/// <summary>
/// Reads a metadata directory from an input stream.
/// </summary>
/// <param name="context">The reader context.</param>
/// <param name="directoryReader">The input stream containing the metadata directory.</param>
/// <exception cref="ArgumentNullException">Occurs when any of the arguments are <c>null</c>.</exception>
/// <exception cref="NotSupportedException">Occurs when an unsupported metadata directory format was encountered.</exception>
/// <exception cref="BadImageFormatException">Occurs when the metadata directory header is invalid.</exception>
public SerializedMetadata(PEReaderContext context, IBinaryStreamReader directoryReader)
{
if (directoryReader == null)
{
throw new ArgumentNullException(nameof(directoryReader));
}
_context = context ?? throw new ArgumentNullException(nameof(context));
_streamContentsReader = directoryReader.Fork();
var signature = (MetadataSignature)directoryReader.ReadUInt32();
switch (signature)
{
case MetadataSignature.Bsjb:
// BSJB header is the default header.
break;
case MetadataSignature.Moc:
_context.NotSupported("Old +MOC metadata header format is not supported.");
return;
default:
_context.BadImage($"Invalid metadata header ({(uint) signature:X8}).");
return;
}
MajorVersion = directoryReader.ReadUInt16();
MinorVersion = directoryReader.ReadUInt16();
Reserved = directoryReader.ReadUInt32();
int versionLength = directoryReader.ReadInt32();
if (!directoryReader.CanRead(versionLength))
{
_context.BadImage($"Invalid version length in metadata header ({versionLength.ToString()} characters).");
return;
}
var versionBytes = new byte[versionLength];
directoryReader.ReadBytes(versionBytes, 0, versionBytes.Length);
VersionString = Encoding.ASCII.GetString(versionBytes);
Flags = directoryReader.ReadUInt16();
_numberOfStreams = directoryReader.ReadInt16();
_streamEntriesReader = directoryReader.Fork();
}
