minix/lib/libmagicrt/include/magic_splay_tree.h

   1 /* A splay-tree datatype.
   2    Copyright 1998, 1999, 2000, 2002 Free Software Foundation, Inc.
   3    Contributed by Mark Mitchell (mark@markmitchell.com).
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it
   8 under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 51 Franklin Street - Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22 /* For an easily readable description of splay-trees, see:
  23
  24      Lewis, Harry R. and Denenberg, Larry.  Data Structures and Their
  25      Algorithms.  Harper-Collins, Inc.  1991.
  26
  27    The major feature of splay trees is that all basic tree operations
  28    are amortized O(log n) time for a tree with n nodes.  */
  29
  30 #ifndef _SPLAY_TREE_H
  31 #define _SPLAY_TREE_H
  32
  33 #ifdef __cplusplus
  34 extern "C" {
  35 #endif /* __cplusplus */
  36
  37 #ifndef GTY
  38 #define GTY(X)
  39 #endif
  40
  41 #ifndef ATTRIBUTE_UNUSED
  42 #define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
  43 #endif /* ATTRIBUTE_UNUSED */
  44
  45 /* Use typedefs for the key and data types to facilitate changing
  46    these types, if necessary.  These types should be sufficiently wide
  47    that any pointer or scalar can be cast to these types, and then
  48    cast back, without loss of precision.  */
  49 typedef unsigned long int splay_tree_key;
  50 typedef unsigned long int splay_tree_value;
  51
  52 /* Forward declaration for a node in the tree.  */
  53 typedef struct splay_tree_node_s *splay_tree_node;
  54
  55 /* The type of a function which compares two splay-tree keys.  The
  56    function should return values as for qsort.  */
  57 typedef int (*splay_tree_compare_fn) (splay_tree_key, splay_tree_key);
  58
  59 /* The type of a function used to deallocate any resources associated
  60    with the key.  */
  61 typedef void (*splay_tree_delete_key_fn) (splay_tree_key);
  62
  63 /* The type of a function used to deallocate any resources associated
  64    with the value.  */
  65 typedef void (*splay_tree_delete_value_fn) (splay_tree_value);
  66
  67 /* The type of a function used to iterate over the tree.  */
  68 typedef int (*splay_tree_foreach_fn) (splay_tree_node, void*);
  69
  70 /* The type of a function used to allocate memory for tree root and
  71    node structures.  The first argument is the number of bytes needed;
  72    the second is a data pointer the splay tree functions pass through
  73    to the allocator.  This function must never return zero.  */
  74 typedef void *(*splay_tree_allocate_fn) (int, void *);
  75
  76 /* The type of a function used to free memory allocated using the
  77    corresponding splay_tree_allocate_fn.  The first argument is the
  78    memory to be freed; the latter is a data pointer the splay tree
  79    functions pass through to the freer.  */
  80 typedef void (*splay_tree_deallocate_fn) (void *, void *);
  81
  82 /* The nodes in the splay tree.  */
  83 struct splay_tree_node_s GTY(())
  84 {
  85   /* The key.  */
  86   splay_tree_key GTY ((use_param1)) key;
  87
  88   /* The value.  */
  89   splay_tree_value GTY ((use_param2)) value;
  90
  91   /* The left and right children, respectively.  */
  92   splay_tree_node GTY ((use_params)) left;
  93   splay_tree_node GTY ((use_params)) right;
  94 };
  95
  96 /* The splay tree itself.  */
  97 struct splay_tree_s GTY(())
  98 {
  99   /* The root of the tree.  */
 100   splay_tree_node GTY ((use_params)) root;
 101
 102   /* The comparision function.  */
 103   splay_tree_compare_fn comp;
 104
 105   /* The deallocate-key function.  NULL if no cleanup is necessary.  */
 106   splay_tree_delete_key_fn delete_key;
 107
 108   /* The deallocate-value function.  NULL if no cleanup is necessary.  */
 109   splay_tree_delete_value_fn delete_value;
 110
 111   /* Allocate/free functions, and a data pointer to pass to them.  */
 112   splay_tree_allocate_fn allocate;
 113   splay_tree_deallocate_fn deallocate;
 114   void * GTY((skip)) allocate_data;
 115
 116 };
 117 typedef struct splay_tree_s *splay_tree;
 118
 119 extern splay_tree splay_tree_new (splay_tree_compare_fn,
 120                                   splay_tree_delete_key_fn,
 121                                   splay_tree_delete_value_fn);
 122 extern splay_tree splay_tree_new_with_allocator (splay_tree_compare_fn,
 123                                                  splay_tree_delete_key_fn,
 124                                                  splay_tree_delete_value_fn,
 125                                                  splay_tree_allocate_fn,
 126                                                  splay_tree_deallocate_fn,
 127                                                  void *);
 128 extern void splay_tree_delete (splay_tree);
 129 extern splay_tree_node splay_tree_insert (splay_tree,
 130                                           splay_tree_key,
 131                                           splay_tree_value);
 132 extern void splay_tree_remove (splay_tree, splay_tree_key);
 133 extern splay_tree_node splay_tree_lookup (splay_tree, splay_tree_key);
 134 extern splay_tree_node splay_tree_predecessor (splay_tree, splay_tree_key);
 135 extern splay_tree_node splay_tree_successor (splay_tree, splay_tree_key);
 136 extern splay_tree_node splay_tree_max (splay_tree);
 137 extern splay_tree_node splay_tree_min (splay_tree);
 138 extern int splay_tree_foreach (splay_tree, splay_tree_foreach_fn, void*);
 139 extern int splay_tree_compare_ints (splay_tree_key, splay_tree_key);
 140 extern int splay_tree_compare_pointers (splay_tree_key, splay_tree_key);
 141
 142 #ifdef __cplusplus
 143 }
 144 #endif /* __cplusplus */
 145
 146 #endif /* _SPLAY_TREE_H */
 147