*s",
1658 "refs/remotes/%.*s",
1659 "refs/remotes/%.*s/HEAD",
1660 NULL
1661};
1662
1663int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1664{
1665 const char **p;
1666 const int abbrev_name_len = strlen(abbrev_name);
1667
1668 for (p = rules; *p; p++) {
1669 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1670 return 1;
1671 }
1672 }
1673
1674 return 0;
1675}
1676
e5f38ec3 1677static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1678 const unsigned char *old_sha1, int mustexist)
1679{
c6893323 1680 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 1681 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
1682 unlock_ref(lock);
1683 return NULL;
1684 }
a89fccd2 1685 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1686 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1687 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1688 unlock_ref(lock);
1689 return NULL;
1690 }
1691 return lock;
1692}
1693
7155b727 1694static int remove_empty_directories(const char *file)
bc7127ef
JH
1695{
1696 /* we want to create a file but there is a directory there;
1697 * if that is an empty directory (or a directory that contains
1698 * only empty directories), remove them.
1699 */
7155b727
JS
1700 struct strbuf path;
1701 int result;
bc7127ef 1702
7155b727
JS
1703 strbuf_init(&path, 20);
1704 strbuf_addstr(&path, file);
1705
a0f4afbe 1706 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1707
1708 strbuf_release(&path);
1709
1710 return result;
bc7127ef
JH
1711}
1712
ff74f7f1
JH
1713/*
1714 * *string and *len will only be substituted, and *string returned (for
1715 * later free()ing) if the string passed in is a magic short-hand form
1716 * to name a branch.
1717 */
1718static char *substitute_branch_name(const char **string, int *len)
1719{
1720 struct strbuf buf = STRBUF_INIT;
1721 int ret = interpret_branch_name(*string, &buf);
1722
1723 if (ret == *len) {
1724 size_t size;
1725 *string = strbuf_detach(&buf, &size);
1726 *len = size;
1727 return (char *)*string;
1728 }
1729
1730 return NULL;
1731}
1732
1733int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1734{
1735 char *last_branch = substitute_branch_name(&str, &len);
1736 const char **p, *r;
1737 int refs_found = 0;
1738
1739 *ref = NULL;
1740 for (p = ref_rev_parse_rules; *p; p++) {
1741 char fullref[PATH_MAX];
1742 unsigned char sha1_from_ref[20];
1743 unsigned char *this_result;
1744 int flag;
1745
1746 this_result = refs_found ? sha1_from_ref : sha1;
1747 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 1748 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
1749 if (r) {
1750 if (!refs_found++)
1751 *ref = xstrdup(r);
1752 if (!warn_ambiguous_refs)
1753 break;
55956350 1754 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 1755 warning("ignoring dangling symref %s.", fullref);
55956350
JH
1756 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1757 warning("ignoring broken ref %s.", fullref);
1758 }
ff74f7f1
JH
1759 }
1760 free(last_branch);
1761 return refs_found;
1762}
1763
1764int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1765{
1766 char *last_branch = substitute_branch_name(&str, &len);
1767 const char **p;
1768 int logs_found = 0;
1769
1770 *log = NULL;
1771 for (p = ref_rev_parse_rules; *p; p++) {
1772 struct stat st;
1773 unsigned char hash[20];
1774 char path[PATH_MAX];
1775 const char *ref, *it;
1776
1777 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 1778 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
1779 if (!ref)
1780 continue;
1781 if (!stat(git_path("logs/%s", path), &st) &&
1782 S_ISREG(st.st_mode))
1783 it = path;
1784 else if (strcmp(ref, path) &&
1785 !stat(git_path("logs/%s", ref), &st) &&
1786 S_ISREG(st.st_mode))
1787 it = ref;
1788 else
1789 continue;
1790 if (!logs_found++) {
1791 *log = xstrdup(it);
1792 hashcpy(sha1, hash);
1793 }
1794 if (!warn_ambiguous_refs)
1795 break;
1796 }
1797 free(last_branch);
1798 return logs_found;
1799}
1800
dfefa935
MH
1801static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1802 const unsigned char *old_sha1,
1803 int flags, int *type_p)
4bd18c43 1804{
434cd0cd 1805 char *ref_file;
dfefa935 1806 const char *orig_refname = refname;
4bd18c43 1807 struct ref_lock *lock;
5cc3cef9 1808 int last_errno = 0;
acd3b9ec 1809 int type, lflags;
4431fcc4 1810 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1811 int missing = 0;
4bd18c43
SP
1812
1813 lock = xcalloc(1, sizeof(struct ref_lock));
1814 lock->lock_fd = -1;
1815
8d68493f 1816 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 1817 if (!refname && errno == EISDIR) {
bc7127ef
JH
1818 /* we are trying to lock foo but we used to
1819 * have foo/bar which now does not exist;
1820 * it is normal for the empty directory 'foo'
1821 * to remain.
1822 */
dfefa935 1823 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
1824 if (remove_empty_directories(ref_file)) {
1825 last_errno = errno;
dfefa935 1826 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
1827 goto error_return;
1828 }
8d68493f 1829 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 1830 }
68db31cc
SV
1831 if (type_p)
1832 *type_p = type;
dfefa935 1833 if (!refname) {
5cc3cef9 1834 last_errno = errno;
818f477c 1835 error("unable to resolve reference %s: %s",
dfefa935 1836 orig_refname, strerror(errno));
5cc3cef9 1837 goto error_return;
4bd18c43 1838 }
5bdd8d4a 1839 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1840 /* When the ref did not exist and we are creating it,
1841 * make sure there is no existing ref that is packed
1842 * whose name begins with our refname, nor a ref whose
1843 * name is a proper prefix of our refname.
1844 */
5bdd8d4a 1845 if (missing &&
316b097a 1846 !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
f475e08e 1847 last_errno = ENOTDIR;
c976d415 1848 goto error_return;
f475e08e 1849 }
22a3844e 1850
c33d5174 1851 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1852
acd3b9ec
JH
1853 lflags = LOCK_DIE_ON_ERROR;
1854 if (flags & REF_NODEREF) {
dfefa935 1855 refname = orig_refname;
acd3b9ec
JH
1856 lflags |= LOCK_NODEREF;
1857 }
dfefa935
MH
1858 lock->ref_name = xstrdup(refname);
1859 lock->orig_ref_name = xstrdup(orig_refname);
1860 ref_file = git_path("%s", refname);
5bdd8d4a 1861 if (missing)
68db31cc
SV
1862 lock->force_write = 1;
1863 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1864 lock->force_write = 1;
4bd18c43 1865
5cc3cef9
JH
1866 if (safe_create_leading_directories(ref_file)) {
1867 last_errno = errno;
1868 error("unable to create directory for %s", ref_file);
1869 goto error_return;
1870 }
4bd18c43 1871
acd3b9ec 1872 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1873 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1874
1875 error_return:
1876 unlock_ref(lock);
1877 errno = last_errno;
1878 return NULL;
4bd18c43
SP
1879}
1880
dfefa935 1881struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 1882{
53cce84c 1883 char refpath[PATH_MAX];
dfefa935 1884 if (check_refname_format(refname, 0))
4bd18c43 1885 return NULL;
dfefa935 1886 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 1887 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1888}
1889
dfefa935
MH
1890struct ref_lock *lock_any_ref_for_update(const char *refname,
1891 const unsigned char *old_sha1, int flags)
4bd18c43 1892{
dfefa935 1893 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 1894 return NULL;
dfefa935 1895 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
c0277d15
JH
1896}
1897
d66da478
MH
1898struct repack_without_ref_sb {
1899 const char *refname;
1900 int fd;
1901};
1902
624cac35 1903static int repack_without_ref_fn(struct ref_entry *entry, void *cb_data)
d66da478
MH
1904{
1905 struct repack_without_ref_sb *data = cb_data;
1906 char line[PATH_MAX + 100];
1907 int len;
1908
624cac35 1909 if (!strcmp(data->refname, entry->name))
d66da478 1910 return 0;
ab292bc4
MH
1911 if (entry->flag & REF_ISBROKEN) {
1912 /* This shouldn't happen to packed refs. */
1913 error("%s is broken!", entry->name);
1914 return 0;
1915 }
1916 if (!has_sha1_file(entry->u.value.sha1)) {
1917 unsigned char sha1[20];
1918 int flags;
1919
1920 if (read_ref_full(entry->name, sha1, 0, &flags))
1921 /* We should at least have found the packed ref. */
1922 die("Internal error");
1923 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED))
1924 /*
1925 * This packed reference is overridden by a
1926 * loose reference, so it is OK that its value
1927 * is no longer valid; for example, it might
1928 * refer to an object that has been garbage
1929 * collected. For this purpose we don't even
1930 * care whether the loose reference itself is
1931 * invalid, broken, symbolic, etc. Silently
1932 * omit the packed reference from the output.
1933 */
1934 return 0;
1935 /*
1936 * There is no overriding loose reference, so the fact
1937 * that this reference doesn't refer to a valid object
1938 * indicates some kind of repository corruption.
1939 * Report the problem, then omit the reference from
1940 * the output.
1941 */
1942 error("%s does not point to a valid object!", entry->name);
1943 return 0;
1944 }
1945
d66da478 1946 len = snprintf(line, sizeof(line), "%s %s\n",
624cac35 1947 sha1_to_hex(entry->u.value.sha1), entry->name);
d66da478
MH
1948 /* this should not happen but just being defensive */
1949 if (len > sizeof(line))
624cac35 1950 die("too long a refname '%s'", entry->name);
d66da478
MH
1951 write_or_die(data->fd, line, len);
1952 return 0;
1953}
1954
26a063a1
JH
1955static struct lock_file packlock;
1956
c0277d15
JH
1957static int repack_without_ref(const char *refname)
1958{
d66da478 1959 struct repack_without_ref_sb data;
b3f1280e 1960 struct ref_cache *refs = get_ref_cache(NULL);
7618fd80
MH
1961 struct ref_dir *packed;
1962
1963 if (!get_packed_ref(refname))
1964 return 0; /* refname does not exist in packed refs */
1965
d66da478
MH
1966 data.refname = refname;
1967 data.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1968 if (data.fd < 0) {
1b018fd9 1969 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 1970 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 1971 }
b3f1280e
JK
1972 clear_packed_ref_cache(refs);
1973 packed = get_packed_refs(refs);
624cac35 1974 do_for_each_entry_in_dir(packed, 0, repack_without_ref_fn, &data);
c0277d15
JH
1975 return commit_lock_file(&packlock);
1976}
1977
eca35a25 1978int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
1979{
1980 struct ref_lock *lock;
eca35a25 1981 int err, i = 0, ret = 0, flag = 0;
c0277d15 1982
547d058f 1983 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
1984 if (!lock)
1985 return 1;
045a476f 1986 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 1987 /* loose */
547d058f
RS
1988 i = strlen(lock->lk->filename) - 5; /* .lock */
1989 lock->lk->filename[i] = 0;
1990 err = unlink_or_warn(lock->lk->filename);
691f1a28 1991 if (err && errno != ENOENT)
c0277d15 1992 ret = 1;
691f1a28 1993
547d058f 1994 lock->lk->filename[i] = '.';
c0277d15
JH
1995 }
1996 /* removing the loose one could have resurrected an earlier
1997 * packed one. Also, if it was not loose we need to repack
1998 * without it.
1999 */
b274a714 2000 ret |= repack_without_ref(lock->ref_name);
c0277d15 2001
691f1a28 2002 unlink_or_warn(git_path("logs/%s", lock->ref_name));
3870a0d1 2003 invalidate_ref_cache(NULL);
c0277d15
JH
2004 unlock_ref(lock);
2005 return ret;
4bd18c43
SP
2006}
2007
765c2258
PH
2008/*
2009 * People using contrib's git-new-workdir have .git/logs/refs ->
2010 * /some/other/path/.git/logs/refs, and that may live on another device.
2011 *
2012 * IOW, to avoid cross device rename errors, the temporary renamed log must
2013 * live into logs/refs.
2014 */
2015#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2016
dfefa935 2017int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 2018{
c976d415
LH
2019 unsigned char sha1[20], orig_sha1[20];
2020 int flag = 0, logmoved = 0;
2021 struct ref_lock *lock;
c976d415 2022 struct stat loginfo;
dfefa935 2023 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 2024 const char *symref = NULL;
316b097a 2025 struct ref_cache *refs = get_ref_cache(NULL);
c976d415 2026
450d4c0f 2027 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 2028 return error("reflog for %s is a symlink", oldrefname);
c976d415 2029
8d68493f 2030 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 2031 if (flag & REF_ISSYMREF)
fa58186c 2032 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 2033 oldrefname);
eca35a25 2034 if (!symref)
dfefa935 2035 return error("refname %s not found", oldrefname);
c976d415 2036
316b097a 2037 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
c976d415
LH
2038 return 1;
2039
316b097a 2040 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
c976d415
LH
2041 return 1;
2042
dfefa935 2043 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 2044 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 2045 oldrefname, strerror(errno));
c976d415 2046
dfefa935
MH
2047 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2048 error("unable to delete old %s", oldrefname);
c976d415
LH
2049 goto rollback;
2050 }
2051
dfefa935
MH
2052 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2053 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 2054 if (errno==EISDIR) {
dfefa935
MH
2055 if (remove_empty_directories(git_path("%s", newrefname))) {
2056 error("Directory not empty: %s", newrefname);
c976d415
LH
2057 goto rollback;
2058 }
2059 } else {
dfefa935 2060 error("unable to delete existing %s", newrefname);
c976d415
LH
2061 goto rollback;
2062 }
2063 }
2064
dfefa935
MH
2065 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2066 error("unable to create directory for %s", newrefname);
c976d415
LH
2067 goto rollback;
2068 }
2069
2070 retry:
dfefa935 2071 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
d9e74d57
JR
2072 if (errno==EISDIR || errno==ENOTDIR) {
2073 /*
2074 * rename(a, b) when b is an existing
2075 * directory ought to result in ISDIR, but
2076 * Solaris 5.8 gives ENOTDIR. Sheesh.
2077 */
dfefa935
MH
2078 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2079 error("Directory not empty: logs/%s", newrefname);
c976d415
LH
2080 goto rollback;
2081 }
2082 goto retry;
2083 } else {
765c2258 2084 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
dfefa935 2085 newrefname, strerror(errno));
c976d415
LH
2086 goto rollback;
2087 }
2088 }
2089 logmoved = log;
2090
dfefa935 2091 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 2092 if (!lock) {
dfefa935 2093 error("unable to lock %s for update", newrefname);
c976d415
LH
2094 goto rollback;
2095 }
c976d415
LH
2096 lock->force_write = 1;
2097 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 2098 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 2099 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
2100 goto rollback;
2101 }
2102
2103 return 0;
2104
2105 rollback:
dfefa935 2106 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 2107 if (!lock) {
dfefa935 2108 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
2109 goto rollbacklog;
2110 }
2111
2112 lock->force_write = 1;
2113 flag = log_all_ref_updates;
2114 log_all_ref_updates = 0;
2115 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2116 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2117 log_all_ref_updates = flag;
2118
2119 rollbacklog:
dfefa935 2120 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2121 error("unable to restore logfile %s from %s: %s",
dfefa935 2122 oldrefname, newrefname, strerror(errno));
c976d415 2123 if (!logmoved && log &&
dfefa935 2124 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2125 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2126 oldrefname, strerror(errno));
c976d415
LH
2127
2128 return 1;
2129}
2130
435fc852 2131int close_ref(struct ref_lock *lock)
b531394d
BC
2132{
2133 if (close_lock_file(lock->lk))
2134 return -1;
2135 lock->lock_fd = -1;
2136 return 0;
2137}
2138
435fc852 2139int commit_ref(struct ref_lock *lock)
b531394d
BC
2140{
2141 if (commit_lock_file(lock->lk))
2142 return -1;
2143 lock->lock_fd = -1;
2144 return 0;
2145}
2146
e5f38ec3 2147void unlock_ref(struct ref_lock *lock)
4bd18c43 2148{
4ed7cd3a
BC
2149 /* Do not free lock->lk -- atexit() still looks at them */
2150 if (lock->lk)
2151 rollback_lock_file(lock->lk);
434cd0cd 2152 free(lock->ref_name);
1655707c 2153 free(lock->orig_ref_name);
4bd18c43
SP
2154 free(lock);
2155}
2156
0ec29a47
JH
2157/*
2158 * copy the reflog message msg to buf, which has been allocated sufficiently
2159 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2160 * because reflog file is one line per entry.
2161 */
2162static int copy_msg(char *buf, const char *msg)
2163{
2164 char *cp = buf;
2165 char c;
2166 int wasspace = 1;
2167
2168 *cp++ = '\t';
2169 while ((c = *msg++)) {
2170 if (wasspace && isspace(c))
2171 continue;
2172 wasspace = isspace(c);
2173 if (wasspace)
2174 c = ' ';
2175 *cp++ = c;
2176 }
2177 while (buf < cp && isspace(cp[-1]))
2178 cp--;
2179 *cp++ = '\n';
2180 return cp - buf;
2181}
2182
dfefa935 2183int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2184{
859c3017 2185 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2186
dfefa935 2187 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2188 if (log_all_ref_updates &&
dfefa935
MH
2189 (!prefixcmp(refname, "refs/heads/") ||
2190 !prefixcmp(refname, "refs/remotes/") ||
2191 !prefixcmp(refname, "refs/notes/") ||
2192 !strcmp(refname, "HEAD"))) {
157aaea5 2193 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 2194 return error("unable to create directory for %s",
157aaea5 2195 logfile);
6de08ae6
SP
2196 oflags |= O_CREAT;
2197 }
2198
157aaea5 2199 logfd = open(logfile, oflags, 0666);
6de08ae6 2200 if (logfd < 0) {
1974bf62 2201 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2202 return 0;
3b463c3f
JH
2203
2204 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2205 if (remove_empty_directories(logfile)) {
3b463c3f 2206 return error("There are still logs under '%s'",
157aaea5 2207 logfile);
3b463c3f 2208 }
157aaea5 2209 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2210 }
2211
2212 if (logfd < 0)
2213 return error("Unable to append to %s: %s",
157aaea5 2214 logfile, strerror(errno));
6de08ae6
SP
2215 }
2216
157aaea5 2217 adjust_shared_perm(logfile);
859c3017
EM
2218 close(logfd);
2219 return 0;
2220}
443b92b6 2221
dfefa935 2222static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2223 const unsigned char *new_sha1, const char *msg)
2224{
2225 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2226 unsigned maxlen, len;
2227 int msglen;
157aaea5 2228 char log_file[PATH_MAX];
859c3017
EM
2229 char *logrec;
2230 const char *committer;
2231
2232 if (log_all_ref_updates < 0)
2233 log_all_ref_updates = !is_bare_repository();
2234
dfefa935 2235 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2236 if (result)
2237 return result;
2238
2239 logfd = open(log_file, oflags);
2240 if (logfd < 0)
2241 return 0;
0ec29a47 2242 msglen = msg ? strlen(msg) : 0;
774751a8 2243 committer = git_committer_info(0);
8ac65937
JH
2244 maxlen = strlen(committer) + msglen + 100;
2245 logrec = xmalloc(maxlen);
2246 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2247 sha1_to_hex(old_sha1),
2248 sha1_to_hex(new_sha1),
8ac65937
JH
2249 committer);
2250 if (msglen)
0ec29a47 2251 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2252 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2253 free(logrec);
91c8d590 2254 if (close(logfd) != 0 || written != len)
9a13f0b7 2255 return error("Unable to append to %s", log_file);
6de08ae6
SP
2256 return 0;
2257}
2258
c3b0dec5
LT
2259static int is_branch(const char *refname)
2260{
2261 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2262}
2263
4bd18c43
SP
2264int write_ref_sha1(struct ref_lock *lock,
2265 const unsigned char *sha1, const char *logmsg)
2266{
2267 static char term = '\n';
c3b0dec5 2268 struct object *o;
4bd18c43
SP
2269
2270 if (!lock)
95fc7512 2271 return -1;
a89fccd2 2272 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2273 unlock_ref(lock);
2274 return 0;
95fc7512 2275 }
c3b0dec5
LT
2276 o = parse_object(sha1);
2277 if (!o) {
7be8b3ba 2278 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2279 lock->ref_name, sha1_to_hex(sha1));
2280 unlock_ref(lock);
2281 return -1;
2282 }
2283 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2284 error("Trying to write non-commit object %s to branch %s",
2285 sha1_to_hex(sha1), lock->ref_name);
2286 unlock_ref(lock);
2287 return -1;
2288 }
93822c22
AW
2289 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2290 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 2291 || close_ref(lock) < 0) {
c33d5174 2292 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
2293 unlock_ref(lock);
2294 return -1;
2295 }
8bf90dc9 2296 clear_loose_ref_cache(get_ref_cache(NULL));
bd104db1
NP
2297 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2298 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2299 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2300 unlock_ref(lock);
2301 return -1;
2302 }
605fac8b
NP
2303 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2304 /*
2305 * Special hack: If a branch is updated directly and HEAD
2306 * points to it (may happen on the remote side of a push
2307 * for example) then logically the HEAD reflog should be
2308 * updated too.
2309 * A generic solution implies reverse symref information,
2310 * but finding all symrefs pointing to the given branch
2311 * would be rather costly for this rare event (the direct
2312 * update of a branch) to be worth it. So let's cheat and
2313 * check with HEAD only which should cover 99% of all usage
2314 * scenarios (even 100% of the default ones).
2315 */
2316 unsigned char head_sha1[20];
2317 int head_flag;
2318 const char *head_ref;
8cad4744 2319 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2320 if (head_ref && (head_flag & REF_ISSYMREF) &&
2321 !strcmp(head_ref, lock->ref_name))
2322 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2323 }
b531394d 2324 if (commit_ref(lock)) {
434cd0cd 2325 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2326 unlock_ref(lock);
2327 return -1;
2328 }
4bd18c43
SP
2329 unlock_ref(lock);
2330 return 0;
95fc7512 2331}
d556fae2 2332
8b5157e4
NP
2333int create_symref(const char *ref_target, const char *refs_heads_master,
2334 const char *logmsg)
41b625b0
NP
2335{
2336 const char *lockpath;
2337 char ref[1000];
2338 int fd, len, written;
a4f34cbb 2339 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2340 unsigned char old_sha1[20], new_sha1[20];
2341
2342 if (logmsg && read_ref(ref_target, old_sha1))
2343 hashclr(old_sha1);
41b625b0 2344
d48744d1
JH
2345 if (safe_create_leading_directories(git_HEAD) < 0)
2346 return error("unable to create directory for %s", git_HEAD);
2347
41b625b0
NP
2348#ifndef NO_SYMLINK_HEAD
2349 if (prefer_symlink_refs) {
2350 unlink(git_HEAD);
2351 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2352 goto done;
41b625b0
NP
2353 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2354 }
2355#endif
2356
2357 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2358 if (sizeof(ref) <= len) {
2359 error("refname too long: %s", refs_heads_master);
47fc52e2 2360 goto error_free_return;
41b625b0
NP
2361 }
2362 lockpath = mkpath("%s.lock", git_HEAD);
2363 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2364 if (fd < 0) {
2365 error("Unable to open %s for writing", lockpath);
47fc52e2 2366 goto error_free_return;
41b625b0
NP
2367 }
2368 written = write_in_full(fd, ref, len);
91c8d590 2369 if (close(fd) != 0 || written != len) {
41b625b0 2370 error("Unable to write to %s", lockpath);
47fc52e2 2371 goto error_unlink_return;
41b625b0
NP
2372 }
2373 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 2374 error("Unable to create %s", git_HEAD);
47fc52e2 2375 goto error_unlink_return;
41b625b0
NP
2376 }
2377 if (adjust_shared_perm(git_HEAD)) {
41b625b0 2378 error("Unable to fix permissions on %s", lockpath);
47fc52e2 2379 error_unlink_return:
691f1a28 2380 unlink_or_warn(lockpath);
47fc52e2
JH
2381 error_free_return:
2382 free(git_HEAD);
2383 return -1;
41b625b0 2384 }
8b5157e4 2385
ee96d11b 2386#ifndef NO_SYMLINK_HEAD
8b5157e4 2387 done:
ee96d11b 2388#endif
8b5157e4
NP
2389 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2390 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2391
47fc52e2 2392 free(git_HEAD);
41b625b0
NP
2393 return 0;
2394}
2395
16d7cc90
JH
2396static char *ref_msg(const char *line, const char *endp)
2397{
2398 const char *ep;
16d7cc90 2399 line += 82;
182af834
PH
2400 ep = memchr(line, '\n', endp - line);
2401 if (!ep)
2402 ep = endp;
2403 return xmemdupz(line, ep - line);
16d7cc90
JH
2404}
2405
dfefa935
MH
2406int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2407 unsigned char *sha1, char **msg,
2408 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 2409{
e5229042 2410 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 2411 char *tz_c;
e29cb53a 2412 int logfd, tz, reccnt = 0;
d556fae2
SP
2413 struct stat st;
2414 unsigned long date;
e5229042 2415 unsigned char logged_sha1[20];
cb48cb58 2416 void *log_mapped;
dc49cd76 2417 size_t mapsz;
d556fae2 2418
dfefa935 2419 logfile = git_path("logs/%s", refname);
d556fae2
SP
2420 logfd = open(logfile, O_RDONLY, 0);
2421 if (logfd < 0)
d824cbba 2422 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
2423 fstat(logfd, &st);
2424 if (!st.st_size)
2425 die("Log %s is empty.", logfile);
dc49cd76
SP
2426 mapsz = xsize_t(st.st_size);
2427 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 2428 logdata = log_mapped;
d556fae2
SP
2429 close(logfd);
2430
e5229042 2431 lastrec = NULL;
d556fae2
SP
2432 rec = logend = logdata + st.st_size;
2433 while (logdata < rec) {
e29cb53a 2434 reccnt++;
d556fae2
SP
2435 if (logdata < rec && *(rec-1) == '\n')
2436 rec--;
e5229042
SP
2437 lastgt = NULL;
2438 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 2439 rec--;
e5229042
SP
2440 if (*rec == '>')
2441 lastgt = rec;
2442 }
2443 if (!lastgt)
d556fae2 2444 die("Log %s is corrupt.", logfile);
e5229042 2445 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 2446 if (date <= at_time || cnt == 0) {
76a44c5c 2447 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
2448 if (msg)
2449 *msg = ref_msg(rec, logend);
2450 if (cutoff_time)
2451 *cutoff_time = date;
2452 if (cutoff_tz)
2453 *cutoff_tz = tz;
2454 if (cutoff_cnt)
76a44c5c 2455 *cutoff_cnt = reccnt - 1;
e5229042
SP
2456 if (lastrec) {
2457 if (get_sha1_hex(lastrec, logged_sha1))
2458 die("Log %s is corrupt.", logfile);
2459 if (get_sha1_hex(rec + 41, sha1))
2460 die("Log %s is corrupt.", logfile);
a89fccd2 2461 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2462 warning("Log %s has gap after %s.",
73013afd 2463 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 2464 }
e5f38ec3
JH
2465 }
2466 else if (date == at_time) {
e5229042
SP
2467 if (get_sha1_hex(rec + 41, sha1))
2468 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
2469 }
2470 else {
e5229042
SP
2471 if (get_sha1_hex(rec + 41, logged_sha1))
2472 die("Log %s is corrupt.", logfile);
a89fccd2 2473 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2474 warning("Log %s unexpectedly ended on %s.",
73013afd 2475 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
2476 }
2477 }
dc49cd76 2478 munmap(log_mapped, mapsz);
d556fae2
SP
2479 return 0;
2480 }
e5229042 2481 lastrec = rec;
ab2a1a32
JH
2482 if (cnt > 0)
2483 cnt--;
d556fae2
SP
2484 }
2485
e5229042
SP
2486 rec = logdata;
2487 while (rec < logend && *rec != '>' && *rec != '\n')
2488 rec++;
2489 if (rec == logend || *rec == '\n')
d556fae2 2490 die("Log %s is corrupt.", logfile);
e5229042 2491 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
2492 tz = strtoul(tz_c, NULL, 10);
2493 if (get_sha1_hex(logdata, sha1))
2494 die("Log %s is corrupt.", logfile);
d1a4489a
JK
2495 if (is_null_sha1(sha1)) {
2496 if (get_sha1_hex(logdata + 41, sha1))
2497 die("Log %s is corrupt.", logfile);
2498 }
16d7cc90
JH
2499 if (msg)
2500 *msg = ref_msg(logdata, logend);
dc49cd76 2501 munmap(log_mapped, mapsz);
16d7cc90
JH
2502
2503 if (cutoff_time)
2504 *cutoff_time = date;
2505 if (cutoff_tz)
2506 *cutoff_tz = tz;
2507 if (cutoff_cnt)
2508 *cutoff_cnt = reccnt;
2509 return 1;
d556fae2 2510}
2ff81662 2511
dfefa935 2512int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)
2ff81662
JH
2513{
2514 const char *logfile;
2515 FILE *logfp;
8ca78803 2516 struct strbuf sb = STRBUF_INIT;
2266bf27 2517 int ret = 0;
2ff81662 2518
dfefa935 2519 logfile = git_path("logs/%s", refname);
2ff81662
JH
2520 logfp = fopen(logfile, "r");
2521 if (!logfp)
883d60fa 2522 return -1;
101d15e0
JH
2523
2524 if (ofs) {
2525 struct stat statbuf;
2526 if (fstat(fileno(logfp), &statbuf) ||
2527 statbuf.st_size < ofs ||
2528 fseek(logfp, -ofs, SEEK_END) ||
8ca78803 2529 strbuf_getwholeline(&sb, logfp, '\n')) {
9d33f7c2 2530 fclose(logfp);
8ca78803 2531 strbuf_release(&sb);
101d15e0 2532 return -1;
9d33f7c2 2533 }
101d15e0
JH
2534 }
2535
8ca78803 2536 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2ff81662 2537 unsigned char osha1[20], nsha1[20];
883d60fa
JS
2538 char *email_end, *message;
2539 unsigned long timestamp;
8ca78803 2540 int tz;
2ff81662
JH
2541
2542 /* old SP new SP name <email> SP time TAB msg LF */
8ca78803
RS
2543 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
2544 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
2545 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
2546 !(email_end = strchr(sb.buf + 82, '>')) ||
883d60fa
JS
2547 email_end[1] != ' ' ||
2548 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2549 !message || message[0] != ' ' ||
2550 (message[1] != '+' && message[1] != '-') ||
2551 !isdigit(message[2]) || !isdigit(message[3]) ||
b4dd4856 2552 !isdigit(message[4]) || !isdigit(message[5]))
2ff81662 2553 continue; /* corrupt? */
883d60fa
JS
2554 email_end[1] = '\0';
2555 tz = strtol(message + 1, NULL, 10);
b4dd4856
JS
2556 if (message[6] != '\t')
2557 message += 6;
2558 else
2559 message += 7;
8ca78803
RS
2560 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
2561 cb_data);
883d60fa 2562 if (ret)
2266bf27 2563 break;
2ff81662
JH
2564 }
2565 fclose(logfp);
8ca78803 2566 strbuf_release(&sb);
2266bf27 2567 return ret;
2ff81662 2568}
e29cb53a 2569
dfefa935 2570int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 2571{
dfefa935 2572 return for_each_recent_reflog_ent(refname, fn, 0, cb_data);
101d15e0
JH
2573}
2574
989c0e5d
MH
2575/*
2576 * Call fn for each reflog in the namespace indicated by name. name
2577 * must be empty or end with '/'. Name will be used as a scratch
2578 * space, but its contents will be restored before return.
2579 */
2580static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 2581{
989c0e5d 2582 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 2583 int retval = 0;
93c603fc 2584 struct dirent *de;
989c0e5d 2585 int oldlen = name->len;
eb8381c8 2586
93c603fc 2587 if (!d)
989c0e5d 2588 return name->len ? errno : 0;
eb8381c8 2589
93c603fc
MH
2590 while ((de = readdir(d)) != NULL) {
2591 struct stat st;
eb8381c8 2592
93c603fc
MH
2593 if (de->d_name[0] == '.')
2594 continue;
93c603fc
MH
2595 if (has_extension(de->d_name, ".lock"))
2596 continue;
989c0e5d
MH
2597 strbuf_addstr(name, de->d_name);
2598 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
2599 ; /* silently ignore */
93c603fc 2600 } else {
eb8381c8 2601 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
2602 strbuf_addch(name, '/');
2603 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
2604 } else {
2605 unsigned char sha1[20];
989c0e5d
MH
2606 if (read_ref_full(name->buf, sha1, 0, NULL))
2607 retval = error("bad ref for %s", name->buf);
eb8381c8 2608 else
989c0e5d 2609 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
2610 }
2611 if (retval)
2612 break;
2613 }
989c0e5d 2614 strbuf_setlen(name, oldlen);
eb8381c8 2615 }
93c603fc 2616 closedir(d);
eb8381c8
NP
2617 return retval;
2618}
2619
2620int for_each_reflog(each_ref_fn fn, void *cb_data)
2621{
989c0e5d
MH
2622 int retval;
2623 struct strbuf name;
2624 strbuf_init(&name, PATH_MAX);
2625 retval = do_for_each_reflog(&name, fn, cb_data);
2626 strbuf_release(&name);
2627 return retval;
eb8381c8 2628}
3d9f037c
CR
2629
2630int update_ref(const char *action, const char *refname,
2631 const unsigned char *sha1, const unsigned char *oldval,
2632 int flags, enum action_on_err onerr)
2633{
2634 static struct ref_lock *lock;
2635 lock = lock_any_ref_for_update(refname, oldval, flags);
2636 if (!lock) {
2637 const char *str = "Cannot lock the ref '%s'.";
2638 switch (onerr) {
2639 case MSG_ON_ERR: error(str, refname); break;
2640 case DIE_ON_ERR: die(str, refname); break;
2641 case QUIET_ON_ERR: break;
2642 }
2643 return 1;
2644 }
2645 if (write_ref_sha1(lock, sha1, action) < 0) {
2646 const char *str = "Cannot update the ref '%s'.";
2647 switch (onerr) {
2648 case MSG_ON_ERR: error(str, refname); break;
2649 case DIE_ON_ERR: die(str, refname); break;
2650 case QUIET_ON_ERR: break;
2651 }
2652 return 1;
2653 }
2654 return 0;
2655}
cda69f48 2656
5483f799 2657struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
2658{
2659 for ( ; list; list = list->next)
2660 if (!strcmp(list->name, name))
5483f799 2661 return (struct ref *)list;
cda69f48
JK
2662 return NULL;
2663}
7c2b3029
JK
2664
2665/*
2666 * generate a format suitable for scanf from a ref_rev_parse_rules
2667 * rule, that is replace the "%.*s" spec with a "%s" spec
2668 */
2669static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
2670{
2671 char *spec;
2672
2673 spec = strstr(rule, "%.*s");
2674 if (!spec || strstr(spec + 4, "%.*s"))
2675 die("invalid rule in ref_rev_parse_rules: %s", rule);
2676
2677 /* copy all until spec */
2678 strncpy(scanf_fmt, rule, spec - rule);
2679 scanf_fmt[spec - rule] = '\0';
2680 /* copy new spec */
2681 strcat(scanf_fmt, "%s");
2682 /* copy remaining rule */
2683 strcat(scanf_fmt, spec + 4);
2684
2685 return;
2686}
2687
dfefa935 2688char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
2689{
2690 int i;
2691 static char **scanf_fmts;
2692 static int nr_rules;
2693 char *short_name;
2694
2695 /* pre generate scanf formats from ref_rev_parse_rules[] */
2696 if (!nr_rules) {
2697 size_t total_len = 0;
2698
2699 /* the rule list is NULL terminated, count them first */
2700 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2701 /* no +1 because strlen("%s") < strlen("%.*s") */
2702 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2703
2704 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2705
2706 total_len = 0;
2707 for (i = 0; i < nr_rules; i++) {
2708 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2709 + total_len;
2710 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2711 total_len += strlen(ref_rev_parse_rules[i]);
2712 }
2713 }
2714
2715 /* bail out if there are no rules */
2716 if (!nr_rules)
dfefa935 2717 return xstrdup(refname);
7c2b3029 2718
dfefa935
MH
2719 /* buffer for scanf result, at most refname must fit */
2720 short_name = xstrdup(refname);
7c2b3029
JK
2721
2722 /* skip first rule, it will always match */
2723 for (i = nr_rules - 1; i > 0 ; --i) {
2724 int j;
6e7b3309 2725 int rules_to_fail = i;
7c2b3029
JK
2726 int short_name_len;
2727
dfefa935 2728 if (1 != sscanf(refname, scanf_fmts[i], short_name))
7c2b3029
JK
2729 continue;
2730
2731 short_name_len = strlen(short_name);
2732
6e7b3309
BW
2733 /*
2734 * in strict mode, all (except the matched one) rules
2735 * must fail to resolve to a valid non-ambiguous ref
2736 */
2737 if (strict)
2738 rules_to_fail = nr_rules;
2739
7c2b3029
JK
2740 /*
2741 * check if the short name resolves to a valid ref,
2742 * but use only rules prior to the matched one
2743 */
6e7b3309 2744 for (j = 0; j < rules_to_fail; j++) {
7c2b3029 2745 const char *rule = ref_rev_parse_rules[j];
7c2b3029
JK
2746 char refname[PATH_MAX];
2747
6e7b3309
BW
2748 /* skip matched rule */
2749 if (i == j)
2750 continue;
2751
7c2b3029
JK
2752 /*
2753 * the short name is ambiguous, if it resolves
2754 * (with this previous rule) to a valid ref
2755 * read_ref() returns 0 on success
2756 */
2757 mksnpath(refname, sizeof(refname),
2758 rule, short_name_len, short_name);
c6893323 2759 if (ref_exists(refname))
7c2b3029
JK
2760 break;
2761 }
2762
2763 /*
2764 * short name is non-ambiguous if all previous rules
2765 * haven't resolved to a valid ref
2766 */
6e7b3309 2767 if (j == rules_to_fail)
7c2b3029
JK
2768 return short_name;
2769 }
2770
2771 free(short_name);
dfefa935 2772 return xstrdup(refname);
7c2b3029 2773}