pcep_utils_double_linked_list.c

// SPDX-License-Identifier: LGPL-2.1-or-later
/*
 * This file is part of the PCEPlib, a PCEP protocol library.
 *
 * Copyright (C) 2020 Volta Networks https://voltanet.io/
 *
 * Author : Brady Johnson <brady@voltanet.io>
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stddef.h>
#include <string.h>

#include "pcep_utils_double_linked_list.h"
#include "pcep_utils_logging.h"
#include "pcep_utils_memory.h"

double_linked_list *dll_initialize(void)
{
	double_linked_list *handle =
		pceplib_malloc(PCEPLIB_INFRA, sizeof(double_linked_list));
	if (handle != NULL) {
		memset(handle, 0, sizeof(double_linked_list));
		handle->num_entries = 0;
		handle->head = NULL;
		handle->tail = NULL;
	} else {
		pcep_log(LOG_WARNING,
			 "%s: dll_initialize cannot allocate memory for handle",
			 __func__);
		return NULL;
	}

	return handle;
}


void dll_destroy(double_linked_list *handle)
{
	if (handle == NULL) {
		pcep_log(LOG_WARNING,
			 "%s: dll_destroy cannot destroy NULL handle",
			 __func__);
		return;
	}

	double_linked_list_node *node = handle->head;
	while (node != NULL) {
		double_linked_list_node *node_to_delete = node;
		node = node->next_node;
		pceplib_free(PCEPLIB_INFRA, node_to_delete);
	}

	pceplib_free(PCEPLIB_INFRA, handle);
}


void dll_destroy_with_data_memtype(double_linked_list *handle,
				   void *data_memory_type)
{
	if (handle == NULL) {
		pcep_log(LOG_WARNING,
			 "%s: dll_destroy_with_data cannot destroy NULL handle",
			 __func__);
		return;
	}

	double_linked_list_node *node = handle->head;
	while (node != NULL) {
		double_linked_list_node *node_to_delete = node;
		pceplib_free(data_memory_type, node->data);
		node = node->next_node;
		pceplib_free(PCEPLIB_INFRA, node_to_delete);
	}

	pceplib_free(PCEPLIB_INFRA, handle);
}


void dll_destroy_with_data(double_linked_list *handle)
{
	/* Default to destroying the data with the INFRA mem type */
	dll_destroy_with_data_memtype(handle, PCEPLIB_INFRA);
}


/* Creates a node and adds it as the first item in the list */
double_linked_list_node *dll_prepend(double_linked_list *handle, void *data)
{
	if (handle == NULL) {
		pcep_log(LOG_WARNING, "%s: dll_prepend_data NULL handle",
			 __func__);
		return NULL;
	}

	/* Create the new node */
	double_linked_list_node *new_node =
		pceplib_malloc(PCEPLIB_INFRA, sizeof(double_linked_list_node));
	memset(new_node, 0, sizeof(double_linked_list_node));
	new_node->data = data;

	if (handle->head == NULL) {
		handle->head = new_node;
		handle->tail = new_node;
	} else {
		new_node->next_node = handle->head;
		handle->head->prev_node = new_node;
		handle->head = new_node;
	}

	(handle->num_entries)++;

	return new_node;
}


/* Creates a node and adds it as the last item in the list */
double_linked_list_node *dll_append(double_linked_list *handle, void *data)
{
	if (handle == NULL) {
		pcep_log(LOG_WARNING, "%s: dll_append_data NULL handle",
			 __func__);
		return NULL;
	}

	/* Create the new node */
	double_linked_list_node *new_node =
		pceplib_malloc(PCEPLIB_INFRA, sizeof(double_linked_list_node));
	memset(new_node, 0, sizeof(double_linked_list_node));
	new_node->data = data;

	if (handle->head == NULL) {
		handle->head = new_node;
		handle->tail = new_node;
	} else {
		new_node->prev_node = handle->tail;
		handle->tail->next_node = new_node;
		handle->tail = new_node;
	}

	(handle->num_entries)++;

	return new_node;
}


/* Delete the first node in the list, and return the data */
void *dll_delete_first_node(double_linked_list *handle)
{
	if (handle == NULL) {
		pcep_log(LOG_WARNING, "%s: dll_delete_first_node NULL handle",
			 __func__);
		return NULL;
	}

	if (handle->head == NULL) {
		return NULL;
	}

	double_linked_list_node *delete_node = handle->head;
	void *data = delete_node->data;

	if (delete_node->next_node == NULL) {
		/* Its the last node in the list */
		handle->head = NULL;
		handle->tail = NULL;
	} else {
		handle->head = delete_node->next_node;
		handle->head->prev_node = NULL;
	}

	pceplib_free(PCEPLIB_INFRA, delete_node);
	(handle->num_entries)--;

	return data;
}


/* Delete the last node in the list, and return the data */
void *dll_delete_last_node(double_linked_list *handle)
{
	if (handle == NULL) {
		pcep_log(LOG_WARNING, "%s: dll_delete_last_node NULL handle",
			 __func__);
		return NULL;
	}

	if (handle->head == NULL) {
		return NULL;
	}

	double_linked_list_node *delete_node = handle->tail;
	void *data = delete_node->data;

	if (delete_node->prev_node == NULL) {
		/* Its the last node in the list */
		handle->head = NULL;
		handle->tail = NULL;
	} else {
		handle->tail = delete_node->prev_node;
		handle->tail->next_node = NULL;
	}

	pceplib_free(PCEPLIB_INFRA, delete_node);
	(handle->num_entries)--;

	return data;
}


/* Delete the designated node in the list, and return the data */
void *dll_delete_node(double_linked_list *handle, double_linked_list_node *node)
{
	if (handle == NULL) {
		pcep_log(LOG_WARNING, "%s: dll_delete_node NULL handle",
			 __func__);
		return NULL;
	}

	if (node == NULL) {
		return NULL;
	}

	if (handle->head == NULL) {
		return NULL;
	}

	void *data = node->data;

	if (handle->head == handle->tail) {
		/* Its the last node in the list */
		handle->head = NULL;
		handle->tail = NULL;
	} else if (handle->head == node) {
		handle->head = node->next_node;
		handle->head->prev_node = NULL;
	} else if (handle->tail == node) {
		handle->tail = node->prev_node;
		handle->tail->next_node = NULL;
	} else {
		/* Its somewhere in the middle of the list */
		node->next_node->prev_node = node->prev_node;
		node->prev_node->next_node = node->next_node;
	}

	pceplib_free(PCEPLIB_INFRA, node);
	(handle->num_entries)--;

	return data;
}