Function readCommandBounds

packages/core/src/__tests__/drawlistDecode.ts:69–89

(bytes: Uint8Array)

}

function readCommandBounds(bytes: Uint8Array): Readonly<{ cmdOffset: number; cmdEnd: number }> {
  if (bytes.byteLength < HEADER_SIZE) {
    throw new Error(`drawlist too small for header (len=${String(bytes.byteLength)})`);
  }

  const cmdOffset = u32(bytes, 16);
  const cmdBytes = u32(bytes, 20);
  const cmdEnd = cmdOffset + cmdBytes;
  if (cmdBytes === 0) return { cmdOffset, cmdEnd };
  if (cmdOffset < HEADER_SIZE || cmdOffset > bytes.byteLength) {
    throw new Error(
      `drawlist cmdOffset out of bounds (cmdOffset=${String(cmdOffset)}, len=${String(bytes.byteLength)})`,
    );
  }
  if (cmdEnd < cmdOffset || cmdEnd > bytes.byteLength) {
    throw new Error(
      `drawlist cmd range out of bounds (cmdOffset=${String(cmdOffset)}, cmdBytes=${String(cmdBytes)}, len=${String(bytes.byteLength)})`,
    );
  }
  return { cmdOffset, cmdEnd };
}

export function parseCommandHeaders(bytes: Uint8Array): readonly DrawlistCommandHeader[] {
  const { cmdOffset, cmdEnd } = readCommandBounds(bytes);