initial version of talloc based red-black trees

very initial version

(This used to be ctdb commit 121f5c9dfc8e441313e42d94bed9c9f13ec91398)

1 files changed, 593 insertions, 0 deletions

diff --git a/ctdb/common/rb_tree.c b/ctdb/common/rb_tree.c
new file mode 100644
index 0000000000..acc175b965
--- /dev/null
+++ b/ctdb/common/rb_tree.c
@@ -0,0 +1,593 @@
+/* 
+   a talloc based red-black tree
+
+   Copyright (C) Ronnie Sahlberg  2007
+
+   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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "rb_tree.h"
+
+#define NO_MEMORY_FATAL(p) do { if (!(p)) { \
+          DEBUG(0,("Out of memory for %s at %s\n", #p, __location__)); \
+	  exit(10); \
+	  }} while (0)
+
+
+trbt_tree_t *
+trbt_create(TALLOC_CTX *memctx)
+{
+	trbt_tree_t *tree;
+
+	tree = talloc_zero(memctx, trbt_tree_t);
+	NO_MEMORY_FATAL(tree);
+
+	return tree;
+}
+
+static inline trbt_node_t *
+trbt_parent(trbt_node_t *node)
+{
+	return node->parent;
+}
+
+static inline trbt_node_t *
+trbt_grandparent(trbt_node_t *node)
+{
+	trbt_node_t *parent;
+
+	parent=trbt_parent(node);
+	if(parent){
+		return parent->parent;
+	}
+	return NULL;
+}
+
+static inline trbt_node_t *
+trbt_uncle(trbt_node_t *node)
+{
+	trbt_node_t *parent, *grandparent;
+
+	parent=trbt_parent(node);
+	if(!parent){
+		return NULL;
+	}
+	grandparent=trbt_parent(parent);
+	if(!grandparent){
+		return NULL;
+	}
+	if(parent==grandparent->left){
+		return grandparent->right;
+	}
+	return grandparent->left;
+}
+
+
+static inline void trbt_insert_case1(trbt_tree_t *tree, trbt_node_t *node);
+static inline void trbt_insert_case2(trbt_tree_t *tree, trbt_node_t *node);
+
+static inline void
+trbt_rotate_left(trbt_node_t *node)
+{
+	trbt_tree_t *tree = node->tree;
+
+	if(node->parent){
+		if(node->parent->left==node){
+			node->parent->left=node->right;
+		} else {
+			node->parent->right=node->right;
+		}
+	} else {
+		tree->tree=node->right;
+	}
+	node->right->parent=node->parent;
+	node->parent=node->right;
+	node->right=node->right->left;
+	if(node->right){
+		node->right->parent=node;
+	}
+	node->parent->left=node;
+}
+
+static inline void
+trbt_rotate_right(trbt_node_t *node)
+{
+	trbt_tree_t *tree = node->tree;
+
+	if(node->parent){
+		if(node->parent->left==node){
+			node->parent->left=node->left;
+		} else {
+			node->parent->right=node->left;
+		}
+	} else {
+		tree->tree=node->left;
+	}
+	node->left->parent=node->parent;
+	node->parent=node->left;
+	node->left=node->left->right;
+	if(node->left){
+		node->left->parent=node;
+	}
+	node->parent->right=node;
+}
+
+static inline void
+trbt_insert_case5(trbt_tree_t *tree, trbt_node_t *node)
+{
+	trbt_node_t *grandparent;
+	trbt_node_t *parent;
+
+	parent=trbt_parent(node);
+	grandparent=trbt_parent(parent);
+	parent->rb_color=TRBT_BLACK;
+	grandparent->rb_color=TRBT_RED;
+	if( (node==parent->left) && (parent==grandparent->left) ){
+		trbt_rotate_right(grandparent);
+	} else {
+		trbt_rotate_left(grandparent);
+	}
+}
+
+static inline void
+trbt_insert_case4(trbt_tree_t *tree, trbt_node_t *node)
+{
+	trbt_node_t *grandparent;
+	trbt_node_t *parent;
+
+	parent=trbt_parent(node);
+	grandparent=trbt_parent(parent);
+	if(!grandparent){
+		return;
+	}
+	if( (node==parent->right) && (parent==grandparent->left) ){
+		trbt_rotate_left(parent);
+		node=node->left;
+	} else if( (node==parent->left) && (parent==grandparent->right) ){
+		trbt_rotate_right(parent);
+		node=node->right;
+	}
+	trbt_insert_case5(tree, node);
+}
+
+static inline void
+trbt_insert_case3(trbt_tree_t *tree, trbt_node_t *node)
+{
+	trbt_node_t *grandparent;
+	trbt_node_t *parent;
+	trbt_node_t *uncle;
+
+	uncle=trbt_uncle(node);
+	if(uncle && (uncle->rb_color==TRBT_RED)){
+		parent=trbt_parent(node);
+		parent->rb_color=TRBT_BLACK;
+		uncle->rb_color=TRBT_BLACK;
+		grandparent=trbt_grandparent(node);
+		grandparent->rb_color=TRBT_RED;
+		trbt_insert_case1(tree, grandparent);
+	} else {
+		trbt_insert_case4(tree, node);
+	}
+}
+
+static inline void
+trbt_insert_case2(trbt_tree_t *tree, trbt_node_t *node)
+{
+	trbt_node_t *parent;
+
+	parent=trbt_parent(node);
+	/* parent is always non-NULL here */
+	if(parent->rb_color==TRBT_BLACK){
+		return;
+	}
+	trbt_insert_case3(tree, node);
+}
+
+static inline void
+trbt_insert_case1(trbt_tree_t *tree, trbt_node_t *node)
+{
+	trbt_node_t *parent;
+
+	parent=trbt_parent(node);
+	if(!parent){
+		node->rb_color=TRBT_BLACK;
+		return;
+	}
+	trbt_insert_case2(tree, node);
+}
+
+static inline trbt_node_t *
+trbt_sibling(trbt_node_t *node)
+{
+	trbt_node_t *parent;
+
+	parent=trbt_parent(node);
+	if(!parent){
+		return NULL;
+	}
+
+	if (node == parent->left) {
+		return parent->right;
+	} else {
+		return parent->left;
+	}
+}
+
+static inline trbt_node_t *
+trbt_sibline(trbt_node_t *node)
+{
+	if (node==node->parent->left) {
+		return node->parent->right;
+	} else {
+		return node->parent->left;
+	}
+}
+
+static inline void
+trbt_delete_case6(trbt_node_t *node)
+{
+	trbt_node_t *sibling, *parent;
+
+	sibling = trbt_sibling(node);
+	parent  = trbt_parent(node);
+
+	sibling->rb_color = parent->rb_color;
+	parent->rb_color = TRBT_BLACK;
+	if (node == parent->left) {
+		sibling->right->rb_color = TRBT_BLACK;
+		trbt_rotate_left(parent);
+	} else {
+		sibling->left->rb_color = TRBT_BLACK;
+		trbt_rotate_right(parent);
+	}
+}
+
+
+static inline void
+trbt_delete_case5(trbt_node_t *node)
+{
+	trbt_node_t *parent, *sibling;
+
+	parent = trbt_parent(node);
+	sibling = trbt_sibling(node);
+	if ( (node == parent->left)
+	   &&(sibling->rb_color == TRBT_BLACK)
+	   &&(sibling->left->rb_color == TRBT_RED)
+	   &&(sibling->right->rb_color == TRBT_BLACK) ){
+		sibling->rb_color = TRBT_RED;
+		sibling->left->rb_color = TRBT_BLACK;
+		trbt_rotate_right(sibling);
+		trbt_delete_case6(node);
+		return;
+	}
+	if ( (node == parent->right)
+	   &&(sibling->rb_color == TRBT_BLACK)
+	   &&(sibling->right->rb_color == TRBT_RED)
+	   &&(sibling->left->rb_color == TRBT_BLACK) ){
+		sibling->rb_color = TRBT_RED;
+		sibling->right->rb_color = TRBT_BLACK;
+		trbt_rotate_left(sibling);
+		trbt_delete_case6(node);
+		return;
+	}
+
+	trbt_delete_case6(node);
+}
+
+static inline void
+trbt_delete_case4(trbt_node_t *node)
+{
+	trbt_node_t *sibling;
+
+	sibling = trbt_sibling(node);
+	if ( (node->parent->rb_color == TRBT_RED)
+	   &&(sibling->rb_color == TRBT_BLACK)
+	   &&(sibling->left->rb_color == TRBT_BLACK)
+	   &&(sibling->right->rb_color == TRBT_BLACK) ){
+		sibling->rb_color = TRBT_RED;
+		node->parent->rb_color = TRBT_BLACK;
+	} else {
+		trbt_delete_case5(node);
+	}
+}
+
+static void trbt_delete_case1(trbt_node_t *node);
+
+static inline void
+trbt_delete_case3(trbt_node_t *node)
+{
+	trbt_node_t *sibling;
+
+	sibling = trbt_sibling(node);
+	if ( (node->parent->rb_color == TRBT_BLACK)
+	   &&(sibling->rb_color == TRBT_BLACK)
+	   &&(sibling->left->rb_color == TRBT_BLACK)
+	   &&(sibling->right->rb_color == TRBT_BLACK) ){
+		sibling->rb_color = TRBT_RED;
+		trbt_delete_case1(node->parent);
+	} else {
+		trbt_delete_case4(node);
+	}
+}
+	
+static inline void
+trbt_delete_case2(trbt_node_t *node)
+{
+	trbt_node_t *sibling;
+
+	sibling = trbt_sibling(node);
+	if (sibling->rb_color == TRBT_RED) {
+		if (node == node->parent->left) {
+			trbt_rotate_left(node->parent);
+		} else {
+			trbt_rotate_right(node->parent);
+		}
+	}
+	trbt_delete_case3(node);
+}	
+
+static void
+trbt_delete_case1(trbt_node_t *node)
+{
+	if (!node->parent) {
+		return;
+	} else {
+		trbt_delete_case2(node);
+	}
+}
+
+static void
+delete_node(trbt_node_t *node)
+{
+	trbt_node_t *child, *parent;
+
+	if (node->left != NULL && node->right != NULL) {
+		/* This node has two children, just copy the data */
+		/* find the predecessor */
+		trbt_node_t *temp = node->left;
+
+		while (temp->right != NULL) {
+			temp = temp->right;
+		}
+
+		/* swap the predecessor data and key with the node to
+		   be deleted.
+		 */
+		talloc_free(node->data);
+		node->data  = talloc_steal(node, temp->data);
+		node->key32 = temp->key32;
+		temp->data  = NULL;
+		temp->key32 = -1;
+		/* then delete the temp node.
+		   this node is guaranteed to have at least one leaf child */
+		delete_node(temp);
+		return;
+	}
+
+	/* There is at most one child to this node to be deleted */
+	child = node->left;
+	if (node->right) {
+		child = node->right;
+	}
+
+	/* replace node with child */
+	parent=trbt_parent(node);
+	if (parent) {
+		if (parent->left == node) {
+			parent->left = child;
+		} else {
+			parent->right = child;
+		}
+	} else {
+		node->tree->tree = child;
+	}
+
+	if (child) {
+		child->parent = node->parent;
+
+		if (node->rb_color == TRBT_BLACK) {
+			if (child->rb_color == TRBT_RED) {
+				child->rb_color = TRBT_BLACK;
+			} else {
+				trbt_delete_case1(child);
+			}
+		}
+	}
+	
+	talloc_free(node);
+	return;
+}
+
+static inline trbt_node_t *
+trbt_create_node(trbt_tree_t *tree, trbt_node_t *parent, uint32_t key, void *data)
+{
+	trbt_node_t *node;
+
+	node=talloc_zero(tree, trbt_node_t);
+	NO_MEMORY_FATAL(node);
+
+	node->tree=tree;
+	node->rb_color=TRBT_BLACK;
+	node->parent=parent;
+	node->left=NULL;
+	node->right=NULL;
+	node->key32=key;
+	node->data=talloc_steal(node, data);
+
+	return node;
+}
+
+/* insert a new node in the tree. 
+   if there is already a node with a matching key in the tree 
+   we reurn an error
+ */
+int
+trbt_insert32(trbt_tree_t *tree, uint32_t key, void *data)
+{
+	trbt_node_t *node;
+
+	node=tree->tree;
+
+	/* is this the first node ?*/
+	if(!node){
+		node = trbt_create_node(tree, NULL, key, data);
+
+		tree->tree=node;
+		return 0;
+	}
+
+	/* it was not the new root so walk the tree until we find where to
+	 * insert this new leaf.
+	 */
+	while(1){
+		/* this node already exists, so just return an error */
+		if(key==node->key32){
+			return -1;
+		}
+		if(key<node->key32) {
+			if(!node->left){
+				/* new node to the left */
+				trbt_node_t *new_node;
+
+				new_node = trbt_create_node(tree, node, key, data);
+				node->left=new_node;
+				node=new_node;
+
+				break;
+			}
+			node=node->left;
+			continue;
+		}
+		if(key>node->key32) {
+			if(!node->right){
+				/* new node to the right */
+				trbt_node_t *new_node;
+
+				new_node = trbt_create_node(tree, node, key, data);
+				node->right=new_node;
+				node=new_node;
+				break;
+			}
+			node=node->right;
+			continue;
+		}
+	}
+
+	/* node will now point to the newly created node */
+	node->rb_color=TRBT_RED;
+	trbt_insert_case1(tree, node);
+	return 0;
+}
+
+void *
+trbt_lookup32(trbt_tree_t *tree, uint32_t key)
+{
+	trbt_node_t *node;
+
+	node=tree->tree;
+
+	while(node){
+		if(key==node->key32){
+			return node->data;
+		}
+		if(key<node->key32){
+			node=node->left;
+			continue;
+		}
+		if(key>node->key32){
+			node=node->right;
+			continue;
+		}
+	}
+	return NULL;
+}
+
+void 
+trbt_delete32(trbt_tree_t *tree, uint32_t key)
+{
+	trbt_node_t *node;
+
+	node=tree->tree;
+
+	while(node){
+		if(key==node->key32){
+			delete_node(node);
+			return;
+		}
+		if(key<node->key32){
+			node=node->left;
+			continue;
+		}
+		if(key>node->key32){
+			node=node->right;
+			continue;
+		}
+	}
+}
+
+
+
+# if 0
+static void printtree(trbt_node_t *node, int levels)
+{
+	int i;
+	if(node==NULL)return;
+	printtree(node->left, levels+1);
+
+	for(i=0;i<levels;i++)printf("    ");
+	printf("key:%d COLOR:%s\n",node->key32,node->rb_color==TRBT_BLACK?"BLACK":"RED");
+
+	printtree(node->right, levels+1);
+	printf("\n");
+}
+
+void print_tree(trbt_tree_t *tree)
+{
+	printtree(tree->tree->left, 1);
+	printf("root node key:%d COLOR:%s\n",tree->tree->key32,tree->tree->rb_color==TRBT_BLACK?"BLACK":"RED");
+	printtree(tree->tree->right, 1);
+}
+
+
+#include "../common/rb_tree.h"
+void 
+test_tree(void)
+{
+	trbt_tree_t *tree;
+	char *str;
+	int i, ret;
+
+#define NUM 10
+	tree=trbt_create(talloc_new(NULL));
+	printf("tree:0x%08x  %d nodes\n",(int)tree,NUM);
+	for(i=0;i<NUM;i++){
+		str=talloc_asprintf(tree, "STRING#%d", i);
+		ret=trbt_insert32(tree, i, str);
+		printf("%s ret:%d\n",str, ret);
+	}
+	print_tree(tree);
+	for(i=0;i<NUM;i++){
+		str=trbt_lookup32(tree, i);
+		printf("lookedup i:%d str:%s\n",i,str);
+	}
+	trbt_delete32(tree, 9);
+	print_tree(tree);
+	for(i=0;i<NUM;i++){
+		str=trbt_lookup32(tree, i);
+		printf("lookedup i:%d str:%s\n",i,str);
+	}
+}
+
+#endif
\ No newline at end of file