nghttp2/lib/spdylay_map.c

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/*
* Spdylay - SPDY 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 "spdylay_map.h"
void spdylay_map_init(spdylay_map *map)
{
map->root = NULL;
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map->size = 0;
}
static void spdylay_map_entry_free(spdylay_map_entry *entry)
{
if(entry != NULL) {
free(entry);
}
}
static void spdylay_map_entry_free_recur(spdylay_map_entry *entry)
{
if(entry != NULL) {
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spdylay_map_entry_free_recur(entry->left);
spdylay_map_entry_free_recur(entry->right);
free(entry);
}
}
void spdylay_map_free(spdylay_map *map)
{
spdylay_map_entry_free_recur(map->root);
map->root = NULL;
}
/*
* 32 bit Mix Functions by Thomas Wang
*
* http://www.concentric.net/~Ttwang/tech/inthash.htm
*/
static uint32_t hash32shift(uint32_t key)
{
key = ~key + (key << 15); /* key = (key << 15) - key - 1; */
key = key ^ (key >> 12);
key = key + (key << 2);
key = key ^ (key >> 4);
key = key * 2057; /* key = (key + (key << 3)) + (key << 11); */
key = key ^ (key >> 16);
return key;
}
static spdylay_map_entry* spdylay_map_entry_new(key_type key, void *val)
{
spdylay_map_entry *entry =
(spdylay_map_entry*)malloc(sizeof(spdylay_map_entry));
if(entry != NULL) {
entry->key = key;
entry->val = val;
entry->left = entry->right = NULL;
entry->priority = hash32shift(key);
}
return entry;
}
static spdylay_map_entry* rotate_left(spdylay_map_entry *entry)
{
spdylay_map_entry *root = entry->right;
entry->right = root->left;
root->left = entry;
return root;
}
static spdylay_map_entry* rotate_right(spdylay_map_entry* entry)
{
spdylay_map_entry *root = entry->left;
entry->left = root->right;
root->right = entry;
return root;
}
static spdylay_map_entry* insert_recur(spdylay_map_entry *entry,
key_type key, void *val,
int *error)
{
if(entry == NULL) {
entry = spdylay_map_entry_new(key, val);
if(entry == NULL) {
*error = SPDYLAY_ERR_NOMEM;
}
} else if(key == entry->key) {
*error = SPDYLAY_ERR_INVALID_ARGUMENT;
} else if(key < entry->key) {
entry->left = insert_recur(entry->left, key, val, error);
} else {
entry->right = insert_recur(entry->right, key, val, error);
}
if(entry->left != NULL && entry->priority > entry->left->priority) {
entry = rotate_right(entry);
} else if(entry->right != NULL && entry->priority > entry->right->priority) {
entry = rotate_left(entry);
}
return entry;
}
int spdylay_map_insert(spdylay_map *map, key_type key, void *val)
{
int error = 0;
map->root = insert_recur(map->root, key, val, &error);
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if(!error) {
++map->size;
}
return error;
}
void* spdylay_map_find(spdylay_map *map, key_type key)
{
spdylay_map_entry *entry = map->root;
while(entry != NULL) {
if(key < entry->key) {
entry = entry->left;
} else if(key > entry->key) {
entry = entry->right;
} else {
return entry->val;
}
}
return NULL;
}
static spdylay_map_entry* erase_rotate_recur(spdylay_map_entry *entry)
{
if(entry->left == NULL) {
spdylay_map_entry *right = entry->right;
spdylay_map_entry_free(entry);
return right;
} else if(entry->right == NULL) {
spdylay_map_entry *left = entry->left;
spdylay_map_entry_free(entry);
return left;
} else if(entry->left->priority < entry->right->priority) {
entry = rotate_right(entry);
return erase_rotate_recur(entry->right);
} else {
entry = rotate_left(entry);
return erase_rotate_recur(entry->left);
}
}
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static spdylay_map_entry* erase_recur(spdylay_map_entry *entry, key_type key,
int *error)
{
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if(entry == NULL) {
*error = SPDYLAY_ERR_INVALID_ARGUMENT;
} else if(key < entry->key) {
entry->left = erase_recur(entry->left, key, error);
} else if(key > entry->key) {
entry->right = erase_recur(entry->right, key, error);
} else {
entry = erase_rotate_recur(entry);
}
return entry;
}
void spdylay_map_erase(spdylay_map *map, key_type key)
{
if(map->root != NULL) {
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int error = 0;
map->root = erase_recur(map->root, key, &error);
if(!error) {
--map->size;
}
}
}
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size_t spdylay_map_size(spdylay_map *map)
{
return map->size;
}
static void for_each(spdylay_map_entry *entry,
void (*func)(key_type key, void *val, void *ptr),
void *ptr)
{
if(entry != NULL) {
for_each(entry->left, func, ptr);
func(entry->key, entry->val, ptr);
for_each(entry->right, func, ptr);
}
}
void spdylay_map_each(spdylay_map *map,
void (*func)(key_type key, void *val, void *ptr),
void *ptr)
{
for_each(map->root, func, ptr);
}