SilverMUD/source/server/lists.c

// =========================================
// | SilverMUD Server - lists.c            |
// | Copyright (C) 2023, Barra Ó Catháin   |
// | See end of file for copyright notice. |
// =========================================
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

#include "lists.h"

// Functions:
// ==========
struct List * createList(enum DataType type)
{
	struct List * newList = calloc(1, sizeof(struct List));
	newList->itemCount = 0;
	newList->head = NULL;
	newList->tail = NULL;
	newList->type = type;
	return newList;
}

size_t appendToList(enum DataType type, struct List * list, void * data)
{
	// First check that you're adding the correct type:
	assert(type == list->type);

	struct ListNode * newListNode = calloc(1, sizeof(struct ListNode));
	newListNode->next = NULL;
	newListNode->previous = list->tail;
	newListNode->data = data;
	
	if (list->itemCount == 0)
	{
		list->head = newListNode;
	}
	else
	{
		list->tail->next = newListNode;	   
	}
	
	list->tail = newListNode;	
	list->itemCount++;
	
	return list->itemCount;
}

void * deleteListNodeFromList(size_t index, struct List * list)
{
	void * toReturn;

	if ((list->itemCount - 1) < index)
	{
		return NULL;
	}

	struct ListNode * currentListNode = NULL;
	
	if (index < (list->itemCount / 2))
	{
		currentListNode = list->head;

		// Get to the correct point in the linked list:
		for (int currentIndex = 0; currentIndex < index; currentIndex++)
		{
			currentListNode = currentListNode->next;
		}
 	}
	else
	{

		currentListNode = list->tail;
		
		// Get to the correct point in the linked list:
		for (int currentIndex = list->itemCount - 1; currentIndex > index; currentIndex--)
		{
			currentListNode = currentListNode->previous;
		}	
	}

	if (currentListNode == list->head)
	{
		list->head = list->head->next;
		if (list->head)
		{
			list->head->previous = NULL;
		}
	}
	if (currentListNode == list->tail)
	{
		list->tail = list->tail->previous;
		if (list->tail)
		{
			list->tail->next = NULL;
		}
	}	

	if (currentListNode->next != NULL)
	{
		currentListNode->next->previous = currentListNode->previous;
	}

	if (currentListNode->previous != NULL)
	{
		currentListNode->previous->next = currentListNode->next;
	}
	
	toReturn = currentListNode->data;
	free(currentListNode);

	list->itemCount--;

	return toReturn;
}

ssize_t indexOfFromList(bool (*comparisonFunction)(void *, void *), void * data, struct List * list)
{
	size_t index = 0;
	if (list->head == NULL)
	{
		return -1;
	}
	else
	{
		struct ListNode * currentListNode = list->head;
		do
		{
			if (comparisonFunction(currentListNode->data, data) == true)
			{
				return index;
			}
			index++;
			currentListNode = currentListNode->next;
		}
		while (currentListNode != NULL);
		
		return -1;
	}
}

void * getFirstFromList(bool (*comparisonFunction)(void *, void *), void * data, struct List * list)
{
	size_t index = 0;
	if (list->head == NULL)
	{
		return NULL;
	}
	else
	{
		struct ListNode * currentListNode = list->head;
		do
		{
			if (comparisonFunction(currentListNode->data, data) == true)
			{
				return currentListNode;
			}
			index++;
			currentListNode = currentListNode->next;
		}
		while (currentListNode != NULL);
		
		return NULL;
	}
}

bool isInList(bool (*comparisonFunction)(void *, void *), void * data, struct List * list)
{
	if (list->head == NULL)
	{
		return false;
	}
	else
	{
		struct ListNode * currentListNode = list->head;
		do
		{
			if (comparisonFunction(currentListNode->data, data) == 0)
			{
				return true;
			}
			currentListNode = currentListNode->next;
		}
		while (currentListNode != NULL);
		
		return false;
	}
}

bool isPointerInList(void * data, struct List * list)
{
	if (list->head == NULL)
	{
		return false;
	}
	else
	{
		struct ListNode * currentListNode = list->head;
		do
		{
			if (currentListNode->data == data)
			{
				return true;
			}
			currentListNode = currentListNode->next;
		}
		while (currentListNode != NULL);
		
		return false;
	}
}

// =============================================
// | End of lists.h, copyright notice follows. |
// =============================================

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero 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 Affero General Public License for more details.

// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.