stream-helper

---

Description

Install

$ npm install stream-helper

Usage

Define payload

export class DataTest extends Serializable {
 
    @SerializableInfo.position(0)
    @SerializableInfo.numberType(NumberType.UInt32)
    public number: number;
 
    @SerializableInfo.position(4)
    @SerializableInfo.textEncoding(TextEncoding.ASCII)
    @SerializableInfo.length(10)
    public text: string;
}

Create streams

Builder, write-only stream:

let builder = new StreamBuilder();
builder.startByte = 0x7E;
 
// Optional
builder.checksum = (d: Buffer) => CRC.default("CRC16_CCITT_FALSE").computeBuffer(d);

Parser, read-only stream:

let parser = new StreamParser(plManager);
parser.startByte = 0x7E;
 
// Optional
parser.crcFunction = (d: Buffer) => CRC.default("CRC16_CCITT_FALSE").computeBuffer(d);

Duplex, read-write stream:

var duplex = new StreamDuplex(plManager);
duplex.startByte = 0x7E;
 
// Optional
duplex.checksum = (d: Buffer) => CRC.default('CRC16_CCITT_FALSE').computeBuffer(d);

Configure I/O

builder.pipe(serialport);
 
serialport.pipe(parser);
 
serialport.pipe(duplex);
duplex.builder.pipe(serialport);

Send payload

let data = new DataTest();
data.number = 55;
data.text = "Hello!"
builder.write(data);

Configure payload manager using head

var plManager = new PayloadManager(1);
plManager.registerMessage([2], new DataTest());

Send payload with head

let data = new DataTest();
data.number = 55;
data.text = "Hello!"
builder.write(data);
// Or
duplex.send(data);

Receive and parse data

parser.on("data", (c) => console.info(c));

Log data

parser.trace = true;
parser.logFunction = (direction, start, len, head, payload, checksum) => 
    console.log(`${Buffer.from(direction).toString('hex')} 
                 ${Buffer.from(start).toString('hex')} 
                 ${Buffer.from(len).toString('hex')} 
                 ${Buffer.from(head).toString('hex').replace(/(\S{2})/g,"$1 ")} 
                 ${Buffer.from(payload).toString('hex').replace(/(\S{2})/g,"$1 ")} 
                 ${Buffer.from(checksum).toString('hex').replace(/(\S{2})/g,"$1 ")}`);

Samples

To build and run samples:

git clone https://github.com/RioloGiuseppe/stream-helper.git
cd stream-helper
 
npm run create-samples
# npm run build-samples 
 
node build/demo/examples/duplex-serialport.js

License

stream-helper packages are all MIT licensed and all it's dependencies are MIT licensed.

Related

• serial-port - Serial port library
• crc-full - Crc library
• byte-serializer - Crc library