Method clear

src/cmap/connection_pool.ts:417–468

* Clear the pool * * Pool reset is handled by incrementing the pool's generation count. Any existing connection of a * previous generation will eventually be pruned during subsequent checkouts.

(options: { serviceId?: ObjectId; interruptInUseConnections?: boolean } = {})

   * previous generation will eventually be pruned during subsequent checkouts.
   */
  clear(options: { serviceId?: ObjectId; interruptInUseConnections?: boolean } = {}): void {
    if (this.closed) {
      return;
    }

    // handle load balanced case
    if (this.loadBalanced) {
      const { serviceId } = options;
      if (!serviceId) {
        throw new MongoRuntimeError(
          'ConnectionPool.clear() called in load balanced mode with no serviceId.'
        );
      }
      const sid = serviceId.toHexString();
      const generation = this.serviceGenerations.get(sid);
      // Only need to worry if the generation exists, since it should
      // always be there but typescript needs the check.
      if (generation == null) {
        throw new MongoRuntimeError('Service generations are required in load balancer mode.');
      } else {
        // Increment the generation for the service id.
        this.serviceGenerations.set(sid, generation + 1);
      }
      this.emitAndLog(
        ConnectionPool.CONNECTION_POOL_CLEARED,
        new ConnectionPoolClearedEvent(this, { serviceId })
      );
      return;
    }
    // handle non load-balanced case
    const interruptInUseConnections = options.interruptInUseConnections ?? false;
    const oldGeneration = this.generation;
    this.generation += 1;
    const alreadyPaused = this.poolState === PoolState.paused;
    this.poolState = PoolState.paused;

    this.clearMinPoolSizeTimer();
    if (!alreadyPaused) {
      this.emitAndLog(
        ConnectionPool.CONNECTION_POOL_CLEARED,
        new ConnectionPoolClearedEvent(this, {
          interruptInUseConnections
        })
      );
    }

    if (interruptInUseConnections) {
      queueMicrotask(() => this.interruptInUseConnections(oldGeneration));
    }

    this.processWaitQueue();
  }

  /**
   * Closes all stale in-use connections in the pool with a resumable PoolClearedOnNetworkError.