Function createLegacyDetectionSample

src/pkg/utils/encoding.ts:110–128

(data: Uint8Array)

};

const createLegacyDetectionSample = (data: Uint8Array): Uint8Array => {
  const n = data.length;
  if (n <= LEGACY_SAMPLE_LIMIT) return data;

  let firstHighByteIndex = -1;
  for (let i = 0; i < n; i++) {
    if (data[i] >= 0x80) {
      firstHighByteIndex = i;
      break;
    }
  }

  if (firstHighByteIndex < 0) {
    return data.subarray(0, LEGACY_SAMPLE_LIMIT);
  }

  const sampleStart = Math.max(0, Math.min(firstHighByteIndex - 8 * 1024, n - LEGACY_SAMPLE_LIMIT));
  return data.subarray(sampleStart, sampleStart + LEGACY_SAMPLE_LIMIT);
};

const assertLikelyUtf8 = (data: Uint8Array): void => {
  if (data.length <= FULL_UTF8_VALIDATE_LIMIT) {