fix: Makes gump type id stable (#1358)

This commit is contained in:
Kamron Batman 2023-03-02 19:29:57 -08:00 committed by GitHub
parent 57ff488d51
commit 50d52fb25e
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 60 additions and 4 deletions

View file

@ -81,7 +81,15 @@ public partial class Gump
public bool Closable { get; set; } = true;
public static int GetTypeID(Type type) => type?.FullName?.GetHashCode(StringComparison.Ordinal) ?? -1;
public static int GetTypeID(Type type)
{
unchecked
{
// To use the original .NET Framework deterministic hash code (with really bad performance)
// change the next line to use HashUtility.GetNetFrameworkHashCode
return (int)HashUtility.ComputeHash32(type?.FullName);
}
}
public void AddPage(int page)
{

View file

@ -14,6 +14,7 @@
*************************************************************************/
using System;
using System.Numerics;
using System.Runtime.CompilerServices;
using Standart.Hash.xxHash;
@ -25,7 +26,8 @@ namespace Server;
public enum FastHashAlgorithm
{
None, // Used for collisions where full-data is serialized instead
XXHash3_64, // xxHash3 64bit
XxHash3_64, // xxHash3 64bit
XxHash_32, // xxHash 32bit
}
public static class HashUtility
@ -34,15 +36,61 @@ public static class HashUtility
// * Computed hashes might be serialized against this seed! *
// **********************************************************
private const ulong xxHash3Seed = 9609125370673258709ul; // Randomly generated 64-bit prime number
private const uint xxHash1Seed = 665738807u; // Randomly generated 32-bit prime number
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static ulong ComputeHash64(string? data, FastHashAlgorithm algorithm = FastHashAlgorithm.XXHash3_64) =>
public static ulong ComputeHash64(string? data, FastHashAlgorithm algorithm = FastHashAlgorithm.XxHash3_64) =>
algorithm switch
{
FastHashAlgorithm.XXHash3_64 => ComputeXXHash3_64(data),
FastHashAlgorithm.XxHash3_64 => ComputeXXHash3_64(data),
_ => throw new NotSupportedException($"Hash {algorithm} is not supported.")
};
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static ulong ComputeXXHash3_64(string? data) => data == null ? 0 : xxHash3.ComputeHash(data, xxHash3Seed);
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint ComputeHash32(string? data, FastHashAlgorithm algorithm = FastHashAlgorithm.XxHash_32) =>
algorithm switch
{
FastHashAlgorithm.XxHash_32 => ComputeXXHash_32(data),
_ => throw new NotSupportedException($"Hash {algorithm} is not supported.")
};
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint ComputeXXHash_32(string? data) => data == null ? 0 : xxHash32.ComputeHash(data, xxHash1Seed);
public static unsafe int GetNetFrameworkHashCode(this string? str)
{
if (str == null)
{
return 0;
}
fixed (char* src = &str.GetPinnableReference())
{
uint hash1 = (5381 << 16) + 5381;
uint hash2 = hash1;
uint* ptr = (uint*)src;
int length = str.Length;
while (length > 2)
{
length -= 4;
// Where length is 4n-1 (e.g. 3,7,11,15,19) this additionally consumes the null terminator
hash1 = (BitOperations.RotateLeft(hash1, 5) + hash1) ^ ptr[0];
hash2 = (BitOperations.RotateLeft(hash2, 5) + hash2) ^ ptr[1];
ptr += 2;
}
if (length > 0)
{
// Where length is 4n-3 (e.g. 1,5,9,13,17) this additionally consumes the null terminator
hash2 = (BitOperations.RotateLeft(hash2, 5) + hash2) ^ ptr[0];
}
return (int)(hash1 + hash2 * 1566083941);
}
}
}