159 lines
2.5 KiB
C
159 lines
2.5 KiB
C
#include <stdlib.h>
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#include <string.h>
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#include "hash.h"
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static unsigned int
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iso_hash_path(const char *path)
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{
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unsigned int hash_num=0;
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const char *c;
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c=path;
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while(*c)
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hash_num = (hash_num << 15) + (hash_num << 3) + (hash_num >> 3) + *c++;
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return hash_num % HASH_NODES;
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}
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int
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iso_hash_lookup(struct iso_hash_node **table, const char *path)
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{
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struct iso_hash_node *node;
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unsigned int hash_num;
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hash_num = iso_hash_path(path);
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node=table[hash_num];
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if (!node)
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return 0;
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if (!strcmp(path, node->path))
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return 1;
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while (node->next) {
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node=node->next;
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if (!strcmp(path, node->path))
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return 1;
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}
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return 0;
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}
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static struct iso_hash_node*
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iso_hash_node_new (const char *path)
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{
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struct iso_hash_node *node;
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/*create an element to be inserted in the hash table */
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node=malloc(sizeof(struct iso_hash_node));
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node->path=strdup(path);
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node->next=NULL;
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return node;
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}
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int
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iso_hash_insert(struct iso_hash_node **table, const char *path)
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{
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struct iso_hash_node *node;
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unsigned int hash_num;
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/* find the hash number */
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hash_num = iso_hash_path(path);
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/* insert it */
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node = table[hash_num];
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/* unfortunately, we can't safely consider that a path
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* won't be twice in the hash table so make sure it
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* doesn't already exists */
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if (!node) {
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table[hash_num]=iso_hash_node_new(path);
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return 1;
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}
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/* if it's already in, we don't do anything */
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if (!strcmp(path, node->path))
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return 0;
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while (node->next) {
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node = node->next;
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/* if it's already in, we don't do anything */
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if (!strcmp (path, node->path))
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return 0;
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}
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node->next = iso_hash_node_new(path);
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return 1;
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}
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static void
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iso_hash_node_free(struct iso_hash_node *node)
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{
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free(node->path);
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free(node);
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}
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int
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iso_hash_remove(struct iso_hash_node **table, const char *path)
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{
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unsigned int hash_num;
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struct iso_hash_node *node;
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hash_num = iso_hash_path(path);
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node=table[hash_num];
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if (!node)
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return 0;
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if (!strcmp(path, node->path)) {
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table[hash_num]=node->next;
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iso_hash_node_free(node);
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return 1;
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}
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while (node->next) {
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struct iso_hash_node *prev;
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prev = node;
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node = node->next;
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if (!strcmp (path, node->path)) {
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prev->next=node->next;
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iso_hash_node_free(node);
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return 1;
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}
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}
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return 0;
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}
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void
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iso_hash_empty(struct iso_hash_node **table)
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{
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int i;
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for (i=0; i < HASH_NODES; i++) {
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struct iso_hash_node *node;
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node=table[i];
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if (!node)
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continue;
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table[i]=NULL;
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do {
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struct iso_hash_node *next;
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next=node->next;
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iso_hash_node_free(node);
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node=next;
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} while (node);
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}
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}
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