add realloc, rename bloc to chunk, start thinking of chunk sizes

srcs/realloc.c

@@ -0,0 +1,77 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   realloc.c                                          :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: tomoron <tomoron@student.42angouleme.fr>   +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2024/12/02 14:41:22 by tomoron           #+#    #+#             */
+/*   Updated: 2024/12/02 19:54:00 by tomoron          ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "includes/malloc.h"
+t_mem_chunk *get_alloc_chunk(t_alloc *alloc, t_mem_chunk *first, size_t size);
+int	get_prev_alloc(t_alloc **alloc, t_alloc **res, t_alloc *cur);
+
+void *realloc_recreate(t_alloc *alloc, size_t size)
+{
+	void *new;
+	
+	new = malloc(size);
+	if(alloc->size < size)
+		size = alloc->size;
+	ft_memcpy(new, alloc + 1, size);
+	free(alloc + 1);	
+	return(new);
+}
+
+void *realloc_prealloc(t_alloc *alloc, t_mem_chunk *chunk, int is_small, size_t size)
+{
+	t_alloc *prev;
+
+	chunk = get_alloc_chunk(alloc, chunk, is_small);
+	if(!chunk)
+		return(0);
+	if(!get_prev_alloc(&alloc, &prev, chunk->first))
+		return(0);
+	if(alloc->size >= size)
+	{
+		chunk->space_left += alloc->size - size;
+		alloc->size = size;
+		return(alloc + 1);
+	}
+	if((size > (size_t)TINY_CHUNK_SIZE && is_small == 0)
+		|| (size > SMALL_CHUNK_SIZE && is_small == 1)
+		|| (t_ul)(alloc->next) - (t_ul)(alloc + 1) < size)
+		return(realloc_recreate(alloc, size));
+	chunk->space_left -= size - alloc->size;
+	alloc->size = size;
+	return(alloc + 1);
+}
+
+void *realloc_large(t_alloc *alloc, size_t size)
+{
+	t_alloc *prev;
+
+	if(!get_prev_alloc(&alloc, &prev, g_allocs.large))
+		return(0);
+	return(realloc_recreate(alloc, size));
+}
+
+void *realloc(void *ptr, size_t size)
+{
+	t_alloc *alloc;
+
+	if(!ptr)
+		return(malloc(size));
+	alloc = (t_alloc *)ptr - 1;
+	ptr = realloc_prealloc(alloc, g_allocs.tiny, 0, size);
+	if(ptr)
+		return(ptr);
+	ptr = realloc_prealloc(alloc, g_allocs.tiny, 1, size);
+	if(ptr)
+		return(ptr);
+	return(realloc_large(alloc, size));
+
+}