1 /* cache.h - definitions for the LRU cache 2 * 3 * Copyright (C) 2004-2010 Gerhard H�ring <gh@ghaering.de> 4 * 5 * This file is part of pysqlite. 6 * 7 * This software is provided 'as-is', without any express or implied 8 * warranty. In no event will the authors be held liable for any damages 9 * arising from the use of this software. 10 * 11 * Permission is granted to anyone to use this software for any purpose, 12 * including commercial applications, and to alter it and redistribute it 13 * freely, subject to the following restrictions: 14 * 15 * 1. The origin of this software must not be misrepresented; you must not 16 * claim that you wrote the original software. If you use this software 17 * in a product, an acknowledgment in the product documentation would be 18 * appreciated but is not required. 19 * 2. Altered source versions must be plainly marked as such, and must not be 20 * misrepresented as being the original software. 21 * 3. This notice may not be removed or altered from any source distribution. 22 */ 23 24 #ifndef PYSQLITE_CACHE_H 25 #define PYSQLITE_CACHE_H 26 #include "Python.h" 27 28 /* The LRU cache is implemented as a combination of a doubly-linked with a 29 * dictionary. The list items are of type 'Node' and the dictionary has the 30 * nodes as values. */ 31 32 typedef struct _pysqlite_Node 33 { 34 PyObject_HEAD 35 PyObject* key; 36 PyObject* data; 37 long count; 38 struct _pysqlite_Node* prev; 39 struct _pysqlite_Node* next; 40 } pysqlite_Node; 41 42 typedef struct 43 { 44 PyObject_HEAD 45 int size; 46 47 /* a dictionary mapping keys to Node entries */ 48 PyObject* mapping; 49 50 /* the factory callable */ 51 PyObject* factory; 52 53 pysqlite_Node* first; 54 pysqlite_Node* last; 55 56 /* if set, decrement the factory function when the Cache is deallocated. 57 * this is almost always desirable, but not in the pysqlite context */ 58 int decref_factory; 59 } pysqlite_Cache; 60 61 extern PyTypeObject pysqlite_NodeType; 62 extern PyTypeObject pysqlite_CacheType; 63 64 int pysqlite_node_init(pysqlite_Node* self, PyObject* args, PyObject* kwargs); 65 void pysqlite_node_dealloc(pysqlite_Node* self); 66 67 int pysqlite_cache_init(pysqlite_Cache* self, PyObject* args, PyObject* kwargs); 68 void pysqlite_cache_dealloc(pysqlite_Cache* self); 69 PyObject* pysqlite_cache_get(pysqlite_Cache* self, PyObject* args); 70 71 int pysqlite_cache_setup_types(void); 72 73 #endif 74