* limitations under the License.
 */
package okhttp3.internal

import java.net.InetAddress
import okhttp3.Dns

/**
 * A network that always resolves two IP addresses per host. Use this when testing route selection
 * fallbacks to guarantee that a fallback address is available.
 */
class DoubleInetAddressDns : Dns {
  override fun lookup(hostname: String): List<InetAddress> {
    val addresses = Dns.SYSTEM.lookup(hostname)

 *  Fix: Don't track unusable routes beyond their usefulness. We had a bug where we could track
    certain bad routes indefinitely; now we only track the ones that could be necessary.
 *  Fix: Defer proxy selection until a proxy is required. This saves calls to `ProxySelector` on
    calls that use a pooled connection.


## Version 4.3.1

_2020-01-07_

   */
  operator fun hasNext(): Boolean = hasNextProxy() || postponedRoutes.isNotEmpty()

  @Throws(IOException::class)
  operator fun next(): Selection {
    if (!hasNext()) throw NoSuchElementException()

    // Compute the next set of routes to attempt.
    val routes = mutableListOf<Route>()
    while (hasNextProxy()) {

    dns[uriHost] = dns.allocate(1)
    var selection = routeSelector.next()
    val route = selection.next()
    routeDatabase.failed(route)
    routeSelector = newRouteSelector(address)
    selection = routeSelector.next()
    assertRoute(selection.next(), address, Proxy.NO_PROXY, dns.lookup(uriHost, 0), uriPort)
    assertThat(selection.hasNext()).isFalse()
    assertFailsWith<NoSuchElementException> {

  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
  private var nextRouteToTry: Route? = null

  override val deferredPlans = ArrayDeque<Plan>()

 *  * **IP address:** whether connecting directly to an origin server or a proxy, opening a socket
 *    requires an IP address. The DNS server may return multiple IP addresses to attempt.
 *
 * Each route is a specific selection of these options.
 */
class Route(
  @get:JvmName("address") val address: Address,
  /**
   * Returns the [Proxy] of this route.
   *

    return connectionListener.recordedEventTypes()
  }

  companion object {
    /**
     * A network that resolves only one IP address per host. Use this when testing route selection
     * fallbacks to prevent the host machine's various IP addresses from interfering.
     */
    private val SINGLE_INET_ADDRESS_DNS =
      Dns { hostname ->
        val addresses = Dns.SYSTEM.lookup(hostname)

    fun proxy(proxy: Proxy?) =
      apply {
        if (proxy != this.proxy) {
          this.routeDatabase = null
        }
        this.proxy = proxy
      }

    /**
     * Sets the proxy selection policy to be used if no [proxy][proxy] is specified explicitly. The
     * proxy selector may return multiple proxies; in that case they will be tried in sequence until
     * a successful connection is established.
     *

   * will be handled within the boundaries of a single [callStart] and [callEnd]/[callFailed] pair.
   */
  open fun callStart(call: Call) {
  }

  /**
   * Invoked prior to a proxy selection.
   *
   * This will be invoked for route selection regardless of whether the client
   * is configured with a single proxy, a proxy selector, or neither.
   *
   * @param url a URL with only the scheme, hostname, and port specified.
   */

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3

import okio.IOException

/**
 * Protocols that OkHttp implements for [ALPN][ietf_alpn] selection.
 *
 * ## Protocol vs Scheme
 *
 * Despite its name, [java.net.URL.getProtocol] returns the [scheme][java.net.URI.getScheme] (http,