}

    override fun pushPromise(
      streamId: Int,
      associatedStreamId: Int,
      headerBlock: List<Header>,
    ) {
      this.type = Http2.TYPE_PUSH_PROMISE
      this.streamId = streamId
      this.associatedStreamId = associatedStreamId
      this.headerBlock = headerBlock
    }

    override fun alternateService(
      streamId: Int,
      origin: String,

            upstreamReader = Thread.currentThread()
            return@synchronized SOURCE_UPSTREAM
          }

          val bufferPos = upstreamPos - buffer.size

          // Bytes of the read precede the buffer. Read from the file.
          if (sourcePos < bufferPos) {
            return@synchronized SOURCE_FILE
          }

          // The buffer has the data we need. Read from there and return immediately.

    /**
     * When [protocols][MockWebServer.protocols] include [HTTP_2][okhttp3.Protocol], this attaches a
     * pushed stream to this response.
     */
    fun addPush(promise: PushPromise) =
      apply {
        this.pushPromises += promise
      }

    /**
     * When [protocols][MockWebServer.protocols] include [HTTP_2][okhttp3.Protocol], this pushes
     * [settings] before writing the response.
     */

    /** HTTP/2: Size in bytes of the table used to decode the sender's header blocks. */
    const val HEADER_TABLE_SIZE = 1

    /** HTTP/2: The peer must not send a PUSH_PROMISE frame when this is 0. */
    const val ENABLE_PUSH = 2

    /** Sender's maximum number of concurrent streams. */
    const val MAX_CONCURRENT_STREAMS = 4

        flags = FLAG_ACK,
      )
      sink.flush()
    }
  }

  /**
   * HTTP/2 only. Send a push promise header block.
   *
   * A push promise contains all the headers that pertain to a server-initiated request, and a
   * `promisedStreamId` to which response frames will be delivered. Push promise frames are sent as
   * a part of the response to `streamId`. The `promisedStreamId` has a priority of one greater than

      weight: Int,
      exclusive: Boolean,
    )

    /**
     * HTTP/2 only. Receive a push promise header block.
     *
     * A push promise contains all the headers that pertain to a server-initiated request, and a
     * `promisedStreamId` to which response frames will be delivered. Push promise frames are sent
     * as a part of the response to `streamId`.
     *

    private val dashDashBoundary =
      Buffer()
        .writeUtf8("--")
        .writeUtf8(boundary)
        .readByteString()

    /**
     * This delimiter typically precedes all subsequent parts. It may also precede the first part
     * if the body contains a preamble.
     */
    private val crlfDashDashBoundary =
      Buffer()
        .writeUtf8("\r\n--")
        .writeUtf8(boundary)
        .readByteString()

    headersDelayAmount = delay
    headersDelayUnit = unit
  }

  fun getHeadersDelay(unit: TimeUnit): Long = unit.convert(headersDelayAmount, headersDelayUnit)

  fun withPush(promise: PushPromise) =
    apply {
      promises.add(promise)
    }

  fun withSettings(settings: Settings) =
    apply {
      this.settings = settings
    }

  fun withWebSocketUpgrade(listener: WebSocketListener) =

  private val writerQueue = taskRunner.newQueue()

  /** Ensures push promise callbacks events are sent in order per stream. */
  private val pushQueue = taskRunner.newQueue()

  /** Notifies the listener of settings changes. */
  private val settingsListenerQueue = taskRunner.newQueue()

  /** User code to run in response to push promise events. */
  private val pushObserver: PushObserver = builder.pushObserver

#### Implementation changes

 * Support Android `TrafficStats` socket tagging.
 * Drop authentication headers on redirect.
 * Added support for compressed data frames.
 * Process push promise callbacks in order.
 * Update to http/2 draft 12.
 * Update to HPACK draft 07.
 * Add ALPN support. Maven will use ALPN on OpenJDK 8.
 * Update NPN dependency to target `jdk7u60-b13` and `Oracle jdk7u55-b13`.