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).
 */

  /**
   * Prunes any leaked calls and then returns the number of remaining live calls on [connection].
   * Calls are leaked if the connection is tracking them but the application code has abandoned
   * them. Leak detection is imprecise and relies on garbage collection.
   */
  private fun pruneAndGetAllocationCount(
    connection: RealConnection,
    now: Long,
  ): Int {
    connection.lock.assertHeld()

 * if it is present on the connection spec. The same policy also applies to cipher suites.
 *
 * Use [Builder.allEnabledTlsVersions] and [Builder.allEnabledCipherSuites] to defer all feature
 * selection to the underlying SSL socket.
 *
 * The configuration of each spec changes with each OkHttp release. This is annoying: upgrading
 * your OkHttp library can break connectivity to certain web servers! But it’s a necessary annoyance

    writeControlFrame(OPCODE_CONTROL_PONG, payload)
  }

  /**
   * Send a close frame with optional code and reason.
   *
   * @param code Status code as defined by
   *     [Section 7.4 of RFC 6455](http://tools.ietf.org/html/rfc6455#section-7.4) or `0`.
   * @param reason Reason for shutting down or `null`.
   */
  @Throws(IOException::class)
  fun writeClose(
    code: Int,
    reason: ByteString?,
  ) {

   * a graceful shutdown was already underway or if the web socket is already closed or canceled.
   *
   * @param code Status code as defined by
   *     [Section 7.4 of RFC 6455](http://tools.ietf.org/html/rfc6455#section-7.4).
   * @param reason Reason for shutting down, no longer than 123 bytes of UTF-8 encoded data (**not** characters) or null.

   * stream was canceled.
   *
   * This does nothing if [requestBody] and [responseBody] are already closed.
   *
   * For HTTP/2 this sends the [CANCEL](https://datatracker.ietf.org/doc/html/rfc7540#section-7)
   * error code.
   */
  fun cancel()

 *
 * Do not confuse this class with the misnamed `HttpURLConnection`, which isn't so much a connection
 * as a single request/response exchange.
 *
 * ## Modern TLS
 *
 * There are trade-offs when selecting which options to include when negotiating a secure connection
 * to a remote host. Newer TLS options are quite useful:
 *
 *  * Server Name Indication (SNI) enables one IP address to negotiate secure connections for

      Header("via", ""),
      Header("www-authenticate", ""),
    )

  val NAME_TO_FIRST_INDEX = nameToFirstIndex()

  // http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-12#section-3.1
  class Reader
    @JvmOverloads
    constructor(
      source: Source,
      private val headerTableSizeSetting: Int,
      private var maxDynamicTableByteCount: Int = headerTableSizeSetting,
    ) {

    private const val TE = "te"
    private const val ENCODING = "encoding"
    private const val UPGRADE = "upgrade"

    /** See http://tools.ietf.org/html/draft-ietf-httpbis-http2-09#section-8.1.3. */
    private val HTTP_2_SKIPPED_REQUEST_HEADERS =
      immutableListOf(
        CONNECTION,
        HOST,
        KEEP_ALIVE,
        PROXY_CONNECTION,
        TE,
        TRANSFER_ENCODING,

/**
 * [DNS over HTTPS implementation][doh_spec].
 *
 * > A DNS API client encodes a single DNS query into an HTTP request
 * > using either the HTTP GET or POST method and the other requirements
 * > of this section.  The DNS API server defines the URI used by the
 * > request through the use of a URI Template.
 *
 * [doh_spec]: https://tools.ietf.org/html/draft-ietf-doh-dns-over-https-13
 */
class DnsOverHttps internal constructor(