diff -r fd3368c20413 -r 69a83fad8a35 src/hash_map.c
--- a/src/hash_map.c	Fri May 27 17:40:27 2022 +0200
+++ b/src/hash_map.c	Wed Jun 08 21:33:31 2022 +0200
@@ -30,60 +30,6 @@
 #include "cx/hash_map.h"
 #include "cx/utils.h"
 
-/**
- * Computes a murmur hash-2.
- *
- * @param data the data to hash
- * @param len the length of the data
- * @return the murmur hash-2 of the data
- */
-static unsigned cx_hash_map_murmur(
-        unsigned char const *data,
-        size_t len
-) {
-    unsigned m = 0x5bd1e995;
-    unsigned r = 24;
-    unsigned h = 25 ^ len;
-    unsigned i = 0;
-    while (len >= 4) {
-        unsigned k = data[i + 0] & 0xFF;
-        k |= (data[i + 1] & 0xFF) << 8;
-        k |= (data[i + 2] & 0xFF) << 16;
-        k |= (data[i + 3] & 0xFF) << 24;
-
-        k *= m;
-        k ^= k >> r;
-        k *= m;
-
-        h *= m;
-        h ^= k;
-
-        i += 4;
-        len -= 4;
-    }
-
-    switch (len) {
-        case 3:
-            h ^= (data[i + 2] & 0xFF) << 16;
-                    __attribute__((__fallthrough__));
-        case 2:
-            h ^= (data[i + 1] & 0xFF) << 8;
-                    __attribute__((__fallthrough__));
-        case 1:
-            h ^= (data[i + 0] & 0xFF);
-            h *= m;
-                    __attribute__((__fallthrough__));
-        default:
-            /* do nothing */;
-    }
-
-    h ^= h >> 13;
-    h *= m;
-    h ^= h >> 15;
-
-    return h;
-}
-
 static void cx_hash_map_clear(struct cx_map_s *map) {
     struct cx_hash_map_s *hash_map = (struct cx_hash_map_s *) map;
     cx_for_n(i, hash_map->bucket_count) {
@@ -92,7 +38,7 @@
             do {
                 struct cx_hash_map_element_s *next = elem->next;
                 // free the key data
-                cxFree(map->allocator, elem->key.data);
+                cxFree(map->allocator, elem->key.data.obj);
                 // free the node
                 cxFree(map->allocator, elem);
                 // proceed
@@ -119,13 +65,17 @@
 
 static int cx_hash_map_put(
         CxMap *map,
-        CxDataPtr key,
+        CxHashKey key,
         void *value
 ) {
     struct cx_hash_map_s *hash_map = (struct cx_hash_map_s *) map;
     CxAllocator *allocator = map->allocator;
 
-    unsigned hash = cx_hash_map_murmur(key.data, key.len);
+    unsigned hash = key.hash;
+    if (hash == 0) {
+        cx_hash_murmur(&key);
+        hash = key.hash;
+    }
 
     size_t slot = hash % hash_map->bucket_count;
     struct cx_hash_map_element_s *elm = hash_map->buckets[slot];
@@ -151,8 +101,8 @@
         if (kd == NULL) {
             return -1;
         }
-        memcpy(kd, key.data, key.len);
-        e->key.data = kd;
+        memcpy(kd, key.data.obj, key.len);
+        e->key.data.obj = kd;
         e->key.len = key.len;
         e->key.hash = hash;
 
@@ -187,7 +137,7 @@
         prev->next = elm->next;
     }
     // free element
-    cxFree(hash_map->base.allocator, elm->key.data);
+    cxFree(hash_map->base.allocator, elm->key.data.obj);
     cxFree(hash_map->base.allocator, elm);
     // decrease size
     hash_map->base.size--;
@@ -203,19 +153,23 @@
  */
 static void *cx_hash_map_get_remove(
         CxMap *map,
-        CxDataPtr key,
+        CxHashKey key,
         bool remove
 ) {
     struct cx_hash_map_s *hash_map = (struct cx_hash_map_s *) map;
 
-    unsigned hash = cx_hash_map_murmur(key.data, key.len);
+    unsigned hash = key.hash;
+    if (hash == 0) {
+        cx_hash_murmur(&key);
+        hash = key.hash;
+    }
 
     size_t slot = hash % hash_map->bucket_count;
     struct cx_hash_map_element_s *elm = hash_map->buckets[slot];
     struct cx_hash_map_element_s *prev = NULL;
     while (elm && elm->key.hash <= hash) {
         if (elm->key.hash == hash && elm->key.len == key.len) {
-            if (memcmp(elm->key.data, key.data, key.len) == 0) {
+            if (memcmp(elm->key.data.obj, key.data.obj, key.len) == 0) {
                 void *data = elm->data;
                 if (remove) {
                     cx_hash_map_unlink(hash_map, slot, prev, elm);
@@ -232,7 +186,7 @@
 
 static void *cx_hash_map_get(
         CxMap const *map,
-        CxDataPtr key
+        CxHashKey key
 ) {
     // we can safely cast, because we know when remove=false, the map stays untouched
     return cx_hash_map_get_remove((CxMap *) map, key, false);
@@ -240,7 +194,7 @@
 
 static void *cx_hash_map_remove(
         CxMap *map,
-        CxDataPtr key
+        CxHashKey key
 ) {
     return cx_hash_map_get_remove(map, key, true);
 }