diff options
Diffstat (limited to 'main/astobj2_rbtree.c')
-rw-r--r-- | main/astobj2_rbtree.c | 2097 |
1 files changed, 2097 insertions, 0 deletions
diff --git a/main/astobj2_rbtree.c b/main/astobj2_rbtree.c new file mode 100644 index 000000000..3b69ce347 --- /dev/null +++ b/main/astobj2_rbtree.c @@ -0,0 +1,2097 @@ +/* + * 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" + +ASTERISK_FILE_VERSION(__FILE__, "$Revision$") + +#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(AST_DEVMODE) + 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(AST_DEVMODE) */ +}; + +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. + * + * \retval 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. + * + * \retval 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. + * + * \retval 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. + * + * \retval 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. + * + * \retval 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. + * + * \retval 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 enum 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. + * + * \return Nothing + */ +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. + * + * \return Nothing + */ +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. + * \since 12.0.0 + * + * \param self Container to operate upon. + * + * \retval empty-clone-container on success. + * \retval NULL on error. + */ +static struct ao2_container *rb_ao2_alloc_empty_clone(struct ao2_container_rbtree *self) +{ + if (!is_ao2_object(self)) { + return NULL; + } + + return ao2_t_container_alloc_rbtree(ao2_options_get(self), self->common.options, + self->common.sort_fn, self->common.cmp_fn, "Clone rbtree container"); +} + +/*! + * \internal + * \brief Create an empty copy of this container. (Debug version) + * \since 12.0.0 + * + * \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 + * \param ref_debug TRUE if to output a debug reference message. + * + * \retval empty-clone-container on success. + * \retval NULL on error. + */ +static struct ao2_container *rb_ao2_alloc_empty_clone_debug(struct ao2_container_rbtree *self, const char *tag, const char *file, int line, const char *func, int ref_debug) +{ + if (!is_ao2_object(self)) { + return NULL; + } + + return __ao2_container_alloc_rbtree_debug(ao2_options_get(self), self->common.options, + self->common.sort_fn, self->common.cmp_fn, tag, file, line, func, ref_debug); +} + +/*! + * \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. + * + * \return Nothing + */ +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. + * + * \return Nothing + */ +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. + * + * \return Nothing + */ +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; + __adjust_lock(my_container, AO2_LOCK_REQ_WRLOCK, 1); + +#if defined(AO2_DEBUG) && defined(AST_DEVMODE) + 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) && defined(AST_DEVMODE) */ + rb_delete_node(my_container, doomed); +#if defined(AO2_DEBUG) && defined(AST_DEVMODE) + 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) && defined(AST_DEVMODE) */ + } + + /* + * 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) { + ao2_t_ref(doomed->common.obj, -1, "Container node destruction"); + doomed->common.obj = NULL; + } +} + +/*! + * \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 + * + * \retval 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(sizeof(*node), rb_ao2_node_destructor, AO2_ALLOC_OPT_LOCK_NOLOCK); + if (!node) { + return NULL; + } + + if (tag) { + __ao2_ref_debug(obj_new, +1, tag, file, line, func); + } else { + ao2_t_ref(obj_new, +1, "Container node creation"); + } + 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. + * + * \return Nothing + */ +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 enum 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 dupliate */ + 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); + 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. + * + * \retval 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 + * + * \retval 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. + * + * \retval 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. + * + * \retval 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. + * + * \return Nothing + */ +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(AST_DEVMODE) +/*! + * \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) + * + * \return Nothing + */ +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(AST_DEVMODE) */ + +#if defined(AST_DEVMODE) +/*! + * \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. + * + * \return Nothing + */ +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(AST_DEVMODE) */ + +#if defined(AST_DEVMODE) +/*! + * \internal + * \brief Check the black height of the given node. + * \since 12.0.0 + * + * \param node Node to check black height. + * + * \retval 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(AST_DEVMODE) */ + +#if defined(AST_DEVMODE) +/*! + * \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(AST_DEVMODE) */ + +/*! rbtree container virtual method table. */ +static const struct ao2_container_methods v_table_rbtree = { + .type = AO2_CONTAINER_RTTI_RBTREE, + .alloc_empty_clone = (ao2_container_alloc_empty_clone_fn) rb_ao2_alloc_empty_clone, + .alloc_empty_clone_debug = + (ao2_container_alloc_empty_clone_debug_fn) rb_ao2_alloc_empty_clone_debug, + .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(AST_DEVMODE) + .dump = (ao2_container_display) rb_ao2_dump, + .stats = (ao2_container_statistics) rb_ao2_stats, + .integrity = (ao2_container_integrity) rb_ao2_integrity, +#endif /* defined(AST_DEVMODE) */ +}; + +/*! + * \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 + + 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) +{ + struct ao2_container_rbtree *self; + + if (!sort_fn) { + /* Sanity checks. */ + ast_log(LOG_ERROR, "Missing sort_fn()!\n"); + return NULL; + } + + self = ao2_t_alloc_options(sizeof(*self), container_destruct, ao2_options, + "New rbtree container"); + return rb_ao2_container_init(self, container_options, sort_fn, cmp_fn); +} + +struct ao2_container *__ao2_container_alloc_rbtree_debug(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, int ref_debug) +{ + 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_debug(sizeof(*self), + ref_debug ? container_destruct_debug : container_destruct, ao2_options, + tag, file, line, func, ref_debug); + return rb_ao2_container_init(self, container_options, sort_fn, cmp_fn); +} + |