git/replace-object.c

116 lines
2.9 KiB
C

#include "git-compat-util.h"
#include "gettext.h"
#include "hex.h"
#include "oidmap.h"
#include "object-store-ll.h"
#include "replace-object.h"
#include "refs.h"
#include "repository.h"
#include "commit.h"
static int register_replace_ref(const char *refname,
const char *referent UNUSED,
const struct object_id *oid,
int flag UNUSED,
void *cb_data)
{
struct repository *r = cb_data;
/* Get sha1 from refname */
const char *slash = strrchr(refname, '/');
const char *hash = slash ? slash + 1 : refname;
struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj));
if (get_oid_hex_algop(hash, &repl_obj->original.oid, r->hash_algo)) {
free(repl_obj);
warning(_("bad replace ref name: %s"), refname);
return 0;
}
/* Copy sha1 from the read ref */
oidcpy(&repl_obj->replacement, oid);
/* Register new object */
if (oidmap_put(r->objects->replace_map, repl_obj))
die(_("duplicate replace ref: %s"), refname);
return 0;
}
void prepare_replace_object(struct repository *r)
{
if (r->objects->replace_map_initialized)
return;
pthread_mutex_lock(&r->objects->replace_mutex);
if (r->objects->replace_map_initialized) {
pthread_mutex_unlock(&r->objects->replace_mutex);
return;
}
r->objects->replace_map =
xmalloc(sizeof(*r->objects->replace_map));
oidmap_init(r->objects->replace_map, 0);
refs_for_each_replace_ref(get_main_ref_store(r),
register_replace_ref, r);
r->objects->replace_map_initialized = 1;
pthread_mutex_unlock(&r->objects->replace_mutex);
}
/* We allow "recursive" replacement. Only within reason, though */
#define MAXREPLACEDEPTH 5
/*
* If a replacement for object oid has been set up, return the
* replacement object's name (replaced recursively, if necessary).
* The return value is either oid or a pointer to a
* permanently-allocated value. This function always respects replace
* references, regardless of the value of r->settings.read_replace_refs.
*/
const struct object_id *do_lookup_replace_object(struct repository *r,
const struct object_id *oid)
{
int depth = MAXREPLACEDEPTH;
const struct object_id *cur = oid;
prepare_replace_object(r);
/* Try to recursively replace the object */
while (depth-- > 0) {
struct replace_object *repl_obj =
oidmap_get(r->objects->replace_map, cur);
if (!repl_obj)
return cur;
cur = &repl_obj->replacement;
}
die(_("replace depth too high for object %s"), oid_to_hex(oid));
}
/*
* This indicator determines whether replace references should be
* respected process-wide, regardless of which repository is being
* using at the time.
*/
static int read_replace_refs = 1;
void disable_replace_refs(void)
{
read_replace_refs = 0;
}
int replace_refs_enabled(struct repository *r)
{
if (!read_replace_refs)
return 0;
if (r->gitdir) {
prepare_repo_settings(r);
return r->settings.read_replace_refs;
}
/* repository has no objects or refs. */
return 0;
}