3bee524c6b
This is a very frequently called method during loading, and taking some care to avoid allocations improves performance noticeably.
119 lines
3.3 KiB
C#
119 lines
3.3 KiB
C#
#region Copyright & License Information
|
|
/*
|
|
* Copyright 2007-2021 The OpenRA Developers (see AUTHORS)
|
|
* This file is part of OpenRA, which is free software. It is made
|
|
* available to you under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation, either version 3 of
|
|
* the License, or (at your option) any later version. For more
|
|
* information, see COPYING.
|
|
*/
|
|
#endregion
|
|
|
|
using System;
|
|
using System.Collections.Generic;
|
|
using System.IO;
|
|
using System.Runtime.InteropServices;
|
|
using System.Text;
|
|
using OpenRA.Mods.Cnc.FileFormats;
|
|
|
|
namespace OpenRA.Mods.Cnc.FileSystem
|
|
{
|
|
public enum PackageHashType { Classic, CRC32 }
|
|
|
|
public class PackageEntry
|
|
{
|
|
public const int Size = 12;
|
|
public readonly uint Hash;
|
|
public readonly uint Offset;
|
|
public readonly uint Length;
|
|
|
|
public PackageEntry(uint hash, uint offset, uint length)
|
|
{
|
|
Hash = hash;
|
|
Offset = offset;
|
|
Length = length;
|
|
}
|
|
|
|
public PackageEntry(Stream s)
|
|
{
|
|
Hash = s.ReadUInt32();
|
|
Offset = s.ReadUInt32();
|
|
Length = s.ReadUInt32();
|
|
}
|
|
|
|
public void Write(BinaryWriter w)
|
|
{
|
|
w.Write(Hash);
|
|
w.Write(Offset);
|
|
w.Write(Length);
|
|
}
|
|
|
|
public override string ToString()
|
|
{
|
|
if (names.TryGetValue(Hash, out var filename))
|
|
return $"{filename} - offset 0x{Offset:x8} - length 0x{Length:x8}";
|
|
else
|
|
return $"0x{Hash:x8} - offset 0x{Offset:x8} - length 0x{Length:x8}";
|
|
}
|
|
|
|
public static uint HashFilename(string name, PackageHashType type)
|
|
{
|
|
var padding = name.Length % 4 != 0 ? 4 - name.Length % 4 : 0;
|
|
var paddedLength = name.Length + padding;
|
|
|
|
// Avoid stack overflows by only allocating small buffers on the stack, and larger ones on the heap.
|
|
// 64 chars covers most real filenames.
|
|
var upperPaddedName = paddedLength < 64 ? stackalloc char[paddedLength] : new char[paddedLength];
|
|
name.AsSpan().ToUpperInvariant(upperPaddedName);
|
|
|
|
switch (type)
|
|
{
|
|
case PackageHashType.Classic:
|
|
{
|
|
for (var p = 0; p < padding; p++)
|
|
upperPaddedName[paddedLength - 1 - p] = '\0';
|
|
|
|
var asciiBytes = paddedLength < 64 ? stackalloc byte[paddedLength] : new byte[paddedLength];
|
|
Encoding.ASCII.GetBytes(upperPaddedName, asciiBytes);
|
|
|
|
var data = MemoryMarshal.Cast<byte, uint>(asciiBytes);
|
|
var result = 0u;
|
|
foreach (var next in data)
|
|
result = ((result << 1) | (result >> 31)) + next;
|
|
|
|
return result;
|
|
}
|
|
|
|
case PackageHashType.CRC32:
|
|
{
|
|
var length = name.Length;
|
|
var lengthRoundedDownToFour = length / 4 * 4;
|
|
if (length != lengthRoundedDownToFour)
|
|
{
|
|
upperPaddedName[length] = (char)(length - lengthRoundedDownToFour);
|
|
for (var p = 1; p < padding; p++)
|
|
upperPaddedName[length + p] = upperPaddedName[lengthRoundedDownToFour];
|
|
}
|
|
|
|
var asciiBytes = paddedLength < 64 ? stackalloc byte[paddedLength] : new byte[paddedLength];
|
|
Encoding.ASCII.GetBytes(upperPaddedName, asciiBytes);
|
|
|
|
return CRC32.Calculate(asciiBytes);
|
|
}
|
|
|
|
default: throw new NotImplementedException($"Unknown hash type `{type}`");
|
|
}
|
|
}
|
|
|
|
static Dictionary<uint, string> names = new Dictionary<uint, string>();
|
|
|
|
public static void AddStandardName(string s)
|
|
{
|
|
var hash = HashFilename(s, PackageHashType.Classic); // RA1 and TD
|
|
names.Add(hash, s);
|
|
var crcHash = HashFilename(s, PackageHashType.CRC32); // TS
|
|
names.Add(crcHash, s);
|
|
}
|
|
}
|
|
}
|