buffer: add buffer struct and related functions

Makefile

@@ -19,6 +19,7 @@ ifeq ($(CFLAGS),)
 endif
 export CFLAGS
 srcs = \
+	src/buffer/buffer.c \
 	src/env/env.c \
 	src/env/env_convert.c \
 	src/env/env_manip.c \

src/buffer/buffer.c

@@ -0,0 +1,104 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   buffer.c                                           :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: kcolin <marvin@42.fr>                      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2024/12/12 12:39:58 by kcolin            #+#    #+#             */
+/*   Updated: 2025/02/14 18:19:49 by khais            ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "buffer.h"
+#include "libft.h"
+#include <stdlib.h>
+
+t_buffer	*ft_buffer_new(void)
+{
+	t_buffer	*out;
+
+	out = ft_calloc(1, sizeof(t_buffer));
+	if (out == NULL)
+		return (NULL);
+	out->length = 0;
+	out->capacity = SL_BUFFER_SIZE;
+	out->buffer = ft_calloc(SL_BUFFER_SIZE, sizeof(char));
+	if (out->buffer == NULL)
+	{
+		free(out);
+		return (NULL);
+	}
+	return (out);
+}
+
+void	ft_buffer_free(t_buffer *buffer)
+{
+	if (buffer != NULL)
+		free(buffer->buffer);
+	free(buffer);
+}
+
+/*
+** grows the buffer such that the new capacity is 1.5 times the old.
+**
+** in case of error, free all memory and return null.
+** else return buffer.
+*/
+t_buffer	*ft_buffer_grow(t_buffer *buffer)
+{
+	char	*newbuffer;
+
+	if (buffer == NULL)
+		return (NULL);
+	newbuffer = ft_calloc(buffer->capacity * 1.5, sizeof(char));
+	if (newbuffer == NULL)
+	{
+		ft_buffer_free(buffer);
+		return (NULL);
+	}
+	ft_memcpy(newbuffer, buffer->buffer, buffer->length);
+	free(buffer->buffer);
+	buffer->buffer = newbuffer;
+	buffer->capacity *= 1.5;
+	return (buffer);
+}
+
+t_buffer	*ft_buffer_pushchar(t_buffer *buffer, char c)
+{
+	if (buffer == NULL)
+		return (NULL);
+	if (buffer->length + 1 < buffer->capacity)
+	{
+		buffer->buffer[buffer->length] = c;
+		buffer->length++;
+	}
+	else
+	{
+		buffer = ft_buffer_grow(buffer);
+		buffer = ft_buffer_pushchar(buffer, c);
+	}
+	return (buffer);
+}
+
+/*
+** push buf to the end of buffer, growing buffer if needed.
+**
+** the number of bytes to copy to buffer is n.
+** returns buffer.
+** in case of error, all memory is freed and null is returned.
+*/
+t_buffer	*ft_buffer_push_buf(t_buffer *buffer, char *buf, size_t n)
+{
+	if (buffer == NULL)
+		return (NULL);
+	while (buffer->length + n > buffer->capacity)
+	{
+		buffer = ft_buffer_grow(buffer);
+		if (buffer == NULL)
+			return (NULL);
+	}
+	ft_memcpy(buffer->buffer + buffer->length, buf, n);
+	buffer->length += n;
+	return (buffer);
+}

src/buffer/buffer.h

@@ -0,0 +1,45 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   buffer.h                                           :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: kcolin <marvin@42.fr>                      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2024/12/12 12:35:28 by kcolin            #+#    #+#             */
+/*   Updated: 2025/02/14 18:20:08 by khais            ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#ifndef BUFFER_H
+# define BUFFER_H
+
+# include <stddef.h>
+
+typedef struct s_buffer
+{
+	size_t	length;
+	size_t	capacity;
+	char	*buffer;
+}	t_buffer;
+
+# ifndef SL_BUFFER_SIZE
+#  define SL_BUFFER_SIZE 64
+# endif
+# if SL_BUFFER_SIZE <= 0
+#  error "SL_BUFFER_SIZE must be at least 1"
+# endif
+
+# ifndef SL_READ_BUFFER_SIZE
+#  define SL_READ_BUFFER_SIZE 64
+# endif
+# if SL_READ_BUFFER_SIZE <= 0
+#  error "SL_READ_BUFFER_SIZE must be at least 1"
+# endif
+
+// implemented in buffer.c
+t_buffer	*ft_buffer_new(void);
+void		ft_buffer_free(t_buffer *buffer);
+t_buffer	*ft_buffer_pushchar(t_buffer *buffer, char c);
+t_buffer	*ft_buffer_push_buf(t_buffer *buffer, char *buf, size_t n);
+
+#endif