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/* hash table */
#include <stdio.h>
#include <stdlib.h>
#include "hash.h"
#include "iftop.h"
hash_status_enum hash_insert(hash_type* hash_table, void* key, void* rec) {
hash_node_type *p, *p0;
int bucket;
/************************************************
* allocate node for data and insert in table *
************************************************/
/* insert node at beginning of list */
bucket = hash_table->hash(key);
p = xmalloc(sizeof *p);
p0 = hash_table->table[bucket];
hash_table->table[bucket] = p;
p->next = p0;
p->key = hash_table->copy_key(key);
p->rec = rec;
return HASH_STATUS_OK;
}
hash_status_enum hash_delete(hash_type* hash_table, void* key) {
hash_node_type *p0, *p;
int bucket;
/********************************************
* delete node containing data from table *
********************************************/
/* find node */
p0 = 0;
bucket = hash_table->hash(key);
p = hash_table->table[bucket];
while (p && !hash_table->compare(p->key, key)) {
p0 = p;
p = p->next;
}
if (!p) return HASH_STATUS_KEY_NOT_FOUND;
/* p designates node to delete, remove it from list */
if (p0) {
/* not first node, p0 points to previous node */
p0->next = p->next;
}
else {
/* first node on chain */
hash_table->table[bucket] = p->next;
}
hash_table->delete_key(p->key);
free (p);
return HASH_STATUS_OK;
}
hash_status_enum hash_find(hash_type* hash_table, void* key, void **rec) {
hash_node_type *p;
/*******************************
* find node containing data *
*******************************/
p = hash_table->table[hash_table->hash(key)];
while (p && !hash_table->compare(p->key, key)) {
p = p->next;
}
if (!p) return HASH_STATUS_KEY_NOT_FOUND;
*rec = p->rec;
return HASH_STATUS_OK;
}
hash_status_enum hash_next_item(hash_type* hash_table, hash_node_type** ppnode) {
int i;
if (hash_table == 0) {
return HASH_STATUS_KEY_NOT_FOUND;
}
if(*ppnode != NULL) {
if((*ppnode)->next != NULL) {
*ppnode = (*ppnode)->next;
return HASH_STATUS_OK;
}
i = hash_table->hash((*ppnode)->key) + 1;
}
else {
/* first node */
i = 0;
}
while(i < hash_table->size && hash_table->table[i] == NULL) {
i++;
}
if(i == hash_table->size) {
*ppnode = NULL;
return HASH_STATUS_KEY_NOT_FOUND;
}
*ppnode = hash_table->table[i];
return HASH_STATUS_OK;
}
void hash_delete_all(hash_type* hash_table) {
int i;
hash_node_type *n, *nn;
if(hash_table == 0) {
return;
}
for(i = 0; i < hash_table->size; i++) {
n = hash_table->table[i];
while(n != NULL) {
nn = n->next;
hash_table->delete_key(n->key);
free(n);
n = nn;
}
hash_table->table[i] = NULL;
}
}
/*
* Allocate and return a hash
*/
hash_status_enum hash_initialise(hash_type* hash_table) {
hash_table->table = xcalloc(hash_table->size, sizeof *hash_table->table);
return HASH_STATUS_OK;
}
hash_status_enum hash_destroy(hash_type* hash_table) {
free(hash_table->table);
return HASH_STATUS_OK;
}
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