* used so that OkHttp can learn from its mistakes: if there was a failure attempting to connect to
 * a specific IP address or proxy server, that failure is remembered and alternate routes are
 * preferred.
 */
class RouteDatabase {
  private val _failedRoutes = mutableSetOf<Route>()

  val failedRoutes: Set<Route>
    @Synchronized get() = _failedRoutes.toSet()

  /** Records a failure connecting to [failedRoute]. */

  }

  private fun newRouteSelector(
    address: Address,
    routeDatabase: RouteDatabase = this.routeDatabase,
    fastFallback: Boolean = false,
    call: RealCall = this.call,
  ): RouteSelector {
    return RouteSelector(
      address = address,
      routeDatabase = routeDatabase,
      fastFallback = fastFallback,

    assertNotSame(
      client.routeDatabase,
      OkHttpClient.Builder()
        .build()
        .routeDatabase,
    )

    // same client with no change affecting route db
    assertSame(
      client.routeDatabase,
      client.newBuilder()
        .build()
        .routeDatabase,
    )
    assertSame(
      client.routeDatabase,
      client.newBuilder()

          retryOnConnectionFailure = false
        }
        .build()

    executeSynchronously(request)
      .assertFailureMatches("stream was reset: REFUSED_STREAM")

    assertThat(client.routeDatabase.failedRoutes).isEmpty()
    assertThat(server1.requestCount).isEqualTo(1)
    assertThat(server2.requestCount).isEqualTo(0)

    assertThat(clientTestRule.recordedConnectionEventTypes()).containsExactly(

  private val socketReadTimeoutMillis: Int,
  private val pingIntervalMillis: Int,
  private val retryOnConnectionFailure: Boolean,
  private val fastFallback: Boolean,
  override val address: Address,
  private val routeDatabase: RouteDatabase,
  private val connectionUser: ConnectionUser,
) : RoutePlanner {
  private var routeSelection: RouteSelector.Selection? = null
  private var routeSelector: RouteSelector? = null

    socketReadTimeoutMillis: Int = 10_000,
    pingIntervalMillis: Int = 10_000,
    retryOnConnectionFailure: Boolean = true,
    fastFallback: Boolean = true,
    routeDatabase: RouteDatabase = RouteDatabase(),
  ) : this(
    RealConnectionPool(
      taskRunner = taskRunner,
      maxIdleConnections = maxIdleConnections,
      keepAliveDuration = keepAliveDuration,
      timeUnit = timeUnit,

   * The default is 1024 bytes.
   */
  @get:JvmName("minWebSocketMessageToCompress")
  val minWebSocketMessageToCompress: Long = builder.minWebSocketMessageToCompress

  internal val routeDatabase: RouteDatabase = builder.routeDatabase ?: RouteDatabase()
  internal val taskRunner: TaskRunner = builder.taskRunner ?: TaskRunner.INSTANCE

  @get:JvmName("connectionPool")
  val connectionPool: ConnectionPool =

            socketReadTimeoutMillis = 10_000,
            pingIntervalMillis = 10_000,
            retryOnConnectionFailure = false,
            fastFallback = true,
            address = address,
            routeDatabase = RouteDatabase(),
            connectionUser = user,
          ),
          taskRunner,
        )
      },
    )
  }

 * IP address, and TLS mode. Connections may also be recycled.
 */
class RouteSelector(
  private val address: Address,
  private val routeDatabase: RouteDatabase,
  private val connectionUser: ConnectionUser,
  private val fastFallback: Boolean,
) {
  // State for negotiating the next proxy to use.
  private var proxies = emptyList<Proxy>()

          fastFallback = client.fastFallback,
          address = client.address(request.url),
          connectionUser = CallConnectionUser(this, connectionPool.connectionListener, chain),
          routeDatabase = client.routeDatabase,
        )
      this.exchangeFinder =
        when {
          client.fastFallback -> FastFallbackExchangeFinder(routePlanner, client.taskRunner)
          else -> SequentialExchangeFinder(routePlanner)