demo · v151

Bucketed Formula Explorer

Both quota formulas — the pre-Chrome 151 RAM-derived value and the Chrome 151 bucketed disk-derived value — applied side-by-side to your simulated device. Slide RAM, disk, and used quota and watch the leak open up or close.

Educational simulator. Formulas reproduced from the Chromium quota_calculator and the bucket-quota change-list. Values are illustrative; real Chrome computes from runtime memory and disk reads.
Patch constant: 10 GiB = 10 * 2^30 = 10,737,418,240 bytes. The v151 Incognito fix sets the private-mode estimate to the maximal bucket of usage + this 10 GiB value.

simulated device

16 GB
120 GB
30 MB

results

Pre-Chrome 151

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Chrome 151+

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code (the fix)

// Chromium pseudo-code: pre-Chrome 151 incognito branch.
function quotaIncognito_v0(ramBytes, usageBytes) {
  // Bucketed only against the RAM-derived raw value.
  const raw = ramBytes / 20;
  return Math.ceil(raw / 1e9) * 1e9 + usageBytes;
}

// Chromium pseudo-code: Chrome 151+ Incognito fix.
function quotaIncognito_v151(usageBytes) {
  const TEN_GIB_BYTES = 10n * 2n ** 30n; // 10,737,418,240 bytes
  return TEN_GIB_BYTES + BigInt(usageBytes);
}

see also

implementation reference

Need the exact API surface, compatibility boundaries, errors, lifecycle, and source links? Read the matching gendn reference ↗