Added hashmap source files

hashmap.c

@@ -0,0 +1,164 @@
+// SPDX-License-Identifier: BSD-2
+
+#include <hashmap.h>
+#include <stdlib.h>
+
+#define MAP_INIT_SIZE 1024
+
+struct hashmap_elem {
+	int key;
+	int in_use;
+	void *val;
+};
+
+struct hashmap_map {
+	int max_size;
+	int curr_size;
+	struct hashmap_elem *data;
+};
+
+map_t hashmap_new(void)
+{
+	struct hashmap_map *m;
+
+	m = calloc(1, sizeof(struct hashmap_map));
+	if (!m)
+		goto err;
+
+	m->data = calloc(MAP_INIT_SIZE, sizeof(struct hashmap_elem));
+	if (!m->data)
+		goto err;
+
+	m->max_size = MAP_INIT_SIZE;
+	m->curr_size = 0;
+
+	return m;
+
+err:
+	hashmap_free(m);
+	return NULL;
+}
+
+unsigned int _hashmap_hash_int(struct hashmap_map *m, unsigned int key)
+{
+	key += (key << 12);
+	key ^= (key >> 22);
+	key += (key << 4);
+	key ^= (key >> 9);
+	key += (key << 10);
+	key ^= (key >> 2);
+	key += (key << 7);
+	key ^= (key >> 12);
+
+	key = (key >> 3) * 2654435761;
+
+	return key % m->max_size;
+}
+
+int _hashmap_hash(struct hashmap_map *m, int key)
+{
+	int pos;
+	int i;
+
+	if (m->curr_size == m->max_size)
+		return MAP_FULL;
+
+	pos = _hashmap_hash_int(m, key);
+	i = 0;
+
+	while (i < m->max_size) {
+		if (!m->data[pos].in_use)
+			return pos;
+
+		if (m->data[pos].key == key && m->data[pos].in_use)
+			return pos;
+
+		pos = (pos + 1) % m->max_size;
+		i++;
+	}
+
+	return MAP_FULL;
+}
+
+int _hashmap_rehash(struct hashmap_map *m)
+{
+	int i;
+	int old_size;
+	int status;
+	struct hashmap_elem *curr;
+	struct hashmap_elem *temp;
+
+	temp = calloc(2 * m->max_size, sizeof(struct hashmap_elem));
+	if (!temp)
+		return MAP_OMEM;
+
+	curr = m->data;
+	m->data = temp;
+
+	old_size = m->max_size;
+	m->max_size *= 2;
+	m->curr_size = 0;
+
+	for (i = 0; i < old_size; i++) {
+		status = hashmap_put(m, curr[i].key, curr[i].val);
+		if (status != MAP_OK)
+			return status;
+	}
+
+	free(curr);
+
+	return MAP_OK;
+}
+
+int hashmap_put(map_t map, int key, void *value)
+{
+	int index;
+	struct hashmap_map *m;
+
+	m = (struct hashmap_map *) map;
+	index = _hashmap_hash(m, key);
+
+	while (index == MAP_FULL) {
+		if (_hashmap_rehash(m) == MAP_OMEM)
+			return MAP_OMEM;
+		index = _hashmap_hash(m, key);
+	}
+
+	m->data[index] = (struct hashmap_elem) {key, 1, value};
+	m->curr_size++;
+
+	return MAP_OK;
+}
+
+int hashmap_get(map_t map, int key, void **ret_val)
+{
+	int pos;
+	int i;
+	struct hashmap_map *m;
+
+	m = (struct hashmap_map *) map;
+	pos = _hashmap_hash_int(m, key);
+	i = 0;
+
+	while (i < m->max_size) {
+		if (m->data[pos].key == key && m->data[pos].in_use) {
+			*ret_val = m->data[pos].val;
+			return MAP_OK;
+		}
+
+		pos = (pos + 1) % m->max_size;
+		i++;
+	}
+
+	*ret_val = NULL;
+	return MAP_MISSING;
+}
+
+void hashmap_free(map_t map)
+{
+	struct hashmap_map *m;
+
+	m = (struct hashmap_map *) map;
+	free(m->data);
+	free(m);
+}

include/hashmap.h

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: BSD-2 */
+
+#ifndef _hashmap_h
+#define _hashmap_h
+
+#define MAP_OK       0
+#define MAP_OMEM    -1
+#define MAP_FULL    -2
+#define MAP_MISSING -3
+
+typedef void *map_t;
+
+extern map_t hashmap_new(void);
+extern void hashmap_free(map_t map);
+
+extern int hashmap_put(map_t map, int key, void *val);
+extern int hashmap_get(map_t map, int key, void **ret_val);
+
+#endif

so-cpp.c

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: BSD-2
+
+#include "hashmap.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+int main(void)
+{
+	char *saved_str = calloc(1, sizeof(char *));
+
+	map_t m = hashmap_new();
+	hashmap_put(m, 2, "Salut");
+	hashmap_get(m, 2, (void **) &saved_str);
+	hashmap_free(m);
+
+	printf("%s\n", saved_str);
+	return 0;
+}