Function parseUploadResumeOffset

src/upload-stream.ts:235–252

(
  headers: IncomingHttpHeaders,
  payloadSize: number,
)

}

function parseUploadResumeOffset(
  headers: IncomingHttpHeaders,
  payloadSize: number,
): number | undefined {
  const explicitOffset = parseNonNegativeIntegerHeader(
    headers['x-upload-offset'] ?? headers['upload-offset'],
  );
  if (explicitOffset !== undefined) {
    return Math.min(explicitOffset, payloadSize);
  }

  const range = firstHeaderValue(headers.range);
  const match = range?.match(/^bytes=0-(\d+)$/);
  if (!match) return undefined;
  const endOffset = Number(match[1]);
  if (!Number.isSafeInteger(endOffset) || endOffset < 0) return undefined;
  return Math.min(endOffset + 1, payloadSize);
}

function parseNonNegativeIntegerHeader(value: string | string[] | undefined): number | undefined {
  const raw = firstHeaderValue(value);