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/*
* Copyright © 2014 Intel Corporation
*
* 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 (including the next
* paragraph) 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 DISK_CACHE_H
#define DISK_CACHE_H
#include <stdint.h>
#include <stdbool.h>
#ifdef __cplusplus
extern "C" {
#endif
/* Size of cache keys in bytes. */
#define CACHE_KEY_SIZE 20
typedef uint8_t cache_key[CACHE_KEY_SIZE];
struct disk_cache;
/* Provide inlined stub functions if the shader cache is disabled. */
/**
* Create a new cache object.
*
* This function creates the handle necessary for all subsequent cache_*
* functions.
*
* This cache provides two distinct operations:
*
* o Storage and retrieval of arbitrary objects by cryptographic
* name (or "key"). This is provided via disk_cache_put() and
* disk_cache_get().
*
* o The ability to store a key alone and check later whether the
* key was previously stored. This is provided via disk_cache_put_key()
* and disk_cache_has_key().
*
* The put_key()/has_key() operations are conceptually identical to
* put()/get() with no data, but are provided separately to allow for
* a more efficient implementation.
*
* In all cases, the keys are sequences of 20 bytes. It is anticipated
* that callers will compute appropriate SHA-1 signatures for keys,
* (though nothing in this implementation directly relies on how the
* names are computed). See mesa-sha1.h and _mesa_sha1_compute for
* assistance in computing SHA-1 signatures.
*/
struct disk_cache *
disk_cache_create(void);
/**
* Destroy a cache object, (freeing all associated resources).
*/
void
disk_cache_destroy(struct disk_cache *cache);
/**
* Store an item in the cache under the name \key.
*
* The item can be retrieved later with disk_cache_get(), (unless the item has
* been evicted in the interim).
*
* Any call to disk_cache_put() may cause an existing, random item to be
* evicted from the cache.
*/
void
disk_cache_put(struct disk_cache *cache, cache_key key,
const void *data, size_t size);
/**
* Retrieve an item previously stored in the cache with the name <key>.
*
* The item must have been previously stored with a call to disk_cache_put().
*
* If \size is non-NULL, then, on successful return, it will be set to the
* size of the object.
*
* \return A pointer to the stored object if found. NULL if the object
* is not found, or if any error occurs, (memory allocation failure,
* filesystem error, etc.). The returned data is malloc'ed so the
* caller should call free() it when finished.
*/
void *
disk_cache_get(struct disk_cache *cache, cache_key key, size_t *size);
/**
* Store the name \key within the cache, (without any associated data).
*
* Later this key can be checked with disk_cache_has_key(), (unless the key
* has been evicted in the interim).
*
* Any call to cache_record() may cause an existing, random key to be
* evicted from the cache.
*/
void
disk_cache_put_key(struct disk_cache *cache, cache_key key);
/**
* Test whether the name \key was previously recorded in the cache.
*
* Return value: True if disk_cache_put_key() was previously called with
* \key, (and the key was not evicted in the interim).
*
* Note: disk_cache_has_key() will only return true for keys passed to
* disk_cache_put_key(). Specifically, a call to disk_cache_put() will not cause
* disk_cache_has_key() to return true for the same key.
*/
bool
disk_cache_has_key(struct disk_cache *cache, cache_key key);
#ifdef __cplusplus
}
#endif
#endif /* CACHE_H */
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