1 files changed, 47 insertions, 0 deletions
diff --git a/hashmap.h b/hashmap.h
new file mode 100644
index 0000000000..4c946e35b9
--- /dev/null
+++ b/hashmap.h
@@ -0,0 +1,47 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+#ifndef foohashmaphfoo
+#define foohashmaphfoo
+
+#include <stdbool.h>
+
+/* Pretty straightforward hash table implementation. As a minor
+ * optimization a NULL hashmap object will be treated as empty hashmap
+ * for all read operations. That way it is not necessary to
+ * instantiate an object for each Hashmap use. */
+
+typedef struct Hashmap Hashmap;
+
+typedef unsigned (*hash_func_t)(const void *p);
+typedef int (*compare_func_t)(const void *a, const void *b);
+
+unsigned string_hash_func(const void *p);
+int string_compare_func(const void *a, const void *b);
+
+unsigned trivial_hash_func(const void *p);
+int trivial_compare_func(const void *a, const void *b);
+
+Hashmap *hashmap_new(hash_func_t hash_func, compare_func_t compare_func);
+void hashmap_free(Hashmap*);
+
+int hashmap_put(Hashmap *h, const void *key, void *value);
+void* hashmap_get(Hashmap *h, const void *key);
+void* hashmap_remove(Hashmap *h, const void *key);
+
+unsigned hashmap_size(Hashmap *h);
+bool hashmap_isempty(Hashmap *h);
+
+void *hashmap_iterate(Hashmap *h, void **state, const void **key);
+void *hashmap_iterate_backwards(Hashmap *h, void **state, const void **key);
+
+void *hashmap_steal_first(Hashmap *h);
+void* hashmap_first(Hashmap *h);
+void* hashmap_last(Hashmap *h);
+
+#define HASHMAP_FOREACH(e, h, state) \
+        for ((state) = NULL, (e) = hashmap_iterate((h), &(state), NULL); (e); (e) = hashmap_iterate((h), &(state), NULL))
+
+#define HASHMAP_FOREACH_BACKWARDS(e, h, state) \
+        for ((state) = NULL, (e) = hashmap_iterate_backwards((h), &(state), NULL); (e); (e) = hashmap_iterate_backwards((h), &(state), NULL))
+
+#endif