include/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, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, 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 #include "ansidecl.h"
  38
  39 #ifndef GTY
  40 #define GTY(X)
  41 #endif
  42
  43 /* Use typedefs for the key and data types to facilitate changing
  44    these types, if necessary.  These types should be sufficiently wide
  45    that any pointer or scalar can be cast to these types, and then
  46    cast back, without loss of precision.  */
  47 typedef unsigned long int splay_tree_key;
  48 typedef unsigned long int splay_tree_value;
  49
  50 /* Forward declaration for a node in the tree.  */
  51 typedef struct splay_tree_node_s *splay_tree_node;
  52
  53 /* The type of a function which compares two splay-tree keys.  The
  54    function should return values as for qsort.  */
  55 typedef int (*splay_tree_compare_fn) (splay_tree_key, splay_tree_key);
  56
  57 /* The type of a function used to deallocate any resources associated
  58    with the key.  */
  59 typedef void (*splay_tree_delete_key_fn) (splay_tree_key);
  60
  61 /* The type of a function used to deallocate any resources associated
  62    with the value.  */
  63 typedef void (*splay_tree_delete_value_fn) (splay_tree_value);
  64
  65 /* The type of a function used to iterate over the tree.  */
  66 typedef int (*splay_tree_foreach_fn) (splay_tree_node, void*);
  67
  68 /* The type of a function used to allocate memory for tree root and
  69    node structures.  The first argument is the number of bytes needed;
  70    the second is a data pointer the splay tree functions pass through
  71    to the allocator.  This function must never return zero.  */
  72 typedef PTR (*splay_tree_allocate_fn) (int, void *);
  73
  74 /* The type of a function used to free memory allocated using the
  75    corresponding splay_tree_allocate_fn.  The first argument is the
  76    memory to be freed; the latter is a data pointer the splay tree
  77    functions pass through to the freer.  */
  78 typedef void (*splay_tree_deallocate_fn) (void *, void *);
  79
  80 /* The nodes in the splay tree.  */
  81 struct splay_tree_node_s GTY(())
  82 {
  83   /* The key.  */
  84   splay_tree_key GTY ((use_param1)) key;
  85
  86   /* The value.  */
  87   splay_tree_value GTY ((use_param2)) value;
  88
  89   /* The left and right children, respectively.  */
  90   splay_tree_node GTY ((use_params)) left;
  91   splay_tree_node GTY ((use_params)) right;
  92 };
  93
  94 /* The splay tree itself.  */
  95 struct splay_tree_s GTY(())
  96 {
  97   /* The root of the tree.  */
  98   splay_tree_node GTY ((use_params)) root;
  99
 100   /* The comparision function.  */
 101   splay_tree_compare_fn comp;
 102
 103   /* The deallocate-key function.  NULL if no cleanup is necessary.  */
 104   splay_tree_delete_key_fn delete_key;
 105
 106   /* The deallocate-value function.  NULL if no cleanup is necessary.  */
 107   splay_tree_delete_value_fn delete_value;
 108
 109   /* Allocate/free functions, and a data pointer to pass to them.  */
 110   splay_tree_allocate_fn allocate;
 111   splay_tree_deallocate_fn deallocate;
 112   PTR GTY((skip)) allocate_data;
 113
 114 };
 115 typedef struct splay_tree_s *splay_tree;
 116
 117 extern splay_tree splay_tree_new        (splay_tree_compare_fn,
 118                                          splay_tree_delete_key_fn,
 119                                          splay_tree_delete_value_fn);
 120 extern splay_tree splay_tree_new_with_allocator (splay_tree_compare_fn,
 121                                                  splay_tree_delete_key_fn,
 122                                                 splay_tree_delete_value_fn,
 123                                                  splay_tree_allocate_fn,
 124                                                  splay_tree_deallocate_fn,
 125                                                  void *);
 126 extern void splay_tree_delete           (splay_tree);
 127 extern splay_tree_node splay_tree_insert (splay_tree,
 128                                           splay_tree_key,
 129                                           splay_tree_value);
 130 extern void splay_tree_remove   (splay_tree, splay_tree_key);
 131 extern splay_tree_node splay_tree_lookup (splay_tree, splay_tree_key);
 132 extern splay_tree_node splay_tree_predecessor (splay_tree, splay_tree_key);
 133 extern splay_tree_node splay_tree_successor (splay_tree, splay_tree_key);
 134 extern splay_tree_node splay_tree_max (splay_tree);
 135 extern splay_tree_node splay_tree_min (splay_tree);
 136 extern int splay_tree_foreach (splay_tree, splay_tree_foreach_fn, void*);
 137 extern int splay_tree_compare_ints (splay_tree_key, splay_tree_key);
 138 extern int splay_tree_compare_pointers (splay_tree_key, splay_tree_key);
 139
 140 #ifdef __cplusplus
 141 }
 142 #endif /* __cplusplus */
 143
 144 #endif /* _SPLAY_TREE_H */