diff --git a/uppsrc/Core/Hash.h b/uppsrc/Core/Hash.h
index cf136e495..981be4fc1 100644
--- a/uppsrc/Core/Hash.h
+++ b/uppsrc/Core/Hash.h
@@ -75,4 +75,20 @@ public:
 int xxHash(const void *data, size_t len);
 int xxHash(const String& s);
 
+class xxHash64Stream : public OutStream {
+	byte context[12 * 8];
+	
+	virtual  void  Out(const void *data, dword size);
+
+public:
+	int64 Finish();
+	
+	void Reset(dword seed = 0);
+	
+	xxHash64Stream(dword seed = 0);
+};
+
+int64 xxHash64(const void *data, size_t len);
+int64 xxHash64(const String& s);
+
 #endif
diff --git a/uppsrc/Core/xxHsh.cpp b/uppsrc/Core/xxHsh.cpp
index efadbba47..dfd98cf4c 100644
--- a/uppsrc/Core/xxHsh.cpp
+++ b/uppsrc/Core/xxHsh.cpp
@@ -38,4 +38,38 @@ int xxHash(const String& s)
 	return xxHash(~s, s.GetCount());
 }
 
+xxHash64Stream::xxHash64Stream(dword seed)
+{
+	STATIC_ASSERT(sizeof(context) >= sizeof(XXH64_state_t));
+	Reset(seed);
+}
+
+void xxHash64Stream::Reset(dword seed)
+{
+	XXH64_reset((XXH64_state_t *)context, seed);
+}
+
+void xxHash64Stream::Out(const void *data, dword size)
+{
+	XXH64_update((XXH64_state_t *)context, data, size);
+}
+
+int64 xxHash64Stream::Finish()
+{
+	Flush();
+	return XXH64_digest((XXH64_state_t *)context);
+}
+
+int64 xxHash64(const void *data, size_t len)
+{
+	xxHash64Stream h;
+	h.Put64(data, len);
+	return h.Finish();
+}
+
+int64 xxHash64(const String& s)
+{
+	return xxHash64(~s, s.GetCount());
+}
+
 };
\ No newline at end of file