Btukfyl

I have 1m ohlc data coming from an external WebSocket API and I am trying to generate 5m 15m 30m 1h 1d and 1w streams from it. My current TransformStream can convert 1m to one of the above mentioned timeframes

How do I do

one.pipe(five)

one.pipe(fifteen)

one.pipe(thirty)

without creating multiple instances of the original stream "one". Currently my single TransformStream instance emits the original data plus all the required timeframes.

class TimeFrameGenerator extends Transform {

    constructor(timeframes) {

        super({ readableObjectMode: true, writableObjectMode: true });

        this.kline = {}



        //Consider using an object for this, looping with a for in is much faster for this case than using an array or accessing object keys

        this.timeframes = {

            "1m": 1000 * 60,

            "5m": 1000 * 60 * 5,

            "15m": 1000 * 60 * 15,

            "30m": 1000 * 60 * 30,

            "1h": 1000 * 60 * 60,

            "1d": 1000 * 60 * 60 * 24

        }

    }



    _transform(rawKline, encoding, callback) {



        this.push(rawKline);



        const { pairId, base, quote, interval, openTime, closeTime, timestamp, open, high, low, close, baseVolume, quoteVolume, isFinal, raw } = rawKline;



        if (typeof this.kline[pairId] === "undefined")

            this.kline[pairId] = {};



        for (let timeframe in this.timeframes) {

            if (timeframe === interval)

                continue;



            const millis = this.timeframes[timeframe];



            const resampledOpenTime = Math.floor(openTime / millis) * millis;

            const resampledCloseTime = Math.ceil(openTime / millis) * millis - 1;



            if (typeof this.kline[pairId][timeframe] === "undefined") {

                this.kline[pairId][timeframe] = {};

            }



            if (typeof this.kline[pairId][timeframe][resampledOpenTime] === "undefined") {

                const newKline = {

                    pairId: pairId,

                    base: base,

                    quote: quote,

                    interval: timeframe,

                    openTime: resampledOpenTime,

                    closeTime: resampledCloseTime,

                    timestamp: timestamp,

                    open: open,

                    high: high,

                    low: low,

                    close: close,

                    baseVolume: baseVolume,

                    quoteVolume: quoteVolume,

                    isFinal: false,

                    raw: null

                }



                this.kline[pairId][timeframe][resampledOpenTime] = {

                    kline: newKline,

                    prevBaseVol: 0,

                    prevQuoteVol: 0

                }

            }

            else {

                const { kline, prevBaseVol, prevQuoteVol } = this.kline[pairId][timeframe][resampledOpenTime];

                kline.high = high > kline.high ? high : kline.high;

                kline.low = low < kline.low ? low : kline.low;

                kline.close = close;

                kline.baseVolume = parseFloat((prevBaseVol + baseVolume).toFixed(PRECISION));

                kline.quoteVolume = parseFloat((prevQuoteVol + quoteVolume).toFixed(PRECISION));

            }



            if (isFinal) {

                const { prevBaseVol, prevQuoteVol } = this.kline[pairId][timeframe][resampledOpenTime];

                this.kline[pairId][timeframe][resampledOpenTime].prevBaseVol = parseFloat((prevBaseVol + baseVolume).toFixed(PRECISION));

                this.kline[pairId][timeframe][resampledOpenTime].prevQuoteVol = parseFloat((prevQuoteVol + quoteVolume).toFixed(PRECISION));

            }



            let keys = Object.keys(this.kline[pairId][timeframe]);



            if (keys.length > 1) {

                let previousTimestamp = keys.shift();

                this.kline[pairId][timeframe][previousTimestamp]['kline'].isFinal = true;

                this.push(this.kline[pairId][timeframe][previousTimestamp].kline);

                delete this.kline[pairId][timeframe][previousTimestamp];

                console.log(Object.keys(this.kline[pairId][timeframe]).length, Object.keys(this.kline[pairId]).length)

            }



            this.push(this.kline[pairId][timeframe][resampledOpenTime].kline);

        }



        callback()

    }

}

I am new to streams and some idea would be super appreciated
Should I create multiple TransformStream instances, one for each timeframe