SharpDlt

A pure, dependency free .NET library to read AUTOSAR DLT (Diagnostic Log and Trace) data.

The parser is modelled after the PyDLT reader, but exposes an idiomatic C# API: the entry point is a function that turns a stream into a lazily evaluated sequence of DLT messages.

Usage

using SharpDlt;

// From a file (the file is opened and closed by the reader)
foreach (var message in DltReader.ReadMessages("trace.dlt"))
{
    Console.WriteLine(message);
}

// From any stream (the caller keeps ownership of the stream)
using var stream = File.OpenRead("trace.dlt");
foreach (var message in DltReader.ReadMessages(stream))
{
    if (message.VerbosePayload is { } payload)
    {
        foreach (var argument in payload.Arguments)
        {
            Console.WriteLine(argument);
        }
    }
}

// Asynchronously
await foreach (var message in DltReader.ReadMessagesAsync("trace.dlt"))
{
    Console.WriteLine(message.StandardHeader.Timestamp);
}

Options are passed via DltReaderOptions:

var options = new DltReaderOptions
{
    HasStorageHeader = false,             // messages without a Storage Header, e.g. from a socket
    StringEncoding = Encoding.Latin1,     // encoding of 8 bit coded string arguments (default: ASCII)
};

var messages = DltReader.ReadMessages(stream, options);

A single message can also be parsed from a span of bytes:

var message = DltMessage.Parse(bytes, options);

Object model

Type	Description
DltMessage	Storage Header, Standard Header, Extended Header and payload of one message
StorageHeader	Timestamp and ECU ID of a message stored in a DLT file
StandardHeader	Header type, message counter, length and the optional ECU ID, session ID and timestamp
ExtendedHeader	Verbose flag, message type and type info, argument count, application and context ID
NonVerbosePayload	Message ID and non-static data
VerbosePayload	List of DltArgument values
DltArgument	DltBoolArgument, DltSignedArgument, DltUnsignedArgument, DltFloatArgument, DltStringArgument, DltRawArgument

All of these are records, so they can be compared, deconstructed and pattern matched. DltMessage.ToString() renders the same overview line as the reference implementation.

Behavior

• Reading stops silently as soon as the remaining data does not contain a complete message.
• Malformed data throws a DltParseException.
• If a numeric argument at the end of a payload has fewer bytes than its declared type, it is reduced to the next smaller type, which mirrors DLT Viewer and the reference implementation.
• Not supported (as in the reference implementation): arrays, structs, trace info, variable info, fixed point and 128 bit types.

Development

dotnet build
dotnet test
dotnet csharpier format .

This project uses git hooks for code style checks. Activate them by including the .githooks file:

git config --local include.path ../.githooks