git/decorate.c

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/*
* decorate.c - decorate a git object with some arbitrary
* data.
*/
#include "git-compat-util.h"
#include "object.h"
#include "decorate.h"
static unsigned int hash_obj(const struct object *obj, unsigned int n)
{
return oidhash(&obj->oid) % n;
}
static void *insert_decoration(struct decoration *n, const struct object *base, void *decoration)
{
int size = n->size;
struct decoration_entry *entries = n->entries;
unsigned int j = hash_obj(base, size);
while (entries[j].base) {
if (entries[j].base == base) {
void *old = entries[j].decoration;
entries[j].decoration = decoration;
return old;
}
if (++j >= size)
j = 0;
}
entries[j].base = base;
entries[j].decoration = decoration;
n->nr++;
return NULL;
}
static void grow_decoration(struct decoration *n)
{
int i;
int old_size = n->size;
struct decoration_entry *old_entries = n->entries;
n->size = (old_size + 1000) * 3 / 2;
CALLOC_ARRAY(n->entries, n->size);
n->nr = 0;
for (i = 0; i < old_size; i++) {
const struct object *base = old_entries[i].base;
void *decoration = old_entries[i].decoration;
if (!decoration)
continue;
insert_decoration(n, base, decoration);
}
free(old_entries);
}
void *add_decoration(struct decoration *n, const struct object *obj,
void *decoration)
{
int nr = n->nr + 1;
if (nr > n->size * 2 / 3)
grow_decoration(n);
return insert_decoration(n, obj, decoration);
}
void *lookup_decoration(struct decoration *n, const struct object *obj)
{
unsigned int j;
/* nothing to lookup */
if (!n->size)
return NULL;
j = hash_obj(obj, n->size);
for (;;) {
struct decoration_entry *ref = n->entries + j;
if (ref->base == obj)
return ref->decoration;
if (!ref->base)
return NULL;
if (++j == n->size)
j = 0;
}
}