cache.h 2.3 KB

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  1. /* cache.h - definitions for the LRU cache
  2. *
  3. * Copyright (C) 2004-2007 Gerhard Häring <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. #ifndef PYSQLITE_CACHE_H
  24. #define PYSQLITE_CACHE_H
  25. #include "Python.h"
  26. /* The LRU cache is implemented as a combination of a doubly-linked with a
  27. * dictionary. The list items are of type 'Node' and the dictionary has the
  28. * nodes as values. */
  29. typedef struct _pysqlite_Node
  30. {
  31. PyObject_HEAD
  32. PyObject* key;
  33. PyObject* data;
  34. long count;
  35. struct _pysqlite_Node* prev;
  36. struct _pysqlite_Node* next;
  37. } pysqlite_Node;
  38. typedef struct
  39. {
  40. PyObject_HEAD
  41. int size;
  42. /* a dictionary mapping keys to Node entries */
  43. PyObject* mapping;
  44. /* the factory callable */
  45. PyObject* factory;
  46. pysqlite_Node* first;
  47. pysqlite_Node* last;
  48. /* if set, decrement the factory function when the Cache is deallocated.
  49. * this is almost always desirable, but not in the pysqlite context */
  50. int decref_factory;
  51. } pysqlite_Cache;
  52. extern PyTypeObject pysqlite_NodeType;
  53. extern PyTypeObject pysqlite_CacheType;
  54. int pysqlite_node_init(pysqlite_Node* self, PyObject* args, PyObject* kwargs);
  55. void pysqlite_node_dealloc(pysqlite_Node* self);
  56. int pysqlite_cache_init(pysqlite_Cache* self, PyObject* args, PyObject* kwargs);
  57. void pysqlite_cache_dealloc(pysqlite_Cache* self);
  58. PyObject* pysqlite_cache_get(pysqlite_Cache* self, PyObject* args);
  59. int pysqlite_cache_setup_types(void);
  60. #endif