Function handleTick

examples/candlestick-streaming/main.ts:163–214

(tick: Tick)

}

function handleTick(tick: Tick) {
  // Advance simulated time (so we can close candles faster than real time).
  const now = performance.now();
  const dtRealMs = Math.max(0, now - lastSimPerfNow);
  lastSimPerfNow = now;
  simulatedTimeMs += dtRealMs * timeScale;

  // Drive the candle aggregator from ticks, but using simulated time.
  candleAggregator.processTick({ ...tick, timestamp: Math.floor(simulatedTimeMs) });

  // Update the current (forming) candle in real-time.
  const currentCandle = candleAggregator.getCurrentCandle();
  if (currentCandle) {
    const isSameCandle = data.length > 0 && getTimestamp(data[data.length - 1]) === getTimestamp(currentCandle);

    if (isSameCandle) {
      // Update existing (forming) candle
      data[data.length - 1] = currentCandle;

      // Throttled update for current candle (every ~100ms)
      throttledUpdateCurrentCandle();
    } else {
      // New candle period started — append the new candle once, then update it as it forms.
      data.push(currentCandle);

      // Memory management: trim old candles
      const maxCandles = getMaxCandles(currentCandleCount);
      if (data.length > maxCandles) {
        data = data.slice(data.length - maxCandles);
        // Preserve full options when trimming data
        const series0 = fullChartOptions.series?.[0];
        if (series0 && series0.type === 'candlestick') {
          fullChartOptions = {
            ...fullChartOptions,
            series: [
              {
                ...series0,
                data,
              },
            ],
          };
          chart.setOption(fullChartOptions);
        }
      } else {
        // Efficient append (candlesticks supported)
        chart.appendData(0, [currentCandle]);
      }
    }
  }

  updatePrice(tick.price);
}

// Throttle current candle updates to avoid overwhelming the GPU
let lastCurrentCandleUpdate = 0;