Function parseRawTraceBuffer

src/trace-processing/parse.ts:27–75

(
  buffer: Uint8Array<ArrayBufferLike> | undefined,
  metadata?: {
    cpuThrottling?: number;
    networkThrottling?: string;
  },
)

}

export async function parseRawTraceBuffer(
  buffer: Uint8Array<ArrayBufferLike> | undefined,
  metadata?: {
    cpuThrottling?: number;
    networkThrottling?: string;
  },
): Promise<TraceResult | TraceParseError> {
  engine.resetProcessor();
  if (!buffer) {
    return {
      error: 'No buffer was provided.',
    };
  }
  const asString = new TextDecoder().decode(buffer);
  if (!asString) {
    return {
      error: 'Decoding the trace buffer returned an empty string.',
    };
  }
  try {
    const data = JSON.parse(asString) as
      | {
          traceEvents: DevTools.TraceEngine.Types.Events.Event[];
        }
      | DevTools.TraceEngine.Types.Events.Event[];

    const events = Array.isArray(data) ? data : data.traceEvents;
    await engine.parse(events, {metadata});
    const parsedTrace = engine.parsedTrace();
    if (!parsedTrace) {
      return {
        error: 'No parsed trace was returned from the trace engine.',
      };
    }

    const insights = parsedTrace?.insights ?? null;

    return {
      parsedTrace,
      insights,
    };
  } catch (e) {
    const errorText = e instanceof Error ? e.message : JSON.stringify(e);
    logger?.(`Unexpected error parsing trace: ${errorText}`);
    return {
      error: errorText,
    };
  }
}

const extraFormatDescriptions = `Information on performance traces may contain main thread activity represented as call frames and network requests.