/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 2021 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 linked_list.h
* @brief Linked list implementation.
* @author Mike Becker
* @author Olaf Wintermann
* @copyright 2-Clause BSD License
*/
#ifndef UCX_LINKED_LIST_H
#define UCX_LINKED_LIST_H
#include "common.h"
#include "list.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* Metadata for a linked list.
*/
typedef struct cx_linked_list_s {
/** Base members. */
struct cx_list_s base;
/**
* Location of the prev pointer (mandatory).
*/
off_t loc_prev;
/**
* Location of the next pointer (mandatory).
*/
off_t loc_next;
/**
* Location of the payload (mandatory).
*/
off_t loc_data;
/**
* Location of extra data (optional).
* Negative when no extra data is requested.
* @see cx_linked_list_extra_data()
*/
off_t loc_extra;
/**
* Additional bytes to allocate @em behind the payload (e.g. for metadata).
* @see cx_linked_list_extra_data()
*/
size_t extra_data_len;
/**
* Pointer to the first node.
*/
void *begin;
/**
* Pointer to the last node.
*/
void *end;
} cx_linked_list;
/**
* Allocates a linked list for storing elements with @p elem_size bytes each.
*
* If @p elem_size is #CX_STORE_POINTERS, the created list stores pointers instead of
* copies of the added elements, and the compare function will be automatically set
* to cx_cmp_ptr() if none is given.
*
* @param allocator the allocator for allocating the list nodes
* (if @c NULL, the cxDefaultAllocator will be used)
* @param comparator the comparator for the elements
* (if @c NULL, and the list is not storing pointers, sort and find
* functions will not work)
* @param elem_size the size of each element in bytes
* @return the created list
*/
cx_attr_nodiscard cx_attr_malloc cx_attr_dealloc(cxListFree, 1)
CX_EXPORT CxList *cxLinkedListCreate(const CxAllocator *allocator,
cx_compare_func comparator, size_t elem_size);
/**
* Allocates a linked list for storing elements with @p elem_size bytes each.
*
* The list will use cxDefaultAllocator and no comparator function. If you want
* to call functions that need a comparator, you must either set one immediately
* after list creation or use cxLinkedListCreate().
*
* If @p elem_size is #CX_STORE_POINTERS, the created list stores pointers instead of
* copies of the added elements, and the compare function will be automatically set
* to cx_cmp_ptr().
*
* @param elem_size (@c size_t) the size of each element in bytes
* @return (@c CxList*) the created list
*/
#define cxLinkedListCreateSimple(elem_size) \
cxLinkedListCreate(NULL, NULL, elem_size)
/**
* Instructs the linked list to reserve extra data in each node.
*
* The extra data will be aligned and placed behind the element data.
* The exact location in the node is stored in the @c loc_extra field
* of the linked list.
*
* You should usually not use this function except when you are creating an
* own linked-list implementation that is based on the UCX linked list and
* needs to store extra data in each node.
*
* @param list the list (must be a linked list)
* @param len the length of the extra data
*/
cx_attr_nonnull
CX_EXPORT void cx_linked_list_extra_data(cx_linked_list *list, size_t len);
/**
* Finds the node at a certain index.
*
* This function can be used to start at an arbitrary position within the list.
* If the search index is larger than the start index, @p loc_advance must denote
* the location of a @c next pointer (i.e., a pointer to the next node).
* But it is also possible that the search index is smaller than the start index
* (e.g., in cases where traversing a list backwards is faster).
* In that case @p loc_advance must denote the location of a @c prev pointer
* (i.e., a pointer to the previous node).
*
* @param start a pointer to the start node
* @param start_index the start index
* @param loc_advance the location of the pointer to advance
* @param index the search index
* @return the node found at the specified index
*/
cx_attr_nonnull cx_attr_nodiscard
CX_EXPORT void *cx_linked_list_at(const void *start,size_t start_index,
ptrdiff_t loc_advance, size_t index);
/**
* Finds the node containing an element within a linked list.
*
* @param start a pointer to the start node
* @param loc_advance the location of the pointer to advance
* @param loc_data the location of the @c data pointer within your node struct
* @param cmp_func a compare function to compare @p elem against the node data
* @param elem a pointer to the element to find
* @param found_index an optional pointer where the index of the found node
* (given that @p start has index 0) is stored
* @return a pointer to the found node or @c NULL if no matching node was found
*/
cx_attr_nonnull_arg(1, 4, 5)
CX_EXPORT void *cx_linked_list_find(const void *start, ptrdiff_t loc_advance,
ptrdiff_t loc_data, cx_compare_func cmp_func, const void *elem,
size_t *found_index);
/**
* Finds the first node in a linked list.
*
* The function starts with the pointer denoted by @p node and traverses the list
* along a prev pointer whose location within the node struct is
* denoted by @p loc_prev.
*
* @param node a pointer to a node in the list
* @param loc_prev the location of the @c prev pointer
* @return a pointer to the first node
*/
cx_attr_nonnull cx_attr_returns_nonnull
CX_EXPORT void *cx_linked_list_first(const void *node, ptrdiff_t loc_prev);
/**
* Finds the last node in a linked list.
*
* The function starts with the pointer denoted by @p node and traverses the list
* along a next pointer whose location within the node struct is
* denoted by @p loc_next.
*
* @param node a pointer to a node in the list
* @param loc_next the location of the @c next pointer
* @return a pointer to the last node
*/
cx_attr_nonnull cx_attr_returns_nonnull
CX_EXPORT void *cx_linked_list_last(const void *node, ptrdiff_t loc_next);
/**
* Finds the predecessor of a node in case it is not linked.
*
* @remark If @p node is not contained in the list starting with @p begin, the behavior is undefined.
*
* @param begin the node where to start the search
* @param loc_next the location of the @c next pointer
* @param node the successor of the node to find
* @return the node or @c NULL if @p node has no predecessor
*/
cx_attr_nonnull
CX_EXPORT void *cx_linked_list_prev(const void *begin, ptrdiff_t loc_next, const void *node);
/**
* Adds a new node to a linked list.
* The node must not be part of any list yet.
*
* @remark One of the pointers @p begin or @p end may be @c NULL, but not both.
*
* @param begin a pointer to the beginning node pointer (if your list has one)
* @param end a pointer to the end node pointer (if your list has one)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
* @param new_node a pointer to the node that shall be appended
*/
cx_attr_nonnull_arg(5)
CX_EXPORT void cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node);
/**
* Prepends a new node to a linked list.
* The node must not be part of any list yet.
*
* @remark One of the pointers @p begin or @p end may be @c NULL, but not both.
*
* @param begin a pointer to the beginning node pointer (if your list has one)
* @param end a pointer to the end node pointer (if your list has one)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
* @param new_node a pointer to the node that shall be prepended
*/
cx_attr_nonnull_arg(5)
CX_EXPORT void cx_linked_list_prepend(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node);
/**
* Links two nodes.
*
* @param left the new predecessor of @p right
* @param right the new successor of @p left
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
*/
cx_attr_nonnull
CX_EXPORT void cx_linked_list_link(void *left, void *right, ptrdiff_t loc_prev, ptrdiff_t loc_next);
/**
* Unlinks two nodes.
*
* If right is not the successor of left, the behavior is undefined.
*
* @param left the predecessor of @p right
* @param right the successor of @p left
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
*/
cx_attr_nonnull
CX_EXPORT void cx_linked_list_unlink(void *left, void *right, ptrdiff_t loc_prev, ptrdiff_t loc_next);
/**
* Inserts a new node after a given node of a linked list.
* The new node must not be part of any list yet.
*
* @note If you specify @c NULL as the @p node to insert after, this function needs either the @p begin or
* the @p end pointer to determine the start of the list. Then the new node will be prepended to the list.
*
* @param begin a pointer to the beginning node pointer (if your list has one)
* @param end a pointer to the end node pointer (if your list has one)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
* @param node the node after which to insert (@c NULL if you want to prepend the node to the list)
* @param new_node a pointer to the node that shall be inserted
*/
cx_attr_nonnull_arg(6)
CX_EXPORT void cx_linked_list_insert(void **begin, void **end,
ptrdiff_t loc_prev, ptrdiff_t loc_next, void *node, void *new_node);
/**
* Inserts a chain of nodes after a given node of a linked list.
* The chain must not be part of any list yet.
*
* If you do not explicitly specify the end of the chain, it will be determined by traversing
* the @c next pointer.
*
* @note If you specify @c NULL as the @p node to insert after, this function needs either the @p begin or
* the @p end pointer to determine the start of the list. If only the @p end pointer is specified, you also need
* to provide a valid @p loc_prev location.
* Then the chain will be prepended to the list.
*
* @param begin a pointer to the beginning node pointer (if your list has one)
* @param end a pointer to the end node pointer (if your list has one)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
* @param node the node after which to insert (@c NULL to prepend the chain to the list)
* @param insert_begin a pointer to the first node of the chain that shall be inserted
* @param insert_end a pointer to the last node of the chain (or NULL if the last node shall be determined)
*/
cx_attr_nonnull_arg(6)
CX_EXPORT void cx_linked_list_insert_chain(void **begin, void **end,
ptrdiff_t loc_prev, ptrdiff_t loc_next, void *node, void *insert_begin, void *insert_end);
/**
* Inserts a node into a sorted linked list.
* The new node must not be part of any list yet.
*
* If the list starting with the node pointed to by @p begin is not sorted
* already, the behavior is undefined.
*
* @param begin a pointer to the beginning node pointer (required)
* @param end a pointer to the end node pointer (if your list has one)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
* @param new_node a pointer to the node that shall be inserted
* @param cmp_func a compare function that will receive the node pointers
*/
cx_attr_nonnull_arg(1, 5, 6)
CX_EXPORT void cx_linked_list_insert_sorted(void **begin, void **end,
ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node, cx_compare_func cmp_func);
/**
* Inserts a chain of nodes into a sorted linked list.
* The chain must not be part of any list yet.
*
* If either the list starting with the node pointed to by @p begin or the list
* starting with @p insert_begin is not sorted, the behavior is undefined.
*
* @attention In contrast to cx_linked_list_insert_chain(), the source chain
* will be broken and inserted into the target list so that the resulting list
* will be sorted according to @p cmp_func. That means each node in the source
* chain may be re-linked with nodes from the target list.
*
* @param begin a pointer to the beginning node pointer (required)
* @param end a pointer to the end node pointer (if your list has one)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
* @param insert_begin a pointer to the first node of the chain that shall be inserted
* @param cmp_func a compare function that will receive the node pointers
*/
cx_attr_nonnull_arg(1, 5, 6)
CX_EXPORT void cx_linked_list_insert_sorted_chain(void **begin, void **end,
ptrdiff_t loc_prev, ptrdiff_t loc_next, void *insert_begin, cx_compare_func cmp_func);
/**
* Inserts a node into a sorted linked list if no other node with the same value already exists.
* The new node must not be part of any list yet.
*
* If the list starting with the node pointed to by @p begin is not sorted
* already, the behavior is undefined.
*
* @param begin a pointer to the beginning node pointer (required)
* @param end a pointer to the end node pointer (if your list has one)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
* @param new_node a pointer to the node that shall be inserted
* @param cmp_func a compare function that will receive the node pointers
* @retval zero when the node was inserted
* @retval non-zero when a node with the same value already exists
*/
cx_attr_nonnull_arg(1, 5, 6)
CX_EXPORT int cx_linked_list_insert_unique(void **begin, void **end,
ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node, cx_compare_func cmp_func);
/**
* Inserts a chain of nodes into a sorted linked list, avoiding duplicates.
* The chain must not be part of any list yet.
*
* If either the list starting with the node pointed to by @p begin or the list
* starting with @p insert_begin is not sorted, the behavior is undefined.
*
* @attention In contrast to cx_linked_list_insert_sorted(), not all nodes of the
* chain might be added. This function returns a new chain consisting of all the duplicates.
*
* @param begin a pointer to the beginning node pointer (required)
* @param end a pointer to the end node pointer (if your list has one)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
* @param insert_begin a pointer to the first node of the chain that shall be inserted
* @param cmp_func a compare function that will receive the node pointers
* @return a pointer to a new chain with all duplicates that were not inserted (or @c NULL when there were no duplicates)
*/
cx_attr_nonnull_arg(1, 5, 6) cx_attr_nodiscard
CX_EXPORT void *cx_linked_list_insert_unique_chain(void **begin, void **end,
ptrdiff_t loc_prev, ptrdiff_t loc_next, void *insert_begin, cx_compare_func cmp_func);
/**
* Removes a chain of nodes from the linked list.
*
* If one of the nodes to remove is the beginning (resp. end) node of the list, and if @p begin (resp. @p end)
* addresses are provided, the pointers are adjusted accordingly.
*
* The following combinations of arguments are valid (more arguments are optional):
* @li @p loc_next and @p loc_prev (ancestor node is determined by using the prev pointer, overall O(1) performance)
* @li @p loc_next and @p begin (ancestor node is determined by list traversal, overall O(n) performance)
*
* @remark The @c next and @c prev pointers of the removed chain are not cleared by this function and may still be used
* to traverse to a former adjacent node in the list, or within the chain.
*
* @param begin a pointer to the beginning node pointer (optional)
* @param end a pointer to the end node pointer (optional)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
* @param node the start node of the chain
* @param num the number of nodes to remove
* @return the actual number of nodes that were removed (can be less when the list did not have enough nodes)
*/
cx_attr_nonnull_arg(5)
CX_EXPORT size_t cx_linked_list_remove_chain(void **begin, void **end,
ptrdiff_t loc_prev, ptrdiff_t loc_next, void *node, size_t num);
/**
* Removes a node from the linked list.
*
* If the node to remove is the beginning (resp. end) node of the list, and if @p begin (resp. @p end)
* addresses are provided, the pointers are adjusted accordingly.
*
* The following combinations of arguments are valid (more arguments are optional):
* @li @p loc_next and @p loc_prev (ancestor node is determined by using the prev pointer, overall O(1) performance)
* @li @p loc_next and @p begin (ancestor node is determined by list traversal, overall O(n) performance)
*
* @remark The @c next and @c prev pointers of the removed node are not cleared by this function and may still be used
* to traverse to a former adjacent node in the list.
*
* @param begin a pointer to the beginning node pointer (optional)
* @param end a pointer to the end node pointer (optional)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
* @param node the node to remove
*/
cx_attr_nonnull_arg(5)
CX_EXPORT void cx_linked_list_remove(void **begin, void **end,
ptrdiff_t loc_prev, ptrdiff_t loc_next, void *node);
/**
* Determines the size of a linked list starting with @p node.
*
* @param node the first node
* @param loc_next the location of the @c next pointer within the node struct
* @return the size of the list or zero if @p node is @c NULL
*/
cx_attr_nodiscard
CX_EXPORT size_t cx_linked_list_size(const void *node, ptrdiff_t loc_next);
/**
* Sorts a linked list based on a comparison function.
*
* This function can work with linked lists of the following structure:
* @code
* typedef struct node node;
* struct node {
* node* prev;
* node* next;
* my_payload data;
* }
* @endcode
*
* @note This is a recursive function with at most logarithmic recursion depth.
*
* @param begin a pointer to the beginning node pointer (required)
* @param end a pointer to the end node pointer (optional)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if not present)
* @param loc_next the location of a @c next pointer within your node struct (required)
* @param loc_data the location of the @c data pointer within your node struct
* @param cmp_func the compare function defining the sort order
*/
cx_attr_nonnull_arg(1, 6)
CX_EXPORT void cx_linked_list_sort(void **begin, void **end,
ptrdiff_t loc_prev, ptrdiff_t loc_next, ptrdiff_t loc_data, cx_compare_func cmp_func);
/**
* Compares two lists element wise.
*
* @attention Both lists must have the same structure.
*
* @param begin_left the beginning of the left list (@c NULL denotes an empty list)
* @param begin_right the beginning of the right list (@c NULL denotes an empty list)
* @param loc_advance the location of the pointer to advance
* @param loc_data the location of the @c data pointer within your node struct
* @param cmp_func the function to compare the elements
* @return the first non-zero result of invoking @p cmp_func or: negative if the left list is smaller than the
* right list, positive if the left list is larger than the right list, zero if both lists are equal.
*/
cx_attr_nonnull_arg(5)
CX_EXPORT int cx_linked_list_compare(const void *begin_left, const void *begin_right,
ptrdiff_t loc_advance, ptrdiff_t loc_data, cx_compare_func cmp_func);
/**
* Reverses the order of the nodes in a linked list.
*
* @param begin a pointer to the beginning node pointer (required)
* @param end a pointer to the end node pointer (optional)
* @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
* @param loc_next the location of a @c next pointer within your node struct (required)
*/
cx_attr_nonnull_arg(1)
CX_EXPORT void cx_linked_list_reverse(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next);
#ifdef __cplusplus
} // extern "C"
#endif
#endif // UCX_LINKED_LIST_H