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/*
* Copyright (c) 2014-2016 DeNA Co., Ltd., Kazuho Oku
*
* 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.
*/
#ifndef h2o__cache_h
#define h2o__cache_h
#include <stdint.h>
#include "h2o/linklist.h"
#include "h2o/memory.h"
typedef struct st_h2o_cache_t h2o_cache_t;
typedef uint32_t /* eq. khint_t */ h2o_cache_hashcode_t;
typedef struct st_h2o_cache_key_t {
h2o_iovec_t vec;
h2o_cache_hashcode_t hash;
} h2o_cache_key_t;
typedef struct st_h2o_cache_ref_t {
h2o_iovec_t key;
h2o_cache_hashcode_t keyhash;
uint64_t at;
h2o_iovec_t value;
int _requested_early_update;
h2o_linklist_t _lru_link;
h2o_linklist_t _age_link;
size_t _refcnt;
} h2o_cache_ref_t;
/**
* calculates the hash code of a key
*/
h2o_cache_hashcode_t h2o_cache_calchash(const char *s, size_t len);
enum {
/**
* if set, the internals of the cache is protected by a mutex so that it can be accessed concurrently
*/
H2O_CACHE_FLAG_MULTITHREADED = 0x1,
/**
* if set, the cache triggers an early update
*/
H2O_CACHE_FLAG_EARLY_UPDATE = 0x2
};
/**
* creates a new cache
*/
h2o_cache_t *h2o_cache_create(int flags, size_t capacity, uint64_t duration, void (*destroy_cb)(h2o_iovec_t value));
/**
* destroys a cache
*/
void h2o_cache_destroy(h2o_cache_t *cache);
/**
* clears a cache
*/
void h2o_cache_clear(h2o_cache_t *cache);
/**
* returns a value named by key from the cache if found, or else returns NULL
* @param cache
* @param now
* @param key
* @param keyhash callers may optionally pass in the precalculated hash value (or should be set to 0)
*/
h2o_cache_ref_t *h2o_cache_fetch(h2o_cache_t *cache, uint64_t now, h2o_iovec_t key, h2o_cache_hashcode_t keyhash);
/**
* releases the reference returned by h2o_cache_fetch
*/
void h2o_cache_release(h2o_cache_t *cache, h2o_cache_ref_t *ref);
/**
* sets the value of the cache
* @param cache
* @param now
* @param key
* @param keyhash callers may optionally pass in the precalculated hash value (or should be set to 0)
* @param value (when no longer needed, destroy_cb will be called)
* @return if the specified value already existed
*/
int h2o_cache_set(h2o_cache_t *cache, uint64_t now, h2o_iovec_t key, h2o_cache_hashcode_t keyhash, h2o_iovec_t value);
/**
* deletes a named value from the cache
* @param cache
* @param now
* @param key
* @param keyhash callers may optionally pass in the precalculated hash value (or should be set to 0)
*/
void h2o_cache_delete(h2o_cache_t *cache, uint64_t now, h2o_iovec_t key, h2o_cache_hashcode_t keyhash);
/**
* getter functions
*/
size_t h2o_cache_get_capacity(h2o_cache_t *cache);
uint64_t h2o_cache_get_duration(h2o_cache_t *cache);
#endif
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