@signalk/streams/dist/n2kAnalyzer.js

Utilities for handling streams of Signal K data

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const child_process_1 = require("child_process");
const readline_1 = require("readline");
const stream_1 = require("stream");
class N2kAnalyzer extends stream_1.Transform {
    analyzerOutEvent;
    analyzerProcess;
    pipeTo = null;
    constructor(options) {
        super({ objectMode: true });
        this.analyzerOutEvent = options.analyzerOutEvent ?? 'N2KAnalyzerOut';
        if (process.platform === 'win32') {
            this.analyzerProcess = (0, child_process_1.spawn)('cmd', ['/c', 'analyzer -json -si -camel']);
        }
        else {
            this.analyzerProcess = (0, child_process_1.spawn)('sh', ['-c', 'analyzer -json -si -camel']);
        }
        this.analyzerProcess.stderr?.on('data', (data) => {
            console.error(data.toString());
        });
        this.analyzerProcess.on('close', (code) => {
            console.error('Analyzer process exited with code ' + code);
        });
        const linereader = (0, readline_1.createInterface)(this.analyzerProcess.stdout, this.analyzerProcess.stdin);
        linereader.on('line', (data) => {
            try {
                const parsed = JSON.parse(data);
                if (parsed.version) {
                    console.log('Connected to analyzer v' + parsed.version);
                    return;
                }
                this.push(parsed);
                options.app.emit(this.analyzerOutEvent, parsed);
            }
            catch (ex) {
                console.error(data);
                if (ex instanceof Error) {
                    console.error(ex.stack);
                }
            }
        });
    }
    _transform(chunk, encoding, done) {
        this.analyzerProcess.stdin?.write(chunk.toString() + '\n');
        done();
    }
    pipe(pipeTo) {
        this.pipeTo = pipeTo;
        return super.pipe(pipeTo);
    }
    end() {
        console.log('end, killing child analyzer process');
        this.analyzerProcess.kill();
        if (this.pipeTo) {
            this.pipeTo.end();
        }
        return this;
    }
}
exports.default = N2kAnalyzer;