/* cache.h - definitions for the LRU cache

 *

 * Copyright (C) 2004-2007 Gerhard Häring <gh@ghaering.de>

 *

 * This file is part of pysqlite.

 *

 * This software is provided 'as-is', without any express or implied

 * warranty.  In no event will the authors be held liable for any damages

 * arising from the use of this software.

 *

 * Permission is granted to anyone to use this software for any purpose,

 * including commercial applications, and to alter it and redistribute it

 * freely, subject to the following restrictions:

 *

 * 1. The origin of this software must not be misrepresented; you must not

 *    claim that you wrote the original software. If you use this software

 *    in a product, an acknowledgment in the product documentation would be

 *    appreciated but is not required.

 * 2. Altered source versions must be plainly marked as such, and must not be

 *    misrepresented as being the original software.

 * 3. This notice may not be removed or altered from any source distribution.

 */

#ifndef PYSQLITE_CACHE_H

#define PYSQLITE_CACHE_H

#include "Python.h"

/* The LRU cache is implemented as a combination of a doubly-linked with a

 * dictionary. The list items are of type 'Node' and the dictionary has the

 * nodes as values. */

typedef struct _pysqlite_Node

{

    PyObject_HEAD

    PyObject* key;

    PyObject* data;

    long count;

    struct _pysqlite_Node* prev;

    struct _pysqlite_Node* next;

} pysqlite_Node;

typedef struct

{

    PyObject_HEAD

    int size;

    /* a dictionary mapping keys to Node entries */

    PyObject* mapping;

    /* the factory callable */

    PyObject* factory;

    pysqlite_Node* first;

    pysqlite_Node* last;

    /* if set, decrement the factory function when the Cache is deallocated.

     * this is almost always desirable, but not in the pysqlite context */

    int decref_factory;

} pysqlite_Cache;

extern PyTypeObject pysqlite_NodeType;

extern PyTypeObject pysqlite_CacheType;

int pysqlite_node_init(pysqlite_Node* self, PyObject* args, PyObject* kwargs);

void pysqlite_node_dealloc(pysqlite_Node* self);

int pysqlite_cache_init(pysqlite_Cache* self, PyObject* args, PyObject* kwargs);

void pysqlite_cache_dealloc(pysqlite_Cache* self);

PyObject* pysqlite_cache_get(pysqlite_Cache* self, PyObject* args);

int pysqlite_cache_setup_types(void);

#endif