Simplify hashing approach `map`

2 files changed, 14 insertions, 2 deletions

diff --git a/core/runtime/core.odin b/core/runtime/core.odin
index 74b1338c7..b0c76720a 100644
--- a/core/runtime/core.odin
+++ b/core/runtime/core.odin
@@ -42,8 +42,10 @@ Platform_Endianness :: enum u8 {
 	Big      = 2,
 }
 
-Equal_Proc  :: distinct proc "contextless" (rawptr, rawptr) -> bool;
-Hasher_Proc :: distinct proc "contextless" (data: rawptr, seed: uintptr) -> uintptr;
+// Procedure type to test whether two values of the same type are equal
+Equal_Proc :: distinct proc "contextless" (rawptr, rawptr) -> bool;
+// Procedure type to hash a value, default seed value is 0
+Hasher_Proc :: distinct proc "contextless" (data: rawptr, seed: uintptr = 0) -> uintptr;
 
 Type_Info_Struct_Soa_Kind :: enum u8 {
 	None    = 0,
diff --git a/core/runtime/dynamic_map_internal.odin b/core/runtime/dynamic_map_internal.odin
index 99c2e92ee..8ae366db3 100644
--- a/core/runtime/dynamic_map_internal.odin
+++ b/core/runtime/dynamic_map_internal.odin
@@ -110,6 +110,16 @@ default_hasher_string :: proc "contextless" (data: rawptr, seed: uintptr) -> uin
 	}
 	return uintptr(h);
 }
+default_hasher_cstring :: proc "contextless" (data: rawptr, seed: uintptr) -> uintptr {
+	h := u64(seed) + 0xcbf29ce484222325;
+	ptr := (^uintptr)(data)^;
+	for (^byte)(ptr)^ != 0 {
+		b := (^byte)(ptr)^;
+		h = (h ~ u64(b)) * 0x100000001b3;
+		ptr += 1;
+	}
+	return uintptr(h);
+}