public static RecordType GetNextRecordType(IStreamReader reader)
{
long position = reader.BaseStream.Position;
// read type of the next record
var nextRecord = (RecordType)reader.ReadUInt16();
ushort length = reader.ReadUInt16();
// skip leading StartBlock/EndBlock records
if (nextRecord == RecordType.StartBlock ||
nextRecord == RecordType.EndBlock ||
nextRecord == RecordType.StartObject ||
nextRecord == RecordType.EndObject ||
nextRecord == RecordType.ChartFrtInfo)
{
// skip the body of the record
reader.ReadBytes(length);
// get the type of the next record
return(GetNextRecordType(reader));
}
else if (nextRecord == RecordType.FrtWrapper)
{
// return type of wrapped Biff record
var frtWrapper = new FrtWrapper(reader, nextRecord, length);
reader.BaseStream.Position = position;
return(frtWrapper.wrappedRecord.Id);
}
else
{
// seek back to the begin of the current record
reader.BaseStream.Position = position;
return(nextRecord);
}
}
public static BiffRecord ReadRecord(IStreamReader reader)
{
BiffRecord result = null;
try
{
var id = (RecordType)reader.ReadUInt16();
ushort length = reader.ReadUInt16();
// skip leading StartBlock/EndBlock records
if (id == RecordType.StartBlock ||
id == RecordType.EndBlock ||
id == RecordType.StartObject ||
id == RecordType.EndObject ||
id == RecordType.ChartFrtInfo)
{
// skip the body of this record
reader.ReadBytes(length);
// get the next record
return(ReadRecord(reader));
}
else if (id == RecordType.FrtWrapper)
{
// return type of wrapped Biff record
var frtWrapper = new FrtWrapper(reader, id, length);
return(frtWrapper.wrappedRecord);
}
Type cls;
if (TypeToRecordClassMapping.TryGetValue((ushort)id, out cls))
{
var constructor = cls.GetConstructor(
new Type[] { typeof(IStreamReader), typeof(RecordType), typeof(ushort) }
);
try
{
result = (BiffRecord)constructor.Invoke(
new object[] { reader, id, length }
);
}
catch (TargetInvocationException e)
{
throw e.InnerException;
}
}
else
{
result = new UnknownBiffRecord(reader, (RecordType)id, length);
}
return(result);
}
catch (OutOfMemoryException e)
{
throw new Exception("Invalid BIFF record", e);
}
}
