From 29a98de0e05cb04001b42a55b1ae094ab42f2ab1 Mon Sep 17 00:00:00 2001
From: Matthew <matthew@sleepy.day>
Date: Sat, 13 Sep 2025 11:04:40 +1000
Subject: [PATCH] add alternate hash functions

---
 external/xxhash/xxhash.d | 10 ++++-----
 util.d                   | 46 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 5 deletions(-)

diff --git a/external/xxhash/xxhash.d b/external/xxhash/xxhash.d
index cff5682..fa2b386 100644
--- a/external/xxhash/xxhash.d
+++ b/external/xxhash/xxhash.d
@@ -1052,7 +1052,7 @@ enum XXH3_INTERNALBUFFER_SIZE = 256; ///The size of the internal XXH3 buffer.
  * See: XXH3_INITSTATE() for stack initialization.
  * See: XXH32_state_s, XXH64_state_s
  */
-private align(64) struct XXH3_state_t
+align(64) struct XXH3_state_t
 {
     align(64) XXH64_hash_t[8] acc;
     /** The 8 accumulators. See XXH32_state_s::v and XXH64_state_s::v */
@@ -1799,7 +1799,7 @@ XXH64_hash_t xxh3_64bits_withSecretandSeed(
 
 /* ===   XXH3 streaming   === */
 
-private void XXH3_INITSTATE(XXH3_state_t* XXH3_state_ptr)
+void XXH3_INITSTATE(XXH3_state_t* XXH3_state_ptr)
     @safe nothrow @nogc
 {
     (XXH3_state_ptr).seed = 0;
@@ -1860,7 +1860,7 @@ private XXH_errorcode xxh3_64bits_reset_withSecret(
 }
 
 /* XXH PUBLIC API - hidden in D module */
-private XXH_errorcode xxh3_64bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed)
+XXH_errorcode xxh3_64bits_reset_withSeed(XXH3_state_t* statePtr, XXH64_hash_t seed)
     @safe pure nothrow @nogc
 {
     if (statePtr == null)
@@ -2065,7 +2065,7 @@ do
 }
 
 /* XXH PUBLIC API - hidden in D module */
-private XXH_errorcode xxh3_64bits_update(scope XXH3_state_t* state, scope const(void)* input, size_t len)
+XXH_errorcode xxh3_64bits_update(scope XXH3_state_t* state, scope const(void)* input, size_t len)
     @safe pure nothrow @nogc
 {
     return xxh3_update(state, cast(const(ubyte)*) input, len,
@@ -2104,7 +2104,7 @@ private void xxh3_digest_long(XXH64_hash_t* acc, const XXH3_state_t* state, cons
 }
 
 /* XXH PUBLIC API - hidden in D module */
-private XXH64_hash_t xxh3_64bits_digest(const XXH3_state_t* state)
+XXH64_hash_t xxh3_64bits_digest(const XXH3_state_t* state)
     @trusted pure nothrow @nogc
 {
     const ubyte* secret = (state.extSecret == null) ? &state.customSecret[0] : &state.extSecret[0];
diff --git a/util.d b/util.d
index 53996e0..d1166dd 100644
--- a/util.d
+++ b/util.d
@@ -9,6 +9,7 @@ import includes;
 import std.stdio;
 import std.conv;
 import std.string;
+import std.traits;
 
 import core.stdc.string : memset;
 import core.simd;
@@ -535,6 +536,36 @@ Hash(string str)
 	return xxh3_64bits_withSeed(str.ptr, str.length, HASH_SEED);
 }
 
+pragma(inline) u64
+Hash(void* ptr_1, u64 len_1, void* ptr_2, u64 len_2)
+{
+	XXH3_state_t xxh;
+	XXH3_INITSTATE(&xxh);
+	xxh3_64bits_reset_withSeed(&xxh, HASH_SEED);
+	xxh3_64bits_update(&xxh, ptr_1, len_1);
+	xxh3_64bits_update(&xxh, ptr_2, len_2);
+
+	return xxh3_64bits_digest(&xxh);
+}
+
+pragma(inline) u64
+Hash(T, U)(T value_1, U value_2) if (isArray!(T) && isArray!(U))
+{
+	return Hash(value_1.ptr, value_1.length*T.sizeof, value_2.ptr, value_2.length*U.sizeof);
+}
+
+pragma(inline) u64
+Hash(T, U)(T value_1, U value_2) if (isArray!(T) && !isArray!(U))
+{
+	return Hash(value_1.ptr, value_1.length*value_1[0].sizeof, &value_2, U.sizeof);
+}
+
+pragma(inline) u64
+Hash(T, U)(T value_1, U value_2) if (!isArray!(T) && !isArray!(U))
+{
+	return Hash(&value_1, T.sizeof, &value_2, U.sizeof);
+}
+
 pragma(inline) u64
 RDTSC()
 {
@@ -1002,6 +1033,21 @@ unittest
 		table[100] = 100;
 	}
 
+	{ // Hash
+		u8[10] arr_1 = 5;
+		u64[10] arr_2 = 555;
+		u64 val_1 = 555555;
+		u32 val_2 = 33333;
+
+		u64 v1 = Hash(arr_1, arr_2);
+		u64 v2 = Hash(arr_1, val_1);
+		u64 v3 = Hash(val_1, val_2);
+
+		assert(v1 > 0);
+		assert(v2 > 0);
+		assert(v3 > 0);
+	}
+
 	{ // Stack
 		Stack!(u32) stack;
 		Arena arena = CreateArena(MB(1));