mirror of
https://github.com/git/git
synced 2024-10-30 14:03:28 +00:00
a59b276e18
This allows you to add an arbitrary "decoration" of your choice to any object. It's a space- and time-efficient way to add information to arbitrary objects, especially if most objects probably do not have the decoration. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
89 lines
2 KiB
C
89 lines
2 KiB
C
#include "cache.h"
|
|
#include "object.h"
|
|
#include "decorate.h"
|
|
|
|
int track_object_refs = 0;
|
|
|
|
static struct decoration ref_decorate;
|
|
|
|
struct object_refs *lookup_object_refs(struct object *base)
|
|
{
|
|
return lookup_decoration(&ref_decorate, base);
|
|
}
|
|
|
|
static void add_object_refs(struct object *obj, struct object_refs *refs)
|
|
{
|
|
if (add_decoration(&ref_decorate, obj, refs))
|
|
die("object %s tried to add refs twice!", sha1_to_hex(obj->sha1));
|
|
}
|
|
|
|
struct object_refs *alloc_object_refs(unsigned count)
|
|
{
|
|
struct object_refs *refs;
|
|
size_t size = sizeof(*refs) + count*sizeof(struct object *);
|
|
|
|
refs = xcalloc(1, size);
|
|
refs->count = count;
|
|
return refs;
|
|
}
|
|
|
|
static int compare_object_pointers(const void *a, const void *b)
|
|
{
|
|
const struct object * const *pa = a;
|
|
const struct object * const *pb = b;
|
|
if (*pa == *pb)
|
|
return 0;
|
|
else if (*pa < *pb)
|
|
return -1;
|
|
else
|
|
return 1;
|
|
}
|
|
|
|
void set_object_refs(struct object *obj, struct object_refs *refs)
|
|
{
|
|
unsigned int i, j;
|
|
|
|
/* Do not install empty list of references */
|
|
if (refs->count < 1) {
|
|
free(refs);
|
|
return;
|
|
}
|
|
|
|
/* Sort the list and filter out duplicates */
|
|
qsort(refs->ref, refs->count, sizeof(refs->ref[0]),
|
|
compare_object_pointers);
|
|
for (i = j = 1; i < refs->count; i++) {
|
|
if (refs->ref[i] != refs->ref[i - 1])
|
|
refs->ref[j++] = refs->ref[i];
|
|
}
|
|
if (j < refs->count) {
|
|
/* Duplicates were found - reallocate list */
|
|
size_t size = sizeof(*refs) + j*sizeof(struct object *);
|
|
refs->count = j;
|
|
refs = xrealloc(refs, size);
|
|
}
|
|
|
|
for (i = 0; i < refs->count; i++)
|
|
refs->ref[i]->used = 1;
|
|
add_object_refs(obj, refs);
|
|
}
|
|
|
|
void mark_reachable(struct object *obj, unsigned int mask)
|
|
{
|
|
const struct object_refs *refs;
|
|
|
|
if (!track_object_refs)
|
|
die("cannot do reachability with object refs turned off");
|
|
/* If we've been here already, don't bother */
|
|
if (obj->flags & mask)
|
|
return;
|
|
obj->flags |= mask;
|
|
refs = lookup_object_refs(obj);
|
|
if (refs) {
|
|
unsigned i;
|
|
for (i = 0; i < refs->count; i++)
|
|
mark_reachable(refs->ref[i], mask);
|
|
}
|
|
}
|
|
|
|
|