include/splay-tree.h

   1 /* A splay-tree datatype.
   2    Copyright (C) 1998 Free Software Foundation, Inc.
   3    Contributed by Mark Mitchell (mark@markmitchell.com).
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC 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 GNU CC 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 GNU CC; 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 *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 nodes in the splay tree.  */
  65 struct splay_tree_node
  66 {
  67   /* The key.  */
  68   splay_tree_key key;
  69
  70   /* The value.  */
  71   splay_tree_value value;
  72
  73   /* The left and right children, respectively.  */
  74   splay_tree_node left;
  75   splay_tree_node right;
  76 };
  77
  78 /* The splay tree itself.  */
  79 typedef struct splay_tree
  80 {
  81   /* The root of the tree.  */
  82   splay_tree_node root;
  83
  84   /* The comparision function.  */
  85   splay_tree_compare_fn comp;
  86
  87   /* The deallocate-key function.  NULL if no cleanup is necessary.  */
  88   splay_tree_delete_key_fn delete_key;
  89
  90   /* The deallocate-value function.  NULL if no cleanup is necessary.  */
  91   splay_tree_delete_value_fn delete_value;
  92 } *splay_tree;
  93
  94 extern splay_tree splay_tree_new        PARAMS((splay_tree_compare_fn,
  95                                                 splay_tree_delete_key_fn,
  96                                                 splay_tree_delete_value_fn));
  97 extern void splay_tree_delete           PARAMS((splay_tree));
  98 extern void splay_tree_insert           PARAMS((splay_tree,
  99                                                 splay_tree_key,
 100                                                 splay_tree_value));
 101 extern splay_tree_node splay_tree_lookup
 102                                         PARAMS((splay_tree,
 103                                                 splay_tree_key));
 104 extern int splay_tree_foreach           PARAMS((splay_tree,
 105                                                 splay_tree_foreach_fn,
 106                                                 void*));
 107 extern int splay_tree_compare_ints      PARAMS((splay_tree_key,
 108                                                 splay_tree_key));
 109 extern int splay_tree_compare_pointers  PARAMS((splay_tree_key,
 110                                                 splay_tree_key));
 111
 112 #ifdef __cplusplus
 113 }
 114 #endif /* __cplusplus */
 115
 116 #endif /* _SPLAY_TREE_H */