Hashmap improvements and include guards

Hashmap capacity can be set programmatically and it grows/shrinks in
size when the load increases/decreases to avoid collisions/save memory.

1 files changed, 41 insertions, 8 deletions

diff --git a/src/hashmap.h b/src/hashmap.h
index dbb45da..5a1e22d 100644
--- a/src/hashmap.h
+++ b/src/hashmap.h
@@ -1,13 +1,46 @@
-#define HASHMAP_CAP 26
+#ifndef UNJA_HASHMAP_H
+#define UNJA_HASHMAP_H
+#include <stdbool.h>
+#include <sys/types.h>
+
+#ifndef HASHMAP_CAP
+#define HASHMAP_CAP 32
+#endif
+
+#ifndef HASHMAP_MIN_LOAD
+#define HASHMAP_MIN_LOAD 0.2
+#endif
+
+#ifndef HASHMAP_MAX_LOAD
+#define HASHMAP_MAX_LOAD 0.75
+#endif
+
+#ifndef HASHMAP_GROW_RATE
+#define HASHMAP_GROW_RATE 2
+#endif
 
 struct hashmap {
-    struct node *buckets[HASHMAP_CAP];
+    struct node **buckets;
+    size_t init_cap;
+    size_t cur_cap;
+    size_t size;
 };
 
-struct hashmap *hashmap_new();
-void *hashmap_insert(struct hashmap *hm, char *key, void *value);
-void *hashmap_get(struct hashmap *hm, char *key);
-void *hashmap_resolve(struct hashmap *hm, char *key);
-void *hashmap_remove(struct hashmap *hm, char *key);
+/* allocate a new hashmap */
+struct hashmap *hashmap_new_with_cap(size_t cap);
+
+#define hashmap_new() hashmap_new_with_cap(HASHMAP_CAP)
+
+void *hashmap_insert(struct hashmap *hm, const char *key, void *value);
+
+void *hashmap_get(struct hashmap *hm, const char *key);
+
+void *hashmap_resolve(struct hashmap *hm, const char *key);
+
+void *hashmap_remove(struct hashmap *hm, const char *key);
+
 void hashmap_free(struct hashmap *hm);
-void hashmap_walk(struct hashmap *hm, void (*fn)(void *value));
\ No newline at end of file
+
+void hashmap_walk(struct hashmap *hm, void (*fn)(void *value));
+
+#endif