Class DebugHandler

packages/service-worker/worker/src/debug.ts:21–127

}

export class DebugHandler implements DebugLogger {
  // There are two debug log message arrays. debugLogA records new debugging messages.
  // Once it reaches DEBUG_LOG_BUFFER_SIZE, the array is moved to debugLogB and a new
  // array is assigned to debugLogA. This ensures that insertion to the debug log is
  // always O(1) no matter the number of logged messages, and that the total number
  // of messages in the log never exceeds 2 * DEBUG_LOG_BUFFER_SIZE.
  private debugLogA: DebugMessage[] = [];
  private debugLogB: DebugMessage[] = [];

  constructor(
    readonly driver: Debuggable,
    readonly adapter: Adapter,
  ) {}

  async handleFetch(req: Request): Promise<Response> {
    const [state, versions, idle] = await Promise.all([
      this.driver.debugState(),
      this.driver.debugVersions(),
      this.driver.debugIdleState(),
    ]);

    const msgState = `NGSW Debug Info:

Driver version: ${SW_VERSION}
Driver state: ${state.state} (${state.why})
Latest manifest hash: ${state.latestHash || 'none'}
Last update check: ${this.since(state.lastUpdateCheck)}`;

    const msgVersions = versions
      .map(
        (version) => `=== Version ${version.hash} ===

Clients: ${version.clients.join(', ')}`,
      )
      .join('\n\n');

    const msgIdle = `=== Idle Task Queue ===
Last update tick: ${this.since(idle.lastTrigger)}
Last update run: ${this.since(idle.lastRun)}
Task queue:
${idle.queue.map((v) => ' * ' + v).join('\n')}

Debug log:
${this.formatDebugLog(this.debugLogB)}
${this.formatDebugLog(this.debugLogA)}
`;

    return this.adapter.newResponse(
      `${msgState}

${msgVersions}

${msgIdle}`,
      {headers: this.adapter.newHeaders({'Content-Type': 'text/plain'})},
    );
  }

  since(time: number | null): string {