public LogicalRecordSegmentEncryptionPacket ReadLogicalRecordSegmentEncryptionPacket(Stream dlisStream)
{
if (dlisStream == null)
{
return(null);
}
if (dlisStream.BytesRemaining() < 4)
{
return(null);
}
var size = _unormReader.ReadUNORM(dlisStream);
if (size < 4)
{
return(null);
}
if (dlisStream.BytesRemaining() < size - 4)
{
return(null);
}
return(new LogicalRecordSegmentEncryptionPacket
{
Size = size,
CompanyCode = _unormReader.ReadUNORM(dlisStream),
EncryptionInfo = dlisStream.ReadBytes(size - 4)
});
}
public LogicalRecordSegmentTrailer ReadLogicalRecordSegmentTrailer(Stream dlisStream, LogicalRecordSegmentHeader header)
{
if (dlisStream == null)
{
return(null);
}
if (dlisStream.IsAtBeginningOfStream())
{
return(null);
}
if (header == null)
{
return(null);
}
if (!header.HasTrailer())
{
return(null);
}
var trailer = new LogicalRecordSegmentTrailer();
if (header.TrailingLength)
{
dlisStream.Seek(-2, SeekOrigin.Current);
}
if (header.Checksum)
{
dlisStream.Seek(-2, SeekOrigin.Current);
}
if (header.Padding)
{
dlisStream.Seek(-1, SeekOrigin.Current);
trailer.PadCount = _ushortReader.ReadUSHORT(dlisStream);
dlisStream.Seek(-trailer.PadCount, SeekOrigin.Current);
trailer.Padding = dlisStream.ReadBytes(trailer.PadCount);
}
if (header.Checksum)
{
trailer.Checksum = _unormReader.ReadUNORM(dlisStream);
}
if (header.TrailingLength)
{
trailer.TrailingLength = _unormReader.ReadUNORM(dlisStream);
}
return(trailer);
}
public LogicalRecordSegmentHeader ReadLogicalRecordSegmentHeader(Stream dlisStream)
{
if (dlisStream == null)
{
return(null);
}
if (dlisStream.BytesRemaining() < 4)
{
return(null);
}
return(new LogicalRecordSegmentHeader
{
LogicalRecordSegmentLength = _unormReader.ReadUNORM(dlisStream),
LogicalRecordSegmentAttributes = _ushortReader.ReadUSHORT(dlisStream),
LogicalRecordType = _ushortReader.ReadUSHORT(dlisStream)
});
}
public VisibleRecord ReadVisibleRecord(Stream dlisStream)
{
if (dlisStream == null)
{
return(null);
}
var visibleRecord = new VisibleRecord
{
Length = _unormReader.ReadUNORM(dlisStream),
FormatVersionField1 = _ushortReader.ReadUSHORT(dlisStream),
FormatVersionField2 = _ushortReader.ReadUSHORT(dlisStream)
};
if (visibleRecord.FormatVersionField1 != 255 || visibleRecord.FormatVersionField2 != 1)
{
throw new Exception("invalid visible record format");
}
var logicalRecordSegmentData = dlisStream.ReadBytes(visibleRecord.Length - 4);
if (logicalRecordSegmentData == null)
{
throw new Exception("invalid visible record length");
}
var logicalRecordSegments = new List <LogicalRecordSegment>();
using (var lrsStream = new MemoryStream(logicalRecordSegmentData))
{
while (!lrsStream.IsAtEndOfStream())
{
var lrs = _logicalRecordSegmentBusiness.ReadLogicalRecordSegment(lrsStream);
if (lrs == null)
{
throw new Exception("invalid logical record segment");
}
logicalRecordSegments.Add(lrs);
}
}
visibleRecord.Segments = logicalRecordSegments.ToArray();
return(visibleRecord);
}
