include/splay-tree.h

   1 /* A splay-tree datatype.
   2    Copyright (C) 1998-2017 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.  */
  62 typedef void (*splay_tree_delete_key_fn) (splay_tree_key);
  63
  64 /* The type of a function used to deallocate any resources associated
  65    with the value.  */
  66 typedef void (*splay_tree_delete_value_fn) (splay_tree_value);
  67
  68 /* The type of a function used to iterate over the tree.  */
  69 typedef int (*splay_tree_foreach_fn) (splay_tree_node, void*);
  70
  71 /* The type of a function used to allocate memory for tree root and
  72    node structures.  The first argument is the number of bytes needed;
  73    the second is a data pointer the splay tree functions pass through
  74    to the allocator.  This function must never return zero.  */
  75 typedef void *(*splay_tree_allocate_fn) (int, void *);
  76
  77 /* The type of a function used to free memory allocated using the
  78    corresponding splay_tree_allocate_fn.  The first argument is the
  79    memory to be freed; the latter is a data pointer the splay tree
  80    functions pass through to the freer.  */
  81 typedef void (*splay_tree_deallocate_fn) (void *, void *);
  82
  83 /* The nodes in the splay tree.  */
  84 struct splay_tree_node_s {
  85   /* The key.  */
  86   splay_tree_key key;
  87
  88   /* The value.  */
  89   splay_tree_value value;
  90
  91   /* The left and right children, respectively.  */
  92   splay_tree_node left;
  93   splay_tree_node right;
  94 };
  95
  96 /* The splay tree itself.  */
  97 struct splay_tree_s {
  98   /* The root of the tree.  */
  99   splay_tree_node root;
 100
 101   /* The comparision function.  */
 102   splay_tree_compare_fn comp;
 103
 104   /* The deallocate-key function.  NULL if no cleanup is necessary.  */
 105   splay_tree_delete_key_fn delete_key;
 106
 107   /* The deallocate-value function.  NULL if no cleanup is necessary.  */
 108   splay_tree_delete_value_fn delete_value;
 109
 110   /* Node allocate function.  Takes allocate_data as a parameter. */
 111   splay_tree_allocate_fn allocate;
 112
 113   /* Free function for nodes and trees.  Takes allocate_data as a parameter.  */
 114   splay_tree_deallocate_fn deallocate;
 115
 116   /* Parameter for allocate/free functions.  */
 117   void *allocate_data;
 118 };
 119
 120 typedef struct splay_tree_s *splay_tree;
 121
 122 extern splay_tree splay_tree_new (splay_tree_compare_fn,
 123                                   splay_tree_delete_key_fn,
 124                                   splay_tree_delete_value_fn);
 125 extern splay_tree splay_tree_new_with_allocator (splay_tree_compare_fn,
 126                                                  splay_tree_delete_key_fn,
 127                                                  splay_tree_delete_value_fn,
 128                                                  splay_tree_allocate_fn,
 129                                                  splay_tree_deallocate_fn,
 130                                                  void *);
 131 extern splay_tree splay_tree_new_typed_alloc (splay_tree_compare_fn,
 132                                               splay_tree_delete_key_fn,
 133                                               splay_tree_delete_value_fn,
 134                                               splay_tree_allocate_fn,
 135                                               splay_tree_allocate_fn,
 136                                               splay_tree_deallocate_fn,
 137                                               void *);
 138 extern void splay_tree_delete (splay_tree);
 139 extern splay_tree_node splay_tree_insert (splay_tree,
 140                                           splay_tree_key,
 141                                           splay_tree_value);
 142 extern void splay_tree_remove   (splay_tree, splay_tree_key);
 143 extern splay_tree_node splay_tree_lookup (splay_tree, splay_tree_key);
 144 extern splay_tree_node splay_tree_predecessor (splay_tree, splay_tree_key);
 145 extern splay_tree_node splay_tree_successor (splay_tree, splay_tree_key);
 146 extern splay_tree_node splay_tree_max (splay_tree);
 147 extern splay_tree_node splay_tree_min (splay_tree);
 148 extern int splay_tree_foreach (splay_tree, splay_tree_foreach_fn, void*);
 149 extern int splay_tree_compare_ints (splay_tree_key, splay_tree_key);
 150 extern int splay_tree_compare_pointers (splay_tree_key, splay_tree_key);
 151
 152 #ifdef __cplusplus
 153 }
 154 #endif /* __cplusplus */
 155
 156 #endif /* _SPLAY_TREE_H */