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authorShehjar Tikoo <shehjart@gluster.com>2009-10-05 07:42:02 +0000
committerAnand V. Avati <avati@dev.gluster.com>2009-10-06 07:05:07 -0700
commitf3e46f2cb44e95c453bfa20c870dca6e42fc9a7a (patch)
tree6304d7d0158b66afa0b181597d13988efeaedf45 /contrib
parent39243caeca3322801429afcef5094ea734438669 (diff)
core: Add rbtree based hash table
Signed-off-by: Anand V. Avati <avati@dev.gluster.com> BUG: 145 (NFSv3 related additions to 2.1 task list) URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=145
Diffstat (limited to 'contrib')
-rw-r--r--contrib/rbtree/rb.c929
-rw-r--r--contrib/rbtree/rb.h122
2 files changed, 1051 insertions, 0 deletions
diff --git a/contrib/rbtree/rb.c b/contrib/rbtree/rb.c
new file mode 100644
index 0000000..d1339b9
--- /dev/null
+++ b/contrib/rbtree/rb.c
@@ -0,0 +1,929 @@
+/* Produced by texiweb from libavl.w. */
+
+/* libavl - library for manipulation of binary trees.
+ Copyright (C) 1998-2002, 2004 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 <blp@gnu.org> on the Internet, or
+ write to Ben Pfaff, Stanford University, Computer Science Dept., 353
+ Serra Mall, Stanford CA 94305, USA.
+*/
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "rb.h"
+
+/* Creates and returns a new table
+ with comparison function |compare| using parameter |param|
+ and memory allocator |allocator|.
+ Returns |NULL| if memory allocation failed. */
+struct rb_table *
+rb_create (rb_comparison_func *compare, void *param,
+ struct libavl_allocator *allocator)
+{
+ struct rb_table *tree;
+
+ assert (compare != NULL);
+
+ if (allocator == NULL)
+ allocator = &rb_allocator_default;
+
+ tree = allocator->libavl_malloc (allocator, sizeof *tree);
+ if (tree == NULL)
+ return NULL;
+
+ tree->rb_root = NULL;
+ tree->rb_compare = compare;
+ tree->rb_param = param;
+ tree->rb_alloc = allocator;
+ tree->rb_count = 0;
+ tree->rb_generation = 0;
+
+ return tree;
+}
+
+/* Search |tree| for an item matching |item|, and return it if found.
+ Otherwise return |NULL|. */
+void *
+rb_find (const struct rb_table *tree, const void *item)
+{
+ const struct rb_node *p;
+
+ assert (tree != NULL && item != NULL);
+ for (p = tree->rb_root; p != NULL; )
+ {
+ int cmp = tree->rb_compare (item, p->rb_data, tree->rb_param);
+
+ if (cmp < 0)
+ p = p->rb_link[0];
+ else if (cmp > 0)
+ p = p->rb_link[1];
+ else /* |cmp == 0| */
+ return p->rb_data;
+ }
+
+ return NULL;
+}
+
+/* Inserts |item| into |tree| and returns a pointer to |item|'s address.
+ If a duplicate item is found in the tree,
+ returns a pointer to the duplicate without inserting |item|.
+ Returns |NULL| in case of memory allocation failure. */
+void **
+rb_probe (struct rb_table *tree, void *item)
+{
+ struct rb_node *pa[RB_MAX_HEIGHT]; /* Nodes on stack. */
+ unsigned char da[RB_MAX_HEIGHT]; /* Directions moved from stack nodes. */
+ int k; /* Stack height. */
+
+ struct rb_node *p; /* Traverses tree looking for insertion point. */
+ struct rb_node *n; /* Newly inserted node. */
+
+ assert (tree != NULL && item != NULL);
+
+ pa[0] = (struct rb_node *) &tree->rb_root;
+ da[0] = 0;
+ k = 1;
+ for (p = tree->rb_root; p != NULL; p = p->rb_link[da[k - 1]])
+ {
+ int cmp = tree->rb_compare (item, p->rb_data, tree->rb_param);
+ if (cmp == 0)
+ return &p->rb_data;
+
+ pa[k] = p;
+ da[k++] = cmp > 0;
+ }
+
+ n = pa[k - 1]->rb_link[da[k - 1]] =
+ tree->rb_alloc->libavl_malloc (tree->rb_alloc, sizeof *n);
+ if (n == NULL)
+ return NULL;
+
+ n->rb_data = item;
+ n->rb_link[0] = n->rb_link[1] = NULL;
+ n->rb_color = RB_RED;
+ tree->rb_count++;
+ tree->rb_generation++;
+
+ while (k >= 3 && pa[k - 1]->rb_color == RB_RED)
+ {
+ if (da[k - 2] == 0)
+ {
+ struct rb_node *y = pa[k - 2]->rb_link[1];
+ if (y != NULL && y->rb_color == RB_RED)
+ {
+ pa[k - 1]->rb_color = y->rb_color = RB_BLACK;
+ pa[k - 2]->rb_color = RB_RED;
+ k -= 2;
+ }
+ else
+ {
+ struct rb_node *x;
+
+ if (da[k - 1] == 0)
+ y = pa[k - 1];
+ else
+ {
+ x = pa[k - 1];
+ y = x->rb_link[1];
+ x->rb_link[1] = y->rb_link[0];
+ y->rb_link[0] = x;
+ pa[k - 2]->rb_link[0] = y;
+ }
+
+ x = pa[k - 2];
+ x->rb_color = RB_RED;
+ y->rb_color = RB_BLACK;
+
+ x->rb_link[0] = y->rb_link[1];
+ y->rb_link[1] = x;
+ pa[k - 3]->rb_link[da[k - 3]] = y;
+ break;
+ }
+ }
+ else
+ {
+ struct rb_node *y = pa[k - 2]->rb_link[0];
+ if (y != NULL && y->rb_color == RB_RED)
+ {
+ pa[k - 1]->rb_color = y->rb_color = RB_BLACK;
+ pa[k - 2]->rb_color = RB_RED;
+ k -= 2;
+ }
+ else
+ {
+ struct rb_node *x;
+
+ if (da[k - 1] == 1)
+ y = pa[k - 1];
+ else
+ {
+ x = pa[k - 1];
+ y = x->rb_link[0];
+ x->rb_link[0] = y->rb_link[1];
+ y->rb_link[1] = x;
+ pa[k - 2]->rb_link[1] = y;
+ }
+
+ x = pa[k - 2];
+ x->rb_color = RB_RED;
+ y->rb_color = RB_BLACK;
+
+ x->rb_link[1] = y->rb_link[0];
+ y->rb_link[0] = x;
+ pa[k - 3]->rb_link[da[k - 3]] = y;
+ break;
+ }
+ }
+ }
+ tree->rb_root->rb_color = RB_BLACK;
+
+
+ return &n->rb_data;
+}
+
+/* Inserts |item| into |table|.
+ Returns |NULL| if |item| was successfully inserted
+ or if a memory allocation error occurred.
+ Otherwise, returns the duplicate item. */
+void *
+rb_insert (struct rb_table *table, void *item)
+{
+ void **p = rb_probe (table, item);
+ return p == NULL || *p == item ? NULL : *p;
+}
+
+/* Inserts |item| into |table|, replacing any duplicate item.
+ Returns |NULL| if |item| was inserted without replacing a duplicate,
+ or if a memory allocation error occurred.
+ Otherwise, returns the item that was replaced. */
+void *
+rb_replace (struct rb_table *table, void *item)
+{
+ void **p = rb_probe (table, item);
+ if (p == NULL || *p == item)
+ return NULL;
+ else
+ {
+ void *r = *p;
+ *p = item;
+ return r;
+ }
+}
+
+/* Deletes from |tree| and returns an item matching |item|.
+ Returns a null pointer if no matching item found. */
+void *
+rb_delete (struct rb_table *tree, const void *item)
+{
+ struct rb_node *pa[RB_MAX_HEIGHT]; /* Nodes on stack. */
+ unsigned char da[RB_MAX_HEIGHT]; /* Directions moved from stack nodes. */
+ int k; /* Stack height. */
+
+ struct rb_node *p; /* The node to delete, or a node part way to it. */
+ int cmp; /* Result of comparison between |item| and |p|. */
+
+ assert (tree != NULL && item != NULL);
+
+ k = 0;
+ p = (struct rb_node *) &tree->rb_root;
+ for (cmp = -1; cmp != 0;
+ cmp = tree->rb_compare (item, p->rb_data, tree->rb_param))
+ {
+ int dir = cmp > 0;
+
+ pa[k] = p;
+ da[k++] = dir;
+
+ p = p->rb_link[dir];
+ if (p == NULL)
+ return NULL;
+ }
+ item = p->rb_data;
+
+ if (p->rb_link[1] == NULL)
+ pa[k - 1]->rb_link[da[k - 1]] = p->rb_link[0];
+ else
+ {
+ enum rb_color t;
+ struct rb_node *r = p->rb_link[1];
+
+ if (r->rb_link[0] == NULL)
+ {
+ r->rb_link[0] = p->rb_link[0];
+ t = r->rb_color;
+ r->rb_color = p->rb_color;
+ p->rb_color = t;
+ pa[k - 1]->rb_link[da[k - 1]] = r;
+ da[k] = 1;
+ pa[k++] = r;
+ }
+ else
+ {
+ struct rb_node *s;
+ int j = k++;
+
+ for (;;)
+ {
+ da[k] = 0;
+ pa[k++] = r;
+ s = r->rb_link[0];
+ if (s->rb_link[0] == NULL)
+ break;
+
+ r = s;
+ }
+
+ da[j] = 1;
+ pa[j] = s;
+ pa[j - 1]->rb_link[da[j - 1]] = s;
+
+ s->rb_link[0] = p->rb_link[0];
+ r->rb_link[0] = s->rb_link[1];
+ s->rb_link[1] = p->rb_link[1];
+
+ t = s->rb_color;
+ s->rb_color = p->rb_color;
+ p->rb_color = t;
+ }
+ }
+
+ if (p->rb_color == RB_BLACK)
+ {
+ for (;;)
+ {
+ struct rb_node *x = pa[k - 1]->rb_link[da[k - 1]];
+ if (x != NULL && x->rb_color == RB_RED)
+ {
+ x->rb_color = RB_BLACK;
+ break;
+ }
+ if (k < 2)
+ break;
+
+ if (da[k - 1] == 0)
+ {
+ struct rb_node *w = pa[k - 1]->rb_link[1];
+
+ if (w->rb_color == RB_RED)
+ {
+ w->rb_color = RB_BLACK;
+ pa[k - 1]->rb_color = RB_RED;
+
+ pa[k - 1]->rb_link[1] = w->rb_link[0];
+ w->rb_link[0] = pa[k - 1];
+ pa[k - 2]->rb_link[da[k - 2]] = w;
+
+ pa[k] = pa[k - 1];
+ da[k] = 0;
+ pa[k - 1] = w;
+ k++;
+
+ w = pa[k - 1]->rb_link[1];
+ }
+
+ if ((w->rb_link[0] == NULL
+ || w->rb_link[0]->rb_color == RB_BLACK)
+ && (w->rb_link[1] == NULL
+ || w->rb_link[1]->rb_color == RB_BLACK))
+ w->rb_color = RB_RED;
+ else
+ {
+ if (w->rb_link[1] == NULL
+ || w->rb_link[1]->rb_color == RB_BLACK)
+ {
+ struct rb_node *y = w->rb_link[0];
+ y->rb_color = RB_BLACK;
+ w->rb_color = RB_RED;
+ w->rb_link[0] = y->rb_link[1];
+ y->rb_link[1] = w;
+ w = pa[k - 1]->rb_link[1] = y;
+ }
+
+ w->rb_color = pa[k - 1]->rb_color;
+ pa[k - 1]->rb_color = RB_BLACK;
+ w->rb_link[1]->rb_color = RB_BLACK;
+
+ pa[k - 1]->rb_link[1] = w->rb_link[0];
+ w->rb_link[0] = pa[k - 1];
+ pa[k - 2]->rb_link[da[k - 2]] = w;
+ break;
+ }
+ }
+ else
+ {
+ struct rb_node *w = pa[k - 1]->rb_link[0];
+
+ if (w->rb_color == RB_RED)
+ {
+ w->rb_color = RB_BLACK;
+ pa[k - 1]->rb_color = RB_RED;
+
+ pa[k - 1]->rb_link[0] = w->rb_link[1];
+ w->rb_link[1] = pa[k - 1];
+ pa[k - 2]->rb_link[da[k - 2]] = w;
+
+ pa[k] = pa[k - 1];
+ da[k] = 1;
+ pa[k - 1] = w;
+ k++;
+
+ w = pa[k - 1]->rb_link[0];
+ }
+
+ if ((w->rb_link[0] == NULL
+ || w->rb_link[0]->rb_color == RB_BLACK)
+ && (w->rb_link[1] == NULL
+ || w->rb_link[1]->rb_color == RB_BLACK))
+ w->rb_color = RB_RED;
+ else
+ {
+ if (w->rb_link[0] == NULL
+ || w->rb_link[0]->rb_color == RB_BLACK)
+ {
+ struct rb_node *y = w->rb_link[1];
+ y->rb_color = RB_BLACK;
+ w->rb_color = RB_RED;
+ w->rb_link[1] = y->rb_link[0];
+ y->rb_link[0] = w;
+ w = pa[k - 1]->rb_link[0] = y;
+ }
+
+ w->rb_color = pa[k - 1]->rb_color;
+ pa[k - 1]->rb_color = RB_BLACK;
+ w->rb_link[0]->rb_color = RB_BLACK;
+
+ pa[k - 1]->rb_link[0] = w->rb_link[1];
+ w->rb_link[1] = pa[k - 1];
+ pa[k - 2]->rb_link[da[k - 2]] = w;
+ break;
+ }
+ }
+
+ k--;
+ }
+
+ }
+
+ tree->rb_alloc->libavl_free (tree->rb_alloc, p);
+ tree->rb_count--;
+ tree->rb_generation++;
+ return (void *) item;
+}
+
+/* Refreshes the stack of parent pointers in |trav|
+ and updates its generation number. */
+static void
+trav_refresh (struct rb_traverser *trav)
+{
+ assert (trav != NULL);
+
+ trav->rb_generation = trav->rb_table->rb_generation;
+
+ if (trav->rb_node != NULL)
+ {
+ rb_comparison_func *cmp = trav->rb_table->rb_compare;
+ void *param = trav->rb_table->rb_param;
+ struct rb_node *node = trav->rb_node;
+ struct rb_node *i;
+
+ trav->rb_height = 0;
+ for (i = trav->rb_table->rb_root; i != node; )
+ {
+ assert (trav->rb_height < RB_MAX_HEIGHT);
+ assert (i != NULL);
+
+ trav->rb_stack[trav->rb_height++] = i;
+ i = i->rb_link[cmp (node->rb_data, i->rb_data, param) > 0];
+ }
+ }
+}
+
+/* Initializes |trav| for use with |tree|
+ and selects the null node. */
+void
+rb_t_init (struct rb_traverser *trav, struct rb_table *tree)
+{
+ trav->rb_table = tree;
+ trav->rb_node = NULL;
+ trav->rb_height = 0;
+ trav->rb_generation = tree->rb_generation;
+}
+
+/* Initializes |trav| for |tree|
+ and selects and returns a pointer to its least-valued item.
+ Returns |NULL| if |tree| contains no nodes. */
+void *
+rb_t_first (struct rb_traverser *trav, struct rb_table *tree)
+{
+ struct rb_node *x;
+
+ assert (tree != NULL && trav != NULL);
+
+ trav->rb_table = tree;
+ trav->rb_height = 0;
+ trav->rb_generation = tree->rb_generation;
+
+ x = tree->rb_root;
+ if (x != NULL)
+ while (x->rb_link[0] != NULL)
+ {
+ assert (trav->rb_height < RB_MAX_HEIGHT);
+ trav->rb_stack[trav->rb_height++] = x;
+ x = x->rb_link[0];
+ }
+ trav->rb_node = x;
+
+ return x != NULL ? x->rb_data : NULL;
+}
+
+/* Initializes |trav| for |tree|
+ and selects and returns a pointer to its greatest-valued item.
+ Returns |NULL| if |tree| contains no nodes. */
+void *
+rb_t_last (struct rb_traverser *trav, struct rb_table *tree)
+{
+ struct rb_node *x;
+
+ assert (tree != NULL && trav != NULL);
+
+ trav->rb_table = tree;
+ trav->rb_height = 0;
+ trav->rb_generation = tree->rb_generation;
+
+ x = tree->rb_root;
+ if (x != NULL)
+ while (x->rb_link[1] != NULL)
+ {
+ assert (trav->rb_height < RB_MAX_HEIGHT);
+ trav->rb_stack[trav->rb_height++] = x;
+ x = x->rb_link[1];
+ }
+ trav->rb_node = x;
+
+ return x != NULL ? x->rb_data : NULL;
+}
+
+/* Searches for |item| in |tree|.
+ If found, initializes |trav| to the item found and returns the item
+ as well.
+ If there is no matching item, initializes |trav| to the null item
+ and returns |NULL|. */
+void *
+rb_t_find (struct rb_traverser *trav, struct rb_table *tree, void *item)
+{
+ struct rb_node *p, *q;
+
+ assert (trav != NULL && tree != NULL && item != NULL);
+ trav->rb_table = tree;
+ trav->rb_height = 0;
+ trav->rb_generation = tree->rb_generation;
+ for (p = tree->rb_root; p != NULL; p = q)
+ {
+ int cmp = tree->rb_compare (item, p->rb_data, tree->rb_param);
+
+ if (cmp < 0)
+ q = p->rb_link[0];
+ else if (cmp > 0)
+ q = p->rb_link[1];
+ else /* |cmp == 0| */
+ {
+ trav->rb_node = p;
+ return p->rb_data;
+ }
+
+ assert (trav->rb_height < RB_MAX_HEIGHT);
+ trav->rb_stack[trav->rb_height++] = p;
+ }
+
+ trav->rb_height = 0;
+ trav->rb_node = NULL;
+ return NULL;
+}
+
+/* Attempts to insert |item| into |tree|.
+ If |item| is inserted successfully, it is returned and |trav| is
+ initialized to its location.
+ If a duplicate is found, it is returned and |trav| is initialized to
+ its location. No replacement of the item occurs.
+ If a memory allocation failure occurs, |NULL| is returned and |trav|
+ is initialized to the null item. */
+void *
+rb_t_insert (struct rb_traverser *trav, struct rb_table *tree, void *item)
+{
+ void **p;
+
+ assert (trav != NULL && tree != NULL && item != NULL);
+
+ p = rb_probe (tree, item);
+ if (p != NULL)
+ {
+ trav->rb_table = tree;
+ trav->rb_node =
+ ((struct rb_node *)
+ ((char *) p - offsetof (struct rb_node, rb_data)));
+ trav->rb_generation = tree->rb_generation - 1;
+ return *p;
+ }
+ else
+ {
+ rb_t_init (trav, tree);
+ return NULL;
+ }
+}
+
+/* Initializes |trav| to have the same current node as |src|. */
+void *
+rb_t_copy (struct rb_traverser *trav, const struct rb_traverser *src)
+{
+ assert (trav != NULL && src != NULL);
+
+ if (trav != src)
+ {
+ trav->rb_table = src->rb_table;
+ trav->rb_node = src->rb_node;
+ trav->rb_generation = src->rb_generation;
+ if (trav->rb_generation == trav->rb_table->rb_generation)
+ {
+ trav->rb_height = src->rb_height;
+ memcpy (trav->rb_stack, (const void *) src->rb_stack,
+ sizeof *trav->rb_stack * trav->rb_height);
+ }
+ }
+
+ return trav->rb_node != NULL ? trav->rb_node->rb_data : NULL;
+}
+
+/* Returns the next data item in inorder
+ within the tree being traversed with |trav|,
+ or if there are no more data items returns |NULL|. */
+void *
+rb_t_next (struct rb_traverser *trav)
+{
+ struct rb_node *x;
+
+ assert (trav != NULL);
+
+ if (trav->rb_generation != trav->rb_table->rb_generation)
+ trav_refresh (trav);
+
+ x = trav->rb_node;
+ if (x == NULL)
+ {
+ return rb_t_first (trav, trav->rb_table);
+ }
+ else if (x->rb_link[1] != NULL)
+ {
+ assert (trav->rb_height < RB_MAX_HEIGHT);
+ trav->rb_stack[trav->rb_height++] = x;
+ x = x->rb_link[1];
+
+ while (x->rb_link[0] != NULL)
+ {
+ assert (trav->rb_height < RB_MAX_HEIGHT);
+ trav->rb_stack[trav->rb_height++] = x;
+ x = x->rb_link[0];
+ }
+ }
+ else
+ {
+ struct rb_node *y;
+
+ do
+ {
+ if (trav->rb_height == 0)
+ {
+ trav->rb_node = NULL;
+ return NULL;
+ }
+
+ y = x;
+ x = trav->rb_stack[--trav->rb_height];
+ }
+ while (y == x->rb_link[1]);
+ }
+ trav->rb_node = x;
+
+ return x->rb_data;
+}
+
+/* Returns the previous data item in inorder
+ within the tree being traversed with |trav|,
+ or if there are no more data items returns |NULL|. */
+void *
+rb_t_prev (struct rb_traverser *trav)
+{
+ struct rb_node *x;
+
+ assert (trav != NULL);
+
+ if (trav->rb_generation != trav->rb_table->rb_generation)
+ trav_refresh (trav);
+
+ x = trav->rb_node;
+ if (x == NULL)
+ {
+ return rb_t_last (trav, trav->rb_table);
+ }
+ else if (x->rb_link[0] != NULL)
+ {
+ assert (trav->rb_height < RB_MAX_HEIGHT);
+ trav->rb_stack[trav->rb_height++] = x;
+ x = x->rb_link[0];
+
+ while (x->rb_link[1] != NULL)
+ {
+ assert (trav->rb_height < RB_MAX_HEIGHT);
+ trav->rb_stack[trav->rb_height++] = x;
+ x = x->rb_link[1];
+ }
+ }
+ else
+ {
+ struct rb_node *y;
+
+ do
+ {
+ if (trav->rb_height == 0)
+ {
+ trav->rb_node = NULL;
+ return NULL;
+ }
+
+ y = x;
+ x = trav->rb_stack[--trav->rb_height];
+ }
+ while (y == x->rb_link[0]);
+ }
+ trav->rb_node = x;
+
+ return x->rb_data;
+}
+
+/* Returns |trav|'s current item. */
+void *
+rb_t_cur (struct rb_traverser *trav)
+{
+ assert (trav != NULL);
+
+ return trav->rb_node != NULL ? trav->rb_node->rb_data : NULL;
+}
+
+/* Replaces the current item in |trav| by |new| and returns the item replaced.
+ |trav| must not have the null item selected.
+ The new item must not upset the ordering of the tree. */
+void *
+rb_t_replace (struct rb_traverser *trav, void *new)
+{
+ void *old;
+
+ assert (trav != NULL && trav->rb_node != NULL && new != NULL);
+ old = trav->rb_node->rb_data;
+ trav->rb_node->rb_data = new;
+ return old;
+}
+
+/* Destroys |new| with |rb_destroy (new, destroy)|,
+ first setting right links of nodes in |stack| within |new|
+ to null pointers to avoid touching uninitialized data. */
+static void
+copy_error_recovery (struct rb_node **stack, int height,
+ struct rb_table *new, rb_item_func *destroy)
+{
+ assert (stack != NULL && height >= 0 && new != NULL);
+
+ for (; height > 2; height -= 2)
+ stack[height - 1]->rb_link[1] = NULL;
+ rb_destroy (new, destroy);
+}
+
+/* Copies |org| to a newly created tree, which is returned.
+ If |copy != NULL|, each data item in |org| is first passed to |copy|,
+ and the return values are inserted into the tree,
+ with |NULL| return values taken as indications of failure.
+ On failure, destroys the partially created new tree,
+ applying |destroy|, if non-null, to each item in the new tree so far,
+ and returns |NULL|.
+ If |allocator != NULL|, it is used for allocation in the new tree.
+ Otherwise, the same allocator used for |org| is used. */
+struct rb_table *
+rb_copy (const struct rb_table *org, rb_copy_func *copy,
+ rb_item_func *destroy, struct libavl_allocator *allocator)
+{
+ struct rb_node *stack[2 * (RB_MAX_HEIGHT + 1)];
+ int height = 0;
+
+ struct rb_table *new;
+ const struct rb_node *x;
+ struct rb_node *y;
+
+ assert (org != NULL);
+ new = rb_create (org->rb_compare, org->rb_param,
+ allocator != NULL ? allocator : org->rb_alloc);
+ if (new == NULL)
+ return NULL;
+ new->rb_count = org->rb_count;
+ if (new->rb_count == 0)
+ return new;
+
+ x = (const struct rb_node *) &org->rb_root;
+ y = (struct rb_node *) &new->rb_root;
+ for (;;)
+ {
+ while (x->rb_link[0] != NULL)
+ {
+ assert (height < 2 * (RB_MAX_HEIGHT + 1));
+
+ y->rb_link[0] =
+ new->rb_alloc->libavl_malloc (new->rb_alloc,
+ sizeof *y->rb_link[0]);
+ if (y->rb_link[0] == NULL)
+ {
+ if (y != (struct rb_node *) &new->rb_root)
+ {
+ y->rb_data = NULL;
+ y->rb_link[1] = NULL;
+ }
+
+ copy_error_recovery (stack, height, new, destroy);
+ return NULL;
+ }
+
+ stack[height++] = (struct rb_node *) x;
+ stack[height++] = y;
+ x = x->rb_link[0];
+ y = y->rb_link[0];
+ }
+ y->rb_link[0] = NULL;
+
+ for (;;)
+ {
+ y->rb_color = x->rb_color;
+ if (copy == NULL)
+ y->rb_data = x->rb_data;
+ else
+ {
+ y->rb_data = copy (x->rb_data, org->rb_param);
+ if (y->rb_data == NULL)
+ {
+ y->rb_link[1] = NULL;
+ copy_error_recovery (stack, height, new, destroy);
+ return NULL;
+ }
+ }
+
+ if (x->rb_link[1] != NULL)
+ {
+ y->rb_link[1] =
+ new->rb_alloc->libavl_malloc (new->rb_alloc,
+ sizeof *y->rb_link[1]);
+ if (y->rb_link[1] == NULL)
+ {
+ copy_error_recovery (stack, height, new, destroy);
+ return NULL;
+ }
+
+ x = x->rb_link[1];
+ y = y->rb_link[1];
+ break;
+ }
+ else
+ y->rb_link[1] = NULL;
+
+ if (height <= 2)
+ return new;
+
+ y = stack[--height];
+ x = stack[--height];
+ }
+ }
+}
+
+/* Frees storage allocated for |tree|.
+ If |destroy != NULL|, applies it to each data item in inorder. */
+void
+rb_destroy (struct rb_table *tree, rb_item_func *destroy)
+{
+ struct rb_node *p, *q;
+
+ assert (tree != NULL);
+
+ for (p = tree->rb_root; p != NULL; p = q)
+ if (p->rb_link[0] == NULL)
+ {
+ q = p->rb_link[1];
+ if (destroy != NULL && p->rb_data != NULL)
+ destroy (p->rb_data, tree->rb_param);
+ tree->rb_alloc->libavl_free (tree->rb_alloc, p);
+ }
+ else
+ {
+ q = p->rb_link[0];
+ p->rb_link[0] = q->rb_link[1];
+ q->rb_link[1] = p;
+ }
+
+ tree->rb_alloc->libavl_free (tree->rb_alloc, tree);
+}
+
+/* Allocates |size| bytes of space using |malloc()|.
+ Returns a null pointer if allocation fails. */
+void *
+rb_malloc (struct libavl_allocator *allocator, size_t size)
+{
+ assert (allocator != NULL && size > 0);
+ return malloc (size);
+}
+
+/* Frees |block|. */
+void
+rb_free (struct libavl_allocator *allocator, void *block)
+{
+ assert (allocator != NULL && block != NULL);
+ free (block);
+}
+
+/* Default memory allocator that uses |malloc()| and |free()|. */
+struct libavl_allocator rb_allocator_default =
+ {
+ rb_malloc,
+ rb_free
+ };
+
+#undef NDEBUG
+#include <assert.h>
+
+/* Asserts that |rb_insert()| succeeds at inserting |item| into |table|. */
+void
+(rb_assert_insert) (struct rb_table *table, void *item)
+{
+ void **p = rb_probe (table, item);
+ assert (p != NULL && *p == item);
+}
+
+/* Asserts that |rb_delete()| really removes |item| from |table|,
+ and returns the removed item. */
+void *
+(rb_assert_delete) (struct rb_table *table, void *item)
+{
+ void *p = rb_delete (table, item);
+ assert (p != NULL);
+ return p;
+}
+
diff --git a/contrib/rbtree/rb.h b/contrib/rbtree/rb.h
new file mode 100644
index 0000000..c8858b5
--- /dev/null
+++ b/contrib/rbtree/rb.h
@@ -0,0 +1,122 @@
+/* Produced by texiweb from libavl.w. */
+
+/* libavl - library for manipulation of binary trees.
+ Copyright (C) 1998-2002, 2004 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 <blp@gnu.org> on the Internet, or
+ write to Ben Pfaff, Stanford University, Computer Science Dept., 353
+ Serra Mall, Stanford CA 94305, USA.
+*/
+
+#ifndef RB_H
+#define RB_H 1
+
+#include <stddef.h>
+
+/* Function types. */
+typedef int rb_comparison_func (const void *rb_a, const void *rb_b,
+ void *rb_param);
+typedef void rb_item_func (void *rb_item, void *rb_param);
+typedef void *rb_copy_func (void *rb_item, void *rb_param);
+
+#ifndef LIBAVL_ALLOCATOR
+#define LIBAVL_ALLOCATOR
+/* Memory allocator. */
+struct libavl_allocator
+ {
+ void *(*libavl_malloc) (struct libavl_allocator *, size_t libavl_size);
+ void (*libavl_free) (struct libavl_allocator *, void *libavl_block);
+ };
+#endif
+
+/* Default memory allocator. */
+extern struct libavl_allocator rb_allocator_default;
+void *rb_malloc (struct libavl_allocator *, size_t);
+void rb_free (struct libavl_allocator *, void *);
+
+/* Maximum RB height. */
+#ifndef RB_MAX_HEIGHT
+#define RB_MAX_HEIGHT 48
+#endif
+
+/* Tree data structure. */
+struct rb_table
+ {
+ struct rb_node *rb_root; /* Tree's root. */
+ rb_comparison_func *rb_compare; /* Comparison function. */
+ void *rb_param; /* Extra argument to |rb_compare|. */
+ struct libavl_allocator *rb_alloc; /* Memory allocator. */
+ size_t rb_count; /* Number of items in tree. */
+ unsigned long rb_generation; /* Generation number. */
+ };
+
+/* Color of a red-black node. */
+enum rb_color
+ {
+ RB_BLACK, /* Black. */
+ RB_RED /* Red. */
+ };
+
+/* A red-black tree node. */
+struct rb_node
+ {
+ struct rb_node *rb_link[2]; /* Subtrees. */
+ void *rb_data; /* Pointer to data. */
+ unsigned char rb_color; /* Color. */
+ };
+
+/* RB traverser structure. */
+struct rb_traverser
+ {
+ struct rb_table *rb_table; /* Tree being traversed. */
+ struct rb_node *rb_node; /* Current node in tree. */
+ struct rb_node *rb_stack[RB_MAX_HEIGHT];
+ /* All the nodes above |rb_node|. */
+ size_t rb_height; /* Number of nodes in |rb_parent|. */
+ unsigned long rb_generation; /* Generation number. */
+ };
+
+/* Table functions. */
+struct rb_table *rb_create (rb_comparison_func *, void *,
+ struct libavl_allocator *);
+struct rb_table *rb_copy (const struct rb_table *, rb_copy_func *,
+ rb_item_func *, struct libavl_allocator *);
+void rb_destroy (struct rb_table *, rb_item_func *);
+void **rb_probe (struct rb_table *, void *);
+void *rb_insert (struct rb_table *, void *);
+void *rb_replace (struct rb_table *, void *);
+void *rb_delete (struct rb_table *, const void *);
+void *rb_find (const struct rb_table *, const void *);
+void rb_assert_insert (struct rb_table *, void *);
+void *rb_assert_delete (struct rb_table *, void *);
+
+#define rb_count(table) ((size_t) (table)->rb_count)
+
+/* Table traverser functions. */
+void rb_t_init (struct rb_traverser *, struct rb_table *);
+void *rb_t_first (struct rb_traverser *, struct rb_table *);
+void *rb_t_last (struct rb_traverser *, struct rb_table *);
+void *rb_t_find (struct rb_traverser *, struct rb_table *, void *);
+void *rb_t_insert (struct rb_traverser *, struct rb_table *, void *);
+void *rb_t_copy (struct rb_traverser *, const struct rb_traverser *);
+void *rb_t_next (struct rb_traverser *);
+void *rb_t_prev (struct rb_traverser *);
+void *rb_t_cur (struct rb_traverser *);
+void *rb_t_replace (struct rb_traverser *, void *);
+
+#endif /* rb.h */