## Version 4.2.1

_2019-10-02_

 *  Fix: In 4.1.0 we introduced a performance regression that prevented connections from being
    pooled in certain situations. We have good test coverage for connection pooling but we missed
    this because it only occurs if you have proxy configured and you share a connection pool among
    multiple `OkHttpClient` instances.

    if (address.url.host == this.route().address.url.host) {
      return true // This connection is a perfect match.
    }

    // At this point we don't have a hostname match. But we still be able to carry the request if
    // our connection coalescing requirements are met. See also:
    // https://hpbn.co/optimizing-application-delivery/#eliminate-domain-sharding

 * layer primitives: connections, requests, responses, and streams.
 *
 * This class supports [asynchronous canceling][cancel]. This is intended to have the smallest
 * blast radius possible. If an HTTP/2 stream is active, canceling will cancel that stream but not
 * the other streams sharing its connection. But if the TLS handshake is still in progress then

            continue@eachQueue
          }

          // If we already have more than one task, that's enough work for now. Stop searching.
          readyTask != null -> {
            multipleReadyTasks = true
            break@eachQueue
          }

          // We have a task to execute when we complete the loop.
          else -> {
            readyTask = candidate
          }

    server.listener.assertClosed(1000, "Hi!")
    taskFaker.runTasks()
    assertThat(client.closed).isTrue()
    server.listener.assertExhausted() // Client should not have sent second close.
    client.listener.assertExhausted() // Server should not have sent second close.
  }

  @Test
  fun serverCloseBreaksReadMessageLoop() {
    server.webSocket!!.send("Hello!")
    server.webSocket!!.close(1000, "Bye!")

    assertThat(routeSelector.hasNext()).isFalse()
    dns.assertRequests(uriHost)
    proxySelector.assertRequests() // No proxy selector requests!
  }

  /**
   * Don't call through to the proxy selector if we don't have a host name.
   * https://github.com/square/okhttp/issues/5770
   */
  @Test fun proxySelectorNotCalledForNullHost() {
    // The string '>' is okay in a hostname in HttpUrl, which does very light hostname validation.

    taskRunner.lock.withLock {
      check(currentTask == TestThreadSerialTask)
      nanoTime = newTime
      yieldUntil(ResumePriority.AfterOtherTasks)
    }
  }

  /** Confirm all tasks have completed. Used by the test thread only. */
  fun assertNoMoreTasks() {
    taskRunner.assertThreadDoesntHoldLock()

    taskRunner.lock.withLock {
      assertThat(activeThreads).isEqualTo(0)
    }
  }

 */
class CacheControl internal constructor(
  /**
   * In a response, this field's name "no-cache" is misleading. It doesn't prevent us from caching
   * the response; it only means we have to validate the response with the origin server before
   * returning it. We can do this with a conditional GET.
   *
   * In a request, it means do not use a cache to satisfy the request.
   */

import okio.Sink
import okio.Source
import okio.buffer

/**
 * Caches HTTP and HTTPS responses to the filesystem so they may be reused, saving time and
 * bandwidth.
 *
 * The Cache instance must have exclusive access to the [directory], since the internal data structures
 * may cause corruption or runtime errors if not. It may however be shared amongst multiple OkHttpClient
 * instances.
 *
 * ## Cache Optimization
 *

        return true
      }
    }

    // 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()
  }

  /**