160 lines
2.6 KiB
C
160 lines
2.6 KiB
C
#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <limits.h>
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#include "hashtable.h"
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static void*
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ec_malloc(unsigned int size)
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{
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void *ptr = malloc(size);
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if (ptr == NULL) {
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fprintf(stderr, "[!!] Failed to allocate hashtable\n");
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exit(-1);
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}
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return ptr;
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}
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Hashtable*
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ht_create(unsigned int size)
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{
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Hashtable *table;
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unsigned int i;
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if (size < 1)
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return NULL;
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table = ec_malloc(sizeof(Hashtable));
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table->size = size;
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table->entries = ec_malloc(sizeof(Entry) * size);
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for (i = 0; i < size; ++i) {
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table->entries[i] = NULL;
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}
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return table;
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}
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static unsigned int
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hash(Hashtable *table, const char *key)
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{
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unsigned long int hashval = 0;
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int i = 0;
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while (hashval < ULONG_MAX && i < strlen(key)) {
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hashval = hashval << 8;
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hashval += key[i++];
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}
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return hashval % table->size;
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}
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static Entry*
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entry_create(const char *key, void *value)
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{
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Entry *entry;
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entry = ec_malloc(sizeof(Entry));
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entry->key = strdup(key);
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entry->value = value;
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entry->next = NULL;
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return entry;
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}
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void
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ht_set(Hashtable *table, const char *key, void *val)
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{
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int hashkey = 0;
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Entry *newEntry;
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Entry *next;
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Entry *last;
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hashkey = hash(table, key);
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next = table->entries[hashkey];
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/* Find a position */
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while (next != NULL
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&& next->key != NULL
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&& strcmp(key, next->key) > 0)
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{
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last = next;
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next = next->next;
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}
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if (next && next->key && strcmp(key, next->key) == 0) {
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/* Collision */
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free(next->value);
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next->value = val;
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} else {
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/* New entry */
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newEntry = entry_create(key, val);
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if (next == table->entries[hashkey]) {
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table->entries[hashkey] = newEntry;
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newEntry->next = next;
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} else if(next == NULL) {
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last->next = newEntry;
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} else {
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newEntry->next = next;
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last->next = newEntry;
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}
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}
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}
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void*
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ht_get(Hashtable *table, const char *key)
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{
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int hashkey = 0;
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Entry *entry;
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hashkey = hash(table, key);
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entry = table->entries[hashkey];
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while (entry && entry->key && strcmp(entry->key, key) > 0) {
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entry = entry->next;
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}
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if (!entry || !entry->key || strcmp(entry->key, key) != 0) {
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return NULL;
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}
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return entry->value;
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}
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void
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ht_destroy(Hashtable *table)
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{
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ht_destroy_custom(table, free);
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}
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void
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ht_destroy_custom(Hashtable *table, void (*destroy_value)(void *value))
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{
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Entry *entry, *next;
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unsigned int i;
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if (table == NULL) {
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return;
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}
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for (i = 0; i < table->size; ++i) {
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entry = table->entries[i];
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if (entry == NULL)
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continue;
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while (entry) {
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next = entry->next;
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destroy_value(entry->value);
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entry->value = NULL;
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free(entry->key);
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free(entry);
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entry = next;
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}
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}
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free(table->entries);
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free(table);
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}
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