c_piscine_rush_02/ex00/ft_open.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_open.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: asargsya <asargsya@student.42yerevan.am>   +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/12/03 19:08:11 by asargsya          #+#    #+#             */
/*   Updated: 2023/12/03 23:36:29 by achubuko         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "ft_open.h"

t_file	*ft_open(char *path)
{
	t_file	*file;

	file = malloc(sizeof(t_file));
	file->descriptor = open(path, O_RDONLY);
	file->read_window_size = 4096;
	file->read_window = malloc(sizeof(char) * file->read_window_size);
	file->read_size = 0;
	file->read_window_cursor = 0;
	file->buffer = 0;
	file->buffer_size = 0;
	return (file);
}

void	ft_growbuffer(t_file *f, ssize_t grow)
{
	char	*prev;
	char	*cur;
	ssize_t	pos;

	prev = f->buffer;
	cur = malloc(sizeof(char) * (f->buffer_size + grow));
	pos = 0;
	while (prev && cur && pos < f->buffer_size)
	{
		cur[pos] = prev[pos];
		pos++;
	}
	while (cur && pos < f->buffer_size + grow)
	{
		cur[pos] = 0;
		pos++;
	}
	// free(prev);
	f->buffer = cur;
}

ssize_t	ft_churn(t_file *f)
{
	f->read_size = read(f->descriptor, f->read_window, f->read_window_size);
	f->read_window_cursor = 0;
	return (f->read_size);
}

ssize_t	ft_buffer_line(t_file *f)
{
	char	*c;
	ssize_t	len;

	ft_growbuffer(f, 100);
	len = 0;
	c = 0;
	while (1)
	{
		if (f->read_window_cursor >= f->read_size)
		{
			ft_churn(f);
		}
		f->buffer[len] = f->read_window[f->read_window_cursor];
		if (len + 1 >= f->buffer_size)
			ft_growbuffer(f, 100);
		if (f->read_window[f->read_window_cursor] == '\n')
			return (len);
		len++;
		f->read_window_cursor++;
	}
	return (0);
}