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https://github.com/signalwire/freeswitch.git
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a537d80372
mod_prefix is an in-memory data store optimized for fast lookups according to the longest prefix match (LPM) rule. Tables of key-value string pairs in JSON format can be loaded at startup via configuration and at runtime via the API. The implementation uses a bitwise trie (aka binary prefix tree), so arbitrary string keys are supported.
114 lines
3.4 KiB
C
114 lines
3.4 KiB
C
/*
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* Copyright (c) 2014 Travis Cross <tc@traviscross.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <stdint.h>
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#include <string.h>
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#include "trie.h"
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struct bit_trie_node* bit_trie_create() {
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struct bit_trie_node *node = malloc(sizeof(struct bit_trie_node));
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if (!node) abort();
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memset(node, 0, sizeof(struct bit_trie_node));
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return node;
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}
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uint32_t bit_trie_get(struct bit_trie_node **node_out,
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struct bit_trie_node *node,
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unsigned char *key,
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uint32_t key_len) {
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unsigned char *keyp = key, *keyp0 = key;
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struct bit_trie_node *node0 = node;
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while(keyp < key + key_len) {
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uint8_t offset = 0;
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while(offset < 8) {
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uint8_t bit = (*keyp >> offset) & 0x01;
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struct bit_trie_node *next = node->next[bit];
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if (next) {
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node = next;
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} else {
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*node_out = node0;
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return keyp0 - key;
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}
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offset++;
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}
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keyp++;
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if (node->value) {
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node0 = node;
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keyp0 = keyp;
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}
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}
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*node_out = node0;
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return keyp0 - key;
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}
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struct bit_trie_node* bit_trie_set(struct bit_trie_node *node,
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unsigned char *key,
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uint32_t key_len,
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void *value,
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uint32_t value_len) {
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unsigned char *keyp = key;
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while(keyp < key + key_len) {
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uint8_t offset = 0;
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while(offset < 8) {
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uint8_t bit = (*keyp >> offset) & 0x01;
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struct bit_trie_node *next = node->next[bit];
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if (next) {
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node = next;
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} else {
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next = bit_trie_create();
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node->next[bit] = next;
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node = next;
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}
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offset++;
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}
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keyp++;
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}
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node->value = value;
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node->value_len = value_len;
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return node;
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}
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static uint32_t bit_trie_free_r(struct bit_trie_node *node) {
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uint32_t count = 0;
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if (!node) return count;
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count += bit_trie_free_r(node->next[0]);
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count += bit_trie_free_r(node->next[1]);
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free(node->value);
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free(node);
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count++;
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return count;
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}
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uint32_t bit_trie_free(struct bit_trie_node *node) {
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return bit_trie_free_r(node);
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}
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uint32_t bit_trie_byte_size(struct bit_trie_node *node) {
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uint32_t size = 0;
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if (!node) return size;
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size += bit_trie_byte_size(node->next[0]);
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size += bit_trie_byte_size(node->next[1]);
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size += sizeof(struct bit_trie_node) + node->value_len;
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return size;
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}
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