skeletton untested project

libft/ft_hashmap/ft_hashmap_utils_two.c

@@ -0,0 +1,85 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_hashmap_utils_two.c                             :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: thrieg <thrieg@student.42mulhouse.fr>      +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2024/11/07 16:04:36 by thrieg            #+#    #+#             */
+/*   Updated: 2025/02/16 19:08:31 by thrieg           ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "ft_hashmap_private.h"
+
+//doesn't allocate anything no error possible
+void	ft_copy_hashmap_table(
+t_list **new_table,
+t_list **old_table,
+size_t new_size,
+size_t old_size)
+{
+	t_list			*curr;
+	t_list			*next;
+	t_hash_element	*elem;
+	size_t			i;
+	size_t			new_index;
+
+	i = 0;
+	while (i < old_size)
+	{
+		curr = old_table[i];
+		while (curr)
+		{
+			next = curr->next;
+			elem = (t_hash_element *)curr->content;
+			new_index = elem->hash % new_size;
+			curr->next = new_table[new_index];
+			new_table[new_index] = curr;
+			curr = next;
+		}
+		i++;
+	}
+}
+
+//helper function for delete_hashmap_element to delete the node once found
+void	ft_delete_hashmap_list_node(
+t_list *curr,
+t_list *prev,
+size_t index,
+t_hashmap *map)
+{
+	t_hash_element	*elem;
+
+	elem = (t_hash_element *)curr->content;
+	if (prev)
+		prev->next = curr->next;
+	else
+		map->table[index] = curr->next;
+	ft_free_hash_element(elem, map);
+	free(curr);
+	map->nb_elems--;
+}
+
+//returns 0 without doing anything if the allocation of the new table fails
+//or if the table is too little in that case the old table is still valid!
+//returns 1 if the shrink is a success
+int	ft_shrink_hashmap(t_hashmap *map)
+{
+	size_t	new_size;
+	t_list	**new_table;
+
+	if (map->hashmap_size == HASHMAP_MINIMUM_SIZE)
+		return (0);
+	new_size = map->hashmap_size / HASHMAP_SHRINK_FACTOR;
+	if (new_size < HASHMAP_MINIMUM_SIZE)
+		new_size = HASHMAP_MINIMUM_SIZE;
+	new_table = ft_calloc(new_size, sizeof(t_list *));
+	if (!new_table)
+		return (0);
+	ft_copy_hashmap_table(new_table, map->table, new_size, map->hashmap_size);
+	free(map->table);
+	map->table = new_table;
+	map->hashmap_size = new_size;
+	return (1);
+}