GARbro-mirror/ArcFormats/PalmTree/ArcAR.cs

167 lines
6.0 KiB
C#

//! \file ArcAR.cs
//! \date 2018 Jan 22
//! \brief PalmTree script engine resource archive.
//
// Copyright (C) 2018 by morkt
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.IO;
using GameRes.Formats.PkWare;
namespace GameRes.Formats.PalmTree
{
/// <summary>
/// Ordinary PkWare ZIP archive with 'PK' signature changed to 'AR'
/// </summary>
[Export(typeof(ArchiveFormat))]
public class ArcOpener : ZipOpener
{
public override string Tag { get { return "ARC/AR"; } }
public override string Description { get { return "PalmTree script engine resource archive"; } }
public override uint Signature { get { return 0; } }
public override bool IsHierarchic { get { return true; } }
public override bool CanWrite { get { return false; } }
static readonly byte[] ArDirSignature = { (byte)'A', (byte)'R', 5, 6 };
public override ArcFile TryOpen (ArcView file)
{
if (-1 == SearchForSignature (file, ArDirSignature))
return null;
var input = new ArPkStream (file.CreateStream());
try
{
return OpenZipArchive (file, input);
}
catch
{
input.Dispose();
throw;
}
}
public override ResourceOptions GetDefaultOptions ()
{
return null;
}
}
/// <summary>
/// Stream that changes all 'AR' signatures to 'PK' on the fly.
/// </summary>
/// <remarks>
/// this is almost like reading ZIP file directory, maybe just write custom ZIP archive reader instead?
/// </remarks>
internal class ArPkStream : InputProxyStream
{
List<long> m_ar_blocks;
long m_last_scan_pos;
bool m_scan_failed;
public ArPkStream (Stream input) : base (input)
{
m_ar_blocks = new List<long>();
m_last_scan_pos = 0;
m_scan_failed = false;
}
public override int Read (byte[] buffer, int offset, int count)
{
long pos = this.Position;
if (pos + count > m_last_scan_pos && !m_scan_failed)
{
BuildDirectory (pos + count);
this.Position = pos;
}
count = BaseStream.Read (buffer, offset, count);
if (0 == count)
return count;
long buf_pos = pos;
long buf_end = buf_pos + count;
int index = m_ar_blocks.BinarySearch (buf_pos-1);
if (index < 0)
index = ~index;
for (; index < m_ar_blocks.Count; ++index)
{
var ar_pos = m_ar_blocks[index];
if (buf_end <= ar_pos)
break;
if (buf_pos >= ar_pos+2)
continue;
int signature_pos = (int)(ar_pos - pos);
if (signature_pos >= 0)
buffer[offset+signature_pos] = (byte)'P';
++signature_pos;
if (signature_pos >= 0 && signature_pos < count)
buffer[offset+signature_pos] = (byte)'K';
buf_pos = ar_pos + 2;
}
return count;
}
byte[] pk_buffer = new byte[0x22];
void BuildDirectory (long last_pos)
{
long pos = m_last_scan_pos;
while (pos < last_pos)
{
this.Position = pos;
int read = BaseStream.Read (pk_buffer, 0, 0x22);
if (read < 4 || !pk_buffer.AsciiEqual ("AR"))
{
m_scan_failed = true;
break;
}
m_ar_blocks.Add (pos);
uint block_type = pk_buffer.ToUInt16 (2);
if (0x0201 == block_type && read >= 0x22)
{
uint name_length = pk_buffer.ToUInt16 (0x1C);
uint extra_length = pk_buffer.ToUInt16 (0x1E);
uint cmt_length = pk_buffer.ToUInt16 (0x20);
pos += 0x2EL + name_length + extra_length + cmt_length;
}
else if (0x0403 == block_type && read >= 0x1E)
{
uint packed_size = pk_buffer.ToUInt32 (0x12);
uint name_length = pk_buffer.ToUInt16 (0x1A);
uint extra_length = pk_buffer.ToUInt16 (0x1C);
pos += 0x1EL + name_length + extra_length + packed_size;
}
else if (0x0605 == block_type && read >= 0x16)
{
uint cmt_length = pk_buffer.ToUInt16 (0x14);
pos += 0x16L + cmt_length;
}
else
{
pos += 4;
m_scan_failed = true;
}
}
m_last_scan_pos = pos;
}
}
}