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Diffstat (limited to 'Source/charon/linked_list.c')
| -rw-r--r-- | Source/charon/linked_list.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/Source/charon/linked_list.c b/Source/charon/linked_list.c new file mode 100644 index 000000000..5f4574d20 --- /dev/null +++ b/Source/charon/linked_list.c @@ -0,0 +1,271 @@ +/** + * @file linked_list.c + * + * @brief Generic Double Linked List + * + */ + +/* + * Copyright (C) 2005 Jan Hutter, Martin Willi + * Hochschule fuer Technik Rapperswil + * + * 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 2 of the License, or (at your + * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * 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. + */ + +#include <stdlib.h> +#include <freeswan.h> +#include <pluto/constants.h> +#include <pluto/defs.h> + +#include "linked_list.h" + + +/** + * @brief implements function destroy of linked_list_item_t + */ +static status_t destroy_linked_list_element(linked_list_element_t *linked_list_element) +{ + linked_list_element_t * this = linked_list_element; + pfree(this); + return SUCCESS; +} + +linked_list_element_t *linked_list_element_create(void *value) +{ + linked_list_element_t *this = alloc_thing(linked_list_element_t, "linked_list_element_t"); + + this->destroy = destroy_linked_list_element; + + this->previous=NULL; + this->next=NULL; + this->value = value; + + return this; +} + +/** + * @brief implements function insert_first of linked_list_t + */ +static status_t insert_first(linked_list_t *linked_list, void *item) +{ + linked_list_t *this = linked_list; + + linked_list_element_t *element = linked_list_element_create(item); + + if (this->count == 0) + { + /* first entry in list */ + this->first = element; + this->last = element; + element->previous = NULL; + element->next = NULL; + }else + { + if ((this->first == NULL) || (this->last == NULL)) + { + /* should never happen */ + element->destroy(element); + return FAILED; + } + linked_list_element_t *old_first_element = this->first; + element->next = old_first_element; + old_first_element->previous = element; + this->first = element; + } + + this->count++; + + return SUCCESS; +} + +/** + * @brief implements function remove_first of linked_list_t + */ +static status_t remove_first(linked_list_t *linked_list, void **item) +{ + linked_list_t *this = linked_list; + + if (this->count == 0) + { + return FAILED; + } + + if (this->first == NULL) + { + return FAILED; + } + + linked_list_element_t *element = this->first; + + if (element->next != NULL) + { + element->next->previous = NULL; + } + this->first = element->next; + + *item = element->value; + + this->count--; + + return element->destroy(element); +} + +/** + * @brief implements function get_first of linked_list_t + */ +static status_t get_first(linked_list_t *linked_list, void **item) +{ + linked_list_t *this = linked_list; + + if (this->count == 0) + { + return FAILED; + } + + if (this->first == NULL) + { + return FAILED; + } + + *item = this->first->value; + + return SUCCESS; +} + +/** + * @brief implements function insert_last of linked_list_t + */ +static status_t insert_last(linked_list_t *linked_list, void *item) +{ + linked_list_t *this = linked_list; + + linked_list_element_t *element = linked_list_element_create(item); + + if (this->count == 0) + { + /* first entry in list */ + this->first = element; + this->last = element; + element->previous = NULL; + element->next = NULL; + }else + { + if ((this->first == NULL) || (this->last == NULL)) + { + /* should never happen */ + element->destroy(element); + return FAILED; + } + linked_list_element_t *old_last_element = this->last; + element->previous = old_last_element; + old_last_element->next = element; + this->last = element; + } + + this->count++; + + return SUCCESS; +} + +/** + * @brief implements function remove_last of linked_list_t + */ +static status_t remove_last(linked_list_t *linked_list, void **item) +{ + linked_list_t *this = linked_list; + + if (this->count == 0) + { + return FAILED; + } + + if (this->last == NULL) + { + return FAILED; + } + + linked_list_element_t *element = this->last; + + if (element->previous != NULL) + { + element->previous->next = NULL; + } + this->last = element->previous; + + *item = element->value; + + this->count--; + + return element->destroy(element); +} + +/** + * @brief implements function get_last of linked_list_t + */ +static status_t get_last(linked_list_t *linked_list, void **item) +{ + linked_list_t *this = linked_list; + + if (this->count == 0) + { + return FAILED; + } + + if (this->last == NULL) + { + return FAILED; + } + + *item = this->last->value; + + return SUCCESS; +} + +/** + * @brief implements function destroy of linked_list_t + */ +static status_t destroy_linked_list(linked_list_t *linked_list) +{ + linked_list_t *this = linked_list; + + /* Delete all list items before deleting list */ + while (this->count > 0) + { + void * value; + if (this->remove_first(this,&value) != SUCCESS) + { + pfree(this); + return FAILED; + } + } + pfree(this); + return FAILED; +} + + +linked_list_t *linked_list_create() +{ + linked_list_t *this = alloc_thing(linked_list_t, "linked_list_t"); + + this->get_first = get_first; + this->get_last = get_last; + this->insert_first = insert_first; + this->insert_last = insert_last; + this->remove_first = remove_first; + this->remove_last = remove_last; + this->destroy = destroy_linked_list; + + this->count = 0; + this->first = NULL; + this->last = NULL; + + return this; +} |