blob: 87806c807f488544fb861b066da6542bc7bc5638 [file] [log] [blame]
/**
* @file lyb.c
* @author Michal Vasko <mvasko@cesnet.cz>
* @brief LYB format common functionality.
*
* Copyright (c) 2021 CESNET, z.s.p.o.
*
* This source code is licensed under BSD 3-Clause License (the "License").
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://opensource.org/licenses/BSD-3-Clause
*/
#include "lyb.h"
#include <assert.h>
#include <pthread.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "common.h"
#include "compat.h"
#include "tree_schema.h"
/**
* @brief Generate single hash for a schema node to be used for LYB data.
*
* @param[in] node Node to hash.
* @param[in] collision_id Collision ID of the hash to generate.
* @return Generated hash.
*/
static LYB_HASH
lyb_generate_hash(const struct lysc_node *node, uint8_t collision_id)
{
const struct lys_module *mod = node->module;
uint32_t full_hash;
LYB_HASH hash;
/* generate full hash */
full_hash = dict_hash_multi(0, mod->name, strlen(mod->name));
full_hash = dict_hash_multi(full_hash, node->name, strlen(node->name));
if (collision_id) {
size_t ext_len;
if (collision_id > strlen(mod->name)) {
/* fine, we will not hash more bytes, just use more bits from the hash than previously */
ext_len = strlen(mod->name);
} else {
/* use one more byte from the module name than before */
ext_len = collision_id;
}
full_hash = dict_hash_multi(full_hash, mod->name, ext_len);
}
full_hash = dict_hash_multi(full_hash, NULL, 0);
/* use the shortened hash */
hash = full_hash & (LYB_HASH_MASK >> collision_id);
/* add collision identificator */
hash |= LYB_HASH_COLLISION_ID >> collision_id;
return hash;
}
LYB_HASH
lyb_get_hash(const struct lysc_node *node, uint8_t collision_id)
{
/* hashes must be cached */
assert(node->hash[0]);
if (collision_id < LYS_NODE_HASH_COUNT) {
/* read from cache */
return node->hash[collision_id];
}
/* generate */
return lyb_generate_hash(node, collision_id);
}
/**
* @brief Module DFS callback filling all cached hashes of a schema node.
*/
static LY_ERR
lyb_cache_node_hash_cb(struct lysc_node *node, void *UNUSED(data), ly_bool *UNUSED(dfs_continue))
{
if (node->hash[0]) {
/* already cached, stop the DFS */
return LY_EEXIST;
}
for (uint8_t i = 0; i < LYS_NODE_HASH_COUNT; ++i) {
/* store the hash in the cache */
node->hash[i] = lyb_generate_hash(node, i);
}
return LY_SUCCESS;
}
void
lyb_cache_module_hash(const struct lys_module *mod)
{
/* LOCK */
pthread_mutex_lock(&mod->ctx->lyb_hash_lock);
/* store all cached hashes for all the nodes */
lysc_module_dfs_full(mod, lyb_cache_node_hash_cb, NULL);
/* UNLOCK */
pthread_mutex_unlock(&mod->ctx->lyb_hash_lock);
}
ly_bool
lyb_has_schema_model(const struct lysc_node *node, const struct lys_module **models)
{
LY_ARRAY_COUNT_TYPE u;
LY_ARRAY_FOR(models, u) {
if (node->module == models[u]) {
return 1;
}
}
return 0;
}