Interpretasi flame chart — analisis sample frame { name, startMs, endMs, parent }.

1. buildCallTree(samples)

• Return root-level samples dengan children nested: { name, self, total, children: [...] }
• total = endMs - startMs
• self = total - jumlah total semua direct children
• Bulatkan ke integer

2. longTasks(samples, threshold)

• Return array name dari sample root-level (parent = null) yang total > threshold ms — ini Long Task (> 50ms = jank)
• Sorted descending by total

3. fpsFromFrames(frameStarts)

• frameStarts: array timestamp (ms) saat frame diselesaikan
• Hitung FPS = 1000 / rata-rata gap antar frame (bulatkan)
• Return 0 kalau kurang dari 2 frame

Hint

• buildCallTree: group samples by parent. Root = samples with parent === null. Untuk tiap sample: children = samples.filter(s => s.parent === sample.name). total = endMs - startMs. self = total - sum(children.total).
• Build rekursif: function build(sample) { const children = samples.filter(s => s.parent === sample.name).map(build); const total = sample.endMs - sample.startMs; const self = total - sumChildrenTotal; return { name, self: Math.round(self), total: Math.round(total), children }; }.
• longTasks: samples.filter(s => s.parent === null && (s.endMs - s.startMs) > threshold).sort((a,b) => (b.endMs - b.startMs) - (a.endMs - a.startMs)).map(s => s.name). fpsFromFrames: kalau length < 2 → 0; else avg gap = (last - first)/(length - 1); Math.round(1000/avg).