util/khash: Add hash_hash_string_part()

headers/private/kernel/util/khash.h

@@ -60,7 +60,8 @@ void hash_dump_table(struct hash_table* table);
  *		the key, returning 0 if equal, other if not
  */
 
-uint32 hash_hash_string(const char *str);
+uint32 hash_hash_string(const char *string);
+uint32 hash_hash_string_part(const char *string, size_t maxLength);
 
 #ifdef __cplusplus
 }

src/system/kernel/util/khash.cpp

@@ -398,6 +398,23 @@ hash_hash_string(const char *string)
 }
 
 
+uint32
+hash_hash_string_part(const char *string, size_t maxLength)
+{
+	uint32 hash = 0;
+	char c;
+
+	// we assume hash to be at least 32 bits
+	while (maxLength-- > 0 && (c = *string++) != 0) {
+		hash ^= hash >> 28;
+		hash <<= 4;
+		hash ^= c;
+	}
+
+	return hash;
+}
+
+
 uint32
 hash_count_elements(struct hash_table *table)
 {