public virtual WzooBlock ParseBlock(MemoryStream ms)
{
if (ms.Position == ms.Length)
{
return(null);
}
var sizeBuffer = new byte[4];
var block = new WzooBlock();
ms.Read(sizeBuffer, 0, 4);
block.BlockLength = BigEndian.ToInt32(sizeBuffer, 0);
ms.Read(sizeBuffer, 0, 4);
block.BlockVersion = BigEndian.ToInt32(sizeBuffer, 0);
ms.Read(block.DeviceType, 0, 12);
ms.Read(block.ConfigType, 0, 4);
var dataLength = block.BlockLength - 24;
block.BlockData = new byte[dataLength];
ms.Read(block.BlockData, 0, dataLength);
return(block);
}
public MagicBlock ParseMagicBlock(WzooBlock block)
{
var magicBlock = new MagicBlock();
if (BlockMagic.Length != 4)
{
throw new Exception(
$"the block magic was expected to be 4 bytes in length, found a length of {BlockMagic.Length}");
}
magicBlock.BlockMagic = BlockMagic;
using (var ms = new MemoryStream(block.BlockData))
{
if (!ContainsMagicBlock(block))
{
// Block without magic
magicBlock.IsMagicBlock = false;
ms.Seek(32, SeekOrigin.Begin);
var blockDataLength = block.BlockData.Length - 32;
magicBlock.BlockData = new byte[blockDataLength];
ms.Read(magicBlock.BlockData, 0, blockDataLength);
}
else
{
ms.Seek(36, SeekOrigin.Begin);
var pluginNameLengthBuffer = new byte[4];
ms.Read(pluginNameLengthBuffer, 0, 4);
var pluginNameLength = BigEndian.ToInt32(pluginNameLengthBuffer, 0);
magicBlock.PluginName = new byte[pluginNameLength];
ms.Read(magicBlock.PluginName, 0, pluginNameLength);
var blockDataLength = block.BlockData.Length - 4 - pluginNameLength - 36;
magicBlock.BlockData = new byte[blockDataLength];
ms.Read(magicBlock.BlockData, 0, blockDataLength);
}
}
return(magicBlock);
}
public bool ContainsMagicBlock(WzooBlock block)
{
using (var ms = new MemoryStream(block.BlockData))
{
var emptyBuffer = new byte[4];
var empty = new byte[] { 0xDE, 0xAD, 0xBE, 0xEF };
ms.Seek(-4, SeekOrigin.End);
ms.Read(emptyBuffer, 0, 4);
if (!emptyBuffer.SequenceEqual(empty))
{
return(false);
}
}
return(true);
}
