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authorJunio C Hamano <gitster@pobox.com>2013-05-29 14:23:49 -0700
committerJunio C Hamano <gitster@pobox.com>2013-05-29 14:23:49 -0700
commit2f1ef15070a8664d3194d164f20283d78571e51c (patch)
treef38c2cbca2dc96840ae37e710c2c597f31dee2cd /refs.c
parentc51afbbd18f51beb186afdfa8bbe35c13a782df7 (diff)
parent9da31cb027aa5dac3d4914a88faa8830f0578c88 (diff)
downloadgit-2f1ef15070a8664d3194d164f20283d78571e51c.tar.gz
Merge branch 'mh/packed-refs-various'
Update reading and updating packed-refs file, correcting corner case bugs. * mh/packed-refs-various: (33 commits) refs: handle the main ref_cache specially refs: change do_for_each_*() functions to take ref_cache arguments pack_one_ref(): do some cheap tests before a more expensive one pack_one_ref(): use write_packed_entry() to do the writing pack_one_ref(): use function peel_entry() refs: inline function do_not_prune() pack_refs(): change to use do_for_each_entry() refs: use same lock_file object for both ref-packing functions pack_one_ref(): rename "path" parameter to "refname" pack-refs: merge code from pack-refs.{c,h} into refs.{c,h} pack-refs: rename handle_one_ref() to pack_one_ref() refs: extract a function write_packed_entry() repack_without_ref(): write peeled refs in the rewritten file t3211: demonstrate loss of peeled refs if a packed ref is deleted refs: change how packed refs are deleted search_ref_dir(): return an index rather than a pointer repack_without_ref(): silence errors for dangling packed refs t3210: test for spurious error messages for dangling packed refs refs: change the internal reference-iteration API refs: extract a function peel_entry() ...
Diffstat (limited to 'refs.c')
-rw-r--r--refs.c733
1 files changed, 562 insertions, 171 deletions
diff --git a/refs.c b/refs.c
index de2d8eb866..d17931a8bc 100644
--- a/refs.c
+++ b/refs.c
@@ -109,7 +109,20 @@ struct ref_entry;
* (ref_entry->flag & REF_DIR) is zero.
*/
struct ref_value {
+ /*
+ * The name of the object to which this reference resolves
+ * (which may be a tag object). If REF_ISBROKEN, this is
+ * null. If REF_ISSYMREF, then this is the name of the object
+ * referred to by the last reference in the symlink chain.
+ */
unsigned char sha1[20];
+
+ /*
+ * If REF_KNOWS_PEELED, then this field holds the peeled value
+ * of this reference, or null if the reference is known not to
+ * be peelable. See the documentation for peel_ref() for an
+ * exact definition of "peelable".
+ */
unsigned char peeled[20];
};
@@ -158,7 +171,17 @@ struct ref_dir {
struct ref_entry **entries;
};
-/* ISSYMREF=0x01, ISPACKED=0x02, and ISBROKEN=0x04 are public interfaces */
+/*
+ * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
+ * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
+ * refs.h.
+ */
+
+/*
+ * The field ref_entry->u.value.peeled of this value entry contains
+ * the correct peeled value for the reference, which might be
+ * null_sha1 if the reference is not a tag or if it is broken.
+ */
#define REF_KNOWS_PEELED 0x08
/* ref_entry represents a directory of references */
@@ -343,18 +366,17 @@ static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
}
/*
- * Return the entry with the given refname from the ref_dir
- * (non-recursively), sorting dir if necessary. Return NULL if no
- * such entry is found. dir must already be complete.
+ * Return the index of the entry with the given refname from the
+ * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
+ * no such entry is found. dir must already be complete.
*/
-static struct ref_entry *search_ref_dir(struct ref_dir *dir,
- const char *refname, size_t len)
+static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
{
struct ref_entry **r;
struct string_slice key;
if (refname == NULL || !dir->nr)
- return NULL;
+ return -1;
sort_ref_dir(dir);
key.len = len;
@@ -363,9 +385,9 @@ static struct ref_entry *search_ref_dir(struct ref_dir *dir,
ref_entry_cmp_sslice);
if (r == NULL)
- return NULL;
+ return -1;
- return *r;
+ return r - dir->entries;
}
/*
@@ -379,8 +401,9 @@ static struct ref_dir *search_for_subdir(struct ref_dir *dir,
const char *subdirname, size_t len,
int mkdir)
{
- struct ref_entry *entry = search_ref_dir(dir, subdirname, len);
- if (!entry) {
+ int entry_index = search_ref_dir(dir, subdirname, len);
+ struct ref_entry *entry;
+ if (entry_index == -1) {
if (!mkdir)
return NULL;
/*
@@ -391,6 +414,8 @@ static struct ref_dir *search_for_subdir(struct ref_dir *dir,
*/
entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
add_entry_to_dir(dir, entry);
+ } else {
+ entry = dir->entries[entry_index];
}
return get_ref_dir(entry);
}
@@ -429,12 +454,67 @@ static struct ref_dir *find_containing_dir(struct ref_dir *dir,
*/
static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
{
+ int entry_index;
struct ref_entry *entry;
dir = find_containing_dir(dir, refname, 0);
if (!dir)
return NULL;
- entry = search_ref_dir(dir, refname, strlen(refname));
- return (entry && !(entry->flag & REF_DIR)) ? entry : NULL;
+ entry_index = search_ref_dir(dir, refname, strlen(refname));
+ if (entry_index == -1)
+ return NULL;
+ entry = dir->entries[entry_index];
+ return (entry->flag & REF_DIR) ? NULL : entry;
+}
+
+/*
+ * Remove the entry with the given name from dir, recursing into
+ * subdirectories as necessary. If refname is the name of a directory
+ * (i.e., ends with '/'), then remove the directory and its contents.
+ * If the removal was successful, return the number of entries
+ * remaining in the directory entry that contained the deleted entry.
+ * If the name was not found, return -1. Please note that this
+ * function only deletes the entry from the cache; it does not delete
+ * it from the filesystem or ensure that other cache entries (which
+ * might be symbolic references to the removed entry) are updated.
+ * Nor does it remove any containing dir entries that might be made
+ * empty by the removal. dir must represent the top-level directory
+ * and must already be complete.
+ */
+static int remove_entry(struct ref_dir *dir, const char *refname)
+{
+ int refname_len = strlen(refname);
+ int entry_index;
+ struct ref_entry *entry;
+ int is_dir = refname[refname_len - 1] == '/';
+ if (is_dir) {
+ /*
+ * refname represents a reference directory. Remove
+ * the trailing slash; otherwise we will get the
+ * directory *representing* refname rather than the
+ * one *containing* it.
+ */
+ char *dirname = xmemdupz(refname, refname_len - 1);
+ dir = find_containing_dir(dir, dirname, 0);
+ free(dirname);
+ } else {
+ dir = find_containing_dir(dir, refname, 0);
+ }
+ if (!dir)
+ return -1;
+ entry_index = search_ref_dir(dir, refname, refname_len);
+ if (entry_index == -1)
+ return -1;
+ entry = dir->entries[entry_index];
+
+ memmove(&dir->entries[entry_index],
+ &dir->entries[entry_index + 1],
+ (dir->nr - entry_index - 1) * sizeof(*dir->entries)
+ );
+ dir->nr--;
+ if (dir->sorted > entry_index)
+ dir->sorted--;
+ free_ref_entry(entry);
+ return dir->nr;
}
/*
@@ -503,27 +583,64 @@ static void sort_ref_dir(struct ref_dir *dir)
dir->sorted = dir->nr = i;
}
-#define DO_FOR_EACH_INCLUDE_BROKEN 01
+/* Include broken references in a do_for_each_ref*() iteration: */
+#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
+
+/*
+ * Return true iff the reference described by entry can be resolved to
+ * an object in the database. Emit a warning if the referred-to
+ * object does not exist.
+ */
+static int ref_resolves_to_object(struct ref_entry *entry)
+{
+ if (entry->flag & REF_ISBROKEN)
+ return 0;
+ if (!has_sha1_file(entry->u.value.sha1)) {
+ error("%s does not point to a valid object!", entry->name);
+ return 0;
+ }
+ return 1;
+}
+/*
+ * current_ref is a performance hack: when iterating over references
+ * using the for_each_ref*() functions, current_ref is set to the
+ * current reference's entry before calling the callback function. If
+ * the callback function calls peel_ref(), then peel_ref() first
+ * checks whether the reference to be peeled is the current reference
+ * (it usually is) and if so, returns that reference's peeled version
+ * if it is available. This avoids a refname lookup in a common case.
+ */
static struct ref_entry *current_ref;
-static int do_one_ref(const char *base, each_ref_fn fn, int trim,
- int flags, void *cb_data, struct ref_entry *entry)
+typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
+
+struct ref_entry_cb {
+ const char *base;
+ int trim;
+ int flags;
+ each_ref_fn *fn;
+ void *cb_data;
+};
+
+/*
+ * Handle one reference in a do_for_each_ref*()-style iteration,
+ * calling an each_ref_fn for each entry.
+ */
+static int do_one_ref(struct ref_entry *entry, void *cb_data)
{
+ struct ref_entry_cb *data = cb_data;
int retval;
- if (prefixcmp(entry->name, base))
+ if (prefixcmp(entry->name, data->base))
+ return 0;
+
+ if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
+ !ref_resolves_to_object(entry))
return 0;
- if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
- if (entry->flag & REF_ISBROKEN)
- return 0; /* ignore broken refs e.g. dangling symref */
- if (!has_sha1_file(entry->u.value.sha1)) {
- error("%s does not point to a valid object!", entry->name);
- return 0;
- }
- }
current_ref = entry;
- retval = fn(entry->name + trim, entry->u.value.sha1, entry->flag, cb_data);
+ retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
+ entry->flag, data->cb_data);
current_ref = NULL;
return retval;
}
@@ -532,11 +649,11 @@ static int do_one_ref(const char *base, each_ref_fn fn, int trim,
* Call fn for each reference in dir that has index in the range
* offset <= index < dir->nr. Recurse into subdirectories that are in
* that index range, sorting them before iterating. This function
- * does not sort dir itself; it should be sorted beforehand.
+ * does not sort dir itself; it should be sorted beforehand. fn is
+ * called for all references, including broken ones.
*/
-static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
- const char *base,
- each_ref_fn fn, int trim, int flags, void *cb_data)
+static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
+ each_ref_entry_fn fn, void *cb_data)
{
int i;
assert(dir->sorted == dir->nr);
@@ -546,10 +663,9 @@ static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
if (entry->flag & REF_DIR) {
struct ref_dir *subdir = get_ref_dir(entry);
sort_ref_dir(subdir);
- retval = do_for_each_ref_in_dir(subdir, 0,
- base, fn, trim, flags, cb_data);
+ retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
} else {
- retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
+ retval = fn(entry, cb_data);
}
if (retval)
return retval;
@@ -562,12 +678,12 @@ static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
* by refname. Recurse into subdirectories. If a value entry appears
* in both dir1 and dir2, then only process the version that is in
* dir2. The input dirs must already be sorted, but subdirs will be
- * sorted as needed.
+ * sorted as needed. fn is called for all references, including
+ * broken ones.
*/
-static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
- struct ref_dir *dir2,
- const char *base, each_ref_fn fn, int trim,
- int flags, void *cb_data)
+static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
+ struct ref_dir *dir2,
+ each_ref_entry_fn fn, void *cb_data)
{
int retval;
int i1 = 0, i2 = 0;
@@ -578,12 +694,10 @@ static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
struct ref_entry *e1, *e2;
int cmp;
if (i1 == dir1->nr) {
- return do_for_each_ref_in_dir(dir2, i2,
- base, fn, trim, flags, cb_data);
+ return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
}
if (i2 == dir2->nr) {
- return do_for_each_ref_in_dir(dir1, i1,
- base, fn, trim, flags, cb_data);
+ return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
}
e1 = dir1->entries[i1];
e2 = dir2->entries[i2];
@@ -595,14 +709,13 @@ static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
struct ref_dir *subdir2 = get_ref_dir(e2);
sort_ref_dir(subdir1);
sort_ref_dir(subdir2);
- retval = do_for_each_ref_in_dirs(
- subdir1, subdir2,
- base, fn, trim, flags, cb_data);
+ retval = do_for_each_entry_in_dirs(
+ subdir1, subdir2, fn, cb_data);
i1++;
i2++;
} else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
/* Both are references; ignore the one from dir1. */
- retval = do_one_ref(base, fn, trim, flags, cb_data, e2);
+ retval = fn(e2, cb_data);
i1++;
i2++;
} else {
@@ -621,23 +734,15 @@ static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
if (e->flag & REF_DIR) {
struct ref_dir *subdir = get_ref_dir(e);
sort_ref_dir(subdir);
- retval = do_for_each_ref_in_dir(
- subdir, 0,
- base, fn, trim, flags, cb_data);
+ retval = do_for_each_entry_in_dir(
+ subdir, 0, fn, cb_data);
} else {
- retval = do_one_ref(base, fn, trim, flags, cb_data, e);
+ retval = fn(e, cb_data);
}
}
if (retval)
return retval;
}
- if (i1 < dir1->nr)
- return do_for_each_ref_in_dir(dir1, i1,
- base, fn, trim, flags, cb_data);
- if (i2 < dir2->nr)
- return do_for_each_ref_in_dir(dir2, i2,
- base, fn, trim, flags, cb_data);
- return 0;
}
/*
@@ -661,14 +766,13 @@ struct name_conflict_cb {
const char *conflicting_refname;
};
-static int name_conflict_fn(const char *existingrefname, const unsigned char *sha1,
- int flags, void *cb_data)
+static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
{
struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
- if (data->oldrefname && !strcmp(data->oldrefname, existingrefname))
+ if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
return 0;
- if (names_conflict(data->refname, existingrefname)) {
- data->conflicting_refname = existingrefname;
+ if (names_conflict(data->refname, entry->name)) {
+ data->conflicting_refname = entry->name;
return 1;
}
return 0;
@@ -676,7 +780,7 @@ static int name_conflict_fn(const char *existingrefname, const unsigned char *sh
/*
* Return true iff a reference named refname could be created without
- * conflicting with the name of an existing reference in array. If
+ * conflicting with the name of an existing reference in dir. If
* oldrefname is non-NULL, ignore potential conflicts with oldrefname
* (e.g., because oldrefname is scheduled for deletion in the same
* operation).
@@ -690,9 +794,7 @@ static int is_refname_available(const char *refname, const char *oldrefname,
data.conflicting_refname = NULL;
sort_ref_dir(dir);
- if (do_for_each_ref_in_dir(dir, 0, "", name_conflict_fn,
- 0, DO_FOR_EACH_INCLUDE_BROKEN,
- &data)) {
+ if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
error("'%s' exists; cannot create '%s'",
data.conflicting_refname, refname);
return 0;
@@ -708,9 +810,13 @@ static struct ref_cache {
struct ref_cache *next;
struct ref_entry *loose;
struct ref_entry *packed;
- /* The submodule name, or "" for the main repo. */
- char name[FLEX_ARRAY];
-} *ref_cache;
+ /*
+ * The submodule name, or "" for the main repo. We allocate
+ * length 1 rather than FLEX_ARRAY so that the main ref_cache
+ * is initialized correctly.
+ */
+ char name[1];
+} ref_cache, *submodule_ref_caches;
static void clear_packed_ref_cache(struct ref_cache *refs)
{
@@ -748,18 +854,18 @@ static struct ref_cache *create_ref_cache(const char *submodule)
*/
static struct ref_cache *get_ref_cache(const char *submodule)
{
- struct ref_cache *refs = ref_cache;
- if (!submodule)
- submodule = "";
- while (refs) {
+ struct ref_cache *refs;
+
+ if (!submodule || !*submodule)
+ return &ref_cache;
+
+ for (refs = submodule_ref_caches; refs; refs = refs->next)
if (!strcmp(submodule, refs->name))
return refs;
- refs = refs->next;
- }
refs = create_ref_cache(submodule);
- refs->next = ref_cache;
- ref_cache = refs;
+ refs->next = submodule_ref_caches;
+ submodule_ref_caches = refs;
return refs;
}
@@ -770,6 +876,16 @@ void invalidate_ref_cache(const char *submodule)
clear_loose_ref_cache(refs);
}
+/* The length of a peeled reference line in packed-refs, including EOL: */
+#define PEELED_LINE_LENGTH 42
+
+/*
+ * The packed-refs header line that we write out. Perhaps other
+ * traits will be added later. The trailing space is required.
+ */
+static const char PACKED_REFS_HEADER[] =
+ "# pack-refs with: peeled fully-peeled \n";
+
/*
* Parse one line from a packed-refs file. Write the SHA1 to sha1.
* Return a pointer to the refname within the line (null-terminated),
@@ -862,8 +978,8 @@ static void read_packed_refs(FILE *f, struct ref_dir *dir)
}
if (last &&
refline[0] == '^' &&
- strlen(refline) == 42 &&
- refline[41] == '\n' &&
+ strlen(refline) == PEELED_LINE_LENGTH &&
+ refline[PEELED_LINE_LENGTH - 1] == '\n' &&
!get_sha1_hex(refline + 1, sha1)) {
hashcpy(last->u.value.peeled, sha1);
/*
@@ -898,8 +1014,8 @@ static struct ref_dir *get_packed_refs(struct ref_cache *refs)
void add_packed_ref(const char *refname, const unsigned char *sha1)
{
- add_ref(get_packed_refs(get_ref_cache(NULL)),
- create_ref_entry(refname, sha1, REF_ISPACKED, 1));
+ add_ref(get_packed_refs(&ref_cache),
+ create_ref_entry(refname, sha1, REF_ISPACKED, 1));
}
/*
@@ -1069,18 +1185,12 @@ int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sh
}
/*
- * Try to read ref from the packed references. On success, set sha1
- * and return 0; otherwise, return -1.
+ * Return the ref_entry for the given refname from the packed
+ * references. If it does not exist, return NULL.
*/
-static int get_packed_ref(const char *refname, unsigned char *sha1)
+static struct ref_entry *get_packed_ref(const char *refname)
{
- struct ref_dir *packed = get_packed_refs(get_ref_cache(NULL));
- struct ref_entry *entry = find_ref(packed, refname);
- if (entry) {
- hashcpy(sha1, entry->u.value.sha1);
- return 0;
- }
- return -1;
+ return find_ref(get_packed_refs(&ref_cache), refname);
}
const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
@@ -1108,13 +1218,17 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea
git_snpath(path, sizeof(path), "%s", refname);
if (lstat(path, &st) < 0) {
+ struct ref_entry *entry;
+
if (errno != ENOENT)
return NULL;
/*
* The loose reference file does not exist;
* check for a packed reference.
*/
- if (!get_packed_ref(refname, sha1)) {
+ entry = get_packed_ref(refname);
+ if (entry) {
+ hashcpy(sha1, entry->u.value.sha1);
if (flag)
*flag |= REF_ISPACKED;
return refname;
@@ -1231,54 +1345,130 @@ static int filter_refs(const char *refname, const unsigned char *sha1, int flags
return filter->fn(refname, sha1, flags, filter->cb_data);
}
+enum peel_status {
+ /* object was peeled successfully: */
+ PEEL_PEELED = 0,
+
+ /*
+ * object cannot be peeled because the named object (or an
+ * object referred to by a tag in the peel chain), does not
+ * exist.
+ */
+ PEEL_INVALID = -1,
+
+ /* object cannot be peeled because it is not a tag: */
+ PEEL_NON_TAG = -2,
+
+ /* ref_entry contains no peeled value because it is a symref: */
+ PEEL_IS_SYMREF = -3,
+
+ /*
+ * ref_entry cannot be peeled because it is broken (i.e., the
+ * symbolic reference cannot even be resolved to an object
+ * name):
+ */
+ PEEL_BROKEN = -4
+};
+
+/*
+ * Peel the named object; i.e., if the object is a tag, resolve the
+ * tag recursively until a non-tag is found. If successful, store the
+ * result to sha1 and return PEEL_PEELED. If the object is not a tag
+ * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
+ * and leave sha1 unchanged.
+ */
+static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
+{
+ struct object *o = lookup_unknown_object(name);
+
+ if (o->type == OBJ_NONE) {
+ int type = sha1_object_info(name, NULL);
+ if (type < 0)
+ return PEEL_INVALID;
+ o->type = type;
+ }
+
+ if (o->type != OBJ_TAG)
+ return PEEL_NON_TAG;
+
+ o = deref_tag_noverify(o);
+ if (!o)
+ return PEEL_INVALID;
+
+ hashcpy(sha1, o->sha1);
+ return PEEL_PEELED;
+}
+
+/*
+ * Peel the entry (if possible) and return its new peel_status. If
+ * repeel is true, re-peel the entry even if there is an old peeled
+ * value that is already stored in it.
+ *
+ * It is OK to call this function with a packed reference entry that
+ * might be stale and might even refer to an object that has since
+ * been garbage-collected. In such a case, if the entry has
+ * REF_KNOWS_PEELED then leave the status unchanged and return
+ * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
+ */
+static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
+{
+ enum peel_status status;
+
+ if (entry->flag & REF_KNOWS_PEELED) {
+ if (repeel) {
+ entry->flag &= ~REF_KNOWS_PEELED;
+ hashclr(entry->u.value.peeled);
+ } else {
+ return is_null_sha1(entry->u.value.peeled) ?
+ PEEL_NON_TAG : PEEL_PEELED;
+ }
+ }
+ if (entry->flag & REF_ISBROKEN)
+ return PEEL_BROKEN;
+ if (entry->flag & REF_ISSYMREF)
+ return PEEL_IS_SYMREF;
+
+ status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
+ if (status == PEEL_PEELED || status == PEEL_NON_TAG)
+ entry->flag |= REF_KNOWS_PEELED;
+ return status;
+}
+
int peel_ref(const char *refname, unsigned char *sha1)
{
int flag;
unsigned char base[20];
- struct object *o;
if (current_ref && (current_ref->name == refname
- || !strcmp(current_ref->name, refname))) {
- if (current_ref->flag & REF_KNOWS_PEELED) {
- if (is_null_sha1(current_ref->u.value.peeled))
- return -1;
- hashcpy(sha1, current_ref->u.value.peeled);
- return 0;
- }
- hashcpy(base, current_ref->u.value.sha1);
- goto fallback;
+ || !strcmp(current_ref->name, refname))) {
+ if (peel_entry(current_ref, 0))
+ return -1;
+ hashcpy(sha1, current_ref->u.value.peeled);
+ return 0;
}
if (read_ref_full(refname, base, 1, &flag))
return -1;
- if ((flag & REF_ISPACKED)) {
- struct ref_dir *dir = get_packed_refs(get_ref_cache(NULL));
- struct ref_entry *r = find_ref(dir, refname);
-
- if (r != NULL && r->flag & REF_KNOWS_PEELED) {
+ /*
+ * If the reference is packed, read its ref_entry from the
+ * cache in the hope that we already know its peeled value.
+ * We only try this optimization on packed references because
+ * (a) forcing the filling of the loose reference cache could
+ * be expensive and (b) loose references anyway usually do not
+ * have REF_KNOWS_PEELED.
+ */
+ if (flag & REF_ISPACKED) {
+ struct ref_entry *r = get_packed_ref(refname);
+ if (r) {
+ if (peel_entry(r, 0))
+ return -1;
hashcpy(sha1, r->u.value.peeled);
return 0;
}
}
-fallback:
- o = lookup_unknown_object(base);
- if (o->type == OBJ_NONE) {
- int type = sha1_object_info(base, NULL);
- if (type < 0)
- return -1;
- o->type = type;
- }
-
- if (o->type == OBJ_TAG) {
- o = deref_tag_noverify(o);
- if (o) {
- hashcpy(sha1, o->sha1);
- return 0;
- }
- }
- return -1;
+ return peel_object(base, sha1);
}
struct warn_if_dangling_data {
@@ -1316,10 +1506,16 @@ void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
for_each_rawref(warn_if_dangling_symref, &data);
}
-static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
- int trim, int flags, void *cb_data)
+/*
+ * Call fn for each reference in the specified ref_cache, omitting
+ * references not in the containing_dir of base. fn is called for all
+ * references, including broken ones. If fn ever returns a non-zero
+ * value, stop the iteration and return that value; otherwise, return
+ * 0.
+ */
+static int do_for_each_entry(struct ref_cache *refs, const char *base,
+ each_ref_entry_fn fn, void *cb_data)
{
- struct ref_cache *refs = get_ref_cache(submodule);
struct ref_dir *packed_dir = get_packed_refs(refs);
struct ref_dir *loose_dir = get_loose_refs(refs);
int retval = 0;
@@ -1332,24 +1528,43 @@ static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn
if (packed_dir && loose_dir) {
sort_ref_dir(packed_dir);
sort_ref_dir(loose_dir);
- retval = do_for_each_ref_in_dirs(
- packed_dir, loose_dir,
- base, fn, trim, flags, cb_data);
+ retval = do_for_each_entry_in_dirs(
+ packed_dir, loose_dir, fn, cb_data);
} else if (packed_dir) {
sort_ref_dir(packed_dir);
- retval = do_for_each_ref_in_dir(
- packed_dir, 0,
- base, fn, trim, flags, cb_data);
+ retval = do_for_each_entry_in_dir(
+ packed_dir, 0, fn, cb_data);
} else if (loose_dir) {
sort_ref_dir(loose_dir);
- retval = do_for_each_ref_in_dir(
- loose_dir, 0,
- base, fn, trim, flags, cb_data);
+ retval = do_for_each_entry_in_dir(
+ loose_dir, 0, fn, cb_data);
}
return retval;
}
+/*
+ * Call fn for each reference in the specified ref_cache for which the
+ * refname begins with base. If trim is non-zero, then trim that many
+ * characters off the beginning of each refname before passing the
+ * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
+ * broken references in the iteration. If fn ever returns a non-zero
+ * value, stop the iteration and return that value; otherwise, return
+ * 0.
+ */
+static int do_for_each_ref(struct ref_cache *refs, const char *base,
+ each_ref_fn fn, int trim, int flags, void *cb_data)
+{
+ struct ref_entry_cb data;
+ data.base = base;
+ data.trim = trim;
+ data.flags = flags;
+ data.fn = fn;
+ data.cb_data = cb_data;
+
+ return do_for_each_entry(refs, base, do_one_ref, &data);
+}
+
static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
{
unsigned char sha1[20];
@@ -1380,23 +1595,23 @@ int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
int for_each_ref(each_ref_fn fn, void *cb_data)
{
- return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
+ return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
}
int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
{
- return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
+ return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
}
int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
{
- return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
+ return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
}
int for_each_ref_in_submodule(const char *submodule, const char *prefix,
each_ref_fn fn, void *cb_data)
{
- return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
+ return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
}
int for_each_tag_ref(each_ref_fn fn, void *cb_data)
@@ -1431,7 +1646,7 @@ int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *c
int for_each_replace_ref(each_ref_fn fn, void *cb_data)
{
- return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
+ return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
}
int head_ref_namespaced(each_ref_fn fn, void *cb_data)
@@ -1454,7 +1669,7 @@ int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
struct strbuf buf = STRBUF_INIT;
int ret;
strbuf_addf(&buf, "%srefs/", get_git_namespace());
- ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
+ ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
strbuf_release(&buf);
return ret;
}
@@ -1496,7 +1711,7 @@ int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
int for_each_rawref(each_ref_fn fn, void *cb_data)
{
- return do_for_each_ref(NULL, "", fn, 0,
+ return do_for_each_ref(&ref_cache, "", fn, 0,
DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
}
@@ -1702,7 +1917,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
* name is a proper prefix of our refname.
*/
if (missing &&
- !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
+ !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
last_errno = ENOTDIR;
goto error_return;
}
@@ -1754,47 +1969,224 @@ struct ref_lock *lock_any_ref_for_update(const char *refname,
return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
}
-struct repack_without_ref_sb {
- const char *refname;
- int fd;
-};
-
-static int repack_without_ref_fn(const char *refname, const unsigned char *sha1,
- int flags, void *cb_data)
+/*
+ * Write an entry to the packed-refs file for the specified refname.
+ * If peeled is non-NULL, write it as the entry's peeled value.
+ */
+static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
+ unsigned char *peeled)
{
- struct repack_without_ref_sb *data = cb_data;
char line[PATH_MAX + 100];
int len;
- if (!strcmp(data->refname, refname))
- return 0;
len = snprintf(line, sizeof(line), "%s %s\n",
sha1_to_hex(sha1), refname);
/* this should not happen but just being defensive */
if (len > sizeof(line))
die("too long a refname '%s'", refname);
- write_or_die(data->fd, line, len);
+ write_or_die(fd, line, len);
+
+ if (peeled) {
+ if (snprintf(line, sizeof(line), "^%s\n",
+ sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
+ die("internal error");
+ write_or_die(fd, line, PEELED_LINE_LENGTH);
+ }
+}
+
+struct ref_to_prune {
+ struct ref_to_prune *next;
+ unsigned char sha1[20];
+ char name[FLEX_ARRAY];
+};
+
+struct pack_refs_cb_data {
+ unsigned int flags;
+ struct ref_to_prune *ref_to_prune;
+ int fd;
+};
+
+static int pack_one_ref(struct ref_entry *entry, void *cb_data)
+{
+ struct pack_refs_cb_data *cb = cb_data;
+ enum peel_status peel_status;
+ int is_tag_ref = !prefixcmp(entry->name, "refs/tags/");
+
+ /* ALWAYS pack refs that were already packed or are tags */
+ if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref &&
+ !(entry->flag & REF_ISPACKED))
+ return 0;
+
+ /* Do not pack symbolic or broken refs: */
+ if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
+ return 0;
+
+ peel_status = peel_entry(entry, 1);
+ if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
+ die("internal error peeling reference %s (%s)",
+ entry->name, sha1_to_hex(entry->u.value.sha1));
+ write_packed_entry(cb->fd, entry->name, entry->u.value.sha1,
+ peel_status == PEEL_PEELED ?
+ entry->u.value.peeled : NULL);
+
+ /* If the ref was already packed, there is no need to prune it. */
+ if ((cb->flags & PACK_REFS_PRUNE) && !(entry->flag & REF_ISPACKED)) {
+ int namelen = strlen(entry->name) + 1;
+ struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
+ hashcpy(n->sha1, entry->u.value.sha1);
+ strcpy(n->name, entry->name);
+ n->next = cb->ref_to_prune;
+ cb->ref_to_prune = n;
+ }
return 0;
}
+/*
+ * Remove empty parents, but spare refs/ and immediate subdirs.
+ * Note: munges *name.
+ */
+static void try_remove_empty_parents(char *name)
+{
+ char *p, *q;
+ int i;
+ p = name;
+ for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
+ while (*p && *p != '/')
+ p++;
+ /* tolerate duplicate slashes; see check_refname_format() */
+ while (*p == '/')
+ p++;
+ }
+ for (q = p; *q; q++)
+ ;
+ while (1) {
+ while (q > p && *q != '/')
+ q--;
+ while (q > p && *(q-1) == '/')
+ q--;
+ if (q == p)
+ break;
+ *q = '\0';
+ if (rmdir(git_path("%s", name)))
+ break;
+ }
+}
+
+/* make sure nobody touched the ref, and unlink */
+static void prune_ref(struct ref_to_prune *r)
+{
+ struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
+
+ if (lock) {
+ unlink_or_warn(git_path("%s", r->name));
+ unlock_ref(lock);
+ try_remove_empty_parents(r->name);
+ }
+}
+
+static void prune_refs(struct ref_to_prune *r)
+{
+ while (r) {
+ prune_ref(r);
+ r = r->next;
+ }
+}
+
static struct lock_file packlock;
-static int repack_without_ref(const char *refname)
+int pack_refs(unsigned int flags)
{
- struct repack_without_ref_sb data;
- struct ref_cache *refs = get_ref_cache(NULL);
- struct ref_dir *packed = get_packed_refs(refs);
- if (find_ref(packed, refname) == NULL)
+ struct pack_refs_cb_data cbdata;
+
+ memset(&cbdata, 0, sizeof(cbdata));
+ cbdata.flags = flags;
+
+ cbdata.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"),
+ LOCK_DIE_ON_ERROR);
+
+ write_or_die(cbdata.fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
+
+ do_for_each_entry(&ref_cache, "", pack_one_ref, &cbdata);
+ if (commit_lock_file(&packlock) < 0)
+ die_errno("unable to overwrite old ref-pack file");
+ prune_refs(cbdata.ref_to_prune);
+ return 0;
+}
+
+static int repack_ref_fn(struct ref_entry *entry, void *cb_data)
+{
+ int *fd = cb_data;
+ enum peel_status peel_status;
+
+ if (entry->flag & REF_ISBROKEN) {
+ /* This shouldn't happen to packed refs. */
+ error("%s is broken!", entry->name);
return 0;
- data.refname = refname;
- data.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
- if (data.fd < 0) {
+ }
+ if (!has_sha1_file(entry->u.value.sha1)) {
+ unsigned char sha1[20];
+ int flags;
+
+ if (read_ref_full(entry->name, sha1, 0, &flags))
+ /* We should at least have found the packed ref. */
+ die("Internal error");
+ if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED))
+ /*
+ * This packed reference is overridden by a
+ * loose reference, so it is OK that its value
+ * is no longer valid; for example, it might
+ * refer to an object that has been garbage
+ * collected. For this purpose we don't even
+ * care whether the loose reference itself is
+ * invalid, broken, symbolic, etc. Silently
+ * omit the packed reference from the output.
+ */
+ return 0;
+ /*
+ * There is no overriding loose reference, so the fact
+ * that this reference doesn't refer to a valid object
+ * indicates some kind of repository corruption.
+ * Report the problem, then omit the reference from
+ * the output.
+ */
+ error("%s does not point to a valid object!", entry->name);
+ return 0;
+ }
+
+ peel_status = peel_entry(entry, 0);
+ write_packed_entry(*fd, entry->name, entry->u.value.sha1,
+ peel_status == PEEL_PEELED ?
+ entry->u.value.peeled : NULL);
+
+ return 0;
+}
+
+static int repack_without_ref(const char *refname)
+{
+ int fd;
+ struct ref_dir *packed;
+
+ if (!get_packed_ref(refname))
+ return 0; /* refname does not exist in packed refs */
+
+ fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
+ if (fd < 0) {
unable_to_lock_error(git_path("packed-refs"), errno);
return error("cannot delete '%s' from packed refs", refname);
}
- clear_packed_ref_cache(refs);
- packed = get_packed_refs(refs);
- do_for_each_ref_in_dir(packed, 0, "", repack_without_ref_fn, 0, 0, &data);
+ clear_packed_ref_cache(&ref_cache);
+ packed = get_packed_refs(&ref_cache);
+ /* Remove refname from the cache. */
+ if (remove_entry(packed, refname) == -1) {
+ /*
+ * The packed entry disappeared while we were
+ * acquiring the lock.
+ */
+ rollback_lock_file(&packlock);
+ return 0;
+ }
+ write_or_die(fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
+ do_for_each_entry_in_dir(packed, 0, repack_ref_fn, &fd);
return commit_lock_file(&packlock);
}
@@ -1823,7 +2215,7 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
ret |= repack_without_ref(lock->ref_name);
unlink_or_warn(git_path("logs/%s", lock->ref_name));
- invalidate_ref_cache(NULL);
+ clear_loose_ref_cache(&ref_cache);
unlock_ref(lock);
return ret;
}
@@ -1845,7 +2237,6 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
struct stat loginfo;
int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
const char *symref = NULL;
- struct ref_cache *refs = get_ref_cache(NULL);
if (log && S_ISLNK(loginfo.st_mode))
return error("reflog for %s is a symlink", oldrefname);
@@ -1857,10 +2248,10 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
if (!symref)
return error("refname %s not found", oldrefname);
- if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
+ if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
return 1;
- if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
+ if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
return 1;
if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
@@ -2116,7 +2507,7 @@ int write_ref_sha1(struct ref_lock *lock,
unlock_ref(lock);
return -1;
}
- clear_loose_ref_cache(get_ref_cache(NULL));
+ clear_loose_ref_cache(&ref_cache);
if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
(strcmp(lock->ref_name, lock->orig_ref_name) &&
log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {