/*
* 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
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*/
/**
* \file linked_list.h
* \brief Linked list implementation.
* \details Also provides several low-level functions for custom linked list implementations.
* \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
/**
* The maximum item size that uses SBO swap instead of relinking.
*/
extern unsigned cx_linked_list_swap_sbo_size;
/**
* Allocates a linked list for storing elements with \p elem_size bytes each.
*
* If \p elem_size is CX_STORE_POINTERS, the created list will be created as if
* cxListStorePointers() was called immediately after creation 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
*/
CxList *cxLinkedListCreate(
CxAllocator const *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 will be created as if
* cxListStorePointers() was called immediately after creation and the compare
* function will be automatically set to cx_cmp_ptr().
*
* @param elem_size the size of each element in bytes
* @return the created list
*/
#define cxLinkedListCreateSimple(elem_size) \
cxLinkedListCreate(NULL, NULL, elem_size)
/**
* 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 large than the start index, \p loc_advance must denote
* the location of some sort of \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 which case
* \p loc_advance must denote the location of some sort of \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
*/
void *cx_linked_list_at(
void const *start,
size_t start_index,
ptrdiff_t loc_advance,
size_t index
) __attribute__((__nonnull__));
/**
* Finds the index of 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
* @return the index of the element or a negative value if it could not be found
*/
ssize_t cx_linked_list_find(
void const *start,
ptrdiff_t loc_advance,
ptrdiff_t loc_data,
cx_compare_func cmp_func,
void const *elem
) __attribute__((__nonnull__));
/**
* Finds the node containing an element within a linked list.
*
* @param result a pointer to the memory where the node pointer (or \c NULL if the element
* could not be found) shall be stored to
* @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
* @return the index of the element or a negative value if it could not be found
*/
ssize_t cx_linked_list_find_node(
void **result,
void const *start,
ptrdiff_t loc_advance,
ptrdiff_t loc_data,
cx_compare_func cmp_func,
void const *elem
) __attribute__((__nonnull__));
/**
* 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
*/
void *cx_linked_list_first(
void const *node,
ptrdiff_t loc_prev
) __attribute__((__nonnull__));
/**
* 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
*/
void *cx_linked_list_last(
void const *node,
ptrdiff_t loc_next
) __attribute__((__nonnull__));
/**
* 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
*/
void *cx_linked_list_prev(
void const *begin,
ptrdiff_t loc_next,
void const *node
) __attribute__((__nonnull__));
/**
* Adds a new node to a linked list.
* The node must not be part of any list already.
*
* \remark One of the pointers \p begin or \p end may be \c NULL, but not both.
*
* @param begin a pointer to the begin 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
*/
void cx_linked_list_add(
void **begin,
void **end,
ptrdiff_t loc_prev,
ptrdiff_t loc_next,
void *new_node
) __attribute__((__nonnull__(5)));
/**
* Prepends a new node to a linked list.
* The node must not be part of any list already.
*
* \remark One of the pointers \p begin or \p end may be \c NULL, but not both.
*
* @param begin a pointer to the begin 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
*/
void cx_linked_list_prepend(
void **begin,
void **end,
ptrdiff_t loc_prev,
ptrdiff_t loc_next,
void *new_node
) __attribute__((__nonnull__(5)));
/**
* 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)
*/
void cx_linked_list_link(
void *left,
void *right,
ptrdiff_t loc_prev,
ptrdiff_t loc_next
) __attribute__((__nonnull__));
/**
* 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)
*/
void cx_linked_list_unlink(
void *left,
void *right,
ptrdiff_t loc_prev,
ptrdiff_t loc_next
) __attribute__((__nonnull__));
/**
* Inserts a new node after a given node of a linked list.
* The new node must not be part of any list already.
*
* \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 begin 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 prepended
*/
void cx_linked_list_insert(
void **begin,
void **end,
ptrdiff_t loc_prev,
ptrdiff_t loc_next,
void *node,
void *new_node
) __attribute__((__nonnull__(6)));
/**
* Inserts a chain of nodes after a given node of a linked list.
* The chain must not be part of any list already.
*
* 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 begin 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)
*/
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
) __attribute__((__nonnull__(6)));
/**
* Removes a node from the linked list.
*
* If the node to remove is the begin (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 begin 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
*/
void cx_linked_list_remove(
void **begin,
void **end,
ptrdiff_t loc_prev,
ptrdiff_t loc_next,
void *node
) __attribute__((__nonnull__(5)));
/**
* 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
*/
size_t cx_linked_list_size(
void const *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 begin 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
*/
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
) __attribute__((__nonnull__(1, 6)));
/**
* Compares two lists element wise.
*
* \note Both list must have the same structure.
*
* @param begin_left the begin of the left list (\c NULL denotes an empty list)
* @param begin_right the begin 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.
*/
int cx_linked_list_compare(
void const *begin_left,
void const *begin_right,
ptrdiff_t loc_advance,
ptrdiff_t loc_data,
cx_compare_func cmp_func
) __attribute__((__nonnull__(5)));
/**
* Reverses the order of the nodes in a linked list.
*
* @param begin a pointer to the begin 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)
*/
void cx_linked_list_reverse(
void **begin,
void **end,
ptrdiff_t loc_prev,
ptrdiff_t loc_next
) __attribute__((__nonnull__(1)));
#ifdef __cplusplus
} // extern "C"
#endif
#endif // UCX_LINKED_LIST_H