nghttp2/lib/nghttp2_map.c

200 lines
4.9 KiB
C

/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2012 Tatsuhiro Tsujikawa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "nghttp2_map.h"
#include <string.h>
#define INITIAL_TABLE_LENGTH 16
int nghttp2_map_init(nghttp2_map *map)
{
map->tablelen = INITIAL_TABLE_LENGTH;
map->table = calloc(map->tablelen, sizeof(nghttp2_map_entry*));
if(map->table == NULL) {
return NGHTTP2_ERR_NOMEM;
}
map->size = 0;
return 0;
}
void nghttp2_map_free(nghttp2_map *map)
{
free(map->table);
}
void nghttp2_map_each_free(nghttp2_map *map,
int (*func)(nghttp2_map_entry *entry, void *ptr),
void *ptr)
{
size_t i;
for(i = 0; i < map->tablelen; ++i) {
nghttp2_map_entry *entry;
for(entry = map->table[i]; entry;) {
nghttp2_map_entry *next = entry->next;
func(entry, ptr);
entry = next;
}
map->table[i] = NULL;
}
}
int nghttp2_map_each(nghttp2_map *map,
int (*func)(nghttp2_map_entry *entry, void *ptr),
void *ptr)
{
int rv;
size_t i;
for(i = 0; i < map->tablelen; ++i) {
nghttp2_map_entry *entry;
for(entry = map->table[i]; entry; entry = entry->next) {
rv = func(entry, ptr);
if(rv != 0) {
return rv;
}
}
}
return 0;
}
void nghttp2_map_entry_init(nghttp2_map_entry *entry, key_type key)
{
entry->key = key;
entry->next = NULL;
}
/* Same hash function in android HashMap source code. */
/* The |mod| must be power of 2 */
static int32_t hash(int32_t h, int32_t mod)
{
h ^= (h >> 20) ^ (h >> 12);
h ^= (h >> 7) ^ (h >> 4);
return h & (mod - 1);
}
static int insert(nghttp2_map_entry **table, size_t tablelen,
nghttp2_map_entry *entry)
{
int32_t h = hash(entry->key, tablelen);
if(table[h] == NULL) {
table[h] = entry;
} else {
nghttp2_map_entry *p;
/* We won't allow duplicated key, so check it out. */
for(p = table[h]; p; p = p->next) {
if(p->key == entry->key) {
return NGHTTP2_ERR_INVALID_ARGUMENT;
}
}
entry->next = table[h];
table[h] = entry;
}
return 0;
}
/* new_tablelen must be power of 2 */
static int resize(nghttp2_map *map, size_t new_tablelen)
{
size_t i;
nghttp2_map_entry **new_table;
new_table = calloc(new_tablelen, sizeof(nghttp2_map_entry*));
if(new_table == NULL) {
return NGHTTP2_ERR_NOMEM;
}
for(i = 0; i < map->tablelen; ++i) {
nghttp2_map_entry *entry;
for(entry = map->table[i]; entry;) {
nghttp2_map_entry *next = entry->next;
entry->next = NULL;
/* This function must succeed */
insert(new_table, new_tablelen, entry);
entry = next;
}
}
free(map->table);
map->tablelen = new_tablelen;
map->table = new_table;
return 0;
}
int nghttp2_map_insert(nghttp2_map *map, nghttp2_map_entry *new_entry)
{
int rv;
/* Load factor is 0.75 */
if((map->size + 1) * 4 > map->tablelen * 3) {
rv = resize(map, map->tablelen * 2);
if(rv != 0) {
return rv;
}
}
rv = insert(map->table, map->tablelen, new_entry);
if(rv != 0) {
return rv;
}
++map->size;
return 0;
}
nghttp2_map_entry* nghttp2_map_find(nghttp2_map *map, key_type key)
{
int32_t h;
nghttp2_map_entry *entry;
h = hash(key, map->tablelen);
for(entry = map->table[h]; entry; entry = entry->next) {
if(entry->key == key) {
return entry;
}
}
return NULL;
}
int nghttp2_map_remove(nghttp2_map *map, key_type key)
{
int32_t h;
nghttp2_map_entry *entry, *prev;
h = hash(key, map->tablelen);
prev = NULL;
for(entry = map->table[h]; entry; entry = entry->next) {
if(entry->key == key) {
if(prev == NULL) {
map->table[h] = entry->next;
} else {
prev->next = entry->next;
}
--map->size;
return 0;
}
prev = entry;
}
return NGHTTP2_ERR_INVALID_ARGUMENT;
}
size_t nghttp2_map_size(nghttp2_map *map)
{
return map->size;
}