Gnl/get_next_line.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   get_next_line.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: narnaud <narnaud@student.42.fr>            +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2021/10/25 10:00:41 by narnaud           #+#    #+#             */
/*   Updated: 2021/11/19 17:41:09 by narnaud          ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "get_next_line.h"

int	close_buffer(t_buffer **buffers)
{
	t_buffer	*buffer;

	buffer = *buffers;
	free(buffer->content);
	free(buffer);
	*buffers = NULL;
	return (1);
}

static t_buffer	*load_buffer(t_buffer **buffers)
{
	t_buffer	*buffer;

	buffer = *buffers;
	if (buffer)
		return (buffer);
	buffer = ft_calloc(1, sizeof(*buffer));
	buffer->content = (char *)ft_calloc(BUFFER_SIZE + 1, sizeof(char));
	buffer->pos = 0;
	buffer->read_length = 0;
	return (buffer);
}

int	parse_buffer(t_buffer *buffer, t_split **line)
{
	t_split	*split;

	split = ft_lstlast(*line);
	while (buffer->content[buffer->pos])
	{
		if (buffer->pos >= buffer->read_length)
			break ;
		if (split->i == SPLIT_SIZE)
		{
			split = ft_new_split(ft_calloc(SPLIT_SIZE + 1, sizeof(char)));
			ft_lstadd_back(line, split);
		}
		(split->content)[split->i] = buffer->content[buffer->pos];
		if (buffer->content[buffer->pos++] == '\n')
			return (1);
		(split->i)++;
	}
	buffer->pos = 0;
	return (0);
}

char	*merge_splits(t_split	**split)
{
	t_split	*next;
	char	*ret;
	size_t	i;
	size_t	count;

	next = ft_lstlast(*split);
	count = next->count;
	ret = (char *)ft_calloc((count * SPLIT_SIZE) + 1, sizeof(char));
	i = 0;
	while (split && *split)
	{
		next = (*split)->next;
		(*split)->i = 0;
		while ((*split)->content[(*split)->i])
		{
			ret[i] = (*split)->content[(*split)->i];
			i++;
			((*split)->i)++;
		}
		free((*split)->content);
		free(*split);
		*split = next;
	}
	ret[i] = '\0';
	return (ret);
}

char	*get_next_line(int fd)
{
	static t_buffer	*buffer;
	t_split			*line;
	char			*ret;

	buffer = load_buffer(&buffer);
	if (read(fd, buffer->content, 0) < 0 && close_buffer(&buffer))
		return (NULL);
	line = ft_new_split((char *)ft_calloc(SPLIT_SIZE + 1, sizeof(char)));
	while (!parse_buffer(buffer, &line))
	{
		buffer->read_length = read(fd, buffer->content, BUFFER_SIZE);
		if (!buffer->read_length && close_buffer(&buffer))
			break ;
	}
	ret = merge_splits(&line);
	if (*ret)
		return (ret);
	free(ret);
	return (NULL);
}