toolkit: comparison ucx/cx/tree.h

-:fe49cff3c571
+:bb7da585debc
+/*
+* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+*
+* Copyright 2024 Mike Becker, Olaf Wintermann All rights reserved.
+*
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions are met:
+*
+*   1. Redistributions of source code must retain the above copyright
+*      notice, this list of conditions and the following disclaimer.
+*
+*   2. Redistributions in binary form must reproduce the above copyright
+*      notice, this list of conditions and the following disclaimer in the
+*      documentation and/or other materials provided with the distribution.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+* POSSIBILITY OF SUCH DAMAGE.
+*/
+/**
+* \file tree.h
+* \brief Interface for tree implementations.
+* \author Mike Becker
+* \author Olaf Wintermann
+* \copyright 2-Clause BSD License
+*/
+#ifndef UCX_TREE_H
+#define UCX_TREE_H
+#include "common.h"
+#include "collection.h"
+#ifdef __cplusplus
+extern "C" {
+#endif
+/**
+* A depth-first tree iterator.
+*
+* This iterator is not position-aware in a strict sense, as it does not assume
+* a particular order of elements in the tree. However, the iterator keeps track
+* of the number of nodes it has passed in a counter variable.
+* Each node, regardless of the number of passes, is counted only once.
+*
+* @note Objects that are pointed to by an iterator are mutable through that
+* iterator. However, if the
+* underlying data structure is mutated by other means than this iterator (e.g.
+* elements added or removed), the iterator becomes invalid (regardless of what
+* cxIteratorValid() returns).
+*
+* @see CxIterator
+*/
+typedef struct cx_tree_iterator_s {
+/**
+* Base members.
+*/
+CX_ITERATOR_BASE;
+/**
+* Indicates whether the subtree below the current node shall be skipped.
+*/
+bool skip;
+/**
+* Set to true, when the iterator shall visit a node again
+* when all it's children have been processed.
+*/
+bool visit_on_exit;
+/**
+* True, if this iterator is currently leaving the node.
+*/
+bool exiting;
+/**
+* Offset in the node struct for the children linked list.
+*/
+ptrdiff_t loc_children;
+/**
+* Offset in the node struct for the next pointer.
+*/
+ptrdiff_t loc_next;
+/**
+* The total number of distinct nodes that have been passed so far.
+*/
+size_t counter;
+/**
+* The currently observed node.
+*
+* This is the same what cxIteratorCurrent() would return.
+*/
+void *node;
+/**
+* Stores a copy of the next pointer of the visited node.
+* Allows freeing a node on exit without corrupting the iteration.
+*/
+void *node_next;
+/**
+* Internal stack.
+* Will be automatically freed once the iterator becomes invalid.
+*
+* If you want to discard the iterator before, you need to manually
+* call cxTreeIteratorDispose().
+*/
+void **stack;
+/**
+* Internal capacity of the stack.
+*/
+size_t stack_capacity;
+union {
+/**
+* Internal stack size.
+*/
+size_t stack_size;
+/**
+* The current depth in the tree.
+*/
+size_t depth;
+};
+} CxTreeIterator;
+/**
+* An element in a visitor queue.
+*/
+struct cx_tree_visitor_queue_s {
+/**
+* The tree node to visit.
+*/
+void *node;
+/**
+* The depth of the node.
+*/
+size_t depth;
+/**
+* The next element in the queue or \c NULL.
+*/
+struct cx_tree_visitor_queue_s *next;
+};
+/**
+* A breadth-first tree iterator.
+*
+* This iterator needs to maintain a visitor queue that will be automatically
+* freed once the iterator becomes invalid.
+* If you want to discard the iterator before, you MUST manually call
+* cxTreeVisitorDispose().
+*
+* This iterator is not position-aware in a strict sense, as it does not assume
+* a particular order of elements in the tree. However, the iterator keeps track
+* of the number of nodes it has passed in a counter variable.
+* Each node, regardless of the number of passes, is counted only once.
+*
+* @note Objects that are pointed to by an iterator are mutable through that
+* iterator. However, if the
+* underlying data structure is mutated by other means than this iterator (e.g.
+* elements added or removed), the iterator becomes invalid (regardless of what
+* cxIteratorValid() returns).
+*
+* @see CxIterator
+*/
+typedef struct cx_tree_visitor_s {
+/**
+* Base members.
+*/
+CX_ITERATOR_BASE;
+/**
+* Indicates whether the subtree below the current node shall be skipped.
+*/
+bool skip;
+/**
+* Offset in the node struct for the children linked list.
+*/
+ptrdiff_t loc_children;
+/**
+* Offset in the node struct for the next pointer.
+*/
+ptrdiff_t loc_next;
+/**
+* The total number of distinct nodes that have been passed so far.
+*/
+size_t counter;
+/**
+* The currently observed node.
+*
+* This is the same what cxIteratorCurrent() would return.
+*/
+void *node;
+/**
+* The current depth in the tree.
+*/
+size_t depth;
+/**
+* The next element in the visitor queue.
+*/
+struct cx_tree_visitor_queue_s *queue_next;
+/**
+* The last element in the visitor queue.
+*/
+struct cx_tree_visitor_queue_s *queue_last;
+} CxTreeVisitor;
+/**
+* Releases internal memory of the given tree iterator.
+* @param iter the iterator
+*/
+__attribute__((__nonnull__))
+static inline void cxTreeIteratorDispose(CxTreeIterator *iter) {
+free(iter->stack);
+iter->stack = NULL;
+}
+/**
+* Releases internal memory of the given tree visitor.
+* @param visitor the visitor
+*/
+__attribute__((__nonnull__))
+static inline void cxTreeVisitorDispose(CxTreeVisitor *visitor) {
+struct cx_tree_visitor_queue_s *q = visitor->queue_next;
+while (q != NULL) {
+struct cx_tree_visitor_queue_s *next = q->next;
+free(q);
+q = next;
+}
+}
+/**
+* Advises the iterator to skip the subtree below the current node and
+* also continues the current loop.
+*
+* @param iterator the iterator
+*/
+#define cxTreeIteratorContinue(iterator) (iterator).skip = true; continue
+/**
+* Advises the visitor to skip the subtree below the current node and
+* also continues the current loop.
+*
+* @param visitor the visitor
+*/
+#define cxTreeVisitorContinue(visitor) cxTreeIteratorContinue(visitor)
+/**
+* Links a node to a (new) parent.
+*
+* If the node has already a parent, it is unlinked, first.
+* If the parent has children already, the node is \em appended to the list
+* of all currently existing children.
+*
+* @param parent the parent node
+* @param node the node that shall be linked
+* @param loc_parent offset in the node struct for the parent pointer
+* @param loc_children offset in the node struct for the children linked list
+* @param loc_last_child optional offset in the node struct for the pointer to
+* the last child in the linked list (negative if there is no such pointer)
+* @param loc_prev offset in the node struct for the prev pointer
+* @param loc_next offset in the node struct for the next pointer
+* @see cx_tree_unlink()
+*/
+__attribute__((__nonnull__))
+void cx_tree_link(
+void *restrict parent,
+void *restrict node,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+);
+/**
+* Unlinks a node from its parent.
+*
+* If the node has no parent, this function does nothing.
+*
+* @param node the node that shall be unlinked from its parent
+* @param loc_parent offset in the node struct for the parent pointer
+* @param loc_children offset in the node struct for the children linked list
+* @param loc_last_child optional offset in the node struct for the pointer to
+* the last child in the linked list (negative if there is no such pointer)
+* @param loc_prev offset in the node struct for the prev pointer
+* @param loc_next offset in the node struct for the next pointer
+* @see cx_tree_link()
+*/
+__attribute__((__nonnull__))
+void cx_tree_unlink(
+void *node,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+);
+/**
+* Function pointer for a search function.
+*
+* A function of this kind shall check if the specified \p node
+* contains the given \p data or if one of the children might contain
+* the data.
+*
+* The function should use the returned integer to indicate how close the
+* match is, where a negative number means that it does not match at all.
+*
+* For example if a tree stores file path information, a node that is
+* describing a parent directory of a filename that is searched, shall
+* return a positive number to indicate that a child node might contain the
+* searched item. On the other hand, if the node denotes a path that is not a
+* prefix of the searched filename, the function would return -1 to indicate
+* that the search does not need to be continued in that branch.
+*
+* @param node the node that is currently investigated
+* @param data the data that is searched for
+*
+* @return 0 if the node contains the data,
+* positive if one of the children might contain the data,
+* negative if neither the node, nor the children contains the data
+*/
+typedef int (*cx_tree_search_data_func)(const void *node, const void *data);
+/**
+* Function pointer for a search function.
+*
+* A function of this kind shall check if the specified \p node
+* contains the same \p data as \p new_node or if one of the children might
+* contain the data.
+*
+* The function should use the returned integer to indicate how close the
+* match is, where a negative number means that it does not match at all.
+*
+* For example if a tree stores file path information, a node that is
+* describing a parent directory of a filename that is searched, shall
+* return a positive number to indicate that a child node might contain the
+* searched item. On the other hand, if the node denotes a path that is not a
+* prefix of the searched filename, the function would return -1 to indicate
+* that the search does not need to be continued in that branch.
+*
+* @param node the node that is currently investigated
+* @param new_node a new node with the information which is searched
+*
+* @return 0 if \p node contains the same data as \p new_node,
+* positive if one of the children might contain the data,
+* negative if neither the node, nor the children contains the data
+*/
+typedef int (*cx_tree_search_func)(const void *node, const void *new_node);
+/**
+* Searches for data in a tree.
+*
+* When the data cannot be found exactly, the search function might return a
+* closest result which might be a good starting point for adding a new node
+* to the tree (see also #cx_tree_add()).
+*
+* Depending on the tree structure it is not necessarily guaranteed that the
+* "closest" match is uniquely defined. This function will search for a node
+* with the best match according to the \p sfunc (meaning: the return value of
+* \p sfunc which is closest to zero). If that is also ambiguous, an arbitrary
+* node matching the criteria is returned.
+*
+* @param root the root node
+* @param data the data to search for
+* @param sfunc the search function
+* @param result where the result shall be stored
+* @param loc_children offset in the node struct for the children linked list
+* @param loc_next offset in the node struct for the next pointer
+* @return zero if the node was found exactly, positive if a node was found that
+* could contain the node (but doesn't right now), negative if the tree does not
+* contain any node that might be related to the searched data
+*/
+__attribute__((__nonnull__))
+int cx_tree_search_data(
+const void *root,
+const void *data,
+cx_tree_search_data_func sfunc,
+void **result,
+ptrdiff_t loc_children,
+ptrdiff_t loc_next
+);
+/**
+* Searches for a node in a tree.
+*
+* When no node with the same data can be found, the search function might
+* return a closest result which might be a good starting point for adding the
+* new node to the tree (see also #cx_tree_add()).
+*
+* Depending on the tree structure it is not necessarily guaranteed that the
+* "closest" match is uniquely defined. This function will search for a node
+* with the best match according to the \p sfunc (meaning: the return value of
+* \p sfunc which is closest to zero). If that is also ambiguous, an arbitrary
+* node matching the criteria is returned.
+*
+* @param root the root node
+* @param node the node to search for
+* @param sfunc the search function
+* @param result where the result shall be stored
+* @param loc_children offset in the node struct for the children linked list
+* @param loc_next offset in the node struct for the next pointer
+* @return zero if the node was found exactly, positive if a node was found that
+* could contain the node (but doesn't right now), negative if the tree does not
+* contain any node that might be related to the searched data
+*/
+__attribute__((__nonnull__))
+int cx_tree_search(
+const void *root,
+const void *node,
+cx_tree_search_func sfunc,
+void **result,
+ptrdiff_t loc_children,
+ptrdiff_t loc_next
+);
+/**
+* Creates a depth-first iterator for a tree with the specified root node.
+*
+* @note A tree iterator needs to maintain a stack of visited nodes, which is
+* allocated using stdlib malloc().
+* When the iterator becomes invalid, this memory is automatically released.
+* However, if you wish to cancel the iteration before the iterator becomes
+* invalid by itself, you MUST call cxTreeIteratorDispose() manually to release
+* the memory.
+*
+* @remark The returned iterator does not support cxIteratorFlagRemoval().
+*
+* @param root the root node
+* @param visit_on_exit set to true, when the iterator shall visit a node again
+* after processing all children
+* @param loc_children offset in the node struct for the children linked list
+* @param loc_next offset in the node struct for the next pointer
+* @return the new tree iterator
+* @see cxTreeIteratorDispose()
+*/
+CxTreeIterator cx_tree_iterator(
+void *root,
+bool visit_on_exit,
+ptrdiff_t loc_children,
+ptrdiff_t loc_next
+);
+/**
+* Creates a breadth-first iterator for a tree with the specified root node.
+*
+* @note A tree visitor needs to maintain a queue of to be visited nodes, which
+* is allocated using stdlib malloc().
+* When the visitor becomes invalid, this memory is automatically released.
+* However, if you wish to cancel the iteration before the visitor becomes
+* invalid by itself, you MUST call cxTreeVisitorDispose() manually to release
+* the memory.
+*
+* @remark The returned iterator does not support cxIteratorFlagRemoval().
+*
+* @param root the root node
+* @param loc_children offset in the node struct for the children linked list
+* @param loc_next offset in the node struct for the next pointer
+* @return the new tree visitor
+* @see cxTreeVisitorDispose()
+*/
+CxTreeVisitor cx_tree_visitor(
+void *root,
+ptrdiff_t loc_children,
+ptrdiff_t loc_next
+);
+/**
+* Describes a function that creates a tree node from the specified data.
+* The first argument points to the data the node shall contain and
+* the second argument may be used for additional data (e.g. an allocator).
+* Functions of this type shall either return a new pointer to a newly
+* created node or \c NULL when allocation fails.
+*
+* \note the function may leave the node pointers in the struct uninitialized.
+* The caller is responsible to set them according to the intended use case.
+*/
+typedef void *(*cx_tree_node_create_func)(const void *, void *);
+/**
+* The local search depth for a new subtree when adding multiple elements.
+* The default value is 3.
+* This variable is used by #cx_tree_add_array() and #cx_tree_add_iter() to
+* implement optimized insertion of multiple elements into a tree.
+*/
+extern unsigned int cx_tree_add_look_around_depth;
+/**
+* Adds multiple elements efficiently to a tree.
+*
+* Once an element cannot be added to the tree, this function returns, leaving
+* the iterator in a valid state pointing to the element that could not be
+* added.
+* Also, the pointer of the created node will be stored to \p failed.
+* The integer returned by this function denotes the number of elements obtained
+* from the \p iter that have been successfully processed.
+* When all elements could be processed, a \c NULL pointer will be written to
+* \p failed.
+*
+* The advantage of this function compared to multiple invocations of
+* #cx_tree_add() is that the search for the insert locations is not always
+* started from the root node.
+* Instead, the function checks #cx_tree_add_look_around_depth many parent nodes
+* of the current insert location before starting from the root node again.
+* When the variable is set to zero, only the last found location is checked
+* again.
+*
+* Refer to the documentation of #cx_tree_add() for more details.
+*
+* @param iter a pointer to an arbitrary iterator
+* @param num the maximum number of elements to obtain from the iterator
+* @param sfunc a search function
+* @param cfunc a node creation function
+* @param cdata optional additional data
+* @param root the root node of the tree
+* @param failed location where the pointer to a failed node shall be stored
+* @param loc_parent offset in the node struct for the parent pointer
+* @param loc_children offset in the node struct for the children linked list
+* @param loc_last_child optional offset in the node struct for the pointer to
+* the last child in the linked list (negative if there is no such pointer)
+* @param loc_prev offset in the node struct for the prev pointer
+* @param loc_next offset in the node struct for the next pointer
+* @return the number of nodes created and added
+* @see cx_tree_add()
+*/
+__attribute__((__nonnull__(1, 3, 4, 6, 7)))
+size_t cx_tree_add_iter(
+struct cx_iterator_base_s *iter,
+size_t num,
+cx_tree_search_func sfunc,
+cx_tree_node_create_func cfunc,
+void *cdata,
+void **failed,
+void *root,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+);
+/**
+* Adds multiple elements efficiently to a tree.
+*
+* Once an element cannot be added to the tree, this function returns, storing
+* the pointer of the created node to \p failed.
+* The integer returned by this function denotes the number of elements from
+* the \p src array that have been successfully processed.
+* When all elements could be processed, a \c NULL pointer will be written to
+* \p failed.
+*
+* The advantage of this function compared to multiple invocations of
+* #cx_tree_add() is that the search for the insert locations is not always
+* started from the root node.
+* Instead, the function checks #cx_tree_add_look_around_depth many parent nodes
+* of the current insert location before starting from the root node again.
+* When the variable is set to zero, only the last found location is checked
+* again.
+*
+* Refer to the documentation of #cx_tree_add() for more details.
+*
+* @param src a pointer to the source data array
+* @param num the number of elements in the \p src array
+* @param elem_size the size of each element in the \p src array
+* @param sfunc a search function
+* @param cfunc a node creation function
+* @param cdata optional additional data
+* @param failed location where the pointer to a failed node shall be stored
+* @param root the root node of the tree
+* @param loc_parent offset in the node struct for the parent pointer
+* @param loc_children offset in the node struct for the children linked list
+* @param loc_last_child optional offset in the node struct for the pointer to
+* the last child in the linked list (negative if there is no such pointer)
+* @param loc_prev offset in the node struct for the prev pointer
+* @param loc_next offset in the node struct for the next pointer
+* @return the number of array elements successfully processed
+* @see cx_tree_add()
+*/
+__attribute__((__nonnull__(1, 4, 5, 7, 8)))
+size_t cx_tree_add_array(
+const void *src,
+size_t num,
+size_t elem_size,
+cx_tree_search_func sfunc,
+cx_tree_node_create_func cfunc,
+void *cdata,
+void **failed,
+void *root,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+);
+/**
+* Adds data to a tree.
+*
+* An adequate location where to add the new tree node is searched with the
+* specified \p sfunc.
+*
+* When a location is found, the \p cfunc will be invoked with \p cdata.
+*
+* The node returned by \p cfunc will be linked into the tree.
+* When \p sfunc returned a positive integer, the new node will be linked as a
+* child. The other children (now siblings of the new node) are then checked
+* with \p sfunc, whether they could be children of the new node and re-linked
+* accordingly.
+*
+* When \p sfunc returned zero and the found node has a parent, the new
+* node will be added as sibling - otherwise, the new node will be added
+* as a child.
+*
+* When \p sfunc returned a negative value, the new node will not be added to
+* the tree and this function returns a non-zero value.
+* The caller should check if \p cnode contains a node pointer and deal with the
+* node that could not be added.
+*
+* This function also returns a non-zero value when \p cfunc tries to allocate
+* a new node but fails to do so. In that case, the pointer stored to \p cnode
+* will be \c NULL.
+*
+* Multiple elements can be added more efficiently with
+* #cx_tree_add_array() or #cx_tree_add_iter().
+*
+* @param src a pointer to the data
+* @param sfunc a search function
+* @param cfunc a node creation function
+* @param cdata optional additional data
+* @param cnode the location where a pointer to the new node is stored
+* @param root the root node of the tree
+* @param loc_parent offset in the node struct for the parent pointer
+* @param loc_children offset in the node struct for the children linked list
+* @param loc_last_child optional offset in the node struct for the pointer to
+* the last child in the linked list (negative if there is no such pointer)
+* @param loc_prev offset in the node struct for the prev pointer
+* @param loc_next offset in the node struct for the next pointer
+* @return zero when a new node was created and added to the tree,
+* non-zero otherwise
+*/
+__attribute__((__nonnull__(1, 2, 3, 5, 6)))
+int cx_tree_add(
+const void *src,
+cx_tree_search_func sfunc,
+cx_tree_node_create_func cfunc,
+void *cdata,
+void **cnode,
+void *root,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+);
+/**
+* Tree class type.
+*/
+typedef struct cx_tree_class_s cx_tree_class;
+/**
+* Base structure that can be used for tree nodes in a #CxTree.
+*/
+struct cx_tree_node_base_s {
+/**
+* Pointer to the parent.
+*/
+struct cx_tree_node_base_s *parent;
+/**
+* Pointer to the first child.
+*/
+struct cx_tree_node_base_s *children;
+/**
+* Pointer to the last child.
+*/
+struct cx_tree_node_base_s *last_child;
+/**
+* Pointer to the previous sibling.
+*/
+struct cx_tree_node_base_s *prev;
+/**
+* Pointer to the next sibling.
+*/
+struct cx_tree_node_base_s *next;
+};
+/**
+* Structure for holding the base data of a tree.
+*/
+struct cx_tree_s {
+/**
+* The tree class definition.
+*/
+const cx_tree_class *cl;
+/**
+* Allocator to allocate new nodes.
+*/
+const CxAllocator *allocator;
+/**
+* A pointer to the root node.
+*
+* Will be \c NULL when \c size is 0.
+*/
+void *root;
+/**
+* A function to create new nodes.
+*
+* Invocations to this function will receive a pointer to this tree
+* structure as second argument.
+*
+* Nodes MAY use #cx_tree_node_base_s as base layout, but do not need to.
+*/
+cx_tree_node_create_func node_create;
+/**
+* An optional simple destructor for the tree nodes.
+*/
+cx_destructor_func simple_destructor;
+/**
+* An optional advanced destructor for the tree nodes.
+*/
+cx_destructor_func2 advanced_destructor;
+/**
+* The pointer to additional data that is passed to the advanced destructor.
+*/
+void *destructor_data;
+/**
+* A function to compare two nodes.
+*/
+cx_tree_search_func search;
+/**
+* A function to compare a node with data.
+*/
+cx_tree_search_data_func search_data;
+/**
+* The number of currently stored elements.
+*/
+size_t size;
+/**
+* Offset in the node struct for the parent pointer.
+*/
+ptrdiff_t loc_parent;
+/**
+* Offset in the node struct for the children linked list.
+*/
+ptrdiff_t loc_children;
+/**
+* Optional offset in the node struct for the pointer to the last child
+* in the linked list (negative if there is no such pointer).
+*/
+ptrdiff_t loc_last_child;
+/**
+* Offset in the node struct for the previous sibling pointer.
+*/
+ptrdiff_t loc_prev;
+/**
+* Offset in the node struct for the next sibling pointer.
+*/
+ptrdiff_t loc_next;
+};
+/**
+* Macro to roll out the #cx_tree_node_base_s structure with a custom
+* node type.
+*/
+#define CX_TREE_NODE_BASE(type) \
+type *parent; \
+type *children;\
+type *last_child;\
+type *prev;\
+type *next
+/**
+* Macro for specifying the layout of a base node tree.
+*/
+#define cx_tree_node_base_layout \
+offsetof(struct cx_tree_node_base_s, parent),\
+offsetof(struct cx_tree_node_base_s, children),\
+offsetof(struct cx_tree_node_base_s, last_child),\
+offsetof(struct cx_tree_node_base_s, prev),  \
+offsetof(struct cx_tree_node_base_s, next)
+/**
+* Macro for obtaining the node pointer layout for a specific tree.
+*/
+#define cx_tree_node_layout(tree) \
+(tree)->loc_parent,\
+(tree)->loc_children,\
+(tree)->loc_last_child,\
+(tree)->loc_prev,  \
+(tree)->loc_next
+/**
+* The class definition for arbitrary trees.
+*/
+struct cx_tree_class_s {
+/**
+* Destructor function.
+*
+* Implementations SHALL invoke the node destructor functions if provided
+* and SHALL deallocate the tree memory.
+*/
+void (*destructor)(struct cx_tree_s *);
+/**
+* Member function for inserting a single element.
+*
+* Implementations SHALL NOT simply invoke \p insert_many as this comes
+* with too much overhead.
+*/
+int (*insert_element)(
+struct cx_tree_s *tree,
+const void *data
+);
+/**
+* Member function for inserting multiple elements.
+*
+* Implementations SHALL avoid to perform a full search in the tree for
+* every element even though the source data MAY be unsorted.
+*/
+size_t (*insert_many)(
+struct cx_tree_s *tree,
+struct cx_iterator_base_s *iter,
+size_t n
+);
+/**
+* Member function for finding a node.
+*/
+void *(*find)(
+struct cx_tree_s *tree,
+const void *subtree,
+const void *data
+);
+/**
+* Member function for creating an iterator for the tree.
+*/
+CxTreeIterator (*iterator)(
+struct cx_tree_s *tree,
+bool visit_on_exit
+);
+/**
+* Member function for creating a visitor for the tree.
+*/
+CxTreeVisitor (*visitor)(struct cx_tree_s *tree);
+};
+/**
+* Common type for all tree implementations.
+*/
+typedef struct cx_tree_s CxTree;
+/**
+* Creates a new tree structure based on the specified layout.
+*
+* The specified \p allocator will be used for creating the tree struct
+* and SHALL be used by \p create_func to allocate memory for the nodes.
+*
+* \note This function will also register an advanced destructor which
+* will free the nodes with the allocator's free() method.
+*
+* @param allocator the allocator that shall be used
+* @param create_func a function that creates new nodes
+* @param search_func a function that compares two nodes
+* @param search_data_func a function that compares a node with data
+* @param loc_parent offset in the node struct for the parent pointer
+* @param loc_children offset in the node struct for the children linked list
+* @param loc_last_child optional offset in the node struct for the pointer to
+* the last child in the linked list (negative if there is no such pointer)
+* @param loc_prev offset in the node struct for the prev pointer
+* @param loc_next offset in the node struct for the next pointer
+* @return the new tree
+* @see cxTreeCreateSimple()
+* @see cxTreeCreateWrapped()
+*/
+__attribute__((__nonnull__, __warn_unused_result__))
+CxTree *cxTreeCreate(
+const CxAllocator *allocator,
+cx_tree_node_create_func create_func,
+cx_tree_search_func search_func,
+cx_tree_search_data_func search_data_func,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+);
+/**
+* Creates a new tree structure based on a default layout.
+*
+* Nodes created by \p create_func MUST contain #cx_tree_node_base_s as first
+* member (or at least respect the default offsets specified in the tree
+* struct) and they MUST be allocated with the specified allocator.
+*
+* \note This function will also register an advanced destructor which
+* will free the nodes with the allocator's free() method.
+*
+* @param allocator the allocator that shall be used
+* @param create_func a function that creates new nodes
+* @param search_func a function that compares two nodes
+* @param search_data_func a function that compares a node with data
+* @return the new tree
+* @see cxTreeCreate()
+*/
+__attribute__((__nonnull__, __warn_unused_result__))
+static inline CxTree *cxTreeCreateSimple(
+const CxAllocator *allocator,
+cx_tree_node_create_func create_func,
+cx_tree_search_func search_func,
+cx_tree_search_data_func search_data_func
+) {
+return cxTreeCreate(
+allocator,
+create_func,
+search_func,
+search_data_func,
+cx_tree_node_base_layout
+);
+}
+/**
+* Creates a new tree structure based on an existing tree.
+*
+* The specified \p allocator will be used for creating the tree struct.
+*
+* \attention This function will create an incompletely defined tree structure
+* where neither the create function, the search function, nor a destructor
+* will be set. If you wish to use any of this functionality for the wrapped
+* tree, you need to specify those functions afterwards.
+*
+* @param root the root node of the tree that shall be wrapped
+* @param loc_parent offset in the node struct for the parent pointer
+* @param loc_children offset in the node struct for the children linked list
+* @param loc_last_child optional offset in the node struct for the pointer to
+* the last child in the linked list (negative if there is no such pointer)
+* @param loc_prev offset in the node struct for the prev pointer
+* @param loc_next offset in the node struct for the next pointer
+* @return the new tree
+* @see cxTreeCreate()
+*/
+__attribute__((__nonnull__, __warn_unused_result__))
+CxTree *cxTreeCreateWrapped(
+const CxAllocator *allocator,
+void *root,
+ptrdiff_t loc_parent,
+ptrdiff_t loc_children,
+ptrdiff_t loc_last_child,
+ptrdiff_t loc_prev,
+ptrdiff_t loc_next
+);
+/**
+* Destroys the tree structure.
+*
+* \attention This function will only invoke the destructor functions
+* on the nodes, if specified.
+* It will NOT additionally free the nodes with the tree's allocator, because
+* that would cause a double-free in most scenarios.
+*
+* @param tree the tree to destroy
+*/
+__attribute__((__nonnull__))
+static inline void cxTreeDestroy(CxTree *tree) {
+tree->cl->destructor(tree);
+}
+/**
+* Inserts data into the tree.
+*
+* \remark For this function to work, the tree needs specified search and
+* create functions, which might not be available for wrapped trees
+* (see #cxTreeCreateWrapped()).
+*
+* @param tree the tree
+* @param data the data to insert
+* @return zero on success, non-zero on failure
+*/
+__attribute__((__nonnull__))
+static inline int cxTreeInsert(
+CxTree *tree,
+const void *data
+) {
+return tree->cl->insert_element(tree, data);
+}
+/**
+* Inserts elements provided by an iterator efficiently into the tree.
+*
+* \remark For this function to work, the tree needs specified search and
+* create functions, which might not be available for wrapped trees
+* (see #cxTreeCreateWrapped()).
+*
+* @param tree the tree
+* @param iter the iterator providing the elements
+* @param n the maximum number of elements to insert
+* @return the number of elements that could be successfully inserted
+*/
+__attribute__((__nonnull__))
+static inline size_t cxTreeInsertIter(
+CxTree *tree,
+struct cx_iterator_base_s *iter,
+size_t n
+) {
+return tree->cl->insert_many(tree, iter, n);
+}
+/**
+* Inserts an array of data efficiently into the tree.
+*
+* \remark For this function to work, the tree needs specified search and
+* create functions, which might not be available for wrapped trees
+* (see #cxTreeCreateWrapped()).
+*
+* @param tree the tree
+* @param data the array of data to insert
+* @param elem_size the size of each element in the array
+* @param n the number of elements in the array
+* @return the number of elements that could be successfully inserted
+*/
+__attribute__((__nonnull__))
+static inline size_t cxTreeInsertArray(
+CxTree *tree,
+const void *data,
+size_t elem_size,
+size_t n
+) {
+if (n == 0) return 0;
+if (n == 1) return 0 == cxTreeInsert(tree, data) ? 1 : 0;
+CxIterator iter = cxIterator(data, elem_size, n);
+return cxTreeInsertIter(tree, cxIteratorRef(iter), n);
+}
+/**
+* Searches the data in the specified tree.
+*
+* \remark For this function to work, the tree needs a specified \c search_data
+* function, which might not be available wrapped trees
+* (see #cxTreeCreateWrapped()).
+*
+* @param tree the tree
+* @param data the data to search for
+* @return the first matching node, or \c NULL when the data cannot be found
+*/
+__attribute__((__nonnull__))
+static inline void *cxTreeFind(
+CxTree *tree,
+const void *data
+) {
+return tree->cl->find(tree, tree->root, data);
+}
+/**
+* Searches the data in the specified subtree.
+*
+* \note When \p subtree_root is not part of the \p tree, the behavior is
+* undefined.
+*
+* \remark For this function to work, the tree needs a specified \c search_data
+* function, which might not be the case for wrapped trees
+* (see #cxTreeCreateWrapped()).
+*
+* @param tree the tree
+* @param data the data to search for
+* @param subtree_root the node where to start
+* @return the first matching node, or \c NULL when the data cannot be found
+*/
+__attribute__((__nonnull__))
+static inline void *cxTreeFindInSubtree(
+CxTree *tree,
+const void *data,
+void *subtree_root
+) {
+return tree->cl->find(tree, subtree_root, data);
+}
+/**
+* Determines the size of the specified subtree.
+*
+* @param tree the tree
+* @param subtree_root the root node of the subtree
+* @return the number of nodes in the specified subtree
+*/
+__attribute__((__nonnull__))
+size_t cxTreeSubtreeSize(CxTree *tree, void *subtree_root);
+/**
+* Determines the depth of the specified subtree.
+*
+* @param tree the tree
+* @param subtree_root the root node of the subtree
+* @return the tree depth including the \p subtree_root
+*/
+__attribute__((__nonnull__))
+size_t cxTreeSubtreeDepth(CxTree *tree, void *subtree_root);
+/**
+* Determines the depth of the entire tree.
+*
+* @param tree the tree
+* @return the tree depth, counting the root as one
+*/
+__attribute__((__nonnull__))
+size_t cxTreeDepth(CxTree *tree);
+/**
+* Creates a depth-first iterator for the specified tree.
+*
+* @param tree the tree to iterate
+* @param visit_on_exit true, if the iterator shall visit a node again when
+* leaving the sub-tree
+* @return a tree iterator (depth-first)
+* @see cxTreeVisitor()
+*/
+__attribute__((__nonnull__, __warn_unused_result__))
+static inline CxTreeIterator cxTreeIterator(
+CxTree *tree,
+bool visit_on_exit
+) {
+return tree->cl->iterator(tree, visit_on_exit);
+}
+/**
+* Creates a breadth-first iterator for the specified tree.
+*
+* @param tree the tree to iterate
+* @return a tree visitor (a.k.a. breadth-first iterator)
+* @see cxTreeIterator()
+*/
+__attribute__((__nonnull__, __warn_unused_result__))
+static inline CxTreeVisitor cxTreeVisitor(CxTree *tree) {
+return tree->cl->visitor(tree);
+}
+/**
+* Adds a new node to the tree.
+*
+* \attention The node may be externally created, but MUST obey the same rules
+* as if it was created by the tree itself with #cxTreeAddChild() (e.g. use
+* the same allocator).
+*
+* @param tree the tree
+* @param parent the parent of the node to add
+* @param child the node to add
+*/
+__attribute__((__nonnull__))
+static inline void cxTreeAddChildNode(
+CxTree *tree,
+void *parent,
+void *child) {
+cx_tree_link(parent, child, cx_tree_node_layout(tree));
+tree->size++;
+}
+/**
+* Creates a new node and adds it to the tree.
+*
+* With this function you can decide where exactly the new node shall be added.
+* If you specified an appropriate search function, you may want to consider
+* leaving this task to the tree by using #cxTreeInsert().
+*
+* Be aware that adding nodes at arbitrary locations in the tree might cause
+* wrong or undesired results when subsequently invoking #cxTreeInsert() and
+* the invariant imposed by the search function does not hold any longer.
+*
+* @param tree the tree
+* @param parent the parent node of the new node
+* @param data the data that will be submitted to the create function
+* @return zero when the new node was created, non-zero on allocation failure
+* @see cxTreeInsert()
+*/
+__attribute__((__nonnull__))
+int cxTreeAddChild(
+CxTree *tree,
+void *parent,
+const void *data
+);
+/**
+* A function that is invoked when a node needs to be re-linked to a new parent.
+*
+* When a node is re-linked, sometimes the contents need to be updated.
+* This callback is invoked by #cxTreeRemove() so that those updates can be
+* applied when re-linking the children of the removed node.
+*
+* @param node the affected node
+* @param old_parent the old parent of the node
+* @param new_parent the new parent of the node
+*/
+typedef void (*cx_tree_relink_func)(
+void *node,
+const void *old_parent,
+const void *new_parent
+);
+/**
+* Removes a node and re-links its children to its former parent.
+*
+* If the node is not part of the tree, the behavior is undefined.
+*
+* \note The destructor function, if any, will \em not be invoked. That means
+* you will need to free the removed node by yourself, eventually.
+*
+* @param tree the tree
+* @param node the node to remove (must not be the root node)
+* @param relink_func optional callback to update the content of each re-linked
+* node
+* @return zero on success, non-zero if \p node is the root node of the tree
+*/
+__attribute__((__nonnull__(1,2)))
+int cxTreeRemove(
+CxTree *tree,
+void *node,
+cx_tree_relink_func relink_func
+);
+/**
+* Removes a node and it's subtree from the tree.
+*
+* If the node is not part of the tree, the behavior is undefined.
+*
+* \note The destructor function, if any, will \em not be invoked. That means
+* you will need to free the removed subtree by yourself, eventually.
+*
+* @param tree the tree
+* @param node the node to remove
+*/
+__attribute__((__nonnull__))
+void cxTreeRemoveSubtree(CxTree *tree, void *node);
+#ifdef __cplusplus
+} // extern "C"
+#endif
+#endif //UCX_TREE_H

Mercurial > hg > toolkit / file comparison

comparison: ucx/cx/tree.h

ucx/cx/tree.h