e1e30998ba
## Changes * Improves type hashing by introducing xxHash3 (64bit) * Removes individual `tdb` files in favor of a single `SerializedTypes.db` file. This file is only used to identify a type that is being deserialized, which doesn't exist. * Adds duplicate type alias detection * Adds `AssemblyHandler.FindTypeByHash` View changed files whitespaces: https://github.com/modernuo/ModernUO/pull/1172/files?diff=split&w=1 ## SerializedTypes.db The serialized types file is used to get back the original name of a type in case it no longer exists in code. This can easily be necessary if a class is renamed in code and no `TypeAlias` is provided. ### Format byte[4] - version byte[4] - count --array-- byte[8] - xxHash byte[1] - flag, 0 - null, 1 - not null byte[n] - Full class name in UTF8 ### Example <img width="472" alt="SerializedTypes_Example" src="https://user-images.githubusercontent.com/3953314/195255429-31d24293-6bd1-419e-811b-07874dd0f78d.png"> ## Benchmarks Serialized 500 Type fields. The 8192bytes comes from the _ConcurrentQueue_ that would later be used for SerializedTypes. Note that the queue is never cleared, so it's size grew considerably. ```cs | Method | Mean | Error | StdDev | Allocated | |--------------------- |---------:|---------:|---------:|----------:| | BenchmarkXXHash | 18.44 us | 0.278 us | 0.260 us | 8192 B | | BenchmarkTypeStrings | 25.09 us | 0.292 us | 0.259 us | - | ``` TODO: * Add support in the Serialization Generator for `ReadType()` and `Write(Type)` * Remove `SetTypeRef` from Serialization Generator
48 lines
2.2 KiB
C#
48 lines
2.2 KiB
C#
/*************************************************************************
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* ModernUO *
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* Copyright 2019-2022 - ModernUO Development Team *
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* Email: hi@modernuo.com *
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* File: HashUtility.cs *
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* *
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* This program is free software: you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation, either version 3 of the License, or *
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* (at your option) any later version. *
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* *
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* You should have received a copy of the GNU General Public License *
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* along with this program. If not, see <http://www.gnu.org/licenses/>. *
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*************************************************************************/
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using System;
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using System.Runtime.CompilerServices;
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using Standart.Hash.xxHash;
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namespace Server;
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/// <summary>
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/// Represents supported non-cryptographic fast hash algorithms.
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/// </summary>
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public enum FastHashAlgorithm
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{
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None, // Used for collisions where full-data is serialized instead
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XXHash3_64, // xxHash3 64bit
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}
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public static class HashUtility
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{
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// *************** DO NOT CHANGE THIS NUMBER ****************
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// * Computed hashes might be serialized against this seed! *
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// **********************************************************
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private const ulong xxHash3Seed = 9609125370673258709ul; // Randomly generated 64-bit prime number
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public static ulong ComputeHash64(string? data, FastHashAlgorithm algorithm = FastHashAlgorithm.XXHash3_64) =>
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algorithm switch
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{
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FastHashAlgorithm.XXHash3_64 => ComputeXXHash3_64(data),
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_ => throw new NotSupportedException($"Hash {algorithm} is not supported.")
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};
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public static ulong ComputeXXHash3_64(string? data) => data == null ? 0 : xxHash3.ComputeHash(data, xxHash3Seed);
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}
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