server

1 files changed, 64 insertions, 0 deletions

diff --git a/loader/server/fnv.hpp b/loader/server/fnv.hpp
new file mode 100644
index 0000000..08a478b
--- /dev/null
+++ b/loader/server/fnv.hpp
@@ -0,0 +1,64 @@
+#pragma once
+
+#pragma warning( disable : 4307 ) // '*': integral constant overflow
+#pragma warning( disable : 4244 ) // possible loss of data
+
+#include <cstdint>
+#include <string>
+
+using hash_t = unsigned int;
+
+// used for compile-time FNV-1a 32bit hashes.
+#define fnv( str )                                 \
+    [&]() {                                        \
+        constexpr hash_t out = hash::fnv1a( str ); \
+                                                   \
+        return out;                                \
+    }()
+
+// used for compile-time FNV-1a 32bit hashes when above macro cant be used for constexpr variables.
+#define fnv_const( str ) Hash::fnv1a_32( str )
+
+namespace hash // FNV-1a ( Fowler-Noll-Vo hash ).
+{
+	// FNV-1a constants.
+	enum : hash_t {
+		FNV1A_PRIME = 0x1000193,
+		FNV1A_BASIS = 0x811C9DC5
+	};
+
+	// compile-time strlen.
+	__forceinline constexpr size_t ct_strlen( const char *str ) {
+		size_t out = 1;
+
+		for( ; str[ out ] != '\0'; ++out );
+
+		return out;
+	}
+
+	// hash data.
+	__forceinline constexpr hash_t fnv1a( const uint8_t *data, const size_t len ) {
+		hash_t out = FNV1A_BASIS;
+
+		for( size_t i = 0; i < len; ++i )
+			out = ( out ^ data[ i ] ) * FNV1A_PRIME;
+
+		return out;
+	}
+
+	// hash c-style string.
+	__forceinline constexpr hash_t fnv1a( const char *str ) {
+		hash_t out = FNV1A_BASIS;
+		size_t len = ct_strlen( str );
+
+		for( size_t i = 0; i < len; ++i )
+			out = ( out ^ str[ i ] ) * FNV1A_PRIME;
+
+		return out;
+	}
+
+	// hash C++-style string ( runtime only ).
+	__forceinline hash_t fnv1a( const std::string &str ) {
+		return fnv1a( ( uint8_t* )str.c_str( ), str.length( ) );
+	}
+}
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