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 /* Use typedefs for the key and data types to facilitate changing
  40    these types, if necessary.  These types should be sufficiently wide
  41    that any pointer or scalar can be cast to these types, and then
  42    cast back, without loss of precision.  */
  43 typedef unsigned long int splay_tree_key;
  44 typedef unsigned long int splay_tree_value;
  45
  46 /* Forward declaration for a node in the tree.  */
  47 typedef struct splay_tree_node_s *splay_tree_node;
  48
  49 /* The type of a function which compares two splay-tree keys.  The
  50    function should return values as for qsort.  */
  51 typedef int (*splay_tree_compare_fn) PARAMS((splay_tree_key, splay_tree_key));
  52
  53 /* The type of a function used to deallocate any resources associated
  54    with the key.  */
  55 typedef void (*splay_tree_delete_key_fn) PARAMS((splay_tree_key));
  56
  57 /* The type of a function used to deallocate any resources associated
  58    with the value.  */
  59 typedef void (*splay_tree_delete_value_fn) PARAMS((splay_tree_value));
  60
  61 /* The type of a function used to iterate over the tree.  */
  62 typedef int (*splay_tree_foreach_fn) PARAMS((splay_tree_node, void*));
  63
  64 /* The type of a function used to allocate memory for tree root and
  65    node structures.  The first argument is the number of bytes needed;
  66    the second is a data pointer the splay tree functions pass through
  67    to the allocator.  This function must never return zero.  */
  68 typedef void *(*splay_tree_allocate_fn) PARAMS((int, void *));
  69
  70 /* The type of a function used to free memory allocated using the
  71    corresponding splay_tree_allocate_fn.  The first argument is the
  72    memory to be freed; the latter is a data pointer the splay tree
  73    functions pass through to the freer.  */
  74 typedef void (*splay_tree_deallocate_fn) PARAMS((void *, void *));
  75
  76 /* The nodes in the splay tree.  */
  77 struct splay_tree_node_s
  78 {
  79   /* The key.  */
  80   splay_tree_key key;
  81
  82   /* The value.  */
  83   splay_tree_value value;
  84
  85   /* The left and right children, respectively.  */
  86   splay_tree_node left;
  87   splay_tree_node right;
  88 };
  89
  90 /* The splay tree itself.  */
  91 typedef struct splay_tree_s
  92 {
  93   /* The root of the tree.  */
  94   splay_tree_node root;
  95
  96   /* The comparision function.  */
  97   splay_tree_compare_fn comp;
  98
  99   /* The deallocate-key function.  NULL if no cleanup is necessary.  */
 100   splay_tree_delete_key_fn delete_key;
 101
 102   /* The deallocate-value function.  NULL if no cleanup is necessary.  */
 103   splay_tree_delete_value_fn delete_value;
 104
 105   /* Allocate/free functions, and a data pointer to pass to them.  */
 106   splay_tree_allocate_fn allocate;
 107   splay_tree_deallocate_fn deallocate;
 108   void *allocate_data;
 109
 110 } *splay_tree;
 111
 112 extern splay_tree splay_tree_new        PARAMS((splay_tree_compare_fn,
 113                                                 splay_tree_delete_key_fn,
 114                                                 splay_tree_delete_value_fn));
 115 extern splay_tree splay_tree_new_with_allocator
 116                                         PARAMS((splay_tree_compare_fn,
 117                                                 splay_tree_delete_key_fn,
 118                                                 splay_tree_delete_value_fn,
 119                                                 splay_tree_allocate_fn,
 120                                                 splay_tree_deallocate_fn,
 121                                                 void *));
 122 extern void splay_tree_delete           PARAMS((splay_tree));
 123 extern splay_tree_node splay_tree_insert
 124                                         PARAMS((splay_tree,
 125                                                 splay_tree_key,
 126                                                 splay_tree_value));
 127 extern void splay_tree_remove           PARAMS((splay_tree,
 128                                                 splay_tree_key));
 129 extern splay_tree_node splay_tree_lookup
 130                                         PARAMS((splay_tree,
 131                                                 splay_tree_key));
 132 extern splay_tree_node splay_tree_predecessor
 133                                         PARAMS((splay_tree,
 134                                                 splay_tree_key));
 135 extern splay_tree_node splay_tree_successor
 136                                         PARAMS((splay_tree,
 137                                                 splay_tree_key));
 138 extern splay_tree_node splay_tree_max
 139                                         PARAMS((splay_tree));
 140 extern splay_tree_node splay_tree_min
 141                                         PARAMS((splay_tree));
 142 extern int splay_tree_foreach           PARAMS((splay_tree,
 143                                                 splay_tree_foreach_fn,
 144                                                 void*));
 145 extern int splay_tree_compare_ints      PARAMS((splay_tree_key,
 146                                                 splay_tree_key));
 147 extern int splay_tree_compare_pointers  PARAMS((splay_tree_key,
 148                                                 splay_tree_key));
 149
 150 #ifdef __cplusplus
 151 }
 152 #endif /* __cplusplus */
 153
 154 #endif /* _SPLAY_TREE_H */