diff options
Diffstat (limited to 'src/libmdsserver/linked-list.h')
| -rw-r--r-- | src/libmdsserver/linked-list.h | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/src/libmdsserver/linked-list.h b/src/libmdsserver/linked-list.h new file mode 100644 index 0000000..f1949a5 --- /dev/null +++ b/src/libmdsserver/linked-list.h @@ -0,0 +1,243 @@ +/** + * mds — A micro-display server + * Copyright © 2014 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef MDS_LIBMDSSERVER_LINKED_LIST_H +#define MDS_LIBMDSSERVER_LINKED_LIST_H + + +/** + * Linear array sentinel doubly linked list class. + * An array linked list is a linked list constructed + * by parallel arrays which gives it nice memory + * properties. A linear sentinel linked list is a + * linear linked listed constructed as a circular + * linked listed with a sentinel (dummy) node between + * the first node and the last node. In this + * implementation, when a node is removed the value + * stored that that position is not removed before + * that position is reused. Insertion methods have + * constant amortised time complexity, and constant + * amortised memory complexity, removal methods have + * constant time complexity and constant memory + * complexity. + */ + + +#include <stdlib.h> +#include <stdint.h> + + + +/** + * Sentinel value indicating that the position is unused + */ +#if __WORDSIZE == 64 +# define LINKED_LIST_UNUSED (-__INT64_C(9223372036854775807) - 1) +#else +# define LINKED_LIST_UNUSED (-2147483647 - 1) +#endif + + + +/** + * Linear array sentinel doubly linked list class + */ +typedef struct linked_list +{ + /** + * The size of the arrays + */ + size_t capacity; + + /** + * The index after the last used index in + * `values` and `next` + */ + size_t end; + + /** + * Head of the stack of reusable positions + */ + size_t reuse_head; + + /** + * Stack of indices than are no longer in use + */ + ssize_t* reusable; + + /** + * The value stored in each node + */ + size_t* values; + + /** + * The next node for each node, `edge` if the current + * node is the last node, and `LINKED_LIST_UNUSED` + * if there is no node on this position + */ + ssize_t* next; + + /** + * The previous node for each node, `edge` if + * the current node is the first node, and + * `LINKED_LIST_UNUSED` if there is no node + * on this position + */ + ssize_t* previous; + + /** + * The sentinel node in the list + */ + ssize_t edge; + +} linked_list_t; + + + +/** + * Create a linked list + * + * @param this Memory slot in which to store the new linked list + * @param capacity The minimum initial capacity of the linked list, 0 for default + * @return Non-zero on error, `errno` will have been set accordingly + */ +int linked_list_create(linked_list_t* this, size_t capacity); + +/** + * Release all resources in a linked list, should + * be done even if `linked_list_create` fails + * + * @param this The linked list + */ +void linked_list_destroy(linked_list_t* this); + +/** + * Clone a linked list + * + * @param this The linked list to clone + * @param out Memory slot in which to store the new linked list + * @return Non-zero on error, `errno` will have been set accordingly + */ +int linked_list_clone(linked_list_t* this, linked_list_t* out); + +/** + * Pack the list so that there are no reusable + * positions, and reduce the capacity to the + * smallest capacity that can be used. Not that + * values (nodes) returned by the list's methods + * will become invalid. Additionally (to reduce + * the complexity) the list will be defragment + * so that the nodes' indices are continuous. + * This method has linear time complexity and + * linear memory complexity. + * + * @param this The list + * @return Non-zero on error, `errno` will have been set accordingly + */ +int linked_list_pack(linked_list_t* this); + +/** + * Insert a value in the beginning of the list + * + * @param this:linked_list_t* The list + * @param value:size_t The value to insert + * @return :ssize_t The node that has been created and inserted, + * `LINKED_LIST_UNUSED` on error, `errno` will be set accordingly + */ +#define linked_list_insert_beginning(this, value) \ + (linked_list_insert_after(this, value, this->edge)) + +/** + * Remove the node at the beginning of the list + * + * @param this:linked_list_t* The list + * @return :ssize_t The node that has been removed + */ +#define linked_list_remove_beginning(this) \ + (linked_list_remove_after(this, this->edge)) + +/** + * Insert a value after a specified, reference, node + * + * @param this The list + * @param value The value to insert + * @param predecessor The reference node + * @return The node that has been created and inserted, + * `LINKED_LIST_UNUSED` on error, `errno` will be set accordingly + */ +ssize_t linked_list_insert_after(linked_list_t* this, size_t value, ssize_t predecessor); + +/** + * Remove the node after a specified, reference, node + * + * @param this The list + * @param predecessor The reference node + * @return The node that has been removed + */ +ssize_t linked_list_remove_after(linked_list_t* this, ssize_t predecessor); + +/** + * Insert a value before a specified, reference, node + * + * @param this The list + * @param value The value to insert + * @param successor The reference node + * @return The node that has been created and inserted, + * `LINKED_LIST_UNUSED` on error, `errno` will be set accordingly + */ +ssize_t linked_list_insert_before(linked_list_t* this, size_t value, ssize_t successor); + +/** + * Remove the node before a specified, reference, node + * + * @param this The list + * @param successor The reference node + * @return The node that has been removed + */ +ssize_t linked_list_remove_before(linked_list_t* this, ssize_t successor); + +/** + * Remove the node from the list + * + * @param this The list + * @param node The node to remove + */ +void linked_list_remove(linked_list_t* this, ssize_t node); + +/** + * Insert a value in the end of the list + * + * @param this:linked_list_t* The list + * @param value:size_t The value to insert + * @return :ssize_t The node that has been created and inserted, + * `LINKED_LIST_UNUSED` on error, `errno` will be set accordingly + */ +#define linked_list_insert_end(this, value) \ + (linked_list_insert_before(this, value, this->edge)) + +/** + * Remove the node at the end of the list + * + * @param this:linked_list_t* The list + * @return :ssize_t The node that has been removed + */ +#define linked_list_remove_end(this) \ + (linked_list_remove_before(this, this->edge)) + + +#endif + |