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>
90 lines
2.0 KiB
C
90 lines
2.0 KiB
C
#include "cache.h"
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#include "object.h"
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#include "decorate.h"
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int track_object_refs = 0;
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static struct decoration ref_decorate;
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struct object_refs *lookup_object_refs(struct object *base)
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{
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return lookup_decoration(&ref_decorate, base);
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}
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static void add_object_refs(struct object *obj, struct object_refs *refs)
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{
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if (add_decoration(&ref_decorate, obj, refs))
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die("object %s tried to add refs twice!", sha1_to_hex(obj->sha1));
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}
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struct object_refs *alloc_object_refs(unsigned count)
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{
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struct object_refs *refs;
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size_t size = sizeof(*refs) + count*sizeof(struct object *);
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refs = xcalloc(1, size);
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refs->count = count;
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return refs;
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}
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static int compare_object_pointers(const void *a, const void *b)
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{
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const struct object * const *pa = a;
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const struct object * const *pb = b;
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if (*pa == *pb)
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return 0;
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else if (*pa < *pb)
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return -1;
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else
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return 1;
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}
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void set_object_refs(struct object *obj, struct object_refs *refs)
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{
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unsigned int i, j;
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/* Do not install empty list of references */
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if (refs->count < 1) {
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free(refs);
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return;
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}
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/* Sort the list and filter out duplicates */
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qsort(refs->ref, refs->count, sizeof(refs->ref[0]),
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compare_object_pointers);
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for (i = j = 1; i < refs->count; i++) {
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if (refs->ref[i] != refs->ref[i - 1])
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refs->ref[j++] = refs->ref[i];
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}
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if (j < refs->count) {
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/* Duplicates were found - reallocate list */
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size_t size = sizeof(*refs) + j*sizeof(struct object *);
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refs->count = j;
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refs = xrealloc(refs, size);
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}
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for (i = 0; i < refs->count; i++)
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refs->ref[i]->used = 1;
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add_object_refs(obj, refs);
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}
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void mark_reachable(struct object *obj, unsigned int mask)
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{
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const struct object_refs *refs;
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if (!track_object_refs)
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die("cannot do reachability with object refs turned off");
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/* If we've been here already, don't bother */
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if (obj->flags & mask)
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return;
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obj->flags |= mask;
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refs = lookup_object_refs(obj);
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if (refs) {
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unsigned i;
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for (i = 0; i < refs->count; i++)
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mark_reachable(refs->ref[i], mask);
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}
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}
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