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Diffstat (limited to 'avl-1.4.0/rb.h')
| -rw-r--r-- | avl-1.4.0/rb.h | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/avl-1.4.0/rb.h b/avl-1.4.0/rb.h new file mode 100644 index 0000000..26a9f49 --- /dev/null +++ b/avl-1.4.0/rb.h @@ -0,0 +1,155 @@ +/* libavl - manipulates AVL trees. + Copyright (C) 1998, 1999 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA + 02111-1307, USA. + + The author may be contacted at <pfaffben@pilot.msu.edu> on the + Internet, or as Ben Pfaff, 12167 Airport Rd, DeWitt MI 48820, USA + through more mundane means. */ + +/* This is file rb.h in libavl. */ + +#if !rb_h +#define rb_h 1 + +/* The default maximum height of 32 allows for red-black trees having + between 65,535 and 4,294,967,295 nodes, depending on order of + insertion. You may change this compile-time constant as you + wish. */ +#ifndef RB_MAX_HEIGHT +#define RB_MAX_HEIGHT 32 +#endif + +/* Node colors. */ +enum + { + RB_BLACK, + RB_RED, + }; + +/* Structure for a node in a red-black tree. */ +typedef struct rb_node + { + void *data; /* Pointer to data. */ + struct rb_node *link[2]; /* Subtrees. */ + signed char color; /* Color. */ + char cache; /* Used during insertion. */ + signed char pad[2]; /* Unused. Reserved for threaded trees. */ + } +rb_node; + +/* Used for traversing a red-black tree. */ +typedef struct rb_traverser + { + int init; /* Initialized? */ + int nstack; /* Top of stack. */ + const rb_node *p; /* Used for traversal. */ + const rb_node *stack[RB_MAX_HEIGHT];/* Descended trees. */ + } +rb_traverser; + +/* Initializer for rb_traverser. */ +#define RB_TRAVERSER_INIT {0} + +/* Function types. */ +#if !AVL_FUNC_TYPES +#define AVL_FUNC_TYPES 1 +typedef int (*avl_comparison_func) (const void *a, const void *b, void *param); +typedef void (*avl_node_func) (void *data, void *param); +typedef void *(*avl_copy_func) (void *data, void *param); +#endif + +/* Structure which holds information about a red-black tree. */ +typedef struct rb_tree + { +#if PSPP + struct arena **owner; /* Arena to store nodes. */ +#endif + rb_node root; /* Tree root node. */ + avl_comparison_func cmp; /* Used to compare keys. */ + int count; /* Number of nodes in the tree. */ + void *param; /* Arbitary user data. */ + } +rb_tree; + +#if PSPP +#define MAYBE_ARENA struct arena **owner, +#else +#define MAYBE_ARENA /* nothing */ +#endif + +/* General functions. */ +rb_tree *rb_create (MAYBE_ARENA avl_comparison_func, void *param); +void rb_destroy (rb_tree *, avl_node_func); +void rb_free (rb_tree *); +int rb_count (const rb_tree *); +rb_tree *rb_copy (MAYBE_ARENA const rb_tree *, avl_copy_func); + +/* Walk the tree. */ +void rb_walk (const rb_tree *, avl_node_func, void *param); +void *rb_traverse (const rb_tree *, rb_traverser *); +#define rb_init_traverser(TRAVERSER) ((TRAVERSER)->init = 0) + +/* Search for a given item. */ +void **rb_probe (rb_tree *, void *); +void *rb_delete (rb_tree *, const void *); +void *rb_find (const rb_tree *, const void *); +void *rb_find_close (const rb_tree *, const void *); + +#if __GCC__ >= 2 +extern inline void * +rb_insert (rb_tree *tree, void *item) +{ + void **p = rb_probe (tree, item); + return (*p == item) ? NULL : *p; +} + +extern inline void * +rb_replace (rb_tree *tree, void *item) +{ + void **p = rb_probe (tree, item); + if (*p == item) + return NULL; + else + { + void *r = *p; + *p = item; + return r; + } +} +#else /* not gcc */ +void *rb_insert (rb_tree *tree, void *item); +void *rb_replace (rb_tree *tree, void *item); +#endif /* not gcc */ + +/* Easy assertions on insertion & deletion. */ +#ifndef NDEBUG +#define rb_force_insert(A, B) \ + do \ + { \ + void *r = rb_insert (A, B); \ + assert (r == NULL); \ + } \ + while (0) +void *rb_force_delete (rb_tree *, void *); +#else +#define rb_force_insert(A, B) \ + rb_insert (A, B) +#define rb_force_delete(A, B) \ + rb_delete (A, B) +#endif + +#endif /* rb_h */ |