Files
OpenRA/OpenRA.Mods.Cnc/FileSystem/PackageEntry.cs
2021-05-08 22:20:59 +02:00

111 lines
2.7 KiB
C#

#region Copyright & License Information
/*
* Copyright 2007-2020 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.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 $"0x{Hash:x8} - offset 0x{Offset:x8} - length 0x{Length:x8}";
}
public static uint HashFilename(string name, PackageHashType type)
{
switch (type)
{
case PackageHashType.Classic:
{
name = name.ToUpperInvariant();
if (name.Length % 4 != 0)
name = name.PadRight(name.Length + (4 - name.Length % 4), '\0');
var result = 0u;
var data = Encoding.ASCII.GetBytes(name);
var i = 0;
while (i < data.Length)
{
var next = (uint)(data[i++] | data[i++] << 8 | data[i++] << 16 | data[i++] << 24);
result = ((result << 1) | (result >> 31)) + next;
}
return result;
}
case PackageHashType.CRC32:
{
name = name.ToUpperInvariant();
var l = name.Length;
var a = l >> 2;
if ((l & 3) != 0)
{
name += (char)(l - (a << 2));
var i = 3 - (l & 3);
while (i-- != 0)
name += name[a << 2];
}
return CRC32.Calculate(Encoding.ASCII.GetBytes(name));
}
default: throw new NotImplementedException($"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);
}
}
}