/*
* astobj2_hash - RBTree implementation for astobj2.
*
* Copyright (C) 2006 Marta Carbone, Luigi Rizzo - Univ. di Pisa, Italy
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*! \file
*
* \brief RBTree functions implementing astobj2 containers.
*
* \author Richard Mudgett <rmudgett@digium.com>
*/
#include "asterisk.h"
#include "asterisk/_private.h"
#include "asterisk/astobj2.h"
#include "asterisk/utils.h"
#include "astobj2_private.h"
#include "astobj2_container_private.h"
/*!
* A structure to hold the object held by the container and
* where it is located in it.
*
* A red-black tree has the following properties:
*
* 1) Every node is either black or red.
*
* 2) The root is black.
*
* 3) If a node has a NULL child, that "child" is considered
* black.
*
* 4) If a node is red, then both of its children are black.
*
* 5) Every path from a node to a descendant NULL child has the
* same number of black nodes. (Including the black NULL
* child.)
*/
struct rbtree_node {
/*!
* \brief Items common to all container nodes.
* \note Must be first in the specific node struct.
*/
struct ao2_container_node common;
/*! Parent node of this node. NULL if this is the root node. */
struct rbtree_node *parent;
/*! Left child node of this node. NULL if does not have this child. */
struct rbtree_node *left;
/*! Right child node of this node. NULL if does not have this child. */
struct rbtree_node *right;
/*! TRUE if the node is red. */
unsigned int is_red:1;
};
/*!
* A rbtree container in addition to values common to all
* container types, stores the pointer to the root node of the
* tree.
*/
struct ao2_container_rbtree {
/*!
* \brief Items common to all containers.
* \note Must be first in the specific container struct.
*/
struct ao2_container common;
/*! Root node of the tree. NULL if the tree is empty. */
struct rbtree_node *root;
#if defined(AO2_DEBUG)
struct {
/*! Fixup insert left cases 1-3 */
int fixup_insert_left[3];
/*! Fixup insert right cases 1-3 */
int fixup_insert_right[3];
/*! Fixup delete left cases 1-4 */
int fixup_delete_left[4];
/*! Fixup delete right cases 1-4 */
int fixup_delete_right[4];
/*! Deletion of node with number of children (0-2). */
int delete_children[3];
} stats;
#endif /* defined(AO2_DEBUG) */
};
enum equal_node_bias {
/*! Bias search toward first matching node in the container. */
BIAS_FIRST,
/*! Bias search toward any matching node. */
BIAS_EQUAL,
/*! Bias search toward last matching node in the container. */
BIAS_LAST,
};
enum empty_node_direction {
GO_LEFT,
GO_RIGHT,
};
/*! Traversal state to restart a rbtree container traversal. */
struct rbtree_traversal_state {
/*! Active sort function in the traversal if not NULL. */
ao2_sort_fn *sort_fn;
/*! Saved comparison callback arg pointer. */
void *arg;
/*! Saved search flags to control traversing the container. */
enum search_flags flags;
};
struct rbtree_traversal_state_check {
/*
* If we have a division by zero compile error here then there
* is not enough room for the state. Increase AO2_TRAVERSAL_STATE_SIZE.
*/
char check[1 / (AO2_TRAVERSAL_STATE_SIZE / sizeof(struct rbtree_traversal_state))];
};
/*!
* \internal
* \brief Get the most left node in the tree.
* \since 12.0.0
*
* \param node Starting node to find the most left node.
*
* \return Left most node. Never NULL.
*/
static struct rbtree_node *rb_node_most_left(struct rbtree_node *node)
{
while (node->left) {
node = node->left;
}
return node;
}
/*!
* \internal
* \brief Get the most right node in the tree.
* \since 12.0.0
*
* \param node Starting node to find the most right node.
*
* \return Right most node. Never NULL.
*/
static struct rbtree_node *rb_node_most_right(struct rbtree_node *node)
{
while (node->right) {
node = node->right;
}
return node;
}
/*!
* \internal
* \brief Get the next node in ascending sequence.
* \since 12.0.0
*
* \param node Starting node to find the next node.
*
* \return node on success.
* \retval NULL if no node.
*/
static struct rbtree_node *rb_node_next(struct rbtree_node *node)
{
if (node->right) {
return rb_node_most_left(node->right);
}
/* Find the parent that the node is a left child of. */
while (node->parent) {
if (node->parent->left == node) {
/* We are the left child. The parent is the next node. */
return node->parent;
}
node = node->parent;
}
return NULL;
}
/*!
* \internal
* \brief Get the next node in descending sequence.
* \since 12.0.0
*
* \param node Starting node to find the previous node.
*
* \return node on success.
* \retval NULL if no node.
*/
static struct rbtree_node *rb_node_prev(struct rbtree_node *node)
{
if (node->left) {
return rb_node_most_right(node->left);
}
/* Find the parent that the node is a right child of. */
while (node->parent) {
if (node->parent->right == node) {
/* We are the right child. The parent is the previous node. */
return node->parent;
}
node = node->parent;
}
return NULL;
}
/*!
* \internal
* \brief Get the next node in pre-order sequence.
* \since 12.0.0
*
* \param node Starting node to find the next node.
*
* \return node on success.
* \retval NULL if no node.
*/
static struct rbtree_node *rb_node_pre(struct rbtree_node *node)
{
/* Visit the children if the node has any. */
if (node->left) {
return node->left;
}
if (node->right) {
return node->right;
}
/* Time to go back up. */
for (;;) {
if (!node->parent) {
return NULL;
}
if (node->parent->left == node && node->parent->right) {
/*
* We came up the left child and there's a right child. Visit
* it.
*/
return node->parent->right;
}
node = node->parent;
}
}
/*!
* \internal
* \brief Get the next node in post-order sequence.
* \since 12.0.0
*
* \param node Starting node to find the next node.
*
* \return node on success.
* \retval NULL if no node.
*/
static struct rbtree_node *rb_node_post(struct rbtree_node *node)
{
/* This node's children have already been visited. */
for (;;) {
if (!node->parent) {
return NULL;
}
if (node->parent->left == node) {
/* We came up the left child. */
node = node->parent;
/*
* Find the right child's left most childless node.
*/
while (node->right) {
node = rb_node_most_left(node->right);
}
/*
* This node's left child has already been visited or it doesn't
* have any children.
*/
return node;
}
/*
* We came up the right child.
*
* This node's children have already been visited. Time to
* visit the parent.
*/
return node->parent;
}
}
/*!
* \internal
* \brief Get the next non-empty node in ascending sequence.
* \since 12.0.0
*
* \param node Starting node to find the next node.
*
* \return node on success.
* \retval NULL if no node.
*/
static struct rbtree_node *rb_node_next_full(struct rbtree_node *node)
{
for (;;) {
node = rb_node_next(node);
if (!node || node->common.obj) {
return node;
}
}
}
/*!
* \internal
* \brief Get the next non-empty node in descending sequence.
* \since 12.0.0
*
* \param node Starting node to find the previous node.
*
* \return node on success.
* \retval NULL if no node.
*/
static struct rbtree_node *rb_node_prev_full(struct rbtree_node *node)
{
for (;;) {
node = rb_node_prev(node);
if (!node || node->common.obj) {
return node;
}
}
}
/*!
* \internal
* \brief Determine which way to go from an empty node.
* \since 12.0.0
*
* \param empty Empty node to determine which side obj_right goes on.
* \param sort_fn Sort comparison function for non-empty nodes.
* \param obj_right pointer to the (user-defined part) of an object.
* \param flags flags from ao2_callback()
* OBJ_SEARCH_OBJECT - if set, 'obj_right', is an object.
* OBJ_SEARCH_KEY - if set, 'obj_right', is a search key item that is not an object.
* OBJ_SEARCH_PARTIAL_KEY - if set, 'obj_right', is a partial search key item that is not an object.
* \param bias How to bias search direction for duplicates
*
* \return \ref empty_node_direction to proceed.
*/
static enum empty_node_direction rb_find_empty_direction(struct rbtree_node *empty, ao2_sort_fn *sort_fn, void *obj_right, enum search_flags flags, enum equal_node_bias bias)
{
int cmp;
struct rbtree_node *cur;
struct rbtree_node *right_most;
/* Try for a quick definite go left. */
if (!empty->left) {
/* The empty node has no left child. */
return GO_RIGHT;
}
right_most = rb_node_most_right(empty->left);
if (right_most->common.obj) {
cmp = sort_fn(right_most->common.obj, obj_right, flags);
if (cmp < 0) {
return GO_RIGHT;
}
if (cmp == 0 && bias == BIAS_LAST) {
return GO_RIGHT;
}
return GO_LEFT;
}
/* Try for a quick definite go right. */
if (!empty->right) {
/* The empty node has no right child. */
return GO_LEFT;
}
cur = rb_node_most_left(empty->right);
if (cur->common.obj) {
cmp = sort_fn(cur->common.obj, obj_right, flags);
if (cmp > 0) {
return GO_LEFT;
}
if (cmp == 0 && bias == BIAS_FIRST) {
return GO_LEFT;
}
return GO_RIGHT;
}
/*
* Have to scan the previous nodes from the right_most node of
* the left subtree for the first non-empty node to determine
* direction.
*/
cur = right_most;
for (;;) {
/* Find previous node. */
if (cur->left) {
cur = rb_node_most_right(cur->left);
} else {
/* Find the parent that the node is a right child of. */
for (;;) {
if (cur->parent == empty) {
/* The left side of the empty node is all empty nodes. */
return GO_RIGHT;
}
if (cur->parent->right == cur) {
/* We are the right child. The parent is the previous node. */
cur = cur->parent;
break;
}
cur = cur->parent;
}
}
if (cur->common.obj) {
cmp = sort_fn(cur->common.obj, obj_right, flags);
if (cmp < 0) {
return GO_RIGHT;
}
if (cmp == 0 && bias == BIAS_LAST) {
return GO_RIGHT;
}
return GO_LEFT;
}
}
}
/*!
* \internal
* \brief Tree node rotation left.
* \since 12.0.0
*
* \param self Container holding node.
* \param node Node to perform a left rotation with.
*
* p p
* | Left rotation |
* N ---> Ch
* / \ / \
* a Ch N c
* / \ / \
* b c a b
*
* N = node
* Ch = child
* p = parent
* a,b,c = other nodes that are unaffected by the rotation.
*
* \note It is assumed that the node's right child exists.
*/
static void rb_rotate_left(struct ao2_container_rbtree *self, struct rbtree_node *node)
{
struct rbtree_node *child; /*!< Node's right child. */
child = node->right;
/* Link the node's parent to the child. */
if (!node->parent) {
/* Node is the root so we get a new root node. */
self->root = child;
} else if (node->parent->left == node) {
/* Node is a left child. */
node->parent->left = child;
} else {
/* Node is a right child. */
node->parent->right = child;
}
child->parent = node->parent;
/* Link node's right subtree to the child's left subtree. */
node->right = child->left;
if (node->right) {
node->right->parent = node;
}
/* Link the node to the child's left. */
node->parent = child;
child->left = node;
}
/*!
* \internal
* \brief Tree node rotation right.
* \since 12.0.0
*
* \param self Container holding node.
* \param node Node to perform a right rotation with.
*
* p p
* | Right rotation |
* Ch N
* / \ <--- / \
* a N Ch c
* / \ / \
* b c a b
*
* N = node
* Ch = child
* p = parent
* a,b,c = other nodes that are unaffected by the rotation.
*
* \note It is assumed that the node's left child exists.
*/
static void rb_rotate_right(struct ao2_container_rbtree *self, struct rbtree_node *node)
{
struct rbtree_node *child; /*!< Node's left child. */
child = node->left;
/* Link the node's parent to the child. */
if (!node->parent) {
/* Node is the root so we get a new root node. */
self->root = child;
} else if (node->parent->right == node) {
/* Node is a right child. */
node->parent->right = child;
} else {
/* Node is a left child. */
node->parent->left = child;
}
child->parent = node->parent;
/* Link node's left subtree to the child's right subtree. */
node->left = child->right;
if (node->left) {
node->left->parent = node;
}
/* Link the node to the child's right. */
node->parent = child;
child->right = node;
}
/*!
* \internal
* \brief Create an empty copy of this container. (Debug version)
* \since 14.0.0
*
* \param self Container to operate upon.
* \param tag used for debugging.
* \param file Debug file name invoked from
* \param line Debug line invoked from
* \param func Debug function name invoked from
*
* \return empty-clone-container on success.
* \retval NULL on error.
*/
static struct ao2_container *rb_ao2_alloc_empty_clone(struct ao2_container_rbtree *self,
const char *tag, const char *file, int line, const char *func)
{
if (!__is_ao2_object(self, file, line, func)) {
return NULL;
}
return __ao2_container_alloc_rbtree(ao2_options_get(self), self->common.options,
self->common.sort_fn, self->common.cmp_fn, tag, file, line, func);
}
/*!
* \internal
* \brief Fixup the rbtree after deleting a node.
* \since 12.0.0
*
* \param self Container to operate upon.
* \param child Child of the node just deleted from the container.
*
* \note The child must be a dummy black node if there really
* was no child of the deleted node. Otherwise, the caller must
* pass in the parent node and which child was deleted. In
* addition, the fixup routine would be more complicated.
*/
static void rb_delete_fixup(struct ao2_container_rbtree *self, struct rbtree_node *child)
{
struct rbtree_node *sibling;
while (self->root != child && !child->is_red) {
if (child->parent->left == child) {
/* Child is a left child. */
sibling = child->parent->right;
ast_assert(sibling != NULL);
if (sibling->is_red) {
/* Case 1: The child's sibling is red. */
AO2_DEVMODE_STAT(++self->stats.fixup_delete_left[0]);
sibling->is_red = 0;
child->parent->is_red = 1;
rb_rotate_left(self, child->parent);
sibling = child->parent->right;
ast_assert(sibling != NULL);
}
/*
* The sibling is black. A black node must have two children,
* or one red child, or no children.
*/
if ((!sibling->left || !sibling->left->is_red)
&& (!sibling->right || !sibling->right->is_red)) {
/*
* Case 2: The sibling is black and both of its children are black.
*
* This case handles the two black children or no children
* possibilities of a black node.
*/
AO2_DEVMODE_STAT(++self->stats.fixup_delete_left[1]);
sibling->is_red = 1;
child = child->parent;
} else {
/* At this point the sibling has at least one red child. */
if (!sibling->right || !sibling->right->is_red) {
/*
* Case 3: The sibling is black, its left child is red, and its
* right child is black.
*/
AO2_DEVMODE_STAT(++self->stats.fixup_delete_left[2]);
ast_assert(sibling->left != NULL);
ast_assert(sibling->left->is_red);
sibling->left->is_red = 0;
sibling->is_red = 1;
rb_rotate_right(self, sibling);
sibling = child->parent->right;
ast_assert(sibling != NULL);
}
/* Case 4: The sibling is black and its right child is red. */
AO2_DEVMODE_STAT(++self->stats.fixup_delete_left[3]);
sibling->is_red = child->parent->is_red;
child->parent->is_red = 0;
if (sibling->right) {
sibling->right->is_red = 0;
}
rb_rotate_left(self, child->parent);
child = self->root;
}
} else {
/* Child is a right child. */
sibling = child->parent->left;
ast_assert(sibling != NULL);
if (sibling->is_red) {
/* Case 1: The child's sibling is red. */
AO2_DEVMODE_STAT(++self->stats.fixup_delete_right[0]);
sibling->is_red = 0;
child->parent->is_red = 1;
rb_rotate_right(self, child->parent);
sibling = child->parent->left;
ast_assert(sibling != NULL);
}
/*
* The sibling is black. A black node must have two children,
* or one red child, or no children.
*/
if ((!sibling->right || !sibling->right->is_red)
&& (!sibling->left || !sibling->left->is_red)) {
/*
* Case 2: The sibling is black and both of its children are black.
*
* This case handles the two black children or no children
* possibilities of a black node.
*/
AO2_DEVMODE_STAT(++self->stats.fixup_delete_right[1]);
sibling->is_red = 1;
child = child->parent;
} else {
/* At this point the sibling has at least one red child. */
if (!sibling->left || !sibling->left->is_red) {
/*
* Case 3: The sibling is black, its right child is red, and its
* left child is black.
*/
AO2_DEVMODE_STAT(++self->stats.fixup_delete_right[2]);
ast_assert(sibling->right != NULL);
ast_assert(sibling->right->is_red);
sibling->right->is_red = 0;
sibling->is_red = 1;
rb_rotate_left(self, sibling);
sibling = child->parent->left;
ast_assert(sibling != NULL);
}
/* Case 4: The sibling is black and its left child is red. */
AO2_DEVMODE_STAT(++self->stats.fixup_delete_right[3]);
sibling->is_red = child->parent->is_red;
child->parent->is_red = 0;
if (sibling->left) {
sibling->left->is_red = 0;
}
rb_rotate_right(self, child->parent);
child = self->root;
}
}
}
/*
* Case 2 could leave the child node red and it needs to leave
* with it black.
*
* Case 4 sets the child node to the root which of course must
* be black.
*/
child->is_red = 0;
}
/*!
* \internal
* \brief Delete the doomed node from this container.
* \since 12.0.0
*
* \param self Container to operate upon.
* \param doomed Container node to delete from the container.
*/
static void rb_delete_node(struct ao2_container_rbtree *self, struct rbtree_node *doomed)
{
struct rbtree_node *child;
int need_fixup;
if (doomed->left && doomed->right) {
struct rbtree_node *next;
int is_red;
/*
* The doomed node has two children.
*
* Find the next child node and swap it with the doomed node in
* the tree.
*/
AO2_DEVMODE_STAT(++self->stats.delete_children[2]);
next = rb_node_most_left(doomed->right);
SWAP(doomed->parent, next->parent);
SWAP(doomed->left, next->left);
SWAP(doomed->right, next->right);
is_red = doomed->is_red;
doomed->is_red = next->is_red;
next->is_red = is_red;
/* Link back in the next node. */
if (!next->parent) {
/* Doomed was the root so we get a new root node. */
self->root = next;
} else if (next->parent->left == doomed) {
/* Doomed was the left child. */
next->parent->left = next;
} else {
/* Doomed was the right child. */
next->parent->right = next;
}
next->left->parent = next;
if (next->right == next) {
/* The next node was the right child of doomed. */
next->right = doomed;
doomed->parent = next;
} else {
next->right->parent = next;
doomed->parent->left = doomed;
}
/* The doomed node has no left child now. */
ast_assert(doomed->left == NULL);
/*
* We don't have to link the right child back in with doomed
* since we are going to link it with doomed's parent anyway.
*/
child = doomed->right;
} else {
/* Doomed has at most one child. */
child = doomed->left;
if (!child) {
child = doomed->right;
}
}
if (child) {
AO2_DEVMODE_STAT(++self->stats.delete_children[1]);
} else {
AO2_DEVMODE_STAT(++self->stats.delete_children[0]);
}
need_fixup = (!doomed->is_red && !self->common.destroying);
if (need_fixup && !child) {
/*
* Use the doomed node as a place holder node for the
* nonexistent child so we also don't have to pass to the fixup
* routine the parent and which child the deleted node came
* from.
*/
rb_delete_fixup(self, doomed);
ast_assert(doomed->left == NULL);
ast_assert(doomed->right == NULL);
ast_assert(!doomed->is_red);
}
/* Link the child in place of doomed. */
if (!doomed->parent) {
/* Doomed was the root so we get a new root node. */
self->root = child;
} else if (doomed->parent->left == doomed) {
/* Doomed was the left child. */
doomed->parent->left = child;
} else {
/* Doomed was the right child. */
doomed->parent->right = child;
}
if (child) {
child->parent = doomed->parent;
if (need_fixup) {
rb_delete_fixup(self, child);
}
}
AO2_DEVMODE_STAT(--self->common.nodes);
}
/*!
* \internal
* \brief Destroy a rbtree container node.
* \since 12.0.0
*
* \param v_doomed Container node to destroy.
*
* \details
* The container node unlinks itself from the container as part
* of its destruction. The node must be destroyed while the
* container is already locked.
*
* \note The container must be locked when the node is
* unreferenced.
*/
static void rb_ao2_node_destructor(void *v_doomed)
{
struct rbtree_node *doomed = v_doomed;
if (doomed->common.is_linked) {
struct ao2_container_rbtree *my_container;
/*
* Promote to write lock if not already there. Since
* adjust_lock() can potentially release and block waiting for a
* write lock, care must be taken to ensure that node references
* are released before releasing the container references.
*
* Node references held by an iterator can only be held while
* the iterator also holds a reference to the container. These
* node references must be unreferenced before the container can
* be unreferenced to ensure that the node will not get a
* negative reference and the destructor called twice for the
* same node.
*/
my_container = (struct ao2_container_rbtree *) doomed->common.my_container;
#ifdef AST_DEVMODE
is_ao2_object(my_container);
#endif
__adjust_lock(my_container, AO2_LOCK_REQ_WRLOCK, 1);
#if defined(AO2_DEBUG)
if (!my_container->common.destroying
&& ao2_container_check(doomed->common.my_container, OBJ_NOLOCK)) {
ast_log(LOG_ERROR, "Container integrity failed before node deletion.\n");
}
#endif /* defined(AO2_DEBUG) */
rb_delete_node(my_container, doomed);
#if defined(AO2_DEBUG)
if (!my_container->common.destroying
&& ao2_container_check(doomed->common.my_container, OBJ_NOLOCK)) {
ast_log(LOG_ERROR, "Container integrity failed after node deletion.\n");
}
#endif /* defined(AO2_DEBUG) */
}
/*
* We could have an object in the node if the container is being
* destroyed or the node had not been linked in yet.
*/
if (doomed->common.obj) {
__container_unlink_node(&doomed->common, AO2_UNLINK_NODE_UNLINK_OBJECT);
}
}
/*!
* \internal
* \brief Create a new container node.
* \since 12.0.0
*
* \param self Container to operate upon.
* \param obj_new Object to put into the node.
* \param tag used for debugging.
* \param file Debug file name invoked from
* \param line Debug line invoked from
* \param func Debug function name invoked from
*
* \return initialized-node on success.
* \retval NULL on error.
*/
static struct rbtree_node *rb_ao2_new_node(struct ao2_container_rbtree *self, void *obj_new, const char *tag, const char *file, int line, const char *func)
{
struct rbtree_node *node;
node = ao2_alloc_options(sizeof(*node), rb_ao2_node_destructor,
AO2_ALLOC_OPT_LOCK_NOLOCK | AO2_ALLOC_OPT_NO_REF_DEBUG);
if (!node) {
return NULL;
}
__ao2_ref(obj_new, +1, tag ?: "Container node creation", file, line, func);
node->common.obj = obj_new;
node->common.my_container = (struct ao2_container *) self;
return node;
}
/*!
* \internal
* \brief Fixup the rbtree after inserting a node.
* \since 12.0.0
*
* \param self Container to operate upon.
* \param node Container node just inserted into the container.
*
* \note The just inserted node is red.
*/
static void rb_insert_fixup(struct ao2_container_rbtree *self, struct rbtree_node *node)
{
struct rbtree_node *g_parent; /* Grand parent node. */
while (node->parent && node->parent->is_red) {
g_parent = node->parent->parent;
/* The grand parent must exist if the parent is red. */
ast_assert(g_parent != NULL);
if (node->parent == g_parent->left) {
/* The parent is a left child. */
if (g_parent->right && g_parent->right->is_red) {
/* Case 1: Push the black down from the grand parent node. */
AO2_DEVMODE_STAT(++self->stats.fixup_insert_left[0]);
g_parent->right->is_red = 0;
g_parent->left->is_red = 0;
g_parent->is_red = 1;
node = g_parent;
} else {
/* The uncle node is black. */
if (node->parent->right == node) {
/*
* Case 2: The node is a right child.
*
* Which node is the grand parent does not change.
*/
AO2_DEVMODE_STAT(++self->stats.fixup_insert_left[1]);
node = node->parent;
rb_rotate_left(self, node);
}
/* Case 3: The node is a left child. */
AO2_DEVMODE_STAT(++self->stats.fixup_insert_left[2]);
node->parent->is_red = 0;
g_parent->is_red = 1;
rb_rotate_right(self, g_parent);
}
} else {
/* The parent is a right child. */
if (g_parent->left && g_parent->left->is_red) {
/* Case 1: Push the black down from the grand parent node. */
AO2_DEVMODE_STAT(++self->stats.fixup_insert_right[0]);
g_parent->left->is_red = 0;
g_parent->right->is_red = 0;
g_parent->is_red = 1;
node = g_parent;
} else {
/* The uncle node is black. */
if (node->parent->left == node) {
/*
* Case 2: The node is a left child.
*
* Which node is the grand parent does not change.
*/
AO2_DEVMODE_STAT(++self->stats.fixup_insert_right[1]);
node = node->parent;
rb_rotate_right(self, node);
}
/* Case 3: The node is a right child. */
AO2_DEVMODE_STAT(++self->stats.fixup_insert_right[2]);
node->parent->is_red = 0;
g_parent->is_red = 1;
rb_rotate_left(self, g_parent);
}
}
}
/*
* The root could be red here because:
* 1) We just inserted the root node in an empty tree.
*
* 2) Case 1 could leave the root red if the grand parent were
* the root.
*/
self->root->is_red = 0;
}
/*!
* \internal
* \brief Insert a node into this container.
* \since 12.0.0
*
* \param self Container to operate upon.
* \param node Container node to insert into the container.
*
* \return \ref ao2_container_insert value.
*/
static enum ao2_container_insert rb_ao2_insert_node(struct ao2_container_rbtree *self, struct rbtree_node *node)
{
int cmp;
struct rbtree_node *cur;
struct rbtree_node *next;
ao2_sort_fn *sort_fn;
uint32_t options;
enum equal_node_bias bias;
if (!self->root) {
/* The tree is empty. */
self->root = node;
return AO2_CONTAINER_INSERT_NODE_INSERTED;
}
sort_fn = self->common.sort_fn;
options = self->common.options;
switch (options & AO2_CONTAINER_ALLOC_OPT_DUPS_MASK) {
default:
case AO2_CONTAINER_ALLOC_OPT_DUPS_ALLOW:
if (options & AO2_CONTAINER_ALLOC_OPT_INSERT_BEGIN) {
bias = BIAS_FIRST;
} else {
bias = BIAS_LAST;
}
break;
case AO2_CONTAINER_ALLOC_OPT_DUPS_REJECT:
case AO2_CONTAINER_ALLOC_OPT_DUPS_OBJ_REJECT:
case AO2_CONTAINER_ALLOC_OPT_DUPS_REPLACE:
bias = BIAS_EQUAL;
break;
}
/*
* New nodes are always colored red when initially inserted into
* the tree. (Except for the root which is always black.)
*/
node->is_red = 1;
/* Find node where normal insert would put a new node. */
cur = self->root;
for (;;) {
if (!cur->common.obj) {
/* Which direction do we go to insert this node? */
if (rb_find_empty_direction(cur, sort_fn, node->common.obj, OBJ_SEARCH_OBJECT, bias)
== GO_LEFT) {
if (cur->left) {
cur = cur->left;
continue;
}
/* Node becomes a left child */
cur->left = node;
node->parent = cur;
rb_insert_fixup(self, node);
return AO2_CONTAINER_INSERT_NODE_INSERTED;
}
if (cur->right) {
cur = cur->right;
continue;
}
/* Node becomes a right child */
cur->right = node;
node->parent = cur;
rb_insert_fixup(self, node);
return AO2_CONTAINER_INSERT_NODE_INSERTED;
}
cmp = sort_fn(cur->common.obj, node->common.obj, OBJ_SEARCH_OBJECT);
if (cmp > 0) {
if (cur->left) {
cur = cur->left;
continue;
}
/* Node becomes a left child */
cur->left = node;
node->parent = cur;
rb_insert_fixup(self, node);
return AO2_CONTAINER_INSERT_NODE_INSERTED;
} else if (cmp < 0) {
if (cur->right) {
cur = cur->right;
continue;
}
/* Node becomes a right child */
cur->right = node;
node->parent = cur;
rb_insert_fixup(self, node);
return AO2_CONTAINER_INSERT_NODE_INSERTED;
}
switch (bias) {
case BIAS_FIRST:
/* Duplicate nodes unconditionally accepted. */
if (cur->left) {
cur = cur->left;
continue;
}
/* Node becomes a left child */
cur->left = node;
node->parent = cur;
rb_insert_fixup(self, node);
return AO2_CONTAINER_INSERT_NODE_INSERTED;
case BIAS_EQUAL:
break;
case BIAS_LAST:
/* Duplicate nodes unconditionally accepted. */
if (cur->right) {
cur = cur->right;
continue;
}
/* Node becomes a right child */
cur->right = node;
node->parent = cur;
rb_insert_fixup(self, node);
return AO2_CONTAINER_INSERT_NODE_INSERTED;
}
break;
}
/* Node is a duplicate */
switch (options & AO2_CONTAINER_ALLOC_OPT_DUPS_MASK) {
default:
case AO2_CONTAINER_ALLOC_OPT_DUPS_ALLOW:
ast_assert(0);/* Case already handled by BIAS_FIRST/BIAS_LAST. */
return AO2_CONTAINER_INSERT_NODE_REJECTED;
case AO2_CONTAINER_ALLOC_OPT_DUPS_REJECT:
/* Reject all objects with the same key. */
return AO2_CONTAINER_INSERT_NODE_REJECTED;
case AO2_CONTAINER_ALLOC_OPT_DUPS_OBJ_REJECT:
if (cur->common.obj == node->common.obj) {
/* Reject inserting the same object */
return AO2_CONTAINER_INSERT_NODE_REJECTED;
}
next = cur;
if (options & AO2_CONTAINER_ALLOC_OPT_INSERT_BEGIN) {
/* Search to end of duplicates for the same object. */
for (;;) {
next = rb_node_next_full(next);
if (!next) {
break;
}
if (next->common.obj == node->common.obj) {
/* Reject inserting the same object */
return AO2_CONTAINER_INSERT_NODE_REJECTED;
}
cmp = sort_fn(next->common.obj, node->common.obj, OBJ_SEARCH_OBJECT);
if (cmp) {
break;
}
}
/* Find first duplicate node. */
for (;;) {
next = rb_node_prev_full(cur);
if (!next) {
break;
}
if (next->common.obj == node->common.obj) {
/* Reject inserting the same object */
return AO2_CONTAINER_INSERT_NODE_REJECTED;
}
cmp = sort_fn(next->common.obj, node->common.obj, OBJ_SEARCH_OBJECT);
if (cmp) {
break;
}
cur = next;
}
if (!cur->left) {
/* Node becomes a left child */
cur->left = node;
} else {
/* Node becomes a right child */
cur = rb_node_most_right(cur->left);
cur->right = node;
}
} else {
/* Search to beginning of duplicates for the same object. */
for (;;) {
next = rb_node_prev_full(next);
if (!next) {
break;
}
if (next->common.obj == node->common.obj) {
/* Reject inserting the same object */
return AO2_CONTAINER_INSERT_NODE_REJECTED;
}
cmp = sort_fn(next->common.obj, node->common.obj, OBJ_SEARCH_OBJECT);
if (cmp) {
break;
}
}
/* Find last duplicate node. */
for (;;) {
next = rb_node_next_full(cur);
if (!next) {
break;
}
if (next->common.obj == node->common.obj) {
/* Reject inserting the same object */
return AO2_CONTAINER_INSERT_NODE_REJECTED;
}
cmp = sort_fn(next->common.obj, node->common.obj, OBJ_SEARCH_OBJECT);
if (cmp) {
break;
}
cur = next;
}
if (!cur->right) {
/* Node becomes a right child */
cur->right = node;
} else {
/* Node becomes a left child */
cur = rb_node_most_left(cur->right);
cur->left = node;
}
}
break;
case AO2_CONTAINER_ALLOC_OPT_DUPS_REPLACE:
SWAP(cur->common.obj, node->common.obj);
ao2_ref(node, -1);
return AO2_CONTAINER_INSERT_NODE_OBJ_REPLACED;
}
/* Complete inserting duplicate node. */
node->parent = cur;
rb_insert_fixup(self, node);
return AO2_CONTAINER_INSERT_NODE_INSERTED;
}
/*!
* \internal
* \brief Find the next rbtree container node in a traversal.
* \since 12.0.0
*
* \param self Container to operate upon.
* \param state Traversal state to restart rbtree container traversal.
* \param prev Previous node returned by the traversal search functions.
* The ref ownership is passed back to this function.
*
* \return node-ptr of found node (Reffed).
* \retval NULL when no node found.
*/
static struct rbtree_node *rb_ao2_find_next(struct ao2_container_rbtree *self, struct rbtree_traversal_state *state, struct rbtree_node *prev)
{
struct rbtree_node *node;
void *arg;
enum search_flags flags;
int cmp;
arg = state->arg;
flags = state->flags;
node = prev;
for (;;) {
/* Find next node in traversal order. */
switch (flags & OBJ_ORDER_MASK) {
default:
case OBJ_ORDER_ASCENDING:
node = rb_node_next(node);
break;
case OBJ_ORDER_DESCENDING:
node = rb_node_prev(node);
break;
case OBJ_ORDER_PRE:
node = rb_node_pre(node);
break;
case OBJ_ORDER_POST:
node = rb_node_post(node);
break;
}
if (!node) {
/* No more nodes left to traverse. */
break;
}
if (!node->common.obj) {
/* Node is empty */
continue;
}
if (state->sort_fn) {
/* Filter node through the sort_fn */
cmp = state->sort_fn(node->common.obj, arg, flags & OBJ_SEARCH_MASK);
if (cmp) {
/* No more nodes in this container are possible to match. */
break;
}
}
/* We have the next traversal node */
ao2_ref(node, +1);
/*
* Dereferencing the prev node may result in our next node
* object being removed by another thread. This could happen if
* the container uses RW locks and the container was read
* locked.
*/
ao2_ref(prev, -1);
if (node->common.obj) {
return node;
}
prev = node;
}
/* No more nodes in the container left to traverse. */
ao2_ref(prev, -1);
return NULL;
}
/*!
* \internal
* \brief Find an initial matching node.
* \since 12.0.0
*
* \param self Container to operate upon.
* \param obj_right pointer to the (user-defined part) of an object.
* \param flags flags from ao2_callback()
* OBJ_SEARCH_OBJECT - if set, 'obj_right', is an object.
* OBJ_SEARCH_KEY - if set, 'obj_right', is a search key item that is not an object.
* OBJ_SEARCH_PARTIAL_KEY - if set, 'obj_right', is a partial search key item that is not an object.
* \param bias How to bias search direction for duplicates
*
* \return node on success.
* \retval NULL if not found.
*/
static struct rbtree_node *rb_find_initial(struct ao2_container_rbtree *self, void *obj_right, enum search_flags flags, enum equal_node_bias bias)
{
int cmp;
enum search_flags sort_flags;
struct rbtree_node *node;
struct rbtree_node *next = NULL;
ao2_sort_fn *sort_fn;
sort_flags = flags & OBJ_SEARCH_MASK;
sort_fn = self->common.sort_fn;
/* Find node where normal search would find it. */
node = self->root;
if (!node) {
return NULL;
}
for (;;) {
if (!node->common.obj) {
/* Which direction do we go to find the node? */
if (rb_find_empty_direction(node, sort_fn, obj_right, sort_flags, bias)
== GO_LEFT) {
next = node->left;
} else {
next = node->right;
}
if (!next) {
switch (bias) {
case BIAS_FIRST:
/* Check successor node for match. */
next = rb_node_next_full(node);
break;
case BIAS_EQUAL:
break;
case BIAS_LAST:
/* Check previous node for match. */
next = rb_node_prev_full(node);
break;
}
if (next) {
cmp = sort_fn(next->common.obj, obj_right, sort_flags);
if (cmp == 0) {
/* Found the first/last matching node. */
return next;
}
next = NULL;
}
/* No match found. */
return next;
}
} else {
cmp = sort_fn(node->common.obj, obj_right, sort_flags);
if (cmp > 0) {
next = node->left;
} else if (cmp < 0) {
next = node->right;
} else {
switch (bias) {
case BIAS_FIRST:
next = node->left;
break;
case BIAS_EQUAL:
return node;
case BIAS_LAST:
next = node->right;
break;
}
if (!next) {
/* Found the first/last matching node. */
return node;
}
}
if (!next) {
switch (bias) {
case BIAS_FIRST:
if (cmp < 0) {
/* Check successor node for match. */
next = rb_node_next_full(node);
}
break;
case BIAS_EQUAL:
break;
case BIAS_LAST:
if (cmp > 0) {
/* Check previous node for match. */
next = rb_node_prev_full(node);
}
break;
}
if (next) {
cmp = sort_fn(next->common.obj, obj_right, sort_flags);
if (cmp == 0) {
/* Found the first/last matching node. */
return next;
}
}
/* No match found. */
return NULL;
}
}
node = next;
}
}
/*!
* \internal
* \brief Find the first rbtree container node in a traversal.
* \since 12.0.0
*
* \param self Container to operate upon.
* \param flags search_flags to control traversing the container
* \param arg Comparison callback arg parameter.
* \param state Traversal state to restart rbtree container traversal.
*
* \return node-ptr of found node (Reffed).
* \retval NULL when no node found.
*/
static struct rbtree_node *rb_ao2_find_first(struct ao2_container_rbtree *self, enum search_flags flags, void *arg, struct rbtree_traversal_state *state)
{
struct rbtree_node *node;
enum equal_node_bias bias;
if (self->common.destroying) {
/* Force traversal to be post order for tree destruction. */
flags = OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE | OBJ_ORDER_POST;
}
memset(state, 0, sizeof(*state));
state->arg = arg;
state->flags = flags;
switch (flags & OBJ_SEARCH_MASK) {
case OBJ_SEARCH_OBJECT:
case OBJ_SEARCH_KEY:
case OBJ_SEARCH_PARTIAL_KEY:
/* We are asked to do a directed search. */
state->sort_fn = self->common.sort_fn;
break;
default:
/* Don't know, let's visit all nodes */
state->sort_fn = NULL;
break;
}
if (!self->root) {
/* Tree is empty. */
return NULL;
}
/* Find first traversal node. */
switch (flags & OBJ_ORDER_MASK) {
default:
case OBJ_ORDER_ASCENDING:
if (!state->sort_fn) {
/* Find left most child. */
node = rb_node_most_left(self->root);
if (!node->common.obj) {
node = rb_node_next_full(node);
if (!node) {
return NULL;
}
}
break;
}
/* Search for initial node. */
switch (self->common.options & AO2_CONTAINER_ALLOC_OPT_DUPS_MASK) {
case AO2_CONTAINER_ALLOC_OPT_DUPS_REJECT:
case AO2_CONTAINER_ALLOC_OPT_DUPS_REPLACE:
if ((flags & OBJ_SEARCH_MASK) != OBJ_SEARCH_PARTIAL_KEY) {
/* There are no duplicates allowed. */
bias = BIAS_EQUAL;
break;
}
/* Fall through */
default:
case AO2_CONTAINER_ALLOC_OPT_DUPS_ALLOW:
case AO2_CONTAINER_ALLOC_OPT_DUPS_OBJ_REJECT:
/* Find first duplicate node. */
bias = BIAS_FIRST;
break;
}
node = rb_find_initial(self, arg, flags, bias);
if (!node) {
return NULL;
}
break;
case OBJ_ORDER_DESCENDING:
if (!state->sort_fn) {
/* Find right most child. */
node = rb_node_most_right(self->root);
if (!node->common.obj) {
node = rb_node_prev_full(node);
if (!node) {
return NULL;
}
}
break;
}
/* Search for initial node. */
switch (self->common.options & AO2_CONTAINER_ALLOC_OPT_DUPS_MASK) {
case AO2_CONTAINER_ALLOC_OPT_DUPS_REJECT:
case AO2_CONTAINER_ALLOC_OPT_DUPS_REPLACE:
if ((flags & OBJ_SEARCH_MASK) != OBJ_SEARCH_PARTIAL_KEY) {
/* There are no duplicates allowed. */
bias = BIAS_EQUAL;
break;
}
/* Fall through */
default:
case AO2_CONTAINER_ALLOC_OPT_DUPS_ALLOW:
case AO2_CONTAINER_ALLOC_OPT_DUPS_OBJ_REJECT:
/* Find last duplicate node. */
bias = BIAS_LAST;
break;
}
node = rb_find_initial(self, arg, flags, bias);
if (!node) {
return NULL;
}
break;
case OBJ_ORDER_PRE:
/* This is a tree structure traversal so we must visit all nodes. */
state->sort_fn = NULL;
node = self->root;
/* Find a non-empty node. */
while (!node->common.obj) {
node = rb_node_pre(node);
if (!node) {
return NULL;
}
}
break;
case OBJ_ORDER_POST:
/* This is a tree structure traversal so we must visit all nodes. */
state->sort_fn = NULL;
/* Find the left most childless node. */
node = self->root;
for (;;) {
node = rb_node_most_left(node);
if (!node->right) {
/* This node has no children. */
break;
}
node = node->right;
}
/* Find a non-empty node. */
while (!node->common.obj) {
node = rb_node_post(node);
if (!node) {
return NULL;
}
}
break;
}
/* We have the first traversal node */
ao2_ref(node, +1);
return node;
}
/*!
* \internal
* \brief Find the next non-empty iteration node in the container.
* \since 12.0.0
*
* \param self Container to operate upon.
* \param node Previous node returned by the iterator.
* \param flags search_flags to control iterating the container.
* Only AO2_ITERATOR_DESCENDING is useful by the method.
*
* \note The container is already locked.
*
* \return node on success.
* \retval NULL on error or no more nodes in the container.
*/
static struct rbtree_node *rb_ao2_iterator_next(struct ao2_container_rbtree *self, struct rbtree_node *node, enum ao2_iterator_flags flags)
{
if (flags & AO2_ITERATOR_DESCENDING) {
if (!node) {
/* Find right most node. */
if (!self->root) {
return NULL;
}
node = rb_node_most_right(self->root);
if (node->common.obj) {
/* Found a non-empty node. */
return node;
}
}
/* Find next non-empty node. */
node = rb_node_prev_full(node);
} else {
if (!node) {
/* Find left most node. */
if (!self->root) {
return NULL;
}
node = rb_node_most_left(self->root);
if (node->common.obj) {
/* Found a non-empty node. */
return node;
}
}
/* Find next non-empty node. */
node = rb_node_next_full(node);
}
return node;
}
/*!
* \internal
*
* \brief Destroy this container.
* \since 12.0.0
*
* \param self Container to operate upon.
*/
static void rb_ao2_destroy(struct ao2_container_rbtree *self)
{
/* Check that the container no longer has any nodes */
if (self->root) {
ast_log(LOG_ERROR, "Node ref leak. Red-Black tree container still has nodes!\n");
ast_assert(0);
}
}
#if defined(AO2_DEBUG)
/*!
* \internal
* \brief Display contents of the specified container.
* \since 12.0.0
*
* \param self Container to dump.
* \param where User data needed by prnt to determine where to put output.
* \param prnt Print output callback function to use.
* \param prnt_obj Callback function to print the given object's key. (NULL if not available)
*/
static void rb_ao2_dump(struct ao2_container_rbtree *self, void *where, ao2_prnt_fn *prnt, ao2_prnt_obj_fn *prnt_obj)
{
#define FORMAT "%16s, %16s, %16s, %16s, %5s, %16s, %s\n"
#define FORMAT2 "%16p, %16p, %16p, %16p, %5s, %16p, "
struct rbtree_node *node;
prnt(where, FORMAT, "Node", "Parent", "Left", "Right", "Color", "Obj", "Key");
for (node = self->root; node; node = rb_node_pre(node)) {
prnt(where, FORMAT2,
node,
node->parent,
node->left,
node->right,
node->is_red ? "Red" : "Black",
node->common.obj);
if (node->common.obj && prnt_obj) {
prnt_obj(node->common.obj, where, prnt);
}
prnt(where, "\n");
}
#undef FORMAT
#undef FORMAT2
}
#endif /* defined(AO2_DEBUG) */
#if defined(AO2_DEBUG)
/*!
* \internal
* \brief Display statistics of the specified container.
* \since 12.0.0
*
* \param self Container to display statistics.
* \param where User data needed by prnt to determine where to put output.
* \param prnt Print output callback function to use.
*
* \note The container is already locked for reading.
*/
static void rb_ao2_stats(struct ao2_container_rbtree *self, void *where, ao2_prnt_fn *prnt)
{
int idx;
for (idx = 0; idx < ARRAY_LEN(self->stats.fixup_insert_left); ++idx) {
prnt(where, "Number of left insert fixups case %d: %d\n", idx + 1,
self->stats.fixup_insert_left[idx]);
}
for (idx = 0; idx < ARRAY_LEN(self->stats.fixup_insert_right); ++idx) {
prnt(where, "Number of right insert fixups case %d: %d\n", idx + 1,
self->stats.fixup_insert_right[idx]);
}
for (idx = 0; idx < ARRAY_LEN(self->stats.delete_children); ++idx) {
prnt(where, "Number of nodes deleted with %d children: %d\n", idx,
self->stats.delete_children[idx]);
}
for (idx = 0; idx < ARRAY_LEN(self->stats.fixup_delete_left); ++idx) {
prnt(where, "Number of left delete fixups case %d: %d\n", idx + 1,
self->stats.fixup_delete_left[idx]);
}
for (idx = 0; idx < ARRAY_LEN(self->stats.fixup_delete_right); ++idx) {
prnt(where, "Number of right delete fixups case %d: %d\n", idx + 1,
self->stats.fixup_delete_right[idx]);
}
}
#endif /* defined(AO2_DEBUG) */
#if defined(AO2_DEBUG)
/*!
* \internal
* \brief Check the black height of the given node.
* \since 12.0.0
*
* \param node Node to check black height.
*
* \return black-height of node on success.
* \retval -1 on error. Node black height did not balance.
*/
static int rb_check_black_height(struct rbtree_node *node)
{
int height_left;
int height_right;
if (!node) {
/* A NULL child is a black node. */
return 0;
}
height_left = rb_check_black_height(node->left);
if (height_left < 0) {
return -1;
}
height_right = rb_check_black_height(node->right);
if (height_right < 0) {
return -1;
}
if (height_left != height_right) {
ast_log(LOG_ERROR,
"Tree node black height of children does not match! L:%d != R:%d\n",
height_left, height_right);
return -1;
}
if (!node->is_red) {
/* The node itself is black. */
++height_left;
}
return height_left;
}
#endif /* defined(AO2_DEBUG) */
#if defined(AO2_DEBUG)
/*!
* \internal
* \brief Perform an integrity check on the specified container.
* \since 12.0.0
*
* \param self Container to check integrity.
*
* \note The container is already locked for reading.
*
* \retval 0 on success.
* \retval -1 on error.
*/
static int rb_ao2_integrity(struct ao2_container_rbtree *self)
{
int res;
int count_node;
int count_obj;
void *obj_last;
struct rbtree_node *node;
res = 0;
count_node = 0;
count_obj = 0;
/*
* See the properties listed at struct rbtree_node definition.
*
* The rbtree properties 1 and 3 are not testable.
*
* Property 1 is not testable because we are not rebalancing at
* this time so all nodes are either red or black.
*
* Property 3 is not testable because it is the definition of a
* NULL child.
*/
if (self->root) {
/* Check tree links. */
if (self->root->parent) {
if (self->root->parent == self->root) {
ast_log(LOG_ERROR, "Tree root parent pointer points to itself!\n");
} else {
ast_log(LOG_ERROR, "Tree root is not a root node!\n");
}
return -1;
}
if (self->root->is_red) {
/* Violation rbtree property 2. */
ast_log(LOG_ERROR, "Tree root is red!\n");
res = -1;
}
node = self->root;
do {
if (node->left) {
if (node->left == node) {
ast_log(LOG_ERROR, "Tree node's left pointer points to itself!\n");
return -1;
}
if (node->left->parent != node) {
ast_log(LOG_ERROR, "Tree node's left child does not link back!\n");
return -1;
}
}
if (node->right) {
if (node->right == node) {
ast_log(LOG_ERROR, "Tree node's right pointer points to itself!\n");
return -1;
}
if (node->right->parent != node) {
ast_log(LOG_ERROR, "Tree node's right child does not link back!\n");
return -1;
}
}
/* Check red/black node flags. */
if (node->is_red) {
/* A red node must have two black children or no children. */
if (node->left && node->right) {
/* Node has two children. */
if (node->left->is_red) {
/* Violation rbtree property 4. */
ast_log(LOG_ERROR, "Tree node is red and its left child is red!\n");
res = -1;
}
if (node->right->is_red) {
/* Violation rbtree property 4. */
ast_log(LOG_ERROR, "Tree node is red and its right child is red!\n");
res = -1;
}
} else if (node->left || node->right) {
/*
* Violation rbtree property 4 if the child is red.
* Violation rbtree property 5 if the child is black.
*/
ast_log(LOG_ERROR, "Tree node is red and it only has one child!\n");
res = -1;
}
} else {
/*
* A black node must have two children, or one red child, or no
* children. If the black node has two children and only one of
* them is red, that red child must have two children.
*/
if (node->left && node->right) {
/* Node has two children. */
if (node->left->is_red != node->right->is_red) {
/* The children are not the same color. */
struct rbtree_node *red;
if (node->left->is_red) {
red = node->left;
} else {
red = node->right;
}
if (!red->left || !red->right) {
/* Violation rbtree property 5. */
ast_log(LOG_ERROR,
"Tree node is black and the red child does not have two children!\n");
res = -1;
}
}
} else if ((node->left && !node->left->is_red)
|| (node->right && !node->right->is_red)) {
/* Violation rbtree property 5. */
ast_log(LOG_ERROR, "Tree node is black and its only child is black!\n");
res = -1;
}
}
/* Count nodes and objects. */
++count_node;
if (node->common.obj) {
++count_obj;
}
node = rb_node_pre(node);
} while (node);
/* Check node key sort order. */
obj_last = NULL;
for (node = rb_node_most_left(self->root); node; node = rb_node_next(node)) {
if (!node->common.obj) {
/* Node is empty. */
continue;
}
if (obj_last) {
if (self->common.sort_fn(obj_last, node->common.obj, OBJ_SEARCH_OBJECT) > 0) {
ast_log(LOG_ERROR, "Tree nodes are out of sorted order!\n");
return -1;
}
}
obj_last = node->common.obj;
}
/* Completely check property 5 */
if (!res && rb_check_black_height(self->root) < 0) {
/* Violation rbtree property 5. */
res = -1;
}
}
/* Check total obj count. */
if (count_obj != ao2_container_count(&self->common)) {
ast_log(LOG_ERROR, "Total object count does not match ao2_container_count()!\n");
return -1;
}
/* Check total node count. */
if (count_node != self->common.nodes) {
ast_log(LOG_ERROR, "Total node count of %d does not match stat of %d!\n",
count_node, self->common.nodes);
return -1;
}
return res;
}
#endif /* defined(AO2_DEBUG) */
/*! rbtree container virtual method table. */
static const struct ao2_container_methods v_table_rbtree = {
.alloc_empty_clone = (ao2_container_alloc_empty_clone_fn) rb_ao2_alloc_empty_clone,
.new_node = (ao2_container_new_node_fn) rb_ao2_new_node,
.insert = (ao2_container_insert_fn) rb_ao2_insert_node,
.traverse_first = (ao2_container_find_first_fn) rb_ao2_find_first,
.traverse_next = (ao2_container_find_next_fn) rb_ao2_find_next,
.iterator_next = (ao2_iterator_next_fn) rb_ao2_iterator_next,
.destroy = (ao2_container_destroy_fn) rb_ao2_destroy,
#if defined(AO2_DEBUG)
.dump = (ao2_container_display) rb_ao2_dump,
.stats = (ao2_container_statistics) rb_ao2_stats,
.integrity = (ao2_container_integrity) rb_ao2_integrity,
#endif /* defined(AO2_DEBUG) */
};
/*!
* \brief Initialize a rbtree container.
*
* \param self Container to initialize.
* \param options Container behaviour options (See enum ao2_container_opts)
* \param sort_fn Pointer to a sort function.
* \param cmp_fn Pointer to a compare function used by ao2_find.
*
* \return A pointer to a struct container.
*/
static struct ao2_container *rb_ao2_container_init(struct ao2_container_rbtree *self,
unsigned int options, ao2_sort_fn *sort_fn, ao2_callback_fn *cmp_fn)
{
if (!self) {
return NULL;
}
self->common.v_table = &v_table_rbtree;
self->common.sort_fn = sort_fn;
self->common.cmp_fn = cmp_fn;
self->common.options = options;
#ifdef AO2_DEBUG
ast_atomic_fetchadd_int(&ao2.total_containers, 1);
#endif /* defined(AO2_DEBUG) */
return (struct ao2_container *) self;
}
struct ao2_container *__ao2_container_alloc_rbtree(unsigned int ao2_options, unsigned int container_options,
ao2_sort_fn *sort_fn, ao2_callback_fn *cmp_fn,
const char *tag, const char *file, int line, const char *func)
{
struct ao2_container_rbtree *self;
if (!sort_fn) {
/* Sanity checks. */
ast_log(__LOG_ERROR, file, line, func, "Missing sort_fn()!\n");
return NULL;
}
self = __ao2_alloc(sizeof(*self), container_destruct, ao2_options,
tag ?: __PRETTY_FUNCTION__, file, line, func);
return rb_ao2_container_init(self, container_options, sort_fn, cmp_fn);
}