Generic hash implementation

include/hashtable.h

@@ -0,0 +1,71 @@
+#ifndef HASHTABLE_H
+#define HASHTABLE_H
+
+#include <stdlib.h>
+#include <string.h>
+
+// entry in the hashtable
+typedef struct entry
+{
+	const char *key;
+	void *value;
+	struct entry *next;
+} entry;
+
+// hashtable
+typedef struct
+{
+	int size;
+	entry **table;
+} hashtable;
+
+/**
+ * @brief Create a new hashtable
+ *
+ * This function creates a new hashtable with the specified size.
+ * It initializes the table with NULL entries.
+ *
+ * @param size The size of the hashtable
+ * @return A pointer to the newly created hashtable
+ */
+hashtable *hashtable_new(int size);
+
+/**
+ * @brief Insert a new key-value pair into the hashtable
+ *
+ * This function inserts a new key-value pair into the hashtable.
+ * It calculates the index using the hash function and inserts the
+ * key-value pair at the beginning of the linked list at that index.
+ *
+ * @param h Pointer to the hashtable
+ * @param key Pointer to the key
+ * @param value Pointer to the value
+ */
+void hashtable_insert(hashtable *h, const char *key, void *value);
+
+/**
+ * @brief Get the value associated with a key from the hashtable
+ *
+ * This function takes a hashtable and a key as input and returns the
+ * value associated with the key. If the key is not found in the
+ * hashtable, it returns NULL.
+ *
+ * @param h Pointer to the hashtable
+ * @param key Pointer to the key
+ * @return Pointer to the value associated with the key, or NULL if not found
+ */
+void *hashtable_lookup(hashtable *h, const char *key);
+
+/**
+ * @brief Remove a key-value pair from the hashtable
+ *
+ * This function removes a key-value pair from the hashtable.
+ * It calculates the index using the hash function and traverses
+ * the linked list at that index. If the key is found, it removes
+ * the corresponding entry from the linked list and frees the memory.
+ *
+ * @param h Pointer to the hashtable
+ * @param key Pointer to the key to remove
+ */
+void hashtable_remove(hashtable *h, const char *key);
+#endif