when {
          it.sourceCodePoint1 < codePoint -> -1
          it.sourceCodePoint0 > codePoint -> 1
          else -> 0
        }
      }

    // Code points must be in 0..0x10ffff.
    require(index in mappings.indices) { "unexpected code point: $codePoint" }

    val mapping = mappings[index]
    var result = true

    when (mapping.type) {
      TYPE_IGNORED -> Unit

   * explicitly closed.
   */
  fun truncateLastFrame(length: Int): Http2Writer {
    val lastFrame = outFrames.removeAt(outFrames.size - 1)
    require(length < bytesOut.size - lastFrame.start)

    // Move everything from bytesOut into a new buffer.
    val fullBuffer = Buffer()
    bytesOut.read(fullBuffer, bytesOut.size)

some connectivity failures. In this case, the `connectFailed()` event is not terminal and not followed by `callFailed()`. Event listeners will receive multiple events of the same type when retries are attempted.

A single HTTP call may require follow-up requests to be made to handle authentication challenges, redirects, and HTTP-layer timeouts. In such cases multiple connections, requests, and responses may be attempted. Follow-ups are another reason a single call may trigger multiple events...

  open fun getSelectedProtocol(sslSocket: SSLSocket): String? = null

  /** For MockWebServer. This returns the inbound SNI names. */
  @SuppressLint("NewApi")
  @IgnoreJRERequirement // This function is overridden to require API >= 24.
  open fun getHandshakeServerNames(sslSocket: SSLSocket): List<String> {
    val session = sslSocket.session as? ExtendedSSLSession ?: return listOf()

    upstreamSize: Long,
    metadataSize: Long,
  ) {
    val header =
      Buffer().apply {
        write(prefix)
        writeLong(upstreamSize)
        writeLong(metadataSize)
        require(size == FILE_HEADER_SIZE)
      }

    val fileOperator = FileOperator(file!!.channel)
    fileOperator.write(0, header, FILE_HEADER_SIZE)
  }

  @Throws(IOException::class)

  if (address[11] != 255.toByte()) return false

  return true
}

/** Encodes an IPv4 address in canonical form according to RFC 4001. */
internal fun inet4AddressToAscii(address: ByteArray): String {
  require(address.size == 4)
  return Buffer()
    .writeDecimalLong((address[0] and 0xff).toLong())
    .writeByte('.'.code)
    .writeDecimalLong((address[1] and 0xff).toLong())
    .writeByte('.'.code)

      apply {
        val maxAgeSeconds = maxAge.inWholeSeconds
        require(maxAgeSeconds >= 0) { "maxAge < 0: $maxAgeSeconds" }
        this.maxAgeSeconds = maxAgeSeconds.commonClampToInt()
      }

    fun maxStale(maxStale: Duration) =
      apply {
        val maxStaleSeconds = maxStale.inWholeSeconds
        require(maxStaleSeconds >= 0) { "maxStale < 0: $maxStaleSeconds" }

  return null
}

internal fun Headers.Builder.commonBuild(): Headers = Headers(namesAndValues.toTypedArray())

internal fun headersCheckName(name: String) {
  require(name.isNotEmpty()) { "name is empty" }
  for (i in name.indices) {
    val c = name[i]
    require(c in '\u0021'..'\u007e') {
      "Unexpected char 0x${c.charCode()} at $i in header name: $name"
    }
  }
}

internal fun headersCheckValue(

  method: String,
  body: RequestBody?,
): Request.Builder =
  apply {
    require(method.isNotEmpty()) {
      "method.isEmpty() == true"
    }
    if (body == null) {
      require(!HttpMethod.requiresRequestBody(method)) {
        "method $method must have a request body."
      }
    } else {
      require(HttpMethod.permitsRequestBody(method)) {
        "method $method must not have a request body."

    flags: Int,
  ) {
    if (type != TYPE_WINDOW_UPDATE && logger.isLoggable(FINE)) {
      logger.fine(frameLog(false, streamId, length, type, flags))
    }
    require(length <= maxFrameSize) { "FRAME_SIZE_ERROR length > $maxFrameSize: $length" }
    require(streamId and 0x80000000.toInt() == 0) { "reserved bit set: $streamId" }
    sink.writeMedium(length)
    sink.writeByte(type and 0xff)
    sink.writeByte(flags and 0xff)