Recorded data processing

The resol-vbus-core provides classes to encoded and decode VBus data primitives from and to their storable recording representation as specified by the VBus Recording File Format Specification.

See VBus Recording File Format for details.

Encoding

Encoding VBus data primitives

The three VBus data primitives Packet, Datagram and Telegram can be encoded using their respective function:

• encodePacketRecord
• encodeDatagramRecord
• encodeTelegramRecord

They each encode their VBus data primitive into an Uint8Array containing the bytes in recording representation.

Encode Start-Of-Header-Set

To mark the beginning of a group of VBus data primitives that are stored together at a certain point in time, the encodeStartOfHeaderSetRecord can be used to generate a S-O-H-S record.

See encodeStartOfHeaderSetRecord function API for details.

Encode VBus channel

Some VBus products support more than one channel. The "VBus channel marker" is used announce that all subsequent records originate from the provided VBus channel. The function encodeChannelRecord can be used to generate that record.

See encodeChannelRecord function API for details.

Encode a complete HeaderSet

The encodeHeaderSetRecords combines the five previously mentioned functions by generating an array of Uint8Array buffers of encodeStartOfHeaderSetRecord followed by the encode___Record and optional encodeChannelRecord for every VBus data primitive in the provided HeaderSet argument.

See encodeHeaderSetRecords function API for details.

Decoding

The RecordingDecoder class decodes incoming Uint8Array data and tries to decode records from it. Whenever a record was decoded, the respective callback is called to inform the consumer of the decoded data.

import { RecordingDecoder } from 'resol-vbus-core';

const decoder = new RecordingDecoder({
  onStartOfHeaderSet(timestamp) {
    // ...
  },

  onPacket(packet) {
    // ...
  },

  onEndOfHeaderSet(timestamp) {
    // NOTE: called before the next S-O-H record generates a `onStartOfHeaderSet` or when the stream of data end with `end()`
  },
});

const bytesToDecode = new Uint8Array(... /* TODO: insert data here */);

decoder.decode(bytesToDecode);
// TODO: optionally decode more chunks of data here

// signal to the decoder that no addional data is expected, forcing it to process the data from its internal buffer
decoder.end();

See RecordingDecoder class API for details.