val selection2 = routeSelector.next()
    assertThat(selection2.next()).isEqualTo(regularRoutes[1])
    assertThat(selection2.hasNext()).isFalse()

    // The second selection will contain all failed routes.
    val selection3 = routeSelector.next()
    assertThat(selection3.next()).isEqualTo(regularRoutes[0])
    assertThat(selection3.hasNext()).isFalse()

 *  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_

  /**
   * Invoked after proxy selection.
   *
   * Note that the list of proxies is never null, but it may be a list containing
   * only [Proxy.NO_PROXY]. This comes up in several situations:
   *
   * * If neither a proxy nor proxy selector is configured.
   * * If the proxy is configured explicitly as [Proxy.NO_PROXY].
   * * If the proxy selector returns only [Proxy.NO_PROXY].
   * * If the proxy selector returns an empty list or null.
   *

    // If we have a routes left, use 'em.
    if (routeSelection?.hasNext() == true) return true

    // If we haven't initialized the route selector yet, assume it'll have at least one route.
    val localRouteSelector = routeSelector ?: return true

    // If we do have a route selector, use its routes.
    return localRouteSelector.hasNext()
  }

  /**

    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)

internal fun inet6AddressToAscii(address: ByteArray): String {
  // Go through the address looking for the longest run of 0s. Each group is 2-bytes.
  // A run must be longer than one group (section 4.2.2).
  // If there are multiple equal runs, the first one must be used (section 4.2.3).
  var longestRunOffset = -1
  var longestRunLength = 0
  run {
    var i = 0
    while (i < address.size) {
      val currentRunOffset = i

 * manager that was used to create an [SSLSocketFactory].
 *
 * Not supported by choice on JDK9+ due to access checks.
 *
 * ### Android Cleartext Permit Detection
 *
 * Supported on Android 6.0+ via `NetworkSecurityPolicy`.
 */
open class Platform {
  /** Prefix used on custom headers. */
  fun getPrefix() = "OkHttp"

  internal fun connectFailed(
    client: OkHttpClient,
    failedRoute: Route,
    failure: IOException,
  ) {
    // Tell the proxy selector when we fail to connect on a fresh connection.
    if (failedRoute.proxy.type() != Proxy.Type.DIRECT) {
      val address = failedRoute.address
      address.proxySelector.connectFailed(
        address.url.toUri(),

        override fun checkServerTrusted(
          chain: Array<out X509Certificate>?,
          authType: String?,
        ) {
          withoutHostCalled = true
        }

        // called by Android via reflection in X509TrustManagerExtensions
        @Suppress("unused", "UNUSED_PARAMETER")
        fun checkServerTrusted(
          chain: Array<out X509Certificate>,
          authType: String,
          hostname: String,

import okhttp3.internal.http.toHttpDateOrNull
import okhttp3.internal.toNonNegativeInt

/**
 * Given a request and cached response, this figures out whether to use the network, the cache, or
 * both.
 *
 * Selecting a cache strategy may add conditions to the request (like the "If-Modified-Since" header
 * for conditional GETs) or warnings to the cached response (if the cached data is potentially
 * stale).
 */