iofbird / bird2.0.1 / proto / bgp / map.c @ 6b3f1a54
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/**


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* Copyright (c) 2014 rxi

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*

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* This library is free software; you can redistribute it and/or modify it

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* under the terms of the MIT license. See LICENSE for details.

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*/

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#include <stdlib.h> 
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#include <string.h> 
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#include "map.h" 
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struct map_node_t {

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unsigned hash;

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void *value;

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map_node_t *next; 
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/* char key[]; */

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/* char value[]; */

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}; 
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static unsigned map_hash(const char *str) { 
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unsigned hash = 5381; 
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while (*str) {

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hash = ((hash << 5) + hash) ^ *str++;

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} 
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return hash;

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} 
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static map_node_t *map_newnode(const char *key, void *value, int vsize) { 
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map_node_t *node; 
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int ksize = strlen(key) + 1; 
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int voffset = ksize + ((sizeof(void*)  ksize) % sizeof(void*)); 
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node = malloc(sizeof(*node) + voffset + vsize);

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if (!node) return NULL; 
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memcpy(node + 1, key, ksize);

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node>hash = map_hash(key); 
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node>value = ((char*) (node + 1)) + voffset; 
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memcpy(node>value, value, vsize); 
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return node;

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} 
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static int map_bucketidx(map_base_t *m, unsigned hash) { 
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/* If the implementation is changed to allow a nonpowerof2 bucket count,

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* the line below should be changed to use mod instead of AND */

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return hash & (m>nbuckets  1); 
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} 
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static void map_addnode(map_base_t *m, map_node_t *node) { 
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int n = map_bucketidx(m, node>hash);

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node>next = m>buckets[n]; 
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m>buckets[n] = node; 
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} 
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static int map_resize(map_base_t *m, int nbuckets) { 
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map_node_t *nodes, *node, *next; 
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map_node_t **buckets; 
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int i;

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/* Chain all nodes together */

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nodes = NULL;

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i = m>nbuckets; 
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while (i) {

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node = (m>buckets)[i]; 
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while (node) {

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next = node>next; 
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node>next = nodes; 
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nodes = node; 
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node = next; 
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} 
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} 
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/* Reset buckets */

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buckets = realloc(m>buckets, sizeof(*m>buckets) * nbuckets);

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if (buckets != NULL) { 
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m>buckets = buckets; 
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m>nbuckets = nbuckets; 
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} 
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if (m>buckets) {

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memset(m>buckets, 0, sizeof(*m>buckets) * m>nbuckets); 
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/* Readd nodes to buckets */

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node = nodes; 
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while (node) {

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next = node>next; 
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map_addnode(m, node); 
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node = next; 
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} 
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} 
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/* Return error code if realloc() failed */

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return (buckets == NULL) ? 1 : 0; 
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} 
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static map_node_t **map_getref(map_base_t *m, const char *key) { 
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unsigned hash = map_hash(key);

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map_node_t **next; 
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if (m>nbuckets > 0) { 
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next = &m>buckets[map_bucketidx(m, hash)]; 
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while (*next) {

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if ((*next)>hash == hash && !strcmp((char*) (*next + 1), key)) { 
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return next;

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} 
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next = &(*next)>next; 
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} 
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} 
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return NULL; 
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} 
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void map_deinit_(map_base_t *m) {

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map_node_t *next, *node; 
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int i;

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i = m>nbuckets; 
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while (i) {

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node = m>buckets[i]; 
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while (node) {

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next = node>next; 
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free(node); 
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node = next; 
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} 
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} 
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free(m>buckets); 
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} 
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void *map_get_(map_base_t *m, const char *key) { 
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map_node_t **next = map_getref(m, key); 
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return next ? (*next)>value : NULL; 
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} 
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int map_set_(map_base_t *m, const char *key, void *value, int vsize) { 
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int n, err;

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map_node_t **next, *node; 
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/* Find & replace existing node */

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next = map_getref(m, key); 
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if (next) {

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memcpy((*next)>value, value, vsize); 
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return 0; 
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} 
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/* Add new node */

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node = map_newnode(key, value, vsize); 
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if (node == NULL) goto fail; 
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if (m>nnodes >= m>nbuckets) {

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n = (m>nbuckets > 0) ? (m>nbuckets << 1) : 1; 
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err = map_resize(m, n); 
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if (err) goto fail; 
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} 
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map_addnode(m, node); 
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m>nnodes++; 
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return 0; 
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fail:

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if (node) free(node);

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return 1; 
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} 
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void map_remove_(map_base_t *m, const char *key) { 
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map_node_t *node; 
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map_node_t **next = map_getref(m, key); 
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if (next) {

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node = *next; 
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*next = (*next)>next; 
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free(node); 
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m>nnodes; 
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} 
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} 
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map_iter_t map_iter_(void) {

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map_iter_t iter; 
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iter.bucketidx = 1;

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iter.node = NULL;

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return iter;

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} 
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const char *map_next_(map_base_t *m, map_iter_t *iter) { 
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if (iter>node) {

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iter>node = iter>node>next; 
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if (iter>node == NULL) goto nextBucket; 
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} else {

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nextBucket:

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do {

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if (++iter>bucketidx >= m>nbuckets) {

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return NULL; 
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} 
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iter>node = m>buckets[iter>bucketidx]; 
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} while (iter>node == NULL); 
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} 
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return (char*) (iter>node + 1); 
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} 