Function processWaitQueue

src/sdam/topology.ts:948–1090

(topology: Topology)

}

function processWaitQueue(topology: Topology) {
  if (topology.s.state === STATE_CLOSED) {
    drainWaitQueue(topology.waitQueue, new MongoTopologyClosedError());
    return;
  }

  const isSharded = topology.description.type === TopologyType.Sharded;
  const serverDescriptions = Array.from(topology.description.servers.values());
  const membersToProcess = topology.waitQueue.length;
  for (let i = 0; i < membersToProcess; ++i) {
    const waitQueueMember = topology.waitQueue.shift();
    if (!waitQueueMember) {
      continue;
    }

    if (waitQueueMember.cancelled) {
      continue;
    }

    let selectedDescriptions;
    try {
      const serverSelector = waitQueueMember.serverSelector;
      const deprioritizedServers = waitQueueMember.deprioritizedServers;
      selectedDescriptions = serverSelector
        ? serverSelector(topology.description, serverDescriptions, deprioritizedServers)
        : serverDescriptions;
    } catch (selectorError) {
      if (
        topology.client.mongoLogger?.willLog(
          MongoLoggableComponent.SERVER_SELECTION,
          SeverityLevel.DEBUG
        )
      ) {
        topology.client.mongoLogger?.debug(
          MongoLoggableComponent.SERVER_SELECTION,
          new ServerSelectionFailedEvent(
            waitQueueMember.serverSelector,
            topology.description,
            selectorError,
            waitQueueMember.operationName
          )
        );
      }
      waitQueueMember.reject(selectorError);
      continue;
    }

    let selectedServer: Server | undefined;
    if (selectedDescriptions.length === 0) {
      if (!waitQueueMember.waitingLogged) {
        if (
          topology.client.mongoLogger?.willLog(
            MongoLoggableComponent.SERVER_SELECTION,
            SeverityLevel.INFORMATIONAL
          )
        ) {
          topology.client.mongoLogger?.info(
            MongoLoggableComponent.SERVER_SELECTION,