Started from buttom go to the sky

stdme/src/gnl/get_next_line.c

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+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   get_next_line.c                                    :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: maix <marvin@42.fr>                        +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/11/23 17:38:21 by maix              #+#    #+#             */
+/*   Updated: 2023/12/11 19:10:26 by maiboyer         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "me/buffered_str/buf_str.h"
+#include "me/gnl/gnl.h"
+#include "me/mem/mem_alloc.h"
+#include "me/mem/mem_move.h"
+#include "me/string/str_len.h"
+#include "me/types.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+static t_static_buffer	*get_next_line_buffer(t_file fd)
+{
+	t_usize					index;
+	static t_static_buffer	bufs[BUFFER_LENGTH] = {0};
+
+	index = 0;
+	while (index < BUFFER_LENGTH && (bufs[index].fd != fd && bufs[index].used))
+		index++;
+	if (index == BUFFER_LENGTH)
+		return (NULL);
+	bufs[index].fd = fd;
+	bufs[index].used = true;
+	return (&bufs[index]);
+}
+
+static bool	copy_next_line_into_buffer(t_file fd, t_buffer_str *out,
+		char *temp_buffer, t_usize amount)
+{
+	char	*buf;
+	char	*newline;
+	bool	got_newline;
+	t_usize	other_part_len;
+
+	buf = get_next_line_buffer(fd)->buf;
+	newline = buf;
+	while (*newline != '\n' && *newline && newline < buf + amount)
+		newline++;
+	got_newline = *newline == '\n';
+	other_part_len = amount - (t_usize)(newline - buf + !got_newline);
+	if (amount < (t_usize)(newline - buf + !got_newline))
+		other_part_len = 0;
+	mem_move(temp_buffer, buf, (t_usize)(newline - buf + got_newline));
+	buf[(t_usize)(newline - buf)] = 0;
+	temp_buffer[(t_usize)(newline - buf + got_newline)] = 0;
+	mem_move(buf, newline + 1, other_part_len);
+	push_str_buffer(out, temp_buffer);
+	buf[amount - (t_usize)(newline - buf + got_newline)] = 0;
+	return (got_newline);
+}
+
+static bool	read_and_copy(t_file fd, t_buffer_str *out, char *tmp,
+		t_copy_flags *flags)
+{
+	t_isize			amount;
+	t_static_buffer	*buf;
+
+	buf = get_next_line_buffer(fd);
+	amount = read(fd, &buf->buf, BUFFER_SIZE);
+	flags->error = amount < 0;
+	if (flags->error)
+		return (true);
+	buf->init = true;
+	if ((t_isize)amount < (t_isize)BUFFER_SIZE)
+	{
+		copy_next_line_into_buffer(fd, out, tmp, (t_usize)amount);
+		flags->empty_read = (amount == 0 && out->len == 0);
+		return (true);
+	}
+	buf->buf[(t_usize)amount] = 0;
+	return (copy_next_line_into_buffer(fd, out, tmp, (t_usize)amount));
+}
+
+static bool	handle_leftovers(t_file fd, char *temp_buffer, t_buffer_str *buf)
+{
+	t_static_buffer	*static_buffer;
+
+	static_buffer = get_next_line_buffer(fd);
+	if (static_buffer->init)
+	{
+		if (copy_next_line_into_buffer(fd, buf, temp_buffer,
+				str_len(static_buffer->buf)))
+		{
+			free(temp_buffer);
+			return (true);
+		}
+	}
+	return (false);
+}
+
+t_buffer_str	get_next_line(t_file fd, bool *error)
+{
+	t_buffer_str	buf;
+	char			*temp_buffer;
+	t_copy_flags	flags;
+
+	*error = false;
+	if (fd < 0 || BUFFER_SIZE <= 0)
+		return (*error = true, (t_buffer_str){0});
+	flags = (t_copy_flags){
+		.error = false,
+		.empty_read = false,
+	};
+	temp_buffer = mem_alloc(sizeof(char) * (BUFFER_SIZE + 2));
+	buf = alloc_new_buffer(32);
+	if (handle_leftovers(fd, temp_buffer, &buf))
+		return (buf);
+	while (!read_and_copy(fd, &buf, temp_buffer, &flags) && !flags.empty_read)
+		;
+	free(temp_buffer);
+	if (flags.error || flags.empty_read)
+	{
+		free(buf.buf);
+		return (*error = true, (t_buffer_str){0});
+	}
+	return (buf);
+}