3 #include "refs-internal.h"
4 #include "../lockfile.h"
11 struct object_id old_oid
;
17 * Information used (along with the information in ref_entry) to
18 * describe a single cached reference. This data structure only
19 * occurs embedded in a union in struct ref_entry, and only when
20 * (ref_entry->flag & REF_DIR) is zero.
24 * The name of the object to which this reference resolves
25 * (which may be a tag object). If REF_ISBROKEN, this is
26 * null. If REF_ISSYMREF, then this is the name of the object
27 * referred to by the last reference in the symlink chain.
32 * If REF_KNOWS_PEELED, then this field holds the peeled value
33 * of this reference, or null if the reference is known not to
34 * be peelable. See the documentation for peel_ref() for an
35 * exact definition of "peelable".
37 struct object_id peeled
;
43 * Information used (along with the information in ref_entry) to
44 * describe a level in the hierarchy of references. This data
45 * structure only occurs embedded in a union in struct ref_entry, and
46 * only when (ref_entry.flag & REF_DIR) is set. In that case,
47 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
48 * in the directory have already been read:
50 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
51 * or packed references, already read.
53 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
54 * references that hasn't been read yet (nor has any of its
57 * Entries within a directory are stored within a growable array of
58 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
59 * sorted are sorted by their component name in strcmp() order and the
60 * remaining entries are unsorted.
62 * Loose references are read lazily, one directory at a time. When a
63 * directory of loose references is read, then all of the references
64 * in that directory are stored, and REF_INCOMPLETE stubs are created
65 * for any subdirectories, but the subdirectories themselves are not
66 * read. The reading is triggered by get_ref_dir().
72 * Entries with index 0 <= i < sorted are sorted by name. New
73 * entries are appended to the list unsorted, and are sorted
74 * only when required; thus we avoid the need to sort the list
75 * after the addition of every reference.
79 /* A pointer to the ref_cache that contains this ref_dir. */
80 struct ref_cache
*ref_cache
;
82 struct ref_entry
**entries
;
86 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
87 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are
88 * public values; see refs.h.
92 * The field ref_entry->u.value.peeled of this value entry contains
93 * the correct peeled value for the reference, which might be
94 * null_sha1 if the reference is not a tag or if it is broken.
96 #define REF_KNOWS_PEELED 0x10
98 /* ref_entry represents a directory of references */
102 * Entry has not yet been read from disk (used only for REF_DIR
103 * entries representing loose references)
105 #define REF_INCOMPLETE 0x40
108 * A ref_entry represents either a reference or a "subdirectory" of
111 * Each directory in the reference namespace is represented by a
112 * ref_entry with (flags & REF_DIR) set and containing a subdir member
113 * that holds the entries in that directory that have been read so
114 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
115 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
116 * used for loose reference directories.
118 * References are represented by a ref_entry with (flags & REF_DIR)
119 * unset and a value member that describes the reference's value. The
120 * flag member is at the ref_entry level, but it is also needed to
121 * interpret the contents of the value field (in other words, a
122 * ref_value object is not very much use without the enclosing
125 * Reference names cannot end with slash and directories' names are
126 * always stored with a trailing slash (except for the top-level
127 * directory, which is always denoted by ""). This has two nice
128 * consequences: (1) when the entries in each subdir are sorted
129 * lexicographically by name (as they usually are), the references in
130 * a whole tree can be generated in lexicographic order by traversing
131 * the tree in left-to-right, depth-first order; (2) the names of
132 * references and subdirectories cannot conflict, and therefore the
133 * presence of an empty subdirectory does not block the creation of a
134 * similarly-named reference. (The fact that reference names with the
135 * same leading components can conflict *with each other* is a
136 * separate issue that is regulated by verify_refname_available().)
138 * Please note that the name field contains the fully-qualified
139 * reference (or subdirectory) name. Space could be saved by only
140 * storing the relative names. But that would require the full names
141 * to be generated on the fly when iterating in do_for_each_ref(), and
142 * would break callback functions, who have always been able to assume
143 * that the name strings that they are passed will not be freed during
147 unsigned char flag
; /* ISSYMREF? ISPACKED? */
149 struct ref_value value
; /* if not (flags&REF_DIR) */
150 struct ref_dir subdir
; /* if (flags&REF_DIR) */
153 * The full name of the reference (e.g., "refs/heads/master")
154 * or the full name of the directory with a trailing slash
155 * (e.g., "refs/heads/"):
157 char name
[FLEX_ARRAY
];
160 static void read_loose_refs(const char *dirname
, struct ref_dir
*dir
);
161 static int search_ref_dir(struct ref_dir
*dir
, const char *refname
, size_t len
);
162 static struct ref_entry
*create_dir_entry(struct ref_cache
*ref_cache
,
163 const char *dirname
, size_t len
,
165 static void add_entry_to_dir(struct ref_dir
*dir
, struct ref_entry
*entry
);
167 static struct ref_dir
*get_ref_dir(struct ref_entry
*entry
)
170 assert(entry
->flag
& REF_DIR
);
171 dir
= &entry
->u
.subdir
;
172 if (entry
->flag
& REF_INCOMPLETE
) {
173 read_loose_refs(entry
->name
, dir
);
176 * Manually add refs/bisect, which, being
177 * per-worktree, might not appear in the directory
178 * listing for refs/ in the main repo.
180 if (!strcmp(entry
->name
, "refs/")) {
181 int pos
= search_ref_dir(dir
, "refs/bisect/", 12);
183 struct ref_entry
*child_entry
;
184 child_entry
= create_dir_entry(dir
->ref_cache
,
187 add_entry_to_dir(dir
, child_entry
);
188 read_loose_refs("refs/bisect",
189 &child_entry
->u
.subdir
);
192 entry
->flag
&= ~REF_INCOMPLETE
;
197 static struct ref_entry
*create_ref_entry(const char *refname
,
198 const unsigned char *sha1
, int flag
,
201 struct ref_entry
*ref
;
204 check_refname_format(refname
, REFNAME_ALLOW_ONELEVEL
))
205 die("Reference has invalid format: '%s'", refname
);
206 FLEX_ALLOC_STR(ref
, name
, refname
);
207 hashcpy(ref
->u
.value
.oid
.hash
, sha1
);
208 oidclr(&ref
->u
.value
.peeled
);
213 static void clear_ref_dir(struct ref_dir
*dir
);
215 static void free_ref_entry(struct ref_entry
*entry
)
217 if (entry
->flag
& REF_DIR
) {
219 * Do not use get_ref_dir() here, as that might
220 * trigger the reading of loose refs.
222 clear_ref_dir(&entry
->u
.subdir
);
228 * Add a ref_entry to the end of dir (unsorted). Entry is always
229 * stored directly in dir; no recursion into subdirectories is
232 static void add_entry_to_dir(struct ref_dir
*dir
, struct ref_entry
*entry
)
234 ALLOC_GROW(dir
->entries
, dir
->nr
+ 1, dir
->alloc
);
235 dir
->entries
[dir
->nr
++] = entry
;
236 /* optimize for the case that entries are added in order */
238 (dir
->nr
== dir
->sorted
+ 1 &&
239 strcmp(dir
->entries
[dir
->nr
- 2]->name
,
240 dir
->entries
[dir
->nr
- 1]->name
) < 0))
241 dir
->sorted
= dir
->nr
;
245 * Clear and free all entries in dir, recursively.
247 static void clear_ref_dir(struct ref_dir
*dir
)
250 for (i
= 0; i
< dir
->nr
; i
++)
251 free_ref_entry(dir
->entries
[i
]);
253 dir
->sorted
= dir
->nr
= dir
->alloc
= 0;
258 * Create a struct ref_entry object for the specified dirname.
259 * dirname is the name of the directory with a trailing slash (e.g.,
260 * "refs/heads/") or "" for the top-level directory.
262 static struct ref_entry
*create_dir_entry(struct ref_cache
*ref_cache
,
263 const char *dirname
, size_t len
,
266 struct ref_entry
*direntry
;
267 FLEX_ALLOC_MEM(direntry
, name
, dirname
, len
);
268 direntry
->u
.subdir
.ref_cache
= ref_cache
;
269 direntry
->flag
= REF_DIR
| (incomplete
? REF_INCOMPLETE
: 0);
273 static int ref_entry_cmp(const void *a
, const void *b
)
275 struct ref_entry
*one
= *(struct ref_entry
**)a
;
276 struct ref_entry
*two
= *(struct ref_entry
**)b
;
277 return strcmp(one
->name
, two
->name
);
280 static void sort_ref_dir(struct ref_dir
*dir
);
282 struct string_slice
{
287 static int ref_entry_cmp_sslice(const void *key_
, const void *ent_
)
289 const struct string_slice
*key
= key_
;
290 const struct ref_entry
*ent
= *(const struct ref_entry
* const *)ent_
;
291 int cmp
= strncmp(key
->str
, ent
->name
, key
->len
);
294 return '\0' - (unsigned char)ent
->name
[key
->len
];
298 * Return the index of the entry with the given refname from the
299 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
300 * no such entry is found. dir must already be complete.
302 static int search_ref_dir(struct ref_dir
*dir
, const char *refname
, size_t len
)
304 struct ref_entry
**r
;
305 struct string_slice key
;
307 if (refname
== NULL
|| !dir
->nr
)
313 r
= bsearch(&key
, dir
->entries
, dir
->nr
, sizeof(*dir
->entries
),
314 ref_entry_cmp_sslice
);
319 return r
- dir
->entries
;
323 * Search for a directory entry directly within dir (without
324 * recursing). Sort dir if necessary. subdirname must be a directory
325 * name (i.e., end in '/'). If mkdir is set, then create the
326 * directory if it is missing; otherwise, return NULL if the desired
327 * directory cannot be found. dir must already be complete.
329 static struct ref_dir
*search_for_subdir(struct ref_dir
*dir
,
330 const char *subdirname
, size_t len
,
333 int entry_index
= search_ref_dir(dir
, subdirname
, len
);
334 struct ref_entry
*entry
;
335 if (entry_index
== -1) {
339 * Since dir is complete, the absence of a subdir
340 * means that the subdir really doesn't exist;
341 * therefore, create an empty record for it but mark
342 * the record complete.
344 entry
= create_dir_entry(dir
->ref_cache
, subdirname
, len
, 0);
345 add_entry_to_dir(dir
, entry
);
347 entry
= dir
->entries
[entry_index
];
349 return get_ref_dir(entry
);
353 * If refname is a reference name, find the ref_dir within the dir
354 * tree that should hold refname. If refname is a directory name
355 * (i.e., ends in '/'), then return that ref_dir itself. dir must
356 * represent the top-level directory and must already be complete.
357 * Sort ref_dirs and recurse into subdirectories as necessary. If
358 * mkdir is set, then create any missing directories; otherwise,
359 * return NULL if the desired directory cannot be found.
361 static struct ref_dir
*find_containing_dir(struct ref_dir
*dir
,
362 const char *refname
, int mkdir
)
365 for (slash
= strchr(refname
, '/'); slash
; slash
= strchr(slash
+ 1, '/')) {
366 size_t dirnamelen
= slash
- refname
+ 1;
367 struct ref_dir
*subdir
;
368 subdir
= search_for_subdir(dir
, refname
, dirnamelen
, mkdir
);
380 * Find the value entry with the given name in dir, sorting ref_dirs
381 * and recursing into subdirectories as necessary. If the name is not
382 * found or it corresponds to a directory entry, return NULL.
384 static struct ref_entry
*find_ref(struct ref_dir
*dir
, const char *refname
)
387 struct ref_entry
*entry
;
388 dir
= find_containing_dir(dir
, refname
, 0);
391 entry_index
= search_ref_dir(dir
, refname
, strlen(refname
));
392 if (entry_index
== -1)
394 entry
= dir
->entries
[entry_index
];
395 return (entry
->flag
& REF_DIR
) ? NULL
: entry
;
399 * Remove the entry with the given name from dir, recursing into
400 * subdirectories as necessary. If refname is the name of a directory
401 * (i.e., ends with '/'), then remove the directory and its contents.
402 * If the removal was successful, return the number of entries
403 * remaining in the directory entry that contained the deleted entry.
404 * If the name was not found, return -1. Please note that this
405 * function only deletes the entry from the cache; it does not delete
406 * it from the filesystem or ensure that other cache entries (which
407 * might be symbolic references to the removed entry) are updated.
408 * Nor does it remove any containing dir entries that might be made
409 * empty by the removal. dir must represent the top-level directory
410 * and must already be complete.
412 static int remove_entry(struct ref_dir
*dir
, const char *refname
)
414 int refname_len
= strlen(refname
);
416 struct ref_entry
*entry
;
417 int is_dir
= refname
[refname_len
- 1] == '/';
420 * refname represents a reference directory. Remove
421 * the trailing slash; otherwise we will get the
422 * directory *representing* refname rather than the
423 * one *containing* it.
425 char *dirname
= xmemdupz(refname
, refname_len
- 1);
426 dir
= find_containing_dir(dir
, dirname
, 0);
429 dir
= find_containing_dir(dir
, refname
, 0);
433 entry_index
= search_ref_dir(dir
, refname
, refname_len
);
434 if (entry_index
== -1)
436 entry
= dir
->entries
[entry_index
];
438 memmove(&dir
->entries
[entry_index
],
439 &dir
->entries
[entry_index
+ 1],
440 (dir
->nr
- entry_index
- 1) * sizeof(*dir
->entries
)
443 if (dir
->sorted
> entry_index
)
445 free_ref_entry(entry
);
450 * Add a ref_entry to the ref_dir (unsorted), recursing into
451 * subdirectories as necessary. dir must represent the top-level
452 * directory. Return 0 on success.
454 static int add_ref(struct ref_dir
*dir
, struct ref_entry
*ref
)
456 dir
= find_containing_dir(dir
, ref
->name
, 1);
459 add_entry_to_dir(dir
, ref
);
464 * Emit a warning and return true iff ref1 and ref2 have the same name
465 * and the same sha1. Die if they have the same name but different
468 static int is_dup_ref(const struct ref_entry
*ref1
, const struct ref_entry
*ref2
)
470 if (strcmp(ref1
->name
, ref2
->name
))
473 /* Duplicate name; make sure that they don't conflict: */
475 if ((ref1
->flag
& REF_DIR
) || (ref2
->flag
& REF_DIR
))
476 /* This is impossible by construction */
477 die("Reference directory conflict: %s", ref1
->name
);
479 if (oidcmp(&ref1
->u
.value
.oid
, &ref2
->u
.value
.oid
))
480 die("Duplicated ref, and SHA1s don't match: %s", ref1
->name
);
482 warning("Duplicated ref: %s", ref1
->name
);
487 * Sort the entries in dir non-recursively (if they are not already
488 * sorted) and remove any duplicate entries.
490 static void sort_ref_dir(struct ref_dir
*dir
)
493 struct ref_entry
*last
= NULL
;
496 * This check also prevents passing a zero-length array to qsort(),
497 * which is a problem on some platforms.
499 if (dir
->sorted
== dir
->nr
)
502 qsort(dir
->entries
, dir
->nr
, sizeof(*dir
->entries
), ref_entry_cmp
);
504 /* Remove any duplicates: */
505 for (i
= 0, j
= 0; j
< dir
->nr
; j
++) {
506 struct ref_entry
*entry
= dir
->entries
[j
];
507 if (last
&& is_dup_ref(last
, entry
))
508 free_ref_entry(entry
);
510 last
= dir
->entries
[i
++] = entry
;
512 dir
->sorted
= dir
->nr
= i
;
516 * Return true if refname, which has the specified oid and flags, can
517 * be resolved to an object in the database. If the referred-to object
518 * does not exist, emit a warning and return false.
520 static int ref_resolves_to_object(const char *refname
,
521 const struct object_id
*oid
,
524 if (flags
& REF_ISBROKEN
)
526 if (!has_sha1_file(oid
->hash
)) {
527 error("%s does not point to a valid object!", refname
);
534 * Return true if the reference described by entry can be resolved to
535 * an object in the database; otherwise, emit a warning and return
538 static int entry_resolves_to_object(struct ref_entry
*entry
)
540 return ref_resolves_to_object(entry
->name
,
541 &entry
->u
.value
.oid
, entry
->flag
);
545 * current_ref is a performance hack: when iterating over references
546 * using the for_each_ref*() functions, current_ref is set to the
547 * current reference's entry before calling the callback function. If
548 * the callback function calls peel_ref(), then peel_ref() first
549 * checks whether the reference to be peeled is the current reference
550 * (it usually is) and if so, returns that reference's peeled version
551 * if it is available. This avoids a refname lookup in a common case.
553 static struct ref_entry
*current_ref
;
555 typedef int each_ref_entry_fn(struct ref_entry
*entry
, void *cb_data
);
557 struct ref_entry_cb
{
566 * Handle one reference in a do_for_each_ref*()-style iteration,
567 * calling an each_ref_fn for each entry.
569 static int do_one_ref(struct ref_entry
*entry
, void *cb_data
)
571 struct ref_entry_cb
*data
= cb_data
;
572 struct ref_entry
*old_current_ref
;
575 if (!starts_with(entry
->name
, data
->prefix
))
578 if (!(data
->flags
& DO_FOR_EACH_INCLUDE_BROKEN
) &&
579 !entry_resolves_to_object(entry
))
582 /* Store the old value, in case this is a recursive call: */
583 old_current_ref
= current_ref
;
585 retval
= data
->fn(entry
->name
+ data
->trim
, &entry
->u
.value
.oid
,
586 entry
->flag
, data
->cb_data
);
587 current_ref
= old_current_ref
;
592 * Call fn for each reference in dir that has index in the range
593 * offset <= index < dir->nr. Recurse into subdirectories that are in
594 * that index range, sorting them before iterating. This function
595 * does not sort dir itself; it should be sorted beforehand. fn is
596 * called for all references, including broken ones.
598 static int do_for_each_entry_in_dir(struct ref_dir
*dir
, int offset
,
599 each_ref_entry_fn fn
, void *cb_data
)
602 assert(dir
->sorted
== dir
->nr
);
603 for (i
= offset
; i
< dir
->nr
; i
++) {
604 struct ref_entry
*entry
= dir
->entries
[i
];
606 if (entry
->flag
& REF_DIR
) {
607 struct ref_dir
*subdir
= get_ref_dir(entry
);
608 sort_ref_dir(subdir
);
609 retval
= do_for_each_entry_in_dir(subdir
, 0, fn
, cb_data
);
611 retval
= fn(entry
, cb_data
);
620 * Call fn for each reference in the union of dir1 and dir2, in order
621 * by refname. Recurse into subdirectories. If a value entry appears
622 * in both dir1 and dir2, then only process the version that is in
623 * dir2. The input dirs must already be sorted, but subdirs will be
624 * sorted as needed. fn is called for all references, including
627 static int do_for_each_entry_in_dirs(struct ref_dir
*dir1
,
628 struct ref_dir
*dir2
,
629 each_ref_entry_fn fn
, void *cb_data
)
634 assert(dir1
->sorted
== dir1
->nr
);
635 assert(dir2
->sorted
== dir2
->nr
);
637 struct ref_entry
*e1
, *e2
;
639 if (i1
== dir1
->nr
) {
640 return do_for_each_entry_in_dir(dir2
, i2
, fn
, cb_data
);
642 if (i2
== dir2
->nr
) {
643 return do_for_each_entry_in_dir(dir1
, i1
, fn
, cb_data
);
645 e1
= dir1
->entries
[i1
];
646 e2
= dir2
->entries
[i2
];
647 cmp
= strcmp(e1
->name
, e2
->name
);
649 if ((e1
->flag
& REF_DIR
) && (e2
->flag
& REF_DIR
)) {
650 /* Both are directories; descend them in parallel. */
651 struct ref_dir
*subdir1
= get_ref_dir(e1
);
652 struct ref_dir
*subdir2
= get_ref_dir(e2
);
653 sort_ref_dir(subdir1
);
654 sort_ref_dir(subdir2
);
655 retval
= do_for_each_entry_in_dirs(
656 subdir1
, subdir2
, fn
, cb_data
);
659 } else if (!(e1
->flag
& REF_DIR
) && !(e2
->flag
& REF_DIR
)) {
660 /* Both are references; ignore the one from dir1. */
661 retval
= fn(e2
, cb_data
);
665 die("conflict between reference and directory: %s",
677 if (e
->flag
& REF_DIR
) {
678 struct ref_dir
*subdir
= get_ref_dir(e
);
679 sort_ref_dir(subdir
);
680 retval
= do_for_each_entry_in_dir(
681 subdir
, 0, fn
, cb_data
);
683 retval
= fn(e
, cb_data
);
692 * Load all of the refs from the dir into our in-memory cache. The hard work
693 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
694 * through all of the sub-directories. We do not even need to care about
695 * sorting, as traversal order does not matter to us.
697 static void prime_ref_dir(struct ref_dir
*dir
)
700 for (i
= 0; i
< dir
->nr
; i
++) {
701 struct ref_entry
*entry
= dir
->entries
[i
];
702 if (entry
->flag
& REF_DIR
)
703 prime_ref_dir(get_ref_dir(entry
));
707 struct nonmatching_ref_data
{
708 const struct string_list
*skip
;
709 const char *conflicting_refname
;
712 static int nonmatching_ref_fn(struct ref_entry
*entry
, void *vdata
)
714 struct nonmatching_ref_data
*data
= vdata
;
716 if (data
->skip
&& string_list_has_string(data
->skip
, entry
->name
))
719 data
->conflicting_refname
= entry
->name
;
724 * Return 0 if a reference named refname could be created without
725 * conflicting with the name of an existing reference in dir.
726 * See verify_refname_available for more information.
728 static int verify_refname_available_dir(const char *refname
,
729 const struct string_list
*extras
,
730 const struct string_list
*skip
,
735 const char *extra_refname
;
737 struct strbuf dirname
= STRBUF_INIT
;
741 * For the sake of comments in this function, suppose that
742 * refname is "refs/foo/bar".
747 strbuf_grow(&dirname
, strlen(refname
) + 1);
748 for (slash
= strchr(refname
, '/'); slash
; slash
= strchr(slash
+ 1, '/')) {
749 /* Expand dirname to the new prefix, not including the trailing slash: */
750 strbuf_add(&dirname
, refname
+ dirname
.len
, slash
- refname
- dirname
.len
);
753 * We are still at a leading dir of the refname (e.g.,
754 * "refs/foo"; if there is a reference with that name,
755 * it is a conflict, *unless* it is in skip.
758 pos
= search_ref_dir(dir
, dirname
.buf
, dirname
.len
);
760 (!skip
|| !string_list_has_string(skip
, dirname
.buf
))) {
762 * We found a reference whose name is
763 * a proper prefix of refname; e.g.,
764 * "refs/foo", and is not in skip.
766 strbuf_addf(err
, "'%s' exists; cannot create '%s'",
767 dirname
.buf
, refname
);
772 if (extras
&& string_list_has_string(extras
, dirname
.buf
) &&
773 (!skip
|| !string_list_has_string(skip
, dirname
.buf
))) {
774 strbuf_addf(err
, "cannot process '%s' and '%s' at the same time",
775 refname
, dirname
.buf
);
780 * Otherwise, we can try to continue our search with
781 * the next component. So try to look up the
782 * directory, e.g., "refs/foo/". If we come up empty,
783 * we know there is nothing under this whole prefix,
784 * but even in that case we still have to continue the
785 * search for conflicts with extras.
787 strbuf_addch(&dirname
, '/');
789 pos
= search_ref_dir(dir
, dirname
.buf
, dirname
.len
);
792 * There was no directory "refs/foo/",
793 * so there is nothing under this
794 * whole prefix. So there is no need
795 * to continue looking for conflicting
796 * references. But we need to continue
797 * looking for conflicting extras.
801 dir
= get_ref_dir(dir
->entries
[pos
]);
807 * We are at the leaf of our refname (e.g., "refs/foo/bar").
808 * There is no point in searching for a reference with that
809 * name, because a refname isn't considered to conflict with
810 * itself. But we still need to check for references whose
811 * names are in the "refs/foo/bar/" namespace, because they
814 strbuf_addstr(&dirname
, refname
+ dirname
.len
);
815 strbuf_addch(&dirname
, '/');
818 pos
= search_ref_dir(dir
, dirname
.buf
, dirname
.len
);
822 * We found a directory named "$refname/"
823 * (e.g., "refs/foo/bar/"). It is a problem
824 * iff it contains any ref that is not in
827 struct nonmatching_ref_data data
;
830 data
.conflicting_refname
= NULL
;
831 dir
= get_ref_dir(dir
->entries
[pos
]);
833 if (do_for_each_entry_in_dir(dir
, 0, nonmatching_ref_fn
, &data
)) {
834 strbuf_addf(err
, "'%s' exists; cannot create '%s'",
835 data
.conflicting_refname
, refname
);
841 extra_refname
= find_descendant_ref(dirname
.buf
, extras
, skip
);
843 strbuf_addf(err
, "cannot process '%s' and '%s' at the same time",
844 refname
, extra_refname
);
849 strbuf_release(&dirname
);
853 struct packed_ref_cache
{
854 struct ref_entry
*root
;
857 * Count of references to the data structure in this instance,
858 * including the pointer from ref_cache::packed if any. The
859 * data will not be freed as long as the reference count is
862 unsigned int referrers
;
865 * Iff the packed-refs file associated with this instance is
866 * currently locked for writing, this points at the associated
867 * lock (which is owned by somebody else). The referrer count
868 * is also incremented when the file is locked and decremented
869 * when it is unlocked.
871 struct lock_file
*lock
;
873 /* The metadata from when this packed-refs cache was read */
874 struct stat_validity validity
;
878 * Future: need to be in "struct repository"
879 * when doing a full libification.
881 static struct ref_cache
{
882 struct ref_cache
*next
;
883 struct ref_entry
*loose
;
884 struct packed_ref_cache
*packed
;
886 * The submodule name, or "" for the main repo. We allocate
887 * length 1 rather than FLEX_ARRAY so that the main ref_cache
888 * is initialized correctly.
891 } ref_cache
, *submodule_ref_caches
;
893 /* Lock used for the main packed-refs file: */
894 static struct lock_file packlock
;
897 * Increment the reference count of *packed_refs.
899 static void acquire_packed_ref_cache(struct packed_ref_cache
*packed_refs
)
901 packed_refs
->referrers
++;
905 * Decrease the reference count of *packed_refs. If it goes to zero,
906 * free *packed_refs and return true; otherwise return false.
908 static int release_packed_ref_cache(struct packed_ref_cache
*packed_refs
)
910 if (!--packed_refs
->referrers
) {
911 free_ref_entry(packed_refs
->root
);
912 stat_validity_clear(&packed_refs
->validity
);
920 static void clear_packed_ref_cache(struct ref_cache
*refs
)
923 struct packed_ref_cache
*packed_refs
= refs
->packed
;
925 if (packed_refs
->lock
)
926 die("internal error: packed-ref cache cleared while locked");
928 release_packed_ref_cache(packed_refs
);
932 static void clear_loose_ref_cache(struct ref_cache
*refs
)
935 free_ref_entry(refs
->loose
);
941 * Create a new submodule ref cache and add it to the internal
944 static struct ref_cache
*create_ref_cache(const char *submodule
)
946 struct ref_cache
*refs
;
949 FLEX_ALLOC_STR(refs
, name
, submodule
);
950 refs
->next
= submodule_ref_caches
;
951 submodule_ref_caches
= refs
;
955 static struct ref_cache
*lookup_ref_cache(const char *submodule
)
957 struct ref_cache
*refs
;
959 if (!submodule
|| !*submodule
)
962 for (refs
= submodule_ref_caches
; refs
; refs
= refs
->next
)
963 if (!strcmp(submodule
, refs
->name
))
969 * Return a pointer to a ref_cache for the specified submodule. For
970 * the main repository, use submodule==NULL; such a call cannot fail.
971 * For a submodule, the submodule must exist and be a nonbare
972 * repository, otherwise return NULL.
974 * The returned structure will be allocated and initialized but not
975 * necessarily populated; it should not be freed.
977 static struct ref_cache
*get_ref_cache(const char *submodule
)
979 struct ref_cache
*refs
= lookup_ref_cache(submodule
);
982 struct strbuf submodule_sb
= STRBUF_INIT
;
984 strbuf_addstr(&submodule_sb
, submodule
);
985 if (is_nonbare_repository_dir(&submodule_sb
))
986 refs
= create_ref_cache(submodule
);
987 strbuf_release(&submodule_sb
);
993 /* The length of a peeled reference line in packed-refs, including EOL: */
994 #define PEELED_LINE_LENGTH 42
997 * The packed-refs header line that we write out. Perhaps other
998 * traits will be added later. The trailing space is required.
1000 static const char PACKED_REFS_HEADER
[] =
1001 "# pack-refs with: peeled fully-peeled \n";
1004 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
1005 * Return a pointer to the refname within the line (null-terminated),
1006 * or NULL if there was a problem.
1008 static const char *parse_ref_line(struct strbuf
*line
, unsigned char *sha1
)
1013 * 42: the answer to everything.
1015 * In this case, it happens to be the answer to
1016 * 40 (length of sha1 hex representation)
1017 * +1 (space in between hex and name)
1018 * +1 (newline at the end of the line)
1020 if (line
->len
<= 42)
1023 if (get_sha1_hex(line
->buf
, sha1
) < 0)
1025 if (!isspace(line
->buf
[40]))
1028 ref
= line
->buf
+ 41;
1032 if (line
->buf
[line
->len
- 1] != '\n')
1034 line
->buf
[--line
->len
] = 0;
1040 * Read f, which is a packed-refs file, into dir.
1042 * A comment line of the form "# pack-refs with: " may contain zero or
1043 * more traits. We interpret the traits as follows:
1047 * Probably no references are peeled. But if the file contains a
1048 * peeled value for a reference, we will use it.
1052 * References under "refs/tags/", if they *can* be peeled, *are*
1053 * peeled in this file. References outside of "refs/tags/" are
1054 * probably not peeled even if they could have been, but if we find
1055 * a peeled value for such a reference we will use it.
1059 * All references in the file that can be peeled are peeled.
1060 * Inversely (and this is more important), any references in the
1061 * file for which no peeled value is recorded is not peelable. This
1062 * trait should typically be written alongside "peeled" for
1063 * compatibility with older clients, but we do not require it
1064 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1066 static void read_packed_refs(FILE *f
, struct ref_dir
*dir
)
1068 struct ref_entry
*last
= NULL
;
1069 struct strbuf line
= STRBUF_INIT
;
1070 enum { PEELED_NONE
, PEELED_TAGS
, PEELED_FULLY
} peeled
= PEELED_NONE
;
1072 while (strbuf_getwholeline(&line
, f
, '\n') != EOF
) {
1073 unsigned char sha1
[20];
1074 const char *refname
;
1077 if (skip_prefix(line
.buf
, "# pack-refs with:", &traits
)) {
1078 if (strstr(traits
, " fully-peeled "))
1079 peeled
= PEELED_FULLY
;
1080 else if (strstr(traits
, " peeled "))
1081 peeled
= PEELED_TAGS
;
1082 /* perhaps other traits later as well */
1086 refname
= parse_ref_line(&line
, sha1
);
1088 int flag
= REF_ISPACKED
;
1090 if (check_refname_format(refname
, REFNAME_ALLOW_ONELEVEL
)) {
1091 if (!refname_is_safe(refname
))
1092 die("packed refname is dangerous: %s", refname
);
1094 flag
|= REF_BAD_NAME
| REF_ISBROKEN
;
1096 last
= create_ref_entry(refname
, sha1
, flag
, 0);
1097 if (peeled
== PEELED_FULLY
||
1098 (peeled
== PEELED_TAGS
&& starts_with(refname
, "refs/tags/")))
1099 last
->flag
|= REF_KNOWS_PEELED
;
1104 line
.buf
[0] == '^' &&
1105 line
.len
== PEELED_LINE_LENGTH
&&
1106 line
.buf
[PEELED_LINE_LENGTH
- 1] == '\n' &&
1107 !get_sha1_hex(line
.buf
+ 1, sha1
)) {
1108 hashcpy(last
->u
.value
.peeled
.hash
, sha1
);
1110 * Regardless of what the file header said,
1111 * we definitely know the value of *this*
1114 last
->flag
|= REF_KNOWS_PEELED
;
1118 strbuf_release(&line
);
1122 * Get the packed_ref_cache for the specified ref_cache, creating it
1125 static struct packed_ref_cache
*get_packed_ref_cache(struct ref_cache
*refs
)
1127 char *packed_refs_file
;
1130 packed_refs_file
= git_pathdup_submodule(refs
->name
, "packed-refs");
1132 packed_refs_file
= git_pathdup("packed-refs");
1135 !stat_validity_check(&refs
->packed
->validity
, packed_refs_file
))
1136 clear_packed_ref_cache(refs
);
1138 if (!refs
->packed
) {
1141 refs
->packed
= xcalloc(1, sizeof(*refs
->packed
));
1142 acquire_packed_ref_cache(refs
->packed
);
1143 refs
->packed
->root
= create_dir_entry(refs
, "", 0, 0);
1144 f
= fopen(packed_refs_file
, "r");
1146 stat_validity_update(&refs
->packed
->validity
, fileno(f
));
1147 read_packed_refs(f
, get_ref_dir(refs
->packed
->root
));
1151 free(packed_refs_file
);
1152 return refs
->packed
;
1155 static struct ref_dir
*get_packed_ref_dir(struct packed_ref_cache
*packed_ref_cache
)
1157 return get_ref_dir(packed_ref_cache
->root
);
1160 static struct ref_dir
*get_packed_refs(struct ref_cache
*refs
)
1162 return get_packed_ref_dir(get_packed_ref_cache(refs
));
1166 * Add a reference to the in-memory packed reference cache. This may
1167 * only be called while the packed-refs file is locked (see
1168 * lock_packed_refs()). To actually write the packed-refs file, call
1169 * commit_packed_refs().
1171 static void add_packed_ref(const char *refname
, const unsigned char *sha1
)
1173 struct packed_ref_cache
*packed_ref_cache
=
1174 get_packed_ref_cache(&ref_cache
);
1176 if (!packed_ref_cache
->lock
)
1177 die("internal error: packed refs not locked");
1178 add_ref(get_packed_ref_dir(packed_ref_cache
),
1179 create_ref_entry(refname
, sha1
, REF_ISPACKED
, 1));
1183 * Read the loose references from the namespace dirname into dir
1184 * (without recursing). dirname must end with '/'. dir must be the
1185 * directory entry corresponding to dirname.
1187 static void read_loose_refs(const char *dirname
, struct ref_dir
*dir
)
1189 struct ref_cache
*refs
= dir
->ref_cache
;
1192 int dirnamelen
= strlen(dirname
);
1193 struct strbuf refname
;
1194 struct strbuf path
= STRBUF_INIT
;
1195 size_t path_baselen
;
1198 strbuf_git_path_submodule(&path
, refs
->name
, "%s", dirname
);
1200 strbuf_git_path(&path
, "%s", dirname
);
1201 path_baselen
= path
.len
;
1203 d
= opendir(path
.buf
);
1205 strbuf_release(&path
);
1209 strbuf_init(&refname
, dirnamelen
+ 257);
1210 strbuf_add(&refname
, dirname
, dirnamelen
);
1212 while ((de
= readdir(d
)) != NULL
) {
1213 unsigned char sha1
[20];
1217 if (de
->d_name
[0] == '.')
1219 if (ends_with(de
->d_name
, ".lock"))
1221 strbuf_addstr(&refname
, de
->d_name
);
1222 strbuf_addstr(&path
, de
->d_name
);
1223 if (stat(path
.buf
, &st
) < 0) {
1224 ; /* silently ignore */
1225 } else if (S_ISDIR(st
.st_mode
)) {
1226 strbuf_addch(&refname
, '/');
1227 add_entry_to_dir(dir
,
1228 create_dir_entry(refs
, refname
.buf
,
1236 read_ok
= !resolve_gitlink_ref(refs
->name
,
1239 read_ok
= !read_ref_full(refname
.buf
,
1240 RESOLVE_REF_READING
,
1246 flag
|= REF_ISBROKEN
;
1247 } else if (is_null_sha1(sha1
)) {
1249 * It is so astronomically unlikely
1250 * that NULL_SHA1 is the SHA-1 of an
1251 * actual object that we consider its
1252 * appearance in a loose reference
1253 * file to be repo corruption
1254 * (probably due to a software bug).
1256 flag
|= REF_ISBROKEN
;
1259 if (check_refname_format(refname
.buf
,
1260 REFNAME_ALLOW_ONELEVEL
)) {
1261 if (!refname_is_safe(refname
.buf
))
1262 die("loose refname is dangerous: %s", refname
.buf
);
1264 flag
|= REF_BAD_NAME
| REF_ISBROKEN
;
1266 add_entry_to_dir(dir
,
1267 create_ref_entry(refname
.buf
, sha1
, flag
, 0));
1269 strbuf_setlen(&refname
, dirnamelen
);
1270 strbuf_setlen(&path
, path_baselen
);
1272 strbuf_release(&refname
);
1273 strbuf_release(&path
);
1277 static struct ref_dir
*get_loose_refs(struct ref_cache
*refs
)
1281 * Mark the top-level directory complete because we
1282 * are about to read the only subdirectory that can
1285 refs
->loose
= create_dir_entry(refs
, "", 0, 0);
1287 * Create an incomplete entry for "refs/":
1289 add_entry_to_dir(get_ref_dir(refs
->loose
),
1290 create_dir_entry(refs
, "refs/", 5, 1));
1292 return get_ref_dir(refs
->loose
);
1295 #define MAXREFLEN (1024)
1298 * Called by resolve_gitlink_ref_recursive() after it failed to read
1299 * from the loose refs in ref_cache refs. Find <refname> in the
1300 * packed-refs file for the submodule.
1302 static int resolve_gitlink_packed_ref(struct ref_cache
*refs
,
1303 const char *refname
, unsigned char *sha1
)
1305 struct ref_entry
*ref
;
1306 struct ref_dir
*dir
= get_packed_refs(refs
);
1308 ref
= find_ref(dir
, refname
);
1312 hashcpy(sha1
, ref
->u
.value
.oid
.hash
);
1316 static int resolve_gitlink_ref_recursive(struct ref_cache
*refs
,
1317 const char *refname
, unsigned char *sha1
,
1321 char buffer
[128], *p
;
1324 if (recursion
> SYMREF_MAXDEPTH
|| strlen(refname
) > MAXREFLEN
)
1327 ? git_pathdup_submodule(refs
->name
, "%s", refname
)
1328 : git_pathdup("%s", refname
);
1329 fd
= open(path
, O_RDONLY
);
1332 return resolve_gitlink_packed_ref(refs
, refname
, sha1
);
1334 len
= read(fd
, buffer
, sizeof(buffer
)-1);
1338 while (len
&& isspace(buffer
[len
-1]))
1342 /* Was it a detached head or an old-fashioned symlink? */
1343 if (!get_sha1_hex(buffer
, sha1
))
1347 if (strncmp(buffer
, "ref:", 4))
1353 return resolve_gitlink_ref_recursive(refs
, p
, sha1
, recursion
+1);
1356 int resolve_gitlink_ref(const char *path
, const char *refname
, unsigned char *sha1
)
1358 int len
= strlen(path
), retval
;
1359 struct strbuf submodule
= STRBUF_INIT
;
1360 struct ref_cache
*refs
;
1362 while (len
&& path
[len
-1] == '/')
1367 strbuf_add(&submodule
, path
, len
);
1368 refs
= get_ref_cache(submodule
.buf
);
1370 strbuf_release(&submodule
);
1373 strbuf_release(&submodule
);
1375 retval
= resolve_gitlink_ref_recursive(refs
, refname
, sha1
, 0);
1380 * Return the ref_entry for the given refname from the packed
1381 * references. If it does not exist, return NULL.
1383 static struct ref_entry
*get_packed_ref(const char *refname
)
1385 return find_ref(get_packed_refs(&ref_cache
), refname
);
1389 * A loose ref file doesn't exist; check for a packed ref.
1391 static int resolve_missing_loose_ref(const char *refname
,
1392 unsigned char *sha1
,
1393 unsigned int *flags
)
1395 struct ref_entry
*entry
;
1398 * The loose reference file does not exist; check for a packed
1401 entry
= get_packed_ref(refname
);
1403 hashcpy(sha1
, entry
->u
.value
.oid
.hash
);
1404 *flags
|= REF_ISPACKED
;
1407 /* refname is not a packed reference. */
1411 int read_raw_ref(const char *refname
, unsigned char *sha1
,
1412 struct strbuf
*referent
, unsigned int *type
)
1414 struct strbuf sb_contents
= STRBUF_INIT
;
1415 struct strbuf sb_path
= STRBUF_INIT
;
1424 strbuf_reset(&sb_path
);
1425 strbuf_git_path(&sb_path
, "%s", refname
);
1430 * We might have to loop back here to avoid a race
1431 * condition: first we lstat() the file, then we try
1432 * to read it as a link or as a file. But if somebody
1433 * changes the type of the file (file <-> directory
1434 * <-> symlink) between the lstat() and reading, then
1435 * we don't want to report that as an error but rather
1436 * try again starting with the lstat().
1439 if (lstat(path
, &st
) < 0) {
1440 if (errno
!= ENOENT
)
1442 if (resolve_missing_loose_ref(refname
, sha1
, type
)) {
1450 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1451 if (S_ISLNK(st
.st_mode
)) {
1452 strbuf_reset(&sb_contents
);
1453 if (strbuf_readlink(&sb_contents
, path
, 0) < 0) {
1454 if (errno
== ENOENT
|| errno
== EINVAL
)
1455 /* inconsistent with lstat; retry */
1460 if (starts_with(sb_contents
.buf
, "refs/") &&
1461 !check_refname_format(sb_contents
.buf
, 0)) {
1462 strbuf_swap(&sb_contents
, referent
);
1463 *type
|= REF_ISSYMREF
;
1469 /* Is it a directory? */
1470 if (S_ISDIR(st
.st_mode
)) {
1472 * Even though there is a directory where the loose
1473 * ref is supposed to be, there could still be a
1476 if (resolve_missing_loose_ref(refname
, sha1
, type
)) {
1485 * Anything else, just open it and try to use it as
1488 fd
= open(path
, O_RDONLY
);
1490 if (errno
== ENOENT
)
1491 /* inconsistent with lstat; retry */
1496 strbuf_reset(&sb_contents
);
1497 if (strbuf_read(&sb_contents
, fd
, 256) < 0) {
1498 int save_errno
= errno
;
1504 strbuf_rtrim(&sb_contents
);
1505 buf
= sb_contents
.buf
;
1506 if (starts_with(buf
, "ref:")) {
1508 while (isspace(*buf
))
1511 strbuf_reset(referent
);
1512 strbuf_addstr(referent
, buf
);
1513 *type
|= REF_ISSYMREF
;
1519 * Please note that FETCH_HEAD has additional
1520 * data after the sha.
1522 if (get_sha1_hex(buf
, sha1
) ||
1523 (buf
[40] != '\0' && !isspace(buf
[40]))) {
1524 *type
|= REF_ISBROKEN
;
1533 strbuf_release(&sb_path
);
1534 strbuf_release(&sb_contents
);
1539 static void unlock_ref(struct ref_lock
*lock
)
1541 /* Do not free lock->lk -- atexit() still looks at them */
1543 rollback_lock_file(lock
->lk
);
1544 free(lock
->ref_name
);
1549 * Lock refname, without following symrefs, and set *lock_p to point
1550 * at a newly-allocated lock object. Fill in lock->old_oid, referent,
1551 * and type similarly to read_raw_ref().
1553 * The caller must verify that refname is a "safe" reference name (in
1554 * the sense of refname_is_safe()) before calling this function.
1556 * If the reference doesn't already exist, verify that refname doesn't
1557 * have a D/F conflict with any existing references. extras and skip
1558 * are passed to verify_refname_available_dir() for this check.
1560 * If mustexist is not set and the reference is not found or is
1561 * broken, lock the reference anyway but clear sha1.
1563 * Return 0 on success. On failure, write an error message to err and
1564 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.
1566 * Implementation note: This function is basically
1571 * but it includes a lot more code to
1572 * - Deal with possible races with other processes
1573 * - Avoid calling verify_refname_available_dir() when it can be
1574 * avoided, namely if we were successfully able to read the ref
1575 * - Generate informative error messages in the case of failure
1577 static int lock_raw_ref(const char *refname
, int mustexist
,
1578 const struct string_list
*extras
,
1579 const struct string_list
*skip
,
1580 struct ref_lock
**lock_p
,
1581 struct strbuf
*referent
,
1585 struct ref_lock
*lock
;
1586 struct strbuf ref_file
= STRBUF_INIT
;
1587 int attempts_remaining
= 3;
1588 int ret
= TRANSACTION_GENERIC_ERROR
;
1593 /* First lock the file so it can't change out from under us. */
1595 *lock_p
= lock
= xcalloc(1, sizeof(*lock
));
1597 lock
->ref_name
= xstrdup(refname
);
1598 strbuf_git_path(&ref_file
, "%s", refname
);
1601 switch (safe_create_leading_directories(ref_file
.buf
)) {
1603 break; /* success */
1606 * Suppose refname is "refs/foo/bar". We just failed
1607 * to create the containing directory, "refs/foo",
1608 * because there was a non-directory in the way. This
1609 * indicates a D/F conflict, probably because of
1610 * another reference such as "refs/foo". There is no
1611 * reason to expect this error to be transitory.
1613 if (verify_refname_available(refname
, extras
, skip
, err
)) {
1616 * To the user the relevant error is
1617 * that the "mustexist" reference is
1621 strbuf_addf(err
, "unable to resolve reference '%s'",
1625 * The error message set by
1626 * verify_refname_available_dir() is OK.
1628 ret
= TRANSACTION_NAME_CONFLICT
;
1632 * The file that is in the way isn't a loose
1633 * reference. Report it as a low-level
1636 strbuf_addf(err
, "unable to create lock file %s.lock; "
1637 "non-directory in the way",
1642 /* Maybe another process was tidying up. Try again. */
1643 if (--attempts_remaining
> 0)
1647 strbuf_addf(err
, "unable to create directory for %s",
1653 lock
->lk
= xcalloc(1, sizeof(struct lock_file
));
1655 if (hold_lock_file_for_update(lock
->lk
, ref_file
.buf
, LOCK_NO_DEREF
) < 0) {
1656 if (errno
== ENOENT
&& --attempts_remaining
> 0) {
1658 * Maybe somebody just deleted one of the
1659 * directories leading to ref_file. Try
1664 unable_to_lock_message(ref_file
.buf
, errno
, err
);
1670 * Now we hold the lock and can read the reference without
1671 * fear that its value will change.
1674 if (read_raw_ref(refname
, lock
->old_oid
.hash
, referent
, type
)) {
1675 if (errno
== ENOENT
) {
1677 /* Garden variety missing reference. */
1678 strbuf_addf(err
, "unable to resolve reference '%s'",
1683 * Reference is missing, but that's OK. We
1684 * know that there is not a conflict with
1685 * another loose reference because
1686 * (supposing that we are trying to lock
1687 * reference "refs/foo/bar"):
1689 * - We were successfully able to create
1690 * the lockfile refs/foo/bar.lock, so we
1691 * know there cannot be a loose reference
1694 * - We got ENOENT and not EISDIR, so we
1695 * know that there cannot be a loose
1696 * reference named "refs/foo/bar/baz".
1699 } else if (errno
== EISDIR
) {
1701 * There is a directory in the way. It might have
1702 * contained references that have been deleted. If
1703 * we don't require that the reference already
1704 * exists, try to remove the directory so that it
1705 * doesn't cause trouble when we want to rename the
1706 * lockfile into place later.
1709 /* Garden variety missing reference. */
1710 strbuf_addf(err
, "unable to resolve reference '%s'",
1713 } else if (remove_dir_recursively(&ref_file
,
1714 REMOVE_DIR_EMPTY_ONLY
)) {
1715 if (verify_refname_available_dir(
1716 refname
, extras
, skip
,
1717 get_loose_refs(&ref_cache
),
1720 * The error message set by
1721 * verify_refname_available() is OK.
1723 ret
= TRANSACTION_NAME_CONFLICT
;
1727 * We can't delete the directory,
1728 * but we also don't know of any
1729 * references that it should
1732 strbuf_addf(err
, "there is a non-empty directory '%s' "
1733 "blocking reference '%s'",
1734 ref_file
.buf
, refname
);
1738 } else if (errno
== EINVAL
&& (*type
& REF_ISBROKEN
)) {
1739 strbuf_addf(err
, "unable to resolve reference '%s': "
1740 "reference broken", refname
);
1743 strbuf_addf(err
, "unable to resolve reference '%s': %s",
1744 refname
, strerror(errno
));
1749 * If the ref did not exist and we are creating it,
1750 * make sure there is no existing packed ref whose
1751 * name begins with our refname, nor a packed ref
1752 * whose name is a proper prefix of our refname.
1754 if (verify_refname_available_dir(
1755 refname
, extras
, skip
,
1756 get_packed_refs(&ref_cache
),
1770 strbuf_release(&ref_file
);
1775 * Peel the entry (if possible) and return its new peel_status. If
1776 * repeel is true, re-peel the entry even if there is an old peeled
1777 * value that is already stored in it.
1779 * It is OK to call this function with a packed reference entry that
1780 * might be stale and might even refer to an object that has since
1781 * been garbage-collected. In such a case, if the entry has
1782 * REF_KNOWS_PEELED then leave the status unchanged and return
1783 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1785 static enum peel_status
peel_entry(struct ref_entry
*entry
, int repeel
)
1787 enum peel_status status
;
1789 if (entry
->flag
& REF_KNOWS_PEELED
) {
1791 entry
->flag
&= ~REF_KNOWS_PEELED
;
1792 oidclr(&entry
->u
.value
.peeled
);
1794 return is_null_oid(&entry
->u
.value
.peeled
) ?
1795 PEEL_NON_TAG
: PEEL_PEELED
;
1798 if (entry
->flag
& REF_ISBROKEN
)
1800 if (entry
->flag
& REF_ISSYMREF
)
1801 return PEEL_IS_SYMREF
;
1803 status
= peel_object(entry
->u
.value
.oid
.hash
, entry
->u
.value
.peeled
.hash
);
1804 if (status
== PEEL_PEELED
|| status
== PEEL_NON_TAG
)
1805 entry
->flag
|= REF_KNOWS_PEELED
;
1809 int peel_ref(const char *refname
, unsigned char *sha1
)
1812 unsigned char base
[20];
1814 if (current_ref
&& (current_ref
->name
== refname
1815 || !strcmp(current_ref
->name
, refname
))) {
1816 if (peel_entry(current_ref
, 0))
1818 hashcpy(sha1
, current_ref
->u
.value
.peeled
.hash
);
1822 if (read_ref_full(refname
, RESOLVE_REF_READING
, base
, &flag
))
1826 * If the reference is packed, read its ref_entry from the
1827 * cache in the hope that we already know its peeled value.
1828 * We only try this optimization on packed references because
1829 * (a) forcing the filling of the loose reference cache could
1830 * be expensive and (b) loose references anyway usually do not
1831 * have REF_KNOWS_PEELED.
1833 if (flag
& REF_ISPACKED
) {
1834 struct ref_entry
*r
= get_packed_ref(refname
);
1836 if (peel_entry(r
, 0))
1838 hashcpy(sha1
, r
->u
.value
.peeled
.hash
);
1843 return peel_object(base
, sha1
);
1847 * Call fn for each reference in the specified ref_cache, omitting
1848 * references not in the containing_dir of prefix. Call fn for all
1849 * references, including broken ones. If fn ever returns a non-zero
1850 * value, stop the iteration and return that value; otherwise, return
1853 static int do_for_each_entry(struct ref_cache
*refs
, const char *prefix
,
1854 each_ref_entry_fn fn
, void *cb_data
)
1856 struct packed_ref_cache
*packed_ref_cache
;
1857 struct ref_dir
*loose_dir
;
1858 struct ref_dir
*packed_dir
;
1862 * We must make sure that all loose refs are read before accessing the
1863 * packed-refs file; this avoids a race condition in which loose refs
1864 * are migrated to the packed-refs file by a simultaneous process, but
1865 * our in-memory view is from before the migration. get_packed_ref_cache()
1866 * takes care of making sure our view is up to date with what is on
1869 loose_dir
= get_loose_refs(refs
);
1870 if (prefix
&& *prefix
) {
1871 loose_dir
= find_containing_dir(loose_dir
, prefix
, 0);
1874 prime_ref_dir(loose_dir
);
1876 packed_ref_cache
= get_packed_ref_cache(refs
);
1877 acquire_packed_ref_cache(packed_ref_cache
);
1878 packed_dir
= get_packed_ref_dir(packed_ref_cache
);
1879 if (prefix
&& *prefix
) {
1880 packed_dir
= find_containing_dir(packed_dir
, prefix
, 0);
1883 if (packed_dir
&& loose_dir
) {
1884 sort_ref_dir(packed_dir
);
1885 sort_ref_dir(loose_dir
);
1886 retval
= do_for_each_entry_in_dirs(
1887 packed_dir
, loose_dir
, fn
, cb_data
);
1888 } else if (packed_dir
) {
1889 sort_ref_dir(packed_dir
);
1890 retval
= do_for_each_entry_in_dir(
1891 packed_dir
, 0, fn
, cb_data
);
1892 } else if (loose_dir
) {
1893 sort_ref_dir(loose_dir
);
1894 retval
= do_for_each_entry_in_dir(
1895 loose_dir
, 0, fn
, cb_data
);
1898 release_packed_ref_cache(packed_ref_cache
);
1902 int do_for_each_ref(const char *submodule
, const char *prefix
,
1903 each_ref_fn fn
, int trim
, int flags
, void *cb_data
)
1905 struct ref_entry_cb data
;
1906 struct ref_cache
*refs
;
1908 refs
= get_ref_cache(submodule
);
1912 data
.prefix
= prefix
;
1916 data
.cb_data
= cb_data
;
1918 if (ref_paranoia
< 0)
1919 ref_paranoia
= git_env_bool("GIT_REF_PARANOIA", 0);
1921 data
.flags
|= DO_FOR_EACH_INCLUDE_BROKEN
;
1923 return do_for_each_entry(refs
, prefix
, do_one_ref
, &data
);
1927 * Verify that the reference locked by lock has the value old_sha1.
1928 * Fail if the reference doesn't exist and mustexist is set. Return 0
1929 * on success. On error, write an error message to err, set errno, and
1930 * return a negative value.
1932 static int verify_lock(struct ref_lock
*lock
,
1933 const unsigned char *old_sha1
, int mustexist
,
1938 if (read_ref_full(lock
->ref_name
,
1939 mustexist
? RESOLVE_REF_READING
: 0,
1940 lock
->old_oid
.hash
, NULL
)) {
1942 int save_errno
= errno
;
1943 strbuf_addf(err
, "can't verify ref '%s'", lock
->ref_name
);
1947 hashclr(lock
->old_oid
.hash
);
1951 if (old_sha1
&& hashcmp(lock
->old_oid
.hash
, old_sha1
)) {
1952 strbuf_addf(err
, "ref '%s' is at %s but expected %s",
1954 sha1_to_hex(lock
->old_oid
.hash
),
1955 sha1_to_hex(old_sha1
));
1962 static int remove_empty_directories(struct strbuf
*path
)
1965 * we want to create a file but there is a directory there;
1966 * if that is an empty directory (or a directory that contains
1967 * only empty directories), remove them.
1969 return remove_dir_recursively(path
, REMOVE_DIR_EMPTY_ONLY
);
1973 * Locks a ref returning the lock on success and NULL on failure.
1974 * On failure errno is set to something meaningful.
1976 static struct ref_lock
*lock_ref_sha1_basic(const char *refname
,
1977 const unsigned char *old_sha1
,
1978 const struct string_list
*extras
,
1979 const struct string_list
*skip
,
1980 unsigned int flags
, int *type
,
1983 struct strbuf ref_file
= STRBUF_INIT
;
1984 struct ref_lock
*lock
;
1986 int lflags
= LOCK_NO_DEREF
;
1987 int mustexist
= (old_sha1
&& !is_null_sha1(old_sha1
));
1988 int resolve_flags
= RESOLVE_REF_NO_RECURSE
;
1989 int attempts_remaining
= 3;
1994 lock
= xcalloc(1, sizeof(struct ref_lock
));
1997 resolve_flags
|= RESOLVE_REF_READING
;
1998 if (flags
& REF_DELETING
)
1999 resolve_flags
|= RESOLVE_REF_ALLOW_BAD_NAME
;
2001 strbuf_git_path(&ref_file
, "%s", refname
);
2002 resolved
= !!resolve_ref_unsafe(refname
, resolve_flags
,
2003 lock
->old_oid
.hash
, type
);
2004 if (!resolved
&& errno
== EISDIR
) {
2006 * we are trying to lock foo but we used to
2007 * have foo/bar which now does not exist;
2008 * it is normal for the empty directory 'foo'
2011 if (remove_empty_directories(&ref_file
)) {
2013 if (!verify_refname_available_dir(refname
, extras
, skip
,
2014 get_loose_refs(&ref_cache
), err
))
2015 strbuf_addf(err
, "there are still refs under '%s'",
2019 resolved
= !!resolve_ref_unsafe(refname
, resolve_flags
,
2020 lock
->old_oid
.hash
, type
);
2024 if (last_errno
!= ENOTDIR
||
2025 !verify_refname_available_dir(refname
, extras
, skip
,
2026 get_loose_refs(&ref_cache
), err
))
2027 strbuf_addf(err
, "unable to resolve reference '%s': %s",
2028 refname
, strerror(last_errno
));
2034 * If the ref did not exist and we are creating it, make sure
2035 * there is no existing packed ref whose name begins with our
2036 * refname, nor a packed ref whose name is a proper prefix of
2039 if (is_null_oid(&lock
->old_oid
) &&
2040 verify_refname_available_dir(refname
, extras
, skip
,
2041 get_packed_refs(&ref_cache
), err
)) {
2042 last_errno
= ENOTDIR
;
2046 lock
->lk
= xcalloc(1, sizeof(struct lock_file
));
2048 lock
->ref_name
= xstrdup(refname
);
2051 switch (safe_create_leading_directories_const(ref_file
.buf
)) {
2053 break; /* success */
2055 if (--attempts_remaining
> 0)
2060 strbuf_addf(err
, "unable to create directory for '%s'",
2065 if (hold_lock_file_for_update(lock
->lk
, ref_file
.buf
, lflags
) < 0) {
2067 if (errno
== ENOENT
&& --attempts_remaining
> 0)
2069 * Maybe somebody just deleted one of the
2070 * directories leading to ref_file. Try
2075 unable_to_lock_message(ref_file
.buf
, errno
, err
);
2079 if (verify_lock(lock
, old_sha1
, mustexist
, err
)) {
2090 strbuf_release(&ref_file
);
2096 * Write an entry to the packed-refs file for the specified refname.
2097 * If peeled is non-NULL, write it as the entry's peeled value.
2099 static void write_packed_entry(FILE *fh
, char *refname
, unsigned char *sha1
,
2100 unsigned char *peeled
)
2102 fprintf_or_die(fh
, "%s %s\n", sha1_to_hex(sha1
), refname
);
2104 fprintf_or_die(fh
, "^%s\n", sha1_to_hex(peeled
));
2108 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2110 static int write_packed_entry_fn(struct ref_entry
*entry
, void *cb_data
)
2112 enum peel_status peel_status
= peel_entry(entry
, 0);
2114 if (peel_status
!= PEEL_PEELED
&& peel_status
!= PEEL_NON_TAG
)
2115 error("internal error: %s is not a valid packed reference!",
2117 write_packed_entry(cb_data
, entry
->name
, entry
->u
.value
.oid
.hash
,
2118 peel_status
== PEEL_PEELED
?
2119 entry
->u
.value
.peeled
.hash
: NULL
);
2124 * Lock the packed-refs file for writing. Flags is passed to
2125 * hold_lock_file_for_update(). Return 0 on success. On errors, set
2126 * errno appropriately and return a nonzero value.
2128 static int lock_packed_refs(int flags
)
2130 static int timeout_configured
= 0;
2131 static int timeout_value
= 1000;
2133 struct packed_ref_cache
*packed_ref_cache
;
2135 if (!timeout_configured
) {
2136 git_config_get_int("core.packedrefstimeout", &timeout_value
);
2137 timeout_configured
= 1;
2140 if (hold_lock_file_for_update_timeout(
2141 &packlock
, git_path("packed-refs"),
2142 flags
, timeout_value
) < 0)
2145 * Get the current packed-refs while holding the lock. If the
2146 * packed-refs file has been modified since we last read it,
2147 * this will automatically invalidate the cache and re-read
2148 * the packed-refs file.
2150 packed_ref_cache
= get_packed_ref_cache(&ref_cache
);
2151 packed_ref_cache
->lock
= &packlock
;
2152 /* Increment the reference count to prevent it from being freed: */
2153 acquire_packed_ref_cache(packed_ref_cache
);
2158 * Write the current version of the packed refs cache from memory to
2159 * disk. The packed-refs file must already be locked for writing (see
2160 * lock_packed_refs()). Return zero on success. On errors, set errno
2161 * and return a nonzero value
2163 static int commit_packed_refs(void)
2165 struct packed_ref_cache
*packed_ref_cache
=
2166 get_packed_ref_cache(&ref_cache
);
2171 if (!packed_ref_cache
->lock
)
2172 die("internal error: packed-refs not locked");
2174 out
= fdopen_lock_file(packed_ref_cache
->lock
, "w");
2176 die_errno("unable to fdopen packed-refs descriptor");
2178 fprintf_or_die(out
, "%s", PACKED_REFS_HEADER
);
2179 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache
),
2180 0, write_packed_entry_fn
, out
);
2182 if (commit_lock_file(packed_ref_cache
->lock
)) {
2186 packed_ref_cache
->lock
= NULL
;
2187 release_packed_ref_cache(packed_ref_cache
);
2193 * Rollback the lockfile for the packed-refs file, and discard the
2194 * in-memory packed reference cache. (The packed-refs file will be
2195 * read anew if it is needed again after this function is called.)
2197 static void rollback_packed_refs(void)
2199 struct packed_ref_cache
*packed_ref_cache
=
2200 get_packed_ref_cache(&ref_cache
);
2202 if (!packed_ref_cache
->lock
)
2203 die("internal error: packed-refs not locked");
2204 rollback_lock_file(packed_ref_cache
->lock
);
2205 packed_ref_cache
->lock
= NULL
;
2206 release_packed_ref_cache(packed_ref_cache
);
2207 clear_packed_ref_cache(&ref_cache
);
2210 struct ref_to_prune
{
2211 struct ref_to_prune
*next
;
2212 unsigned char sha1
[20];
2213 char name
[FLEX_ARRAY
];
2216 struct pack_refs_cb_data
{
2218 struct ref_dir
*packed_refs
;
2219 struct ref_to_prune
*ref_to_prune
;
2223 * An each_ref_entry_fn that is run over loose references only. If
2224 * the loose reference can be packed, add an entry in the packed ref
2225 * cache. If the reference should be pruned, also add it to
2226 * ref_to_prune in the pack_refs_cb_data.
2228 static int pack_if_possible_fn(struct ref_entry
*entry
, void *cb_data
)
2230 struct pack_refs_cb_data
*cb
= cb_data
;
2231 enum peel_status peel_status
;
2232 struct ref_entry
*packed_entry
;
2233 int is_tag_ref
= starts_with(entry
->name
, "refs/tags/");
2235 /* Do not pack per-worktree refs: */
2236 if (ref_type(entry
->name
) != REF_TYPE_NORMAL
)
2239 /* ALWAYS pack tags */
2240 if (!(cb
->flags
& PACK_REFS_ALL
) && !is_tag_ref
)
2243 /* Do not pack symbolic or broken refs: */
2244 if ((entry
->flag
& REF_ISSYMREF
) || !entry_resolves_to_object(entry
))
2247 /* Add a packed ref cache entry equivalent to the loose entry. */
2248 peel_status
= peel_entry(entry
, 1);
2249 if (peel_status
!= PEEL_PEELED
&& peel_status
!= PEEL_NON_TAG
)
2250 die("internal error peeling reference %s (%s)",
2251 entry
->name
, oid_to_hex(&entry
->u
.value
.oid
));
2252 packed_entry
= find_ref(cb
->packed_refs
, entry
->name
);
2254 /* Overwrite existing packed entry with info from loose entry */
2255 packed_entry
->flag
= REF_ISPACKED
| REF_KNOWS_PEELED
;
2256 oidcpy(&packed_entry
->u
.value
.oid
, &entry
->u
.value
.oid
);
2258 packed_entry
= create_ref_entry(entry
->name
, entry
->u
.value
.oid
.hash
,
2259 REF_ISPACKED
| REF_KNOWS_PEELED
, 0);
2260 add_ref(cb
->packed_refs
, packed_entry
);
2262 oidcpy(&packed_entry
->u
.value
.peeled
, &entry
->u
.value
.peeled
);
2264 /* Schedule the loose reference for pruning if requested. */
2265 if ((cb
->flags
& PACK_REFS_PRUNE
)) {
2266 struct ref_to_prune
*n
;
2267 FLEX_ALLOC_STR(n
, name
, entry
->name
);
2268 hashcpy(n
->sha1
, entry
->u
.value
.oid
.hash
);
2269 n
->next
= cb
->ref_to_prune
;
2270 cb
->ref_to_prune
= n
;
2276 * Remove empty parents, but spare refs/ and immediate subdirs.
2277 * Note: munges *name.
2279 static void try_remove_empty_parents(char *name
)
2284 for (i
= 0; i
< 2; i
++) { /* refs/{heads,tags,...}/ */
2285 while (*p
&& *p
!= '/')
2287 /* tolerate duplicate slashes; see check_refname_format() */
2291 for (q
= p
; *q
; q
++)
2294 while (q
> p
&& *q
!= '/')
2296 while (q
> p
&& *(q
-1) == '/')
2301 if (rmdir(git_path("%s", name
)))
2306 /* make sure nobody touched the ref, and unlink */
2307 static void prune_ref(struct ref_to_prune
*r
)
2309 struct ref_transaction
*transaction
;
2310 struct strbuf err
= STRBUF_INIT
;
2312 if (check_refname_format(r
->name
, 0))
2315 transaction
= ref_transaction_begin(&err
);
2317 ref_transaction_delete(transaction
, r
->name
, r
->sha1
,
2318 REF_ISPRUNING
| REF_NODEREF
, NULL
, &err
) ||
2319 ref_transaction_commit(transaction
, &err
)) {
2320 ref_transaction_free(transaction
);
2321 error("%s", err
.buf
);
2322 strbuf_release(&err
);
2325 ref_transaction_free(transaction
);
2326 strbuf_release(&err
);
2327 try_remove_empty_parents(r
->name
);
2330 static void prune_refs(struct ref_to_prune
*r
)
2338 int pack_refs(unsigned int flags
)
2340 struct pack_refs_cb_data cbdata
;
2342 memset(&cbdata
, 0, sizeof(cbdata
));
2343 cbdata
.flags
= flags
;
2345 lock_packed_refs(LOCK_DIE_ON_ERROR
);
2346 cbdata
.packed_refs
= get_packed_refs(&ref_cache
);
2348 do_for_each_entry_in_dir(get_loose_refs(&ref_cache
), 0,
2349 pack_if_possible_fn
, &cbdata
);
2351 if (commit_packed_refs())
2352 die_errno("unable to overwrite old ref-pack file");
2354 prune_refs(cbdata
.ref_to_prune
);
2359 * Rewrite the packed-refs file, omitting any refs listed in
2360 * 'refnames'. On error, leave packed-refs unchanged, write an error
2361 * message to 'err', and return a nonzero value.
2363 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.
2365 static int repack_without_refs(struct string_list
*refnames
, struct strbuf
*err
)
2367 struct ref_dir
*packed
;
2368 struct string_list_item
*refname
;
2369 int ret
, needs_repacking
= 0, removed
= 0;
2373 /* Look for a packed ref */
2374 for_each_string_list_item(refname
, refnames
) {
2375 if (get_packed_ref(refname
->string
)) {
2376 needs_repacking
= 1;
2381 /* Avoid locking if we have nothing to do */
2382 if (!needs_repacking
)
2383 return 0; /* no refname exists in packed refs */
2385 if (lock_packed_refs(0)) {
2386 unable_to_lock_message(git_path("packed-refs"), errno
, err
);
2389 packed
= get_packed_refs(&ref_cache
);
2391 /* Remove refnames from the cache */
2392 for_each_string_list_item(refname
, refnames
)
2393 if (remove_entry(packed
, refname
->string
) != -1)
2397 * All packed entries disappeared while we were
2398 * acquiring the lock.
2400 rollback_packed_refs();
2404 /* Write what remains */
2405 ret
= commit_packed_refs();
2407 strbuf_addf(err
, "unable to overwrite old ref-pack file: %s",
2412 static int delete_ref_loose(struct ref_lock
*lock
, int flag
, struct strbuf
*err
)
2416 if (!(flag
& REF_ISPACKED
) || flag
& REF_ISSYMREF
) {
2418 * loose. The loose file name is the same as the
2419 * lockfile name, minus ".lock":
2421 char *loose_filename
= get_locked_file_path(lock
->lk
);
2422 int res
= unlink_or_msg(loose_filename
, err
);
2423 free(loose_filename
);
2430 int delete_refs(struct string_list
*refnames
, unsigned int flags
)
2432 struct strbuf err
= STRBUF_INIT
;
2438 result
= repack_without_refs(refnames
, &err
);
2441 * If we failed to rewrite the packed-refs file, then
2442 * it is unsafe to try to remove loose refs, because
2443 * doing so might expose an obsolete packed value for
2444 * a reference that might even point at an object that
2445 * has been garbage collected.
2447 if (refnames
->nr
== 1)
2448 error(_("could not delete reference %s: %s"),
2449 refnames
->items
[0].string
, err
.buf
);
2451 error(_("could not delete references: %s"), err
.buf
);
2456 for (i
= 0; i
< refnames
->nr
; i
++) {
2457 const char *refname
= refnames
->items
[i
].string
;
2459 if (delete_ref(refname
, NULL
, flags
))
2460 result
|= error(_("could not remove reference %s"), refname
);
2464 strbuf_release(&err
);
2469 * People using contrib's git-new-workdir have .git/logs/refs ->
2470 * /some/other/path/.git/logs/refs, and that may live on another device.
2472 * IOW, to avoid cross device rename errors, the temporary renamed log must
2473 * live into logs/refs.
2475 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2477 static int rename_tmp_log(const char *newrefname
)
2479 int attempts_remaining
= 4;
2480 struct strbuf path
= STRBUF_INIT
;
2484 strbuf_reset(&path
);
2485 strbuf_git_path(&path
, "logs/%s", newrefname
);
2486 switch (safe_create_leading_directories_const(path
.buf
)) {
2488 break; /* success */
2490 if (--attempts_remaining
> 0)
2494 error("unable to create directory for %s", newrefname
);
2498 if (rename(git_path(TMP_RENAMED_LOG
), path
.buf
)) {
2499 if ((errno
==EISDIR
|| errno
==ENOTDIR
) && --attempts_remaining
> 0) {
2501 * rename(a, b) when b is an existing
2502 * directory ought to result in ISDIR, but
2503 * Solaris 5.8 gives ENOTDIR. Sheesh.
2505 if (remove_empty_directories(&path
)) {
2506 error("Directory not empty: logs/%s", newrefname
);
2510 } else if (errno
== ENOENT
&& --attempts_remaining
> 0) {
2512 * Maybe another process just deleted one of
2513 * the directories in the path to newrefname.
2514 * Try again from the beginning.
2518 error("unable to move logfile "TMP_RENAMED_LOG
" to logs/%s: %s",
2519 newrefname
, strerror(errno
));
2525 strbuf_release(&path
);
2529 int verify_refname_available(const char *newname
,
2530 const struct string_list
*extras
,
2531 const struct string_list
*skip
,
2534 struct ref_dir
*packed_refs
= get_packed_refs(&ref_cache
);
2535 struct ref_dir
*loose_refs
= get_loose_refs(&ref_cache
);
2537 if (verify_refname_available_dir(newname
, extras
, skip
,
2538 packed_refs
, err
) ||
2539 verify_refname_available_dir(newname
, extras
, skip
,
2546 static int write_ref_to_lockfile(struct ref_lock
*lock
,
2547 const unsigned char *sha1
, struct strbuf
*err
);
2548 static int commit_ref_update(struct ref_lock
*lock
,
2549 const unsigned char *sha1
, const char *logmsg
,
2550 struct strbuf
*err
);
2552 int rename_ref(const char *oldrefname
, const char *newrefname
, const char *logmsg
)
2554 unsigned char sha1
[20], orig_sha1
[20];
2555 int flag
= 0, logmoved
= 0;
2556 struct ref_lock
*lock
;
2557 struct stat loginfo
;
2558 int log
= !lstat(git_path("logs/%s", oldrefname
), &loginfo
);
2559 struct strbuf err
= STRBUF_INIT
;
2561 if (log
&& S_ISLNK(loginfo
.st_mode
))
2562 return error("reflog for %s is a symlink", oldrefname
);
2564 if (!resolve_ref_unsafe(oldrefname
, RESOLVE_REF_READING
| RESOLVE_REF_NO_RECURSE
,
2566 return error("refname %s not found", oldrefname
);
2568 if (flag
& REF_ISSYMREF
)
2569 return error("refname %s is a symbolic ref, renaming it is not supported",
2571 if (!rename_ref_available(oldrefname
, newrefname
))
2574 if (log
&& rename(git_path("logs/%s", oldrefname
), git_path(TMP_RENAMED_LOG
)))
2575 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG
": %s",
2576 oldrefname
, strerror(errno
));
2578 if (delete_ref(oldrefname
, orig_sha1
, REF_NODEREF
)) {
2579 error("unable to delete old %s", oldrefname
);
2584 * Since we are doing a shallow lookup, sha1 is not the
2585 * correct value to pass to delete_ref as old_sha1. But that
2586 * doesn't matter, because an old_sha1 check wouldn't add to
2587 * the safety anyway; we want to delete the reference whatever
2588 * its current value.
2590 if (!read_ref_full(newrefname
, RESOLVE_REF_READING
| RESOLVE_REF_NO_RECURSE
,
2592 delete_ref(newrefname
, NULL
, REF_NODEREF
)) {
2593 if (errno
==EISDIR
) {
2594 struct strbuf path
= STRBUF_INIT
;
2597 strbuf_git_path(&path
, "%s", newrefname
);
2598 result
= remove_empty_directories(&path
);
2599 strbuf_release(&path
);
2602 error("Directory not empty: %s", newrefname
);
2606 error("unable to delete existing %s", newrefname
);
2611 if (log
&& rename_tmp_log(newrefname
))
2616 lock
= lock_ref_sha1_basic(newrefname
, NULL
, NULL
, NULL
, REF_NODEREF
,
2619 error("unable to rename '%s' to '%s': %s", oldrefname
, newrefname
, err
.buf
);
2620 strbuf_release(&err
);
2623 hashcpy(lock
->old_oid
.hash
, orig_sha1
);
2625 if (write_ref_to_lockfile(lock
, orig_sha1
, &err
) ||
2626 commit_ref_update(lock
, orig_sha1
, logmsg
, &err
)) {
2627 error("unable to write current sha1 into %s: %s", newrefname
, err
.buf
);
2628 strbuf_release(&err
);
2635 lock
= lock_ref_sha1_basic(oldrefname
, NULL
, NULL
, NULL
, REF_NODEREF
,
2638 error("unable to lock %s for rollback: %s", oldrefname
, err
.buf
);
2639 strbuf_release(&err
);
2643 flag
= log_all_ref_updates
;
2644 log_all_ref_updates
= 0;
2645 if (write_ref_to_lockfile(lock
, orig_sha1
, &err
) ||
2646 commit_ref_update(lock
, orig_sha1
, NULL
, &err
)) {
2647 error("unable to write current sha1 into %s: %s", oldrefname
, err
.buf
);
2648 strbuf_release(&err
);
2650 log_all_ref_updates
= flag
;
2653 if (logmoved
&& rename(git_path("logs/%s", newrefname
), git_path("logs/%s", oldrefname
)))
2654 error("unable to restore logfile %s from %s: %s",
2655 oldrefname
, newrefname
, strerror(errno
));
2656 if (!logmoved
&& log
&&
2657 rename(git_path(TMP_RENAMED_LOG
), git_path("logs/%s", oldrefname
)))
2658 error("unable to restore logfile %s from "TMP_RENAMED_LOG
": %s",
2659 oldrefname
, strerror(errno
));
2664 static int close_ref(struct ref_lock
*lock
)
2666 if (close_lock_file(lock
->lk
))
2671 static int commit_ref(struct ref_lock
*lock
)
2673 char *path
= get_locked_file_path(lock
->lk
);
2676 if (!lstat(path
, &st
) && S_ISDIR(st
.st_mode
)) {
2678 * There is a directory at the path we want to rename
2679 * the lockfile to. Hopefully it is empty; try to
2682 size_t len
= strlen(path
);
2683 struct strbuf sb_path
= STRBUF_INIT
;
2685 strbuf_attach(&sb_path
, path
, len
, len
);
2688 * If this fails, commit_lock_file() will also fail
2689 * and will report the problem.
2691 remove_empty_directories(&sb_path
);
2692 strbuf_release(&sb_path
);
2697 if (commit_lock_file(lock
->lk
))
2703 * Create a reflog for a ref. If force_create = 0, the reflog will
2704 * only be created for certain refs (those for which
2705 * should_autocreate_reflog returns non-zero. Otherwise, create it
2706 * regardless of the ref name. Fill in *err and return -1 on failure.
2708 static int log_ref_setup(const char *refname
, struct strbuf
*logfile
, struct strbuf
*err
, int force_create
)
2710 int logfd
, oflags
= O_APPEND
| O_WRONLY
;
2712 strbuf_git_path(logfile
, "logs/%s", refname
);
2713 if (force_create
|| should_autocreate_reflog(refname
)) {
2714 if (safe_create_leading_directories(logfile
->buf
) < 0) {
2715 strbuf_addf(err
, "unable to create directory for '%s': "
2716 "%s", logfile
->buf
, strerror(errno
));
2722 logfd
= open(logfile
->buf
, oflags
, 0666);
2724 if (!(oflags
& O_CREAT
) && (errno
== ENOENT
|| errno
== EISDIR
))
2727 if (errno
== EISDIR
) {
2728 if (remove_empty_directories(logfile
)) {
2729 strbuf_addf(err
, "there are still logs under "
2730 "'%s'", logfile
->buf
);
2733 logfd
= open(logfile
->buf
, oflags
, 0666);
2737 strbuf_addf(err
, "unable to append to '%s': %s",
2738 logfile
->buf
, strerror(errno
));
2743 adjust_shared_perm(logfile
->buf
);
2749 int safe_create_reflog(const char *refname
, int force_create
, struct strbuf
*err
)
2752 struct strbuf sb
= STRBUF_INIT
;
2754 ret
= log_ref_setup(refname
, &sb
, err
, force_create
);
2755 strbuf_release(&sb
);
2759 static int log_ref_write_fd(int fd
, const unsigned char *old_sha1
,
2760 const unsigned char *new_sha1
,
2761 const char *committer
, const char *msg
)
2763 int msglen
, written
;
2764 unsigned maxlen
, len
;
2767 msglen
= msg
? strlen(msg
) : 0;
2768 maxlen
= strlen(committer
) + msglen
+ 100;
2769 logrec
= xmalloc(maxlen
);
2770 len
= xsnprintf(logrec
, maxlen
, "%s %s %s\n",
2771 sha1_to_hex(old_sha1
),
2772 sha1_to_hex(new_sha1
),
2775 len
+= copy_reflog_msg(logrec
+ len
- 1, msg
) - 1;
2777 written
= len
<= maxlen
? write_in_full(fd
, logrec
, len
) : -1;
2785 static int log_ref_write_1(const char *refname
, const unsigned char *old_sha1
,
2786 const unsigned char *new_sha1
, const char *msg
,
2787 struct strbuf
*logfile
, int flags
,
2790 int logfd
, result
, oflags
= O_APPEND
| O_WRONLY
;
2792 if (log_all_ref_updates
< 0)
2793 log_all_ref_updates
= !is_bare_repository();
2795 result
= log_ref_setup(refname
, logfile
, err
, flags
& REF_FORCE_CREATE_REFLOG
);
2800 logfd
= open(logfile
->buf
, oflags
);
2803 result
= log_ref_write_fd(logfd
, old_sha1
, new_sha1
,
2804 git_committer_info(0), msg
);
2806 strbuf_addf(err
, "unable to append to '%s': %s", logfile
->buf
,
2812 strbuf_addf(err
, "unable to append to '%s': %s", logfile
->buf
,
2819 static int log_ref_write(const char *refname
, const unsigned char *old_sha1
,
2820 const unsigned char *new_sha1
, const char *msg
,
2821 int flags
, struct strbuf
*err
)
2823 return files_log_ref_write(refname
, old_sha1
, new_sha1
, msg
, flags
,
2827 int files_log_ref_write(const char *refname
, const unsigned char *old_sha1
,
2828 const unsigned char *new_sha1
, const char *msg
,
2829 int flags
, struct strbuf
*err
)
2831 struct strbuf sb
= STRBUF_INIT
;
2832 int ret
= log_ref_write_1(refname
, old_sha1
, new_sha1
, msg
, &sb
, flags
,
2834 strbuf_release(&sb
);
2839 * Write sha1 into the open lockfile, then close the lockfile. On
2840 * errors, rollback the lockfile, fill in *err and
2843 static int write_ref_to_lockfile(struct ref_lock
*lock
,
2844 const unsigned char *sha1
, struct strbuf
*err
)
2846 static char term
= '\n';
2850 o
= parse_object(sha1
);
2853 "trying to write ref '%s' with nonexistent object %s",
2854 lock
->ref_name
, sha1_to_hex(sha1
));
2858 if (o
->type
!= OBJ_COMMIT
&& is_branch(lock
->ref_name
)) {
2860 "trying to write non-commit object %s to branch '%s'",
2861 sha1_to_hex(sha1
), lock
->ref_name
);
2865 fd
= get_lock_file_fd(lock
->lk
);
2866 if (write_in_full(fd
, sha1_to_hex(sha1
), 40) != 40 ||
2867 write_in_full(fd
, &term
, 1) != 1 ||
2868 close_ref(lock
) < 0) {
2870 "couldn't write '%s'", get_lock_file_path(lock
->lk
));
2878 * Commit a change to a loose reference that has already been written
2879 * to the loose reference lockfile. Also update the reflogs if
2880 * necessary, using the specified lockmsg (which can be NULL).
2882 static int commit_ref_update(struct ref_lock
*lock
,
2883 const unsigned char *sha1
, const char *logmsg
,
2886 clear_loose_ref_cache(&ref_cache
);
2887 if (log_ref_write(lock
->ref_name
, lock
->old_oid
.hash
, sha1
, logmsg
, 0, err
)) {
2888 char *old_msg
= strbuf_detach(err
, NULL
);
2889 strbuf_addf(err
, "cannot update the ref '%s': %s",
2890 lock
->ref_name
, old_msg
);
2896 if (strcmp(lock
->ref_name
, "HEAD") != 0) {
2898 * Special hack: If a branch is updated directly and HEAD
2899 * points to it (may happen on the remote side of a push
2900 * for example) then logically the HEAD reflog should be
2902 * A generic solution implies reverse symref information,
2903 * but finding all symrefs pointing to the given branch
2904 * would be rather costly for this rare event (the direct
2905 * update of a branch) to be worth it. So let's cheat and
2906 * check with HEAD only which should cover 99% of all usage
2907 * scenarios (even 100% of the default ones).
2909 unsigned char head_sha1
[20];
2911 const char *head_ref
;
2913 head_ref
= resolve_ref_unsafe("HEAD", RESOLVE_REF_READING
,
2914 head_sha1
, &head_flag
);
2915 if (head_ref
&& (head_flag
& REF_ISSYMREF
) &&
2916 !strcmp(head_ref
, lock
->ref_name
)) {
2917 struct strbuf log_err
= STRBUF_INIT
;
2918 if (log_ref_write("HEAD", lock
->old_oid
.hash
, sha1
,
2919 logmsg
, 0, &log_err
)) {
2920 error("%s", log_err
.buf
);
2921 strbuf_release(&log_err
);
2926 if (commit_ref(lock
)) {
2927 strbuf_addf(err
, "couldn't set '%s'", lock
->ref_name
);
2936 static int create_ref_symlink(struct ref_lock
*lock
, const char *target
)
2939 #ifndef NO_SYMLINK_HEAD
2940 char *ref_path
= get_locked_file_path(lock
->lk
);
2942 ret
= symlink(target
, ref_path
);
2946 fprintf(stderr
, "no symlink - falling back to symbolic ref\n");
2951 static void update_symref_reflog(struct ref_lock
*lock
, const char *refname
,
2952 const char *target
, const char *logmsg
)
2954 struct strbuf err
= STRBUF_INIT
;
2955 unsigned char new_sha1
[20];
2956 if (logmsg
&& !read_ref(target
, new_sha1
) &&
2957 log_ref_write(refname
, lock
->old_oid
.hash
, new_sha1
, logmsg
, 0, &err
)) {
2958 error("%s", err
.buf
);
2959 strbuf_release(&err
);
2963 static int create_symref_locked(struct ref_lock
*lock
, const char *refname
,
2964 const char *target
, const char *logmsg
)
2966 if (prefer_symlink_refs
&& !create_ref_symlink(lock
, target
)) {
2967 update_symref_reflog(lock
, refname
, target
, logmsg
);
2971 if (!fdopen_lock_file(lock
->lk
, "w"))
2972 return error("unable to fdopen %s: %s",
2973 lock
->lk
->tempfile
.filename
.buf
, strerror(errno
));
2975 update_symref_reflog(lock
, refname
, target
, logmsg
);
2977 /* no error check; commit_ref will check ferror */
2978 fprintf(lock
->lk
->tempfile
.fp
, "ref: %s\n", target
);
2979 if (commit_ref(lock
) < 0)
2980 return error("unable to write symref for %s: %s", refname
,
2985 int create_symref(const char *refname
, const char *target
, const char *logmsg
)
2987 struct strbuf err
= STRBUF_INIT
;
2988 struct ref_lock
*lock
;
2991 lock
= lock_ref_sha1_basic(refname
, NULL
, NULL
, NULL
, REF_NODEREF
, NULL
,
2994 error("%s", err
.buf
);
2995 strbuf_release(&err
);
2999 ret
= create_symref_locked(lock
, refname
, target
, logmsg
);
3004 int set_worktree_head_symref(const char *gitdir
, const char *target
)
3006 static struct lock_file head_lock
;
3007 struct ref_lock
*lock
;
3008 struct strbuf head_path
= STRBUF_INIT
;
3009 const char *head_rel
;
3012 strbuf_addf(&head_path
, "%s/HEAD", absolute_path(gitdir
));
3013 if (hold_lock_file_for_update(&head_lock
, head_path
.buf
,
3014 LOCK_NO_DEREF
) < 0) {
3015 struct strbuf err
= STRBUF_INIT
;
3016 unable_to_lock_message(head_path
.buf
, errno
, &err
);
3017 error("%s", err
.buf
);
3018 strbuf_release(&err
);
3019 strbuf_release(&head_path
);
3023 /* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for
3025 head_rel
= remove_leading_path(head_path
.buf
,
3026 absolute_path(get_git_common_dir()));
3027 /* to make use of create_symref_locked(), initialize ref_lock */
3028 lock
= xcalloc(1, sizeof(struct ref_lock
));
3029 lock
->lk
= &head_lock
;
3030 lock
->ref_name
= xstrdup(head_rel
);
3032 ret
= create_symref_locked(lock
, head_rel
, target
, NULL
);
3034 unlock_ref(lock
); /* will free lock */
3035 strbuf_release(&head_path
);
3039 int reflog_exists(const char *refname
)
3043 return !lstat(git_path("logs/%s", refname
), &st
) &&
3044 S_ISREG(st
.st_mode
);
3047 int delete_reflog(const char *refname
)
3049 return remove_path(git_path("logs/%s", refname
));
3052 static int show_one_reflog_ent(struct strbuf
*sb
, each_reflog_ent_fn fn
, void *cb_data
)
3054 unsigned char osha1
[20], nsha1
[20];
3055 char *email_end
, *message
;
3056 unsigned long timestamp
;
3059 /* old SP new SP name <email> SP time TAB msg LF */
3060 if (sb
->len
< 83 || sb
->buf
[sb
->len
- 1] != '\n' ||
3061 get_sha1_hex(sb
->buf
, osha1
) || sb
->buf
[40] != ' ' ||
3062 get_sha1_hex(sb
->buf
+ 41, nsha1
) || sb
->buf
[81] != ' ' ||
3063 !(email_end
= strchr(sb
->buf
+ 82, '>')) ||
3064 email_end
[1] != ' ' ||
3065 !(timestamp
= strtoul(email_end
+ 2, &message
, 10)) ||
3066 !message
|| message
[0] != ' ' ||
3067 (message
[1] != '+' && message
[1] != '-') ||
3068 !isdigit(message
[2]) || !isdigit(message
[3]) ||
3069 !isdigit(message
[4]) || !isdigit(message
[5]))
3070 return 0; /* corrupt? */
3071 email_end
[1] = '\0';
3072 tz
= strtol(message
+ 1, NULL
, 10);
3073 if (message
[6] != '\t')
3077 return fn(osha1
, nsha1
, sb
->buf
+ 82, timestamp
, tz
, message
, cb_data
);
3080 static char *find_beginning_of_line(char *bob
, char *scan
)
3082 while (bob
< scan
&& *(--scan
) != '\n')
3083 ; /* keep scanning backwards */
3085 * Return either beginning of the buffer, or LF at the end of
3086 * the previous line.
3091 int for_each_reflog_ent_reverse(const char *refname
, each_reflog_ent_fn fn
, void *cb_data
)
3093 struct strbuf sb
= STRBUF_INIT
;
3096 int ret
= 0, at_tail
= 1;
3098 logfp
= fopen(git_path("logs/%s", refname
), "r");
3102 /* Jump to the end */
3103 if (fseek(logfp
, 0, SEEK_END
) < 0)
3104 return error("cannot seek back reflog for %s: %s",
3105 refname
, strerror(errno
));
3107 while (!ret
&& 0 < pos
) {
3113 /* Fill next block from the end */
3114 cnt
= (sizeof(buf
) < pos
) ? sizeof(buf
) : pos
;
3115 if (fseek(logfp
, pos
- cnt
, SEEK_SET
))
3116 return error("cannot seek back reflog for %s: %s",
3117 refname
, strerror(errno
));
3118 nread
= fread(buf
, cnt
, 1, logfp
);
3120 return error("cannot read %d bytes from reflog for %s: %s",
3121 cnt
, refname
, strerror(errno
));
3124 scanp
= endp
= buf
+ cnt
;
3125 if (at_tail
&& scanp
[-1] == '\n')
3126 /* Looking at the final LF at the end of the file */
3130 while (buf
< scanp
) {
3132 * terminating LF of the previous line, or the beginning
3137 bp
= find_beginning_of_line(buf
, scanp
);
3141 * The newline is the end of the previous line,
3142 * so we know we have complete line starting
3143 * at (bp + 1). Prefix it onto any prior data
3144 * we collected for the line and process it.
3146 strbuf_splice(&sb
, 0, 0, bp
+ 1, endp
- (bp
+ 1));
3149 ret
= show_one_reflog_ent(&sb
, fn
, cb_data
);
3155 * We are at the start of the buffer, and the
3156 * start of the file; there is no previous
3157 * line, and we have everything for this one.
3158 * Process it, and we can end the loop.
3160 strbuf_splice(&sb
, 0, 0, buf
, endp
- buf
);
3161 ret
= show_one_reflog_ent(&sb
, fn
, cb_data
);
3168 * We are at the start of the buffer, and there
3169 * is more file to read backwards. Which means
3170 * we are in the middle of a line. Note that we
3171 * may get here even if *bp was a newline; that
3172 * just means we are at the exact end of the
3173 * previous line, rather than some spot in the
3176 * Save away what we have to be combined with
3177 * the data from the next read.
3179 strbuf_splice(&sb
, 0, 0, buf
, endp
- buf
);
3186 die("BUG: reverse reflog parser had leftover data");
3189 strbuf_release(&sb
);
3193 int for_each_reflog_ent(const char *refname
, each_reflog_ent_fn fn
, void *cb_data
)
3196 struct strbuf sb
= STRBUF_INIT
;
3199 logfp
= fopen(git_path("logs/%s", refname
), "r");
3203 while (!ret
&& !strbuf_getwholeline(&sb
, logfp
, '\n'))
3204 ret
= show_one_reflog_ent(&sb
, fn
, cb_data
);
3206 strbuf_release(&sb
);
3210 * Call fn for each reflog in the namespace indicated by name. name
3211 * must be empty or end with '/'. Name will be used as a scratch
3212 * space, but its contents will be restored before return.
3214 static int do_for_each_reflog(struct strbuf
*name
, each_ref_fn fn
, void *cb_data
)
3216 DIR *d
= opendir(git_path("logs/%s", name
->buf
));
3219 int oldlen
= name
->len
;
3222 return name
->len
? errno
: 0;
3224 while ((de
= readdir(d
)) != NULL
) {
3227 if (de
->d_name
[0] == '.')
3229 if (ends_with(de
->d_name
, ".lock"))
3231 strbuf_addstr(name
, de
->d_name
);
3232 if (stat(git_path("logs/%s", name
->buf
), &st
) < 0) {
3233 ; /* silently ignore */
3235 if (S_ISDIR(st
.st_mode
)) {
3236 strbuf_addch(name
, '/');
3237 retval
= do_for_each_reflog(name
, fn
, cb_data
);
3239 struct object_id oid
;
3241 if (read_ref_full(name
->buf
, 0, oid
.hash
, NULL
))
3242 retval
= error("bad ref for %s", name
->buf
);
3244 retval
= fn(name
->buf
, &oid
, 0, cb_data
);
3249 strbuf_setlen(name
, oldlen
);
3255 int for_each_reflog(each_ref_fn fn
, void *cb_data
)
3259 strbuf_init(&name
, PATH_MAX
);
3260 retval
= do_for_each_reflog(&name
, fn
, cb_data
);
3261 strbuf_release(&name
);
3265 static int ref_update_reject_duplicates(struct string_list
*refnames
,
3268 int i
, n
= refnames
->nr
;
3272 for (i
= 1; i
< n
; i
++)
3273 if (!strcmp(refnames
->items
[i
- 1].string
, refnames
->items
[i
].string
)) {
3275 "multiple updates for ref '%s' not allowed.",
3276 refnames
->items
[i
].string
);
3283 * If update is a direct update of head_ref (the reference pointed to
3284 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.
3286 static int split_head_update(struct ref_update
*update
,
3287 struct ref_transaction
*transaction
,
3288 const char *head_ref
,
3289 struct string_list
*affected_refnames
,
3292 struct string_list_item
*item
;
3293 struct ref_update
*new_update
;
3295 if ((update
->flags
& REF_LOG_ONLY
) ||
3296 (update
->flags
& REF_ISPRUNING
) ||
3297 (update
->flags
& REF_UPDATE_VIA_HEAD
))
3300 if (strcmp(update
->refname
, head_ref
))
3304 * First make sure that HEAD is not already in the
3305 * transaction. This insertion is O(N) in the transaction
3306 * size, but it happens at most once per transaction.
3308 item
= string_list_insert(affected_refnames
, "HEAD");
3310 /* An entry already existed */
3312 "multiple updates for 'HEAD' (including one "
3313 "via its referent '%s') are not allowed",
3315 return TRANSACTION_NAME_CONFLICT
;
3318 new_update
= ref_transaction_add_update(
3319 transaction
, "HEAD",
3320 update
->flags
| REF_LOG_ONLY
| REF_NODEREF
,
3321 update
->new_sha1
, update
->old_sha1
,
3324 item
->util
= new_update
;
3330 * update is for a symref that points at referent and doesn't have
3331 * REF_NODEREF set. Split it into two updates:
3332 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set
3333 * - A new, separate update for the referent reference
3334 * Note that the new update will itself be subject to splitting when
3335 * the iteration gets to it.
3337 static int split_symref_update(struct ref_update
*update
,
3338 const char *referent
,
3339 struct ref_transaction
*transaction
,
3340 struct string_list
*affected_refnames
,
3343 struct string_list_item
*item
;
3344 struct ref_update
*new_update
;
3345 unsigned int new_flags
;
3348 * First make sure that referent is not already in the
3349 * transaction. This insertion is O(N) in the transaction
3350 * size, but it happens at most once per symref in a
3353 item
= string_list_insert(affected_refnames
, referent
);
3355 /* An entry already existed */
3357 "multiple updates for '%s' (including one "
3358 "via symref '%s') are not allowed",
3359 referent
, update
->refname
);
3360 return TRANSACTION_NAME_CONFLICT
;
3363 new_flags
= update
->flags
;
3364 if (!strcmp(update
->refname
, "HEAD")) {
3366 * Record that the new update came via HEAD, so that
3367 * when we process it, split_head_update() doesn't try
3368 * to add another reflog update for HEAD. Note that
3369 * this bit will be propagated if the new_update
3370 * itself needs to be split.
3372 new_flags
|= REF_UPDATE_VIA_HEAD
;
3375 new_update
= ref_transaction_add_update(
3376 transaction
, referent
, new_flags
,
3377 update
->new_sha1
, update
->old_sha1
,
3380 new_update
->parent_update
= update
;
3383 * Change the symbolic ref update to log only. Also, it
3384 * doesn't need to check its old SHA-1 value, as that will be
3385 * done when new_update is processed.
3387 update
->flags
|= REF_LOG_ONLY
| REF_NODEREF
;
3388 update
->flags
&= ~REF_HAVE_OLD
;
3390 item
->util
= new_update
;
3396 * Return the refname under which update was originally requested.
3398 static const char *original_update_refname(struct ref_update
*update
)
3400 while (update
->parent_update
)
3401 update
= update
->parent_update
;
3403 return update
->refname
;
3407 * Prepare for carrying out update:
3408 * - Lock the reference referred to by update.
3409 * - Read the reference under lock.
3410 * - Check that its old SHA-1 value (if specified) is correct, and in
3411 * any case record it in update->lock->old_oid for later use when
3412 * writing the reflog.
3413 * - If it is a symref update without REF_NODEREF, split it up into a
3414 * REF_LOG_ONLY update of the symref and add a separate update for
3415 * the referent to transaction.
3416 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY
3419 static int lock_ref_for_update(struct ref_update
*update
,
3420 struct ref_transaction
*transaction
,
3421 const char *head_ref
,
3422 struct string_list
*affected_refnames
,
3425 struct strbuf referent
= STRBUF_INIT
;
3426 int mustexist
= (update
->flags
& REF_HAVE_OLD
) &&
3427 !is_null_sha1(update
->old_sha1
);
3429 struct ref_lock
*lock
;
3431 if ((update
->flags
& REF_HAVE_NEW
) && is_null_sha1(update
->new_sha1
))
3432 update
->flags
|= REF_DELETING
;
3435 ret
= split_head_update(update
, transaction
, head_ref
,
3436 affected_refnames
, err
);
3441 ret
= lock_raw_ref(update
->refname
, mustexist
,
3442 affected_refnames
, NULL
,
3443 &update
->lock
, &referent
,
3444 &update
->type
, err
);
3449 reason
= strbuf_detach(err
, NULL
);
3450 strbuf_addf(err
, "cannot lock ref '%s': %s",
3451 update
->refname
, reason
);
3456 lock
= update
->lock
;
3458 if (update
->type
& REF_ISSYMREF
) {
3459 if (update
->flags
& REF_NODEREF
) {
3461 * We won't be reading the referent as part of
3462 * the transaction, so we have to read it here
3463 * to record and possibly check old_sha1:
3465 if (read_ref_full(update
->refname
,
3466 mustexist
? RESOLVE_REF_READING
: 0,
3467 lock
->old_oid
.hash
, NULL
)) {
3468 if (update
->flags
& REF_HAVE_OLD
) {
3469 strbuf_addf(err
, "cannot lock ref '%s': "
3470 "can't resolve old value",
3472 return TRANSACTION_GENERIC_ERROR
;
3474 hashclr(lock
->old_oid
.hash
);
3477 if ((update
->flags
& REF_HAVE_OLD
) &&
3478 hashcmp(lock
->old_oid
.hash
, update
->old_sha1
)) {
3479 strbuf_addf(err
, "cannot lock ref '%s': "
3480 "is at %s but expected %s",
3482 sha1_to_hex(lock
->old_oid
.hash
),
3483 sha1_to_hex(update
->old_sha1
));
3484 return TRANSACTION_GENERIC_ERROR
;
3489 * Create a new update for the reference this
3490 * symref is pointing at. Also, we will record
3491 * and verify old_sha1 for this update as part
3492 * of processing the split-off update, so we
3493 * don't have to do it here.
3495 ret
= split_symref_update(update
, referent
.buf
, transaction
,
3496 affected_refnames
, err
);
3501 struct ref_update
*parent_update
;
3504 * If this update is happening indirectly because of a
3505 * symref update, record the old SHA-1 in the parent
3508 for (parent_update
= update
->parent_update
;
3510 parent_update
= parent_update
->parent_update
) {
3511 oidcpy(&parent_update
->lock
->old_oid
, &lock
->old_oid
);
3514 if ((update
->flags
& REF_HAVE_OLD
) &&
3515 hashcmp(lock
->old_oid
.hash
, update
->old_sha1
)) {
3516 if (is_null_sha1(update
->old_sha1
))
3517 strbuf_addf(err
, "cannot lock ref '%s': reference already exists",
3518 original_update_refname(update
));
3520 strbuf_addf(err
, "cannot lock ref '%s': is at %s but expected %s",
3521 original_update_refname(update
),
3522 sha1_to_hex(lock
->old_oid
.hash
),
3523 sha1_to_hex(update
->old_sha1
));
3525 return TRANSACTION_GENERIC_ERROR
;
3529 if ((update
->flags
& REF_HAVE_NEW
) &&
3530 !(update
->flags
& REF_DELETING
) &&
3531 !(update
->flags
& REF_LOG_ONLY
)) {
3532 if (!(update
->type
& REF_ISSYMREF
) &&
3533 !hashcmp(lock
->old_oid
.hash
, update
->new_sha1
)) {
3535 * The reference already has the desired
3536 * value, so we don't need to write it.
3538 } else if (write_ref_to_lockfile(lock
, update
->new_sha1
,
3540 char *write_err
= strbuf_detach(err
, NULL
);
3543 * The lock was freed upon failure of
3544 * write_ref_to_lockfile():
3546 update
->lock
= NULL
;
3548 "cannot update the ref '%s': %s",
3549 update
->refname
, write_err
);
3551 return TRANSACTION_GENERIC_ERROR
;
3553 update
->flags
|= REF_NEEDS_COMMIT
;
3556 if (!(update
->flags
& REF_NEEDS_COMMIT
)) {
3558 * We didn't call write_ref_to_lockfile(), so
3559 * the lockfile is still open. Close it to
3560 * free up the file descriptor:
3562 if (close_ref(lock
)) {
3563 strbuf_addf(err
, "couldn't close '%s.lock'",
3565 return TRANSACTION_GENERIC_ERROR
;
3571 int ref_transaction_commit(struct ref_transaction
*transaction
,
3575 struct string_list refs_to_delete
= STRING_LIST_INIT_NODUP
;
3576 struct string_list_item
*ref_to_delete
;
3577 struct string_list affected_refnames
= STRING_LIST_INIT_NODUP
;
3578 char *head_ref
= NULL
;
3580 struct object_id head_oid
;
3584 if (transaction
->state
!= REF_TRANSACTION_OPEN
)
3585 die("BUG: commit called for transaction that is not open");
3587 if (!transaction
->nr
) {
3588 transaction
->state
= REF_TRANSACTION_CLOSED
;
3593 * Fail if a refname appears more than once in the
3594 * transaction. (If we end up splitting up any updates using
3595 * split_symref_update() or split_head_update(), those
3596 * functions will check that the new updates don't have the
3597 * same refname as any existing ones.)
3599 for (i
= 0; i
< transaction
->nr
; i
++) {
3600 struct ref_update
*update
= transaction
->updates
[i
];
3601 struct string_list_item
*item
=
3602 string_list_append(&affected_refnames
, update
->refname
);
3605 * We store a pointer to update in item->util, but at
3606 * the moment we never use the value of this field
3607 * except to check whether it is non-NULL.
3609 item
->util
= update
;
3611 string_list_sort(&affected_refnames
);
3612 if (ref_update_reject_duplicates(&affected_refnames
, err
)) {
3613 ret
= TRANSACTION_GENERIC_ERROR
;
3618 * Special hack: If a branch is updated directly and HEAD
3619 * points to it (may happen on the remote side of a push
3620 * for example) then logically the HEAD reflog should be
3623 * A generic solution would require reverse symref lookups,
3624 * but finding all symrefs pointing to a given branch would be
3625 * rather costly for this rare event (the direct update of a
3626 * branch) to be worth it. So let's cheat and check with HEAD
3627 * only, which should cover 99% of all usage scenarios (even
3628 * 100% of the default ones).
3630 * So if HEAD is a symbolic reference, then record the name of
3631 * the reference that it points to. If we see an update of
3632 * head_ref within the transaction, then split_head_update()
3633 * arranges for the reflog of HEAD to be updated, too.
3635 head_ref
= resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE
,
3636 head_oid
.hash
, &head_type
);
3638 if (head_ref
&& !(head_type
& REF_ISSYMREF
)) {
3644 * Acquire all locks, verify old values if provided, check
3645 * that new values are valid, and write new values to the
3646 * lockfiles, ready to be activated. Only keep one lockfile
3647 * open at a time to avoid running out of file descriptors.
3649 for (i
= 0; i
< transaction
->nr
; i
++) {
3650 struct ref_update
*update
= transaction
->updates
[i
];
3652 ret
= lock_ref_for_update(update
, transaction
, head_ref
,
3653 &affected_refnames
, err
);
3658 /* Perform updates first so live commits remain referenced */
3659 for (i
= 0; i
< transaction
->nr
; i
++) {
3660 struct ref_update
*update
= transaction
->updates
[i
];
3661 struct ref_lock
*lock
= update
->lock
;
3663 if (update
->flags
& REF_NEEDS_COMMIT
||
3664 update
->flags
& REF_LOG_ONLY
) {
3665 if (log_ref_write(lock
->ref_name
, lock
->old_oid
.hash
,
3667 update
->msg
, update
->flags
, err
)) {
3668 char *old_msg
= strbuf_detach(err
, NULL
);
3670 strbuf_addf(err
, "cannot update the ref '%s': %s",
3671 lock
->ref_name
, old_msg
);
3674 update
->lock
= NULL
;
3675 ret
= TRANSACTION_GENERIC_ERROR
;
3679 if (update
->flags
& REF_NEEDS_COMMIT
) {
3680 clear_loose_ref_cache(&ref_cache
);
3681 if (commit_ref(lock
)) {
3682 strbuf_addf(err
, "couldn't set '%s'", lock
->ref_name
);
3684 update
->lock
= NULL
;
3685 ret
= TRANSACTION_GENERIC_ERROR
;
3690 /* Perform deletes now that updates are safely completed */
3691 for (i
= 0; i
< transaction
->nr
; i
++) {
3692 struct ref_update
*update
= transaction
->updates
[i
];
3694 if (update
->flags
& REF_DELETING
&&
3695 !(update
->flags
& REF_LOG_ONLY
)) {
3696 if (delete_ref_loose(update
->lock
, update
->type
, err
)) {
3697 ret
= TRANSACTION_GENERIC_ERROR
;
3701 if (!(update
->flags
& REF_ISPRUNING
))
3702 string_list_append(&refs_to_delete
,
3703 update
->lock
->ref_name
);
3707 if (repack_without_refs(&refs_to_delete
, err
)) {
3708 ret
= TRANSACTION_GENERIC_ERROR
;
3711 for_each_string_list_item(ref_to_delete
, &refs_to_delete
)
3712 unlink_or_warn(git_path("logs/%s", ref_to_delete
->string
));
3713 clear_loose_ref_cache(&ref_cache
);
3716 transaction
->state
= REF_TRANSACTION_CLOSED
;
3718 for (i
= 0; i
< transaction
->nr
; i
++)
3719 if (transaction
->updates
[i
]->lock
)
3720 unlock_ref(transaction
->updates
[i
]->lock
);
3721 string_list_clear(&refs_to_delete
, 0);
3723 string_list_clear(&affected_refnames
, 0);
3728 static int ref_present(const char *refname
,
3729 const struct object_id
*oid
, int flags
, void *cb_data
)
3731 struct string_list
*affected_refnames
= cb_data
;
3733 return string_list_has_string(affected_refnames
, refname
);
3736 int initial_ref_transaction_commit(struct ref_transaction
*transaction
,
3740 struct string_list affected_refnames
= STRING_LIST_INIT_NODUP
;
3744 if (transaction
->state
!= REF_TRANSACTION_OPEN
)
3745 die("BUG: commit called for transaction that is not open");
3747 /* Fail if a refname appears more than once in the transaction: */
3748 for (i
= 0; i
< transaction
->nr
; i
++)
3749 string_list_append(&affected_refnames
,
3750 transaction
->updates
[i
]->refname
);
3751 string_list_sort(&affected_refnames
);
3752 if (ref_update_reject_duplicates(&affected_refnames
, err
)) {
3753 ret
= TRANSACTION_GENERIC_ERROR
;
3758 * It's really undefined to call this function in an active
3759 * repository or when there are existing references: we are
3760 * only locking and changing packed-refs, so (1) any
3761 * simultaneous processes might try to change a reference at
3762 * the same time we do, and (2) any existing loose versions of
3763 * the references that we are setting would have precedence
3764 * over our values. But some remote helpers create the remote
3765 * "HEAD" and "master" branches before calling this function,
3766 * so here we really only check that none of the references
3767 * that we are creating already exists.
3769 if (for_each_rawref(ref_present
, &affected_refnames
))
3770 die("BUG: initial ref transaction called with existing refs");
3772 for (i
= 0; i
< transaction
->nr
; i
++) {
3773 struct ref_update
*update
= transaction
->updates
[i
];
3775 if ((update
->flags
& REF_HAVE_OLD
) &&
3776 !is_null_sha1(update
->old_sha1
))
3777 die("BUG: initial ref transaction with old_sha1 set");
3778 if (verify_refname_available(update
->refname
,
3779 &affected_refnames
, NULL
,
3781 ret
= TRANSACTION_NAME_CONFLICT
;
3786 if (lock_packed_refs(0)) {
3787 strbuf_addf(err
, "unable to lock packed-refs file: %s",
3789 ret
= TRANSACTION_GENERIC_ERROR
;
3793 for (i
= 0; i
< transaction
->nr
; i
++) {
3794 struct ref_update
*update
= transaction
->updates
[i
];
3796 if ((update
->flags
& REF_HAVE_NEW
) &&
3797 !is_null_sha1(update
->new_sha1
))
3798 add_packed_ref(update
->refname
, update
->new_sha1
);
3801 if (commit_packed_refs()) {
3802 strbuf_addf(err
, "unable to commit packed-refs file: %s",
3804 ret
= TRANSACTION_GENERIC_ERROR
;
3809 transaction
->state
= REF_TRANSACTION_CLOSED
;
3810 string_list_clear(&affected_refnames
, 0);
3814 struct expire_reflog_cb
{
3816 reflog_expiry_should_prune_fn
*should_prune_fn
;
3819 unsigned char last_kept_sha1
[20];
3822 static int expire_reflog_ent(unsigned char *osha1
, unsigned char *nsha1
,
3823 const char *email
, unsigned long timestamp
, int tz
,
3824 const char *message
, void *cb_data
)
3826 struct expire_reflog_cb
*cb
= cb_data
;
3827 struct expire_reflog_policy_cb
*policy_cb
= cb
->policy_cb
;
3829 if (cb
->flags
& EXPIRE_REFLOGS_REWRITE
)
3830 osha1
= cb
->last_kept_sha1
;
3832 if ((*cb
->should_prune_fn
)(osha1
, nsha1
, email
, timestamp
, tz
,
3833 message
, policy_cb
)) {
3835 printf("would prune %s", message
);
3836 else if (cb
->flags
& EXPIRE_REFLOGS_VERBOSE
)
3837 printf("prune %s", message
);
3840 fprintf(cb
->newlog
, "%s %s %s %lu %+05d\t%s",
3841 sha1_to_hex(osha1
), sha1_to_hex(nsha1
),
3842 email
, timestamp
, tz
, message
);
3843 hashcpy(cb
->last_kept_sha1
, nsha1
);
3845 if (cb
->flags
& EXPIRE_REFLOGS_VERBOSE
)
3846 printf("keep %s", message
);
3851 int reflog_expire(const char *refname
, const unsigned char *sha1
,
3853 reflog_expiry_prepare_fn prepare_fn
,
3854 reflog_expiry_should_prune_fn should_prune_fn
,
3855 reflog_expiry_cleanup_fn cleanup_fn
,
3856 void *policy_cb_data
)
3858 static struct lock_file reflog_lock
;
3859 struct expire_reflog_cb cb
;
3860 struct ref_lock
*lock
;
3864 struct strbuf err
= STRBUF_INIT
;
3866 memset(&cb
, 0, sizeof(cb
));
3868 cb
.policy_cb
= policy_cb_data
;
3869 cb
.should_prune_fn
= should_prune_fn
;
3872 * The reflog file is locked by holding the lock on the
3873 * reference itself, plus we might need to update the
3874 * reference if --updateref was specified:
3876 lock
= lock_ref_sha1_basic(refname
, sha1
, NULL
, NULL
, REF_NODEREF
,
3879 error("cannot lock ref '%s': %s", refname
, err
.buf
);
3880 strbuf_release(&err
);
3883 if (!reflog_exists(refname
)) {
3888 log_file
= git_pathdup("logs/%s", refname
);
3889 if (!(flags
& EXPIRE_REFLOGS_DRY_RUN
)) {
3891 * Even though holding $GIT_DIR/logs/$reflog.lock has
3892 * no locking implications, we use the lock_file
3893 * machinery here anyway because it does a lot of the
3894 * work we need, including cleaning up if the program
3895 * exits unexpectedly.
3897 if (hold_lock_file_for_update(&reflog_lock
, log_file
, 0) < 0) {
3898 struct strbuf err
= STRBUF_INIT
;
3899 unable_to_lock_message(log_file
, errno
, &err
);
3900 error("%s", err
.buf
);
3901 strbuf_release(&err
);
3904 cb
.newlog
= fdopen_lock_file(&reflog_lock
, "w");
3906 error("cannot fdopen %s (%s)",
3907 get_lock_file_path(&reflog_lock
), strerror(errno
));
3912 (*prepare_fn
)(refname
, sha1
, cb
.policy_cb
);
3913 for_each_reflog_ent(refname
, expire_reflog_ent
, &cb
);
3914 (*cleanup_fn
)(cb
.policy_cb
);
3916 if (!(flags
& EXPIRE_REFLOGS_DRY_RUN
)) {
3918 * It doesn't make sense to adjust a reference pointed
3919 * to by a symbolic ref based on expiring entries in
3920 * the symbolic reference's reflog. Nor can we update
3921 * a reference if there are no remaining reflog
3924 int update
= (flags
& EXPIRE_REFLOGS_UPDATE_REF
) &&
3925 !(type
& REF_ISSYMREF
) &&
3926 !is_null_sha1(cb
.last_kept_sha1
);
3928 if (close_lock_file(&reflog_lock
)) {
3929 status
|= error("couldn't write %s: %s", log_file
,
3931 } else if (update
&&
3932 (write_in_full(get_lock_file_fd(lock
->lk
),
3933 sha1_to_hex(cb
.last_kept_sha1
), 40) != 40 ||
3934 write_str_in_full(get_lock_file_fd(lock
->lk
), "\n") != 1 ||
3935 close_ref(lock
) < 0)) {
3936 status
|= error("couldn't write %s",
3937 get_lock_file_path(lock
->lk
));
3938 rollback_lock_file(&reflog_lock
);
3939 } else if (commit_lock_file(&reflog_lock
)) {
3940 status
|= error("unable to write reflog '%s' (%s)",
3941 log_file
, strerror(errno
));
3942 } else if (update
&& commit_ref(lock
)) {
3943 status
|= error("couldn't set %s", lock
->ref_name
);
3951 rollback_lock_file(&reflog_lock
);