#include <config.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include "sudoers.h"
#include "redblack.h"
static void rbrepair(struct rbtree *, struct rbnode *);
static void rotate_left(struct rbtree *, struct rbnode *);
static void rotate_right(struct rbtree *, struct rbnode *);
static void rbdestroy_int(struct rbtree *, struct rbnode *, void (*)(void *));
struct rbtree *
rbcreate(int (*compar)(const void *, const void*))
{
struct rbtree *tree;
debug_decl(rbcreate, SUDOERS_DEBUG_RBTREE)
if ((tree = malloc(sizeof(*tree))) == NULL) {
sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
"unable to allocate memory");
debug_return_ptr(NULL);
}
tree->compar = compar;
tree->nil.left = tree->nil.right = tree->nil.parent = &tree->nil;
tree->nil.color = black;
tree->nil.data = NULL;
tree->root.left = tree->root.right = tree->root.parent = &tree->nil;
tree->root.color = black;
tree->root.data = NULL;
debug_return_ptr(tree);
}
static void
rotate_left(struct rbtree *tree, struct rbnode *node)
{
struct rbnode *child;
debug_decl(rotate_left, SUDOERS_DEBUG_RBTREE)
child = node->right;
node->right = child->left;
if (child->left != rbnil(tree))
child->left->parent = node;
child->parent = node->parent;
if (node == node->parent->left)
node->parent->left = child;
else
node->parent->right = child;
child->left = node;
node->parent = child;
debug_return;
}
static void
rotate_right(struct rbtree *tree, struct rbnode *node)
{
struct rbnode *child;
debug_decl(rotate_right, SUDOERS_DEBUG_RBTREE)
child = node->left;
node->left = child->right;
if (child->right != rbnil(tree))
child->right->parent = node;
child->parent = node->parent;
if (node == node->parent->left)
node->parent->left = child;
else
node->parent->right = child;
child->right = node;
node->parent = child;
debug_return;
}
int
rbinsert(struct rbtree *tree, void *data, struct rbnode **existing)
{
struct rbnode *node = rbfirst(tree);
struct rbnode *parent = rbroot(tree);
int res;
debug_decl(rbinsert, SUDOERS_DEBUG_RBTREE)
while (node != rbnil(tree)) {
parent = node;
if ((res = tree->compar(data, node->data)) == 0) {
if (existing != NULL)
*existing = node;
debug_return_int(1);
}
node = res < 0 ? node->left : node->right;
}
node = malloc(sizeof(*node));
if (node == NULL) {
sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
"unable to allocate memory");
debug_return_int(-1);
}
node->data = data;
node->left = node->right = rbnil(tree);
node->parent = parent;
if (parent == rbroot(tree) || tree->compar(data, parent->data) < 0)
parent->left = node;
else
parent->right = node;
node->color = red;
while (node->parent->color == red) {
struct rbnode *uncle;
if (node->parent == node->parent->parent->left) {
uncle = node->parent->parent->right;
if (uncle->color == red) {
node->parent->color = black;
uncle->color = black;
node->parent->parent->color = red;
node = node->parent->parent;
} else {
if (node == node->parent->right) {
node = node->parent;
rotate_left(tree, node);
}
node->parent->color = black;
node->parent->parent->color = red;
rotate_right(tree, node->parent->parent);
}
} else {
uncle = node->parent->parent->left;
if (uncle->color == red) {
node->parent->color = black;
uncle->color = black;
node->parent->parent->color = red;
node = node->parent->parent;
} else {
if (node == node->parent->left) {
node = node->parent;
rotate_right(tree, node);
}
node->parent->color = black;
node->parent->parent->color = red;
rotate_left(tree, node->parent->parent);
}
}
}
rbfirst(tree)->color = black;
debug_return_int(0);
}
struct rbnode *
rbfind(struct rbtree *tree, void *key)
{
struct rbnode *node = rbfirst(tree);
int res;
debug_decl(rbfind, SUDOERS_DEBUG_RBTREE)
while (node != rbnil(tree)) {
if ((res = tree->compar(key, node->data)) == 0)
debug_return_ptr(node);
node = res < 0 ? node->left : node->right;
}
debug_return_ptr(NULL);
}
int
rbapply_node(struct rbtree *tree, struct rbnode *node,
int (*func)(void *, void *), void *cookie, enum rbtraversal order)
{
int error;
debug_decl(rbapply_node, SUDOERS_DEBUG_RBTREE)
if (node != rbnil(tree)) {
if (order == preorder)
if ((error = func(node->data, cookie)) != 0)
debug_return_int(error);
if ((error = rbapply_node(tree, node->left, func, cookie, order)) != 0)
debug_return_int(error);
if (order == inorder)
if ((error = func(node->data, cookie)) != 0)
debug_return_int(error);
if ((error = rbapply_node(tree, node->right, func, cookie, order)) != 0)
debug_return_int(error);
if (order == postorder)
if ((error = func(node->data, cookie)) != 0)
debug_return_int(error);
}
debug_return_int(0);
}
static struct rbnode *
rbsuccessor(struct rbtree *tree, struct rbnode *node)
{
struct rbnode *succ;
debug_decl(rbsuccessor, SUDOERS_DEBUG_RBTREE)
if ((succ = node->right) != rbnil(tree)) {
while (succ->left != rbnil(tree))
succ = succ->left;
} else {
for (succ = node->parent; node == succ->right; succ = succ->parent)
node = succ;
if (succ == rbroot(tree))
succ = rbnil(tree);
}
debug_return_ptr(succ);
}
static void
rbdestroy_int(struct rbtree *tree, struct rbnode *node, void (*destroy)(void *))
{
debug_decl(rbdestroy_int, SUDOERS_DEBUG_RBTREE)
if (node != rbnil(tree)) {
rbdestroy_int(tree, node->left, destroy);
rbdestroy_int(tree, node->right, destroy);
if (destroy != NULL)
destroy(node->data);
free(node);
}
debug_return;
}
void
rbdestroy(struct rbtree *tree, void (*destroy)(void *))
{
debug_decl(rbdestroy, SUDOERS_DEBUG_RBTREE)
rbdestroy_int(tree, rbfirst(tree), destroy);
free(tree);
debug_return;
}
void *rbdelete(struct rbtree *tree, struct rbnode *z)
{
struct rbnode *x, *y;
void *data = z->data;
debug_decl(rbdelete, SUDOERS_DEBUG_RBTREE)
if (z->left == rbnil(tree) || z->right == rbnil(tree))
y = z;
else
y = rbsuccessor(tree, z);
x = (y->left == rbnil(tree)) ? y->right : y->left;
if ((x->parent = y->parent) == rbroot(tree)) {
rbfirst(tree) = x;
} else {
if (y == y->parent->left)
y->parent->left = x;
else
y->parent->right = x;
}
if (y->color == black)
rbrepair(tree, x);
if (y != z) {
y->left = z->left;
y->right = z->right;
y->parent = z->parent;
y->color = z->color;
z->left->parent = z->right->parent = y;
if (z == z->parent->left)
z->parent->left = y;
else
z->parent->right = y;
}
free(z);
debug_return_ptr(data);
}
static void
rbrepair(struct rbtree *tree, struct rbnode *node)
{
struct rbnode *sibling;
debug_decl(rbrepair, SUDOERS_DEBUG_RBTREE)
while (node->color == black && node != rbfirst(tree)) {
if (node == node->parent->left) {
sibling = node->parent->right;
if (sibling->color == red) {
sibling->color = black;
node->parent->color = red;
rotate_left(tree, node->parent);
sibling = node->parent->right;
}
if (sibling->right->color == black && sibling->left->color == black) {
sibling->color = red;
node = node->parent;
} else {
if (sibling->right->color == black) {
sibling->left->color = black;
sibling->color = red;
rotate_right(tree, sibling);
sibling = node->parent->right;
}
sibling->color = node->parent->color;
node->parent->color = black;
sibling->right->color = black;
rotate_left(tree, node->parent);
node = rbfirst(tree);
}
} else {
sibling = node->parent->left;
if (sibling->color == red) {
sibling->color = black;
node->parent->color = red;
rotate_right(tree, node->parent);
sibling = node->parent->left;
}
if (sibling->right->color == black && sibling->left->color == black) {
sibling->color = red;
node = node->parent;
} else {
if (sibling->left->color == black) {
sibling->right->color = black;
sibling->color = red;
rotate_left(tree, sibling);
sibling = node->parent->left;
}
sibling->color = node->parent->color;
node->parent->color = black;
sibling->left->color = black;
rotate_right(tree, node->parent);
node = rbfirst(tree);
}
}
}
node->color = black;
debug_return;
}