Add hash map implementation for sector deduplication

include/aaruformat/hash_map.h

@@ -0,0 +1,43 @@
+/*
+ * This file is part of the Aaru Data Preservation Suite.
+ * Copyright (c) 2019-2025 Natalia Portillo.
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of the
+ * License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIBAARUFORMAT_HASH_MAP_H
+#define LIBAARUFORMAT_HASH_MAP_H
+
+#include <stdbool.h>
+#include <stdlib.h>
+
+typedef struct
+{
+    uint64_t key;
+    uint64_t value;
+} kv_pair_t;
+
+typedef struct
+{
+    kv_pair_t *table;
+    size_t     size;
+    size_t     count;
+} hash_map_t;
+
+hash_map_t *create_map(size_t size);
+void free_map(hash_map_t *map);
+bool insert_map(hash_map_t *map, uint64_t key, uint64_t value);
+bool lookup_map(const hash_map_t *map, uint64_t key, uint64_t *out_value);
+
+#endif  // LIBAARUFORMAT_HASH_MAP_H