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hashtable.c
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hashtable.c
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pcs/pcs_mem.h"
#include "hashtable.h"
static unsigned int calcHash1(const char *key, int key_size, int ignore_case)
{
register unsigned int nr = 1, nr2 = 4, ch;
int i;
if (key_size == -1) key_size = strlen(key);
for (i = 0; i < key_size; i++) {
ch = (unsigned int)key[i];
if (ch >= 'A' && ch <= 'Z' && ignore_case && (i == 0 || !(key[i - 1] & 0x80)))
ch += 'a' - 'A';
nr ^= (((nr & 63) + nr2) * ch) + (nr << 8);
nr2 += 3;
}
return nr;
}
static unsigned int calcHash2(const char *key, int key_size, int ignore_case)
{
unsigned int hash = 0, ch;
int i;
if (key_size == -1) key_size = strlen(key);
for (i = 0; i < key_size; i++) {
ch = (unsigned int)key[i];
if (ch >= 'A' && ch <= 'Z' && ignore_case && (i == 0 || !(key[i - 1] & 0x80)))
ch += 'a' - 'A';
hash *= 16777619;
hash ^= ch;
}
return (hash);
}
static unsigned int calcHash3(const char *key, int key_size, int ignore_case)
{
unsigned int h, ch;
int i;
if (key_size == -1) key_size = strlen(key);
for (h = 0, i = 0; i < key_size; i++) {
ch = (unsigned int)key[i];
if (ch >= 'A' && ch <= 'Z' && ignore_case && (i == 0 || !(key[i - 1] & 0x80)))
ch += 'a' - 'A';
h = 31 * h + (ch);
}
return h;
}
static HashtableNode *node_create(const char *key, int key_size, void *value, unsigned int hashA, unsigned int hashB)
{
HashtableNode *node;
node = (HashtableNode *) pcs_malloc(sizeof(HashtableNode));
if (!node)
return NULL;
memset (node, 0, sizeof(HashtableNode));
if (key_size == -1) key_size = strlen(key);
node->key = (char *)pcs_malloc(key_size + 1);
if (!node->key) {
pcs_free(node);
return NULL;
}
memcpy(node->key, key, key_size);
node->key[key_size] = '\0';
node->value = value;
node->hashA = hashA;
node->hashB = hashB;
return node;
}
static void node_destroy(HashtableNode *node, void(*free_value)(void *))
{
HashtableNode *tmp, *cusor;
cusor = node;
while(cusor) {
tmp = cusor;
cusor = cusor->next;
if (tmp->key)
pcs_free(tmp->key);
if (free_value && tmp->value)
(*free_value)(tmp->value);
pcs_free(tmp);
}
}
static int table_add_item(HashtableNode **table, int real_capacity, const char *key, int key_size, void *value, int ignore_case)
{
//不同的字符串三次hash还会碰撞的几率无限接近于不可能
unsigned int nHash, nHashA, nHashB;
unsigned int pos;
HashtableNode *last = NULL, *p;
if (key_size == -1) key_size = strlen(key);
nHash = calcHash1(key, key_size, ignore_case);
nHashA = calcHash2(key, key_size, ignore_case);
nHashB = calcHash3(key, key_size, ignore_case);
pos = nHash % real_capacity;
p = table[pos];
if (!p) {
table[pos] = node_create(key, key_size, value, nHashA, nHashB);
if (!table[pos])
return -1;
return 0;
}
while (p) {
if (p->hashA == nHashA && p->hashB == nHashB) {
break;
}
last = p;
p = p->next;
}
if (p) {
return -1;
}
else {
p = node_create(key, key_size, value, nHashA, nHashB);
if (!p)
return -1;
last->next = p;
}
return 0;
}
static int table_set_item(HashtableNode **table, int real_capacity, const char *key, int key_size, void *value, int ignore_case, int *pHasOld, void **pOldVal)
{
//不同的字符串三次hash还会碰撞的几率无限接近于不可能
unsigned int nHash, nHashA, nHashB;
unsigned int pos;
HashtableNode *last = NULL, *p;
if (key_size == -1) key_size = strlen(key);
nHash = calcHash1(key, key_size, ignore_case);
nHashA = calcHash2(key, key_size, ignore_case);
nHashB = calcHash3(key, key_size, ignore_case);
pos = nHash % real_capacity;
p = table[pos];
if (pHasOld) (*pHasOld) = 0;
if (!p) {
table[pos] = node_create(key, key_size, value, nHashA, nHashB);
if (!table[pos]) return -1;
return 0;
}
while (p) {
if (p->hashA == nHashA && p->hashB == nHashB) {
break;
}
last = p;
p = p->next;
}
if (p) {
if (pHasOld) (*pHasOld) = 1;
if (pOldVal) (*pOldVal) = p->value;
//p->key = key;
p->value = value;
return 0;
}
else {
p = node_create(key, key_size, value, nHashA, nHashB);
if (!p) return -1;
last->next = p;
}
return 0;
}
static HashtableNode *table_get_item(HashtableNode **table, int real_capacity, const char *key, int key_size, int ignore_case)
{
unsigned int nHash, nHashA, nHashB;
unsigned int pos;
HashtableNode *p;
if (key_size == -1) key_size = strlen(key);
nHash = calcHash1(key, key_size, ignore_case);
pos = nHash % real_capacity;
p = table[pos];
if (!p) return NULL;
nHashA = calcHash2(key, key_size, ignore_case);
nHashB = calcHash3(key, key_size, ignore_case);
while (p) {
if (p->hashA == nHashA && p->hashB == nHashB) {
break;
}
p = p->next;
}
return p;
}
static HashtableNode *table_remove_item(HashtableNode **table, int real_capacity, const char *key, int key_size, int ignore_case)
{
unsigned int nHash, nHashA, nHashB;
unsigned int pos;
HashtableNode *p, *prev = NULL;
if (key_size == -1) key_size = strlen(key);
nHash = calcHash1(key, key_size, ignore_case);
pos = nHash % real_capacity;
p = table[pos];
if (p) {
nHashA = calcHash2(key, key_size, ignore_case);
nHashB = calcHash3(key, key_size, ignore_case);
while (p) {
if (p->hashA == nHashA && p->hashB == nHashB) {
break;
}
prev = p;
p = p->next;
}
if (p) {
if (prev) {
prev->next = p->next;
}
else {
table[pos] = p->next;
}
p->next = NULL;
}
}
return p;
}
static void table_clear(HashtableNode **table, int real_capacity, void(*free_value)(void *))
{
int i;
HashtableNode *node;
for(i = 0; i < real_capacity; i++) {
node = table[i];
node_destroy(node, free_value);
table[i] = NULL;
}
}
static void table_destroy(HashtableNode **table, int real_capacity, void(*free_value)(void *))
{
table_clear(table, real_capacity, free_value);
pcs_free(table);
}
Hashtable *ht_create(int capacity, int ignore_case, void (*free_value)(void *))
{
Hashtable *ht;
ht = (Hashtable *) pcs_malloc(sizeof(Hashtable));
if (!ht)
return NULL;
memset (ht, 0, sizeof(Hashtable));
if (capacity < 17) capacity = 17;
ht->capacity = capacity;
ht->real_capacity = (int)(ht->capacity * HASH_EXTEND_MULTIPLIER);
ht->count = 0;
ht->free_value = free_value;
ht->table = (HashtableNode **)pcs_malloc(ht->real_capacity * sizeof(HashtableNode *));
if (!ht->table) {
pcs_free(ht);
return NULL;
}
memset (ht->table, 0, ht->real_capacity * sizeof(HashtableNode *));
ht->ignore_case = ignore_case;
return ht;
}
void ht_destroy(Hashtable *ht)
{
table_destroy(ht->table, ht->real_capacity, ht->free_value);
pcs_free(ht);
}
int ht_expand(Hashtable *ht, int capacity)
{
HashtableNode **table, *node;
int real_capacity, i, cnt;
real_capacity = (int)(capacity * HASH_EXTEND_MULTIPLIER);
table = (HashtableNode **)pcs_malloc(real_capacity * sizeof(HashtableNode *));
if (!table) {
return -1;
}
memset (table, 0, real_capacity * sizeof(HashtableNode *));
cnt = 0;
for(i = 0; i < ht->real_capacity; i++) {
node = ht->table[i];
while(node) {
if (table_add_item(table, real_capacity, node->key, -1, node->value, ht->ignore_case)) {
table_destroy(table, real_capacity, NULL);
return -1;
}
cnt++;
node = node->next;
}
}
table_destroy(ht->table, ht->real_capacity, NULL);
ht->table = table;
ht->capacity = capacity;
ht->real_capacity = real_capacity;
ht->count = cnt;
return 0;
}
int ht_add(Hashtable *ht, const char *key, int key_size, void *value)
{
if (ht->count >= ht->capacity) {
if (ht_expand(ht, ht->count * 2))
return -1;
}
if (table_add_item(ht->table, ht->real_capacity, key, key_size, value, ht->ignore_case))
return -1;
ht->count++;
return 0;
}
int ht_set(Hashtable *ht, const char *key, int key_size, void *value, void **pOldVal)
{
void *oldVal = NULL;
int rc, pHasOld;
rc = table_set_item(ht->table, ht->real_capacity, key, key_size, value, ht->ignore_case, &pHasOld, pOldVal ? pOldVal : &oldVal);
if (oldVal && ht->free_value) (*ht->free_value)(oldVal); /*如果pOldVal传入NULL,且有旧值时,自动释放*/
if (!pHasOld) ht->count++;
return rc;
}
int ht_remove(Hashtable *ht, const char *key, int key_size, void **pVal)
{
HashtableNode *p;
p = table_remove_item(ht->table, ht->real_capacity, key, key_size, ht->ignore_case);
if (p) {
if (pVal) *pVal = p->value;
node_destroy(p, pVal ? NULL : ht->free_value);
ht->count--;
return 0;
}
return -1;
}
void *ht_get(Hashtable *ht, const char *key, int key_size)
{
HashtableNode *p;
p = table_get_item(ht->table, ht->real_capacity, key, key_size, ht->ignore_case);
if (!p)
return NULL;
return p->value;
}
HashtableNode *ht_get_node(Hashtable *ht, const char *key, int key_size)
{
return table_get_item(ht->table, ht->real_capacity, key, key_size, ht->ignore_case);
}
int ht_has(Hashtable *ht, const char *key, int key_size)
{
HashtableNode *p;
p = table_get_item(ht->table, ht->real_capacity, key, key_size, ht->ignore_case);
return (p ? 1 : 0);
}
int ht_clear(Hashtable *ht)
{
table_clear(ht->table, ht->real_capacity, ht->free_value);
ht->count = 0;
return 0;
}
HashtableIterater *ht_it_create(Hashtable *ht)
{
HashtableIterater *iterater;
iterater = (HashtableIterater *) pcs_malloc(sizeof(HashtableIterater));
if (!iterater)
return NULL;
memset(iterater, 0, sizeof(HashtableIterater));
iterater->ht = ht;
iterater->index = -1;
return iterater;
}
void ht_it_destroy(HashtableIterater *iterater)
{
pcs_free(iterater);
}
void ht_it_reset(HashtableIterater *iterater)
{
iterater->index = -1;
}
int ht_it_next(HashtableIterater *iterater)
{
if (iterater->ht->count == 0)
return 0;
if (iterater->p) {
iterater->p = iterater->p->next;
if (iterater->p)
return 1;
}
if (iterater->index >= iterater->ht->real_capacity)
return 0;
iterater->index++;
while(iterater->index < iterater->ht->real_capacity) {
iterater->p = iterater->ht->table[iterater->index];
if (iterater->p)
break;
iterater->index++;
}
if (iterater->p)
return 1;
return 0;
}
void *ht_it_current(HashtableIterater *iterater)
{
if (iterater->p)
return iterater->p->value;
return NULL;
}