readBytesDelivered = readBuffer.read(sink, minOf(byteCount, readBuffer.size))
              readBytes.update(total = readBytesDelivered)

              val unacknowledgedBytesRead = readBytes.unacknowledged
              if (errorExceptionToDeliver == null &&
                unacknowledgedBytesRead >= connection.okHttpSettings.initialWindowSize / 2
              ) {

    this.withLock {
      readBytes.update(total = read)
      val readBytesToAcknowledge = readBytes.unacknowledged
      if (readBytesToAcknowledge >= okHttpSettings.initialWindowSize / 2) {
        writeWindowUpdateLater(0, readBytesToAcknowledge)
        readBytes.update(acknowledged = readBytesToAcknowledge)
      }
      flowControlListener.receivingConnectionWindowChanged(readBytes)
    }
  }

  /**

    val sourceCodePoint1 =
      when (select(optionsDot)) {
        DELIMITER_DOT -> {
          if (readByte() != '.'.code.toByte()) throw IOException("expected '..'")
          readHexadecimalUnsignedLong()
        }

        else -> sourceCodePoint0
      }

    skipWhitespace()
    if (readByte() != ';'.code.toByte()) throw IOException("expected ';'")

    // "valid" or "mapped"
    skipWhitespace()

  @Test
  fun sourceSeesBom() {
    val body = "efbbbf68656c6c6f".decodeHex().toResponseBody()
    val source = body.source()
    assertThat(source.readByte() and 0xff).isEqualTo(0xef)
    assertThat(source.readByte() and 0xff).isEqualTo(0xbb)
    assertThat(source.readByte() and 0xff).isEqualTo(0xbf)
    assertThat(source.readUtf8()).isEqualTo("hello")
  }

  @Test
  fun bytesEmpty() {
    val body = body("")

    byteCount: Long,
    sink: BufferedSink,
  ) {
    var node = root
    var accumulator = 0
    var accumulatorBitCount = 0
    for (i in 0 until byteCount) {
      val byteIn = source.readByte() and 0xff
      accumulator = accumulator shl 8 or byteIn
      accumulatorBitCount += 8
      while (accumulatorBitCount >= 8) {
        val childIndex = (accumulator ushr (accumulatorBitCount - 8)) and 0xff

    source.timeout().timeout(1000, TimeUnit.MILLISECONDS)
    assertThat(source.readByte()).isEqualTo('A'.code.toByte())
    assertThat(source.readByte()).isEqualTo('B'.code.toByte())
    assertThat(source.readByte()).isEqualTo('C'.code.toByte())
    assertFailsWith<SocketTimeoutException> {
      source.readByte() // If Content-Length was accurate, this would return -1 immediately.
    }
    source.close()
  }

    assertThat(frame2.type).isEqualTo(Http2.TYPE_RST_STREAM)
    val frame3 = peer.takeFrame()
    assertThat(frame3.type).isEqualTo(Http2.TYPE_RST_STREAM)
    assertThat(connection.readBytes.acknowledged).isEqualTo(0L)
    assertThat(connection.readBytes.total).isEqualTo(2048L)
  }

  @Test fun receiveGoAwayHttp2() {
    // Write the mocking script.
    peer.sendFrame().settings(Settings())
    peer.acceptFrame() // ACK

  var commaFound = false
  loop@ while (!exhausted()) {
    when (this[0]) {
      ','.code.toByte() -> {
        // Consume ','.
        readByte()
        commaFound = true
      }

      ' '.code.toByte(), '\t'.code.toByte() -> {
        readByte()
        // Consume space or tab.
      }

      else -> break@loop
    }
  }
  return commaFound
}

    val bodySource = response.body.source()
    assertThat(bodySource.readByte()).isEqualTo('d'.code.toByte())

    // The second byte of this request will be delayed by 750ms so we should time out after 250ms.
    val startNanos = System.nanoTime()
    bodySource.use {
      assertFailsWith<IOException> {
        bodySource.readByte()
      }.also { expected ->
        // Timed out as expected.

    val length = source.readMedium()
    if (length > INITIAL_MAX_FRAME_SIZE) {
      throw IOException("FRAME_SIZE_ERROR: $length")
    }
    val type = source.readByte() and 0xff
    val flags = source.readByte() and 0xff
    val streamId = source.readInt() and 0x7fffffff // Ignore reserved bit.
    if (type != TYPE_WINDOW_UPDATE && logger.isLoggable(FINE)) {