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cpython/Modules/_sqlite/cache.h
2010-09-03 23:47:32 +00:00

74 lines
2.3 KiB
C

/* cache.h - definitions for the LRU cache
*
* Copyright (C) 2004-2010 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