prio_tree.h 3.2 KB

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  1. #ifndef _LINUX_PRIO_TREE_H
  2. #define _LINUX_PRIO_TREE_H
  3. /*
  4. * K&R 2nd ed. A8.3 somewhat obliquely hints that initial sequences of struct
  5. * fields with identical types should end up at the same location. We'll use
  6. * this until we can scrap struct raw_prio_tree_node.
  7. *
  8. * Note: all this could be done more elegantly by using unnamed union/struct
  9. * fields. However, gcc 2.95.3 and apparently also gcc 3.0.4 don't support this
  10. * language extension.
  11. */
  12. struct raw_prio_tree_node {
  13. struct prio_tree_node *left;
  14. struct prio_tree_node *right;
  15. struct prio_tree_node *parent;
  16. };
  17. struct prio_tree_node {
  18. struct prio_tree_node *left;
  19. struct prio_tree_node *right;
  20. struct prio_tree_node *parent;
  21. unsigned long start;
  22. unsigned long last; /* last location _in_ interval */
  23. };
  24. struct prio_tree_root {
  25. struct prio_tree_node *prio_tree_node;
  26. unsigned short index_bits;
  27. unsigned short raw;
  28. /*
  29. * 0: nodes are of type struct prio_tree_node
  30. * 1: nodes are of type raw_prio_tree_node
  31. */
  32. };
  33. struct prio_tree_iter {
  34. struct prio_tree_node *cur;
  35. unsigned long mask;
  36. unsigned long value;
  37. int size_level;
  38. struct prio_tree_root *root;
  39. pgoff_t r_index;
  40. pgoff_t h_index;
  41. };
  42. static inline void prio_tree_iter_init(struct prio_tree_iter *iter,
  43. struct prio_tree_root *root, pgoff_t r_index, pgoff_t h_index)
  44. {
  45. iter->root = root;
  46. iter->r_index = r_index;
  47. iter->h_index = h_index;
  48. iter->cur = NULL;
  49. }
  50. #define __INIT_PRIO_TREE_ROOT(ptr, _raw) \
  51. do { \
  52. (ptr)->prio_tree_node = NULL; \
  53. (ptr)->index_bits = 1; \
  54. (ptr)->raw = (_raw); \
  55. } while (0)
  56. #define INIT_PRIO_TREE_ROOT(ptr) __INIT_PRIO_TREE_ROOT(ptr, 0)
  57. #define INIT_RAW_PRIO_TREE_ROOT(ptr) __INIT_PRIO_TREE_ROOT(ptr, 1)
  58. #define INIT_PRIO_TREE_NODE(ptr) \
  59. do { \
  60. (ptr)->left = (ptr)->right = (ptr)->parent = (ptr); \
  61. } while (0)
  62. #define INIT_PRIO_TREE_ITER(ptr) \
  63. do { \
  64. (ptr)->cur = NULL; \
  65. (ptr)->mask = 0UL; \
  66. (ptr)->value = 0UL; \
  67. (ptr)->size_level = 0; \
  68. } while (0)
  69. #define prio_tree_entry(ptr, type, member) \
  70. ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
  71. static inline int prio_tree_empty(const struct prio_tree_root *root)
  72. {
  73. return root->prio_tree_node == NULL;
  74. }
  75. static inline int prio_tree_root(const struct prio_tree_node *node)
  76. {
  77. return node->parent == node;
  78. }
  79. static inline int prio_tree_left_empty(const struct prio_tree_node *node)
  80. {
  81. return node->left == node;
  82. }
  83. static inline int prio_tree_right_empty(const struct prio_tree_node *node)
  84. {
  85. return node->right == node;
  86. }
  87. struct prio_tree_node *prio_tree_replace(struct prio_tree_root *root,
  88. struct prio_tree_node *old, struct prio_tree_node *node);
  89. struct prio_tree_node *prio_tree_insert(struct prio_tree_root *root,
  90. struct prio_tree_node *node);
  91. void prio_tree_remove(struct prio_tree_root *root, struct prio_tree_node *node);
  92. struct prio_tree_node *prio_tree_next(struct prio_tree_iter *iter);
  93. #define raw_prio_tree_replace(root, old, node) \
  94. prio_tree_replace(root, (struct prio_tree_node *) (old), \
  95. (struct prio_tree_node *) (node))
  96. #define raw_prio_tree_insert(root, node) \
  97. prio_tree_insert(root, (struct prio_tree_node *) (node))
  98. #define raw_prio_tree_remove(root, node) \
  99. prio_tree_remove(root, (struct prio_tree_node *) (node))
  100. #endif /* _LINUX_PRIO_TREE_H */