Added hashtable

include/hashtable.h

@@ -1,23 +1,16 @@
 #ifndef HASHTABLE_H
 #define HASHTABLE_H
 
-#include <stdlib.h>
-#include <string.h>
+#include <stdbool.h>
 
-// entry in the hashtable
-typedef struct entry
-{
-	const char *key;
-	void *value;
-	struct entry *next;
-} entry;
+struct htobj;
+typedef struct htobj *hashtable;
 
-// hashtable
-typedef struct
-{
-	int size;
-	entry **table;
-} hashtable;
+typedef struct {
+	struct htobj *h;
+	struct entry *entry;
+	int index;
+} ht_iterator;
 
 /**
  * @brief Create a new hashtable
@@ -28,7 +21,7 @@ typedef struct
  * @param size The size of the hashtable
  * @return A pointer to the newly created hashtable
  */
-hashtable *hashtable_new(int size);
+hashtable hashtable_new(int size);
 
 /**
  * @brief Insert a new key-value pair into the hashtable
@@ -40,8 +33,9 @@ hashtable *hashtable_new(int size);
  * @param h Pointer to the hashtable
  * @param key Pointer to the key
  * @param value Pointer to the value
+ * @return null or pointer to the previous value of the key
  */
-void hashtable_insert(hashtable *h, const char *key, void *value);
+void *hashtable_set(hashtable h, const char *key, void *value);
 
 /**
  * @brief Get the value associated with a key from the hashtable
@@ -54,7 +48,7 @@ void hashtable_insert(hashtable *h, const char *key, void *value);
  * @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);
+void *hashtable_lookup(hashtable h, const char *key);
 
 /**
  * @brief Remove a key-value pair from the hashtable
@@ -66,6 +60,57 @@ void *hashtable_lookup(hashtable *h, const char *key);
  *
  * @param h Pointer to the hashtable
  * @param key Pointer to the key to remove
+ * @return null or value associated with the removed key.
  */
-void hashtable_remove(hashtable *h, const char *key);
+void *hashtable_remove(hashtable h, const char *key);
+
+/**
+ * @brief Destroy hashtable.
+ *
+ * Values must be destroyed by the caller earlier.
+ *
+ * @param h Reference to the hastable.
+ */
+void hashtable_destroy(hashtable h);
+
+/**
+ * @brief Get the iterator of key-value pairs in the hashtable
+ *
+ * This function returns the iterator of key-value pairs in the hashtable.
+ *
+ * @param h Pointer to the hashtable
+ * @return The iterator of key-value pairs in the hashtable
+ */
+ht_iterator hashtable_iter(hashtable h);
+
+/**
+ * @brief Get the next key-value pair from the iterator
+ *
+ * This function returns the next key-value pair from the iterator.
+ *
+ * @param iter Pointer to the iterator
+ * @return true if there is a next key-value pair, false otherwise
+ */
+bool ht_iter_next(ht_iterator *iter);
+
+/**
+ * @brief Get the key from the iterator
+ *
+ * This function returns the key from the iterator.
+ *
+ * @param iter Pointer to the iterator
+ * @return The key from the iterator
+ */
+const char *ht_iter_key(ht_iterator *iter);
+
+/**
+ * @brief Get the value from the iterator
+ *
+ * This function returns the value from the iterator.
+ *
+ * @param iter Pointer to the iterator
+ * @return The value from the iterator
+ */
+void *ht_iter_value(ht_iterator *iter);
+
 #endif