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/*
* A wrapper around cbtree which stores oids
* May be used to replace oid-array for prefix (abbreviation) matches
*/
#include "oidtree.h"
#include "alloc.h"
#include "hash.h"
struct oidtree_iter_data {
oidtree_iter fn;
void *arg;
size_t *last_nibble_at;
int algo;
uint8_t last_byte;
};
void oidtree_init(struct oidtree *ot)
{
cb_init(&ot->tree);
mem_pool_init(&ot->mem_pool, 0);
}
void oidtree_clear(struct oidtree *ot)
{
if (ot) {
mem_pool_discard(&ot->mem_pool, 0);
oidtree_init(ot);
}
}
void oidtree_insert(struct oidtree *ot, const struct object_id *oid)
{
struct cb_node *on;
struct object_id k;
if (!oid->algo)
BUG("oidtree_insert requires oid->algo");
on = mem_pool_alloc(&ot->mem_pool, sizeof(*on) + sizeof(*oid));
/*
* Clear the padding and copy the result in separate steps to
* respect the 4-byte alignment needed by struct object_id.
*/
oidcpy_with_padding(&k, oid);
memcpy(on->k, &k, sizeof(k));
/*
* n.b. Current callers won't get us duplicates, here. If a
* future caller causes duplicates, there'll be a a small leak
* that won't be freed until oidtree_clear. Currently it's not
* worth maintaining a free list
*/
cb_insert(&ot->tree, on, sizeof(*oid));
}
int oidtree_contains(struct oidtree *ot, const struct object_id *oid)
{
struct object_id k;
size_t klen = sizeof(k);
oidcpy_with_padding(&k, oid);
if (oid->algo == GIT_HASH_UNKNOWN)
klen -= sizeof(oid->algo);
/* cb_lookup relies on memcmp on the struct, so order matters: */
klen += BUILD_ASSERT_OR_ZERO(offsetof(struct object_id, hash) <
offsetof(struct object_id, algo));
return cb_lookup(&ot->tree, (const uint8_t *)&k, klen) ? 1 : 0;
}
static enum cb_next iter(struct cb_node *n, void *arg)
{
struct oidtree_iter_data *x = arg;
struct object_id k;
/* Copy to provide 4-byte alignment needed by struct object_id. */
memcpy(&k, n->k, sizeof(k));
if (x->algo != GIT_HASH_UNKNOWN && x->algo != k.algo)
return CB_CONTINUE;
if (x->last_nibble_at) {
if ((k.hash[*x->last_nibble_at] ^ x->last_byte) & 0xf0)
return CB_CONTINUE;
}
return x->fn(&k, x->arg);
}
void oidtree_each(struct oidtree *ot, const struct object_id *oid,
size_t oidhexsz, oidtree_iter fn, void *arg)
{
size_t klen = oidhexsz / 2;
struct oidtree_iter_data x = { 0 };
assert(oidhexsz <= GIT_MAX_HEXSZ);
x.fn = fn;
x.arg = arg;
x.algo = oid->algo;
if (oidhexsz & 1) {
x.last_byte = oid->hash[klen];
x.last_nibble_at = &klen;
}
cb_each(&ot->tree, (const uint8_t *)oid, klen, iter, &x);
}
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