14825944d7
92d8ed8ac1 (oidtree: a crit-bit tree for odb_loose_cache, 2021-07-07)
adds a struct oidtree_node that contains only an n field with a
struct cb_node.
unfortunately, while building in pedantic mode witch clang 12 (as well
as a similar error from gcc 11) it will show:
oidtree.c:11:17: error: 'n' may not be nested in a struct due to flexible array member [-Werror,-Wflexible-array-extensions]
struct cb_node n;
^
because of a constrain coded in ISO C 11 6.7.2.1¶3 that forbids using
structs that contain a flexible array as part of another struct.
use a strict cb_node directly instead.
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
100 lines
2.3 KiB
C
100 lines
2.3 KiB
C
/*
|
|
* 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;
|
|
|
|
if (!oid->algo)
|
|
BUG("oidtree_insert requires oid->algo");
|
|
|
|
on = mem_pool_alloc(&ot->mem_pool, sizeof(*on) + sizeof(*oid));
|
|
oidcpy_with_padding((struct object_id *)on->k, oid);
|
|
|
|
/*
|
|
* 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;
|
|
const struct object_id *oid = (const struct object_id *)n->k;
|
|
|
|
if (x->algo != GIT_HASH_UNKNOWN && x->algo != oid->algo)
|
|
return CB_CONTINUE;
|
|
|
|
if (x->last_nibble_at) {
|
|
if ((oid->hash[*x->last_nibble_at] ^ x->last_byte) & 0xf0)
|
|
return CB_CONTINUE;
|
|
}
|
|
|
|
return x->fn(oid, 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);
|
|
}
|