include/splay-tree.h

   1 /* A splay-tree datatype.
   2    Copyright (C) 1998-2024 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 #include "ansidecl.h"
  38
  39 #ifdef HAVE_STDINT_H
  40 #include <stdint.h>
  41 #endif
  42 #ifdef HAVE_INTTYPES_H
  43 #include <inttypes.h>
  44 #endif
  45
  46 /* Use typedefs for the key and data types to facilitate changing
  47    these types, if necessary.  These types should be sufficiently wide
  48    that any pointer or scalar can be cast to these types, and then
  49    cast back, without loss of precision.  */
  50 typedef uintptr_t splay_tree_key;
  51 typedef uintptr_t splay_tree_value;
  52
  53 /* Forward declaration for a node in the tree.  */
  54 typedef struct splay_tree_node_s *splay_tree_node;
  55
  56 /* The type of a function which compares two splay-tree keys.  The
  57    function should return values as for qsort.  */
  58 typedef int (*splay_tree_compare_fn) (splay_tree_key, splay_tree_key);
  59
  60 /* The type of a function used to deallocate any resources associated
  61    with the key.  If you provide this function, the splay tree
  62    will take the ownership of the memory of the splay_tree_key arg
  63    of splay_tree_insert.  This function is called to release the keys
  64    present in the tree when calling splay_tree_delete or splay_tree_remove.
  65    If splay_tree_insert is called with a key equal to a key already
  66    present in the tree, the old key and old value will be released.  */
  67 typedef void (*splay_tree_delete_key_fn) (splay_tree_key);
  68
  69 /* The type of a function used to deallocate any resources associated
  70    with the value.  If you provide this function, the memory of the
  71    splay_tree_value arg of splay_tree_insert is managed similarly to
  72    the splay_tree_key memory: see splay_tree_delete_key_fn.  */
  73 typedef void (*splay_tree_delete_value_fn) (splay_tree_value);
  74
  75 /* The type of a function used to iterate over the tree.  */
  76 typedef int (*splay_tree_foreach_fn) (splay_tree_node, void*);
  77
  78 /* The type of a function used to allocate memory for tree root and
  79    node structures.  The first argument is the number of bytes needed;
  80    the second is a data pointer the splay tree functions pass through
  81    to the allocator.  This function must never return zero.  */
  82 typedef void *(*splay_tree_allocate_fn) (int, void *);
  83
  84 /* The type of a function used to free memory allocated using the
  85    corresponding splay_tree_allocate_fn.  The first argument is the
  86    memory to be freed; the latter is a data pointer the splay tree
  87    functions pass through to the freer.  */
  88 typedef void (*splay_tree_deallocate_fn) (void *, void *);
  89
  90 /* The nodes in the splay tree.  */
  91 struct splay_tree_node_s {
  92   /* The key.  */
  93   splay_tree_key key;
  94
  95   /* The value.  */
  96   splay_tree_value value;
  97
  98   /* The left and right children, respectively.  */
  99   splay_tree_node left;
 100   splay_tree_node right;
 101 };
 102
 103 /* The splay tree itself.  */
 104 struct splay_tree_s {
 105   /* The root of the tree.  */
 106   splay_tree_node root;
 107
 108   /* The comparision function.  */
 109   splay_tree_compare_fn comp;
 110
 111   /* The deallocate-key function.  NULL if no cleanup is necessary.  */
 112   splay_tree_delete_key_fn delete_key;
 113
 114   /* The deallocate-value function.  NULL if no cleanup is necessary.  */
 115   splay_tree_delete_value_fn delete_value;
 116
 117   /* Node allocate function.  Takes allocate_data as a parameter. */
 118   splay_tree_allocate_fn allocate;
 119
 120   /* Free function for nodes and trees.  Takes allocate_data as a parameter.  */
 121   splay_tree_deallocate_fn deallocate;
 122
 123   /* Parameter for allocate/free functions.  */
 124   void *allocate_data;
 125 };
 126
 127 typedef struct splay_tree_s *splay_tree;
 128
 129 extern splay_tree splay_tree_new (splay_tree_compare_fn,
 130                                   splay_tree_delete_key_fn,
 131                                   splay_tree_delete_value_fn);
 132 extern splay_tree splay_tree_new_with_allocator (splay_tree_compare_fn,
 133                                                  splay_tree_delete_key_fn,
 134                                                  splay_tree_delete_value_fn,
 135                                                  splay_tree_allocate_fn,
 136                                                  splay_tree_deallocate_fn,
 137                                                  void *);
 138 extern splay_tree splay_tree_new_typed_alloc (splay_tree_compare_fn,
 139                                               splay_tree_delete_key_fn,
 140                                               splay_tree_delete_value_fn,
 141                                               splay_tree_allocate_fn,
 142                                               splay_tree_allocate_fn,
 143                                               splay_tree_deallocate_fn,
 144                                               void *);
 145 extern void splay_tree_delete (splay_tree);
 146 extern splay_tree_node splay_tree_insert (splay_tree,
 147                                           splay_tree_key,
 148                                           splay_tree_value);
 149 extern void splay_tree_remove   (splay_tree, splay_tree_key);
 150 extern splay_tree_node splay_tree_lookup (splay_tree, splay_tree_key);
 151 extern splay_tree_node splay_tree_predecessor (splay_tree, splay_tree_key);
 152 extern splay_tree_node splay_tree_successor (splay_tree, splay_tree_key);
 153 extern splay_tree_node splay_tree_max (splay_tree);
 154 extern splay_tree_node splay_tree_min (splay_tree);
 155 extern int splay_tree_foreach (splay_tree, splay_tree_foreach_fn, void*);
 156 extern int splay_tree_compare_ints (splay_tree_key, splay_tree_key);
 157 extern int splay_tree_compare_pointers (splay_tree_key, splay_tree_key);
 158 extern int splay_tree_compare_strings (splay_tree_key, splay_tree_key);
 159 extern void splay_tree_delete_pointers (splay_tree_value);
 160
 161 #ifdef __cplusplus
 162 }
 163 #endif /* __cplusplus */
 164
 165 #endif /* _SPLAY_TREE_H */