)
  fun socketAddress(): InetSocketAddress = socketAddress

  /**
   * Returns true if this route tunnels HTTPS or HTTP/2 through an HTTP proxy.
   * See [RFC 2817, Section 5.2][rfc_2817].
   *
   * [rfc_2817]: http://www.ietf.org/rfc/rfc2817.txt
   */
  fun requiresTunnel(): Boolean {
    if (proxy.type() != Proxy.Type.HTTP) return false
    return (address.sslSocketFactory != null) ||

Caching
=======

OkHttp implements an optional, off by default, Cache. OkHttp aims for RFC correct and
pragmatic caching behaviour, following common real-world browser like Firefox/Chrome and 
server behaviour when ambiguous.

# Basic Usage

```kotlin
  private val client: OkHttpClient = OkHttpClient.Builder()
      .cache(Cache(
          directory = File(application.cacheDir, "http_cache"),
          // $0.05 worth of phone storage in 2020

import okhttp3.internal.skipAll
import okio.Buffer
import okio.ByteString.Companion.encodeUtf8

private val QUOTED_STRING_DELIMITERS = "\"\\".encodeUtf8()
private val TOKEN_DELIMITERS = "\t ,=".encodeUtf8()

/**
 * Parse RFC 7235 challenges. This is awkward because we need to look ahead to know how to
 * interpret a token.
 *
 * For example, the first line has a parameter name/value pair and the second line has a single
 * token68:
 *
 * ```

      "xn--a",
      "xn--a.ß",
      "xn--a.xn--zca",
      "xn--a-yoc",
      // OkHttp doesn't reject U+FFFD encoded in Punycode.
      "xn--zn7c.com",
      // OkHttp doesn't reject a U+200D. https://www.rfc-editor.org/rfc/rfc5892.html#appendix-A.2
      "xn--1ug.example",
      // OkHttp doesn't implement CheckJoiners.
      "\u200D.example",
      // OkHttp doesn't implement CheckBidi.
      "يa",
    )

  @Test

import okio.Path
import okio.buffer
import okio.use

class StringprepTablesReader(
  private val fileSystem: FileSystem,
) {
  /**
   * Returns a [Stringprep] that uses the tables of Nameprep ([RFC 3491]).
   *
   * [RFC 3491]: https://datatracker.ietf.org/doc/html/rfc3491
   */
  fun readNameprep(base: Path): Stringprep {
    val unassigned = readCodePointSet(base / "rfc3454.A.1.txt")
    val mapping =

import okio.buffer
import okio.sink
import okio.source
import okio.use

/**
 * A limited implementation of SOCKS Protocol Version 5, intended to be similar to MockWebServer.
 * See [RFC 1928](https://www.ietf.org/rfc/rfc1928.txt).
 */
class SocksProxy {
  private val executor = Executors.newCachedThreadPool(threadFactory("SocksProxy"))
  private var serverSocket: ServerSocket? = null

  private val inflater =
    Inflater(
      // nowrap (omits zlib header):
      true,
    )

  private val inflaterSource = InflaterSource(deflatedBytes, inflater)

  /** Inflates [buffer] in place as described in RFC 7692 section 7.2.2. */
  @Throws(IOException::class)
  fun inflate(buffer: Buffer) {
    require(deflatedBytes.size == 0L)

    if (noContextTakeover) {
      inflater.reset()
    }

      Deflater.DEFAULT_COMPRESSION,
      // nowrap (omits zlib header):
      true,
    )

  private val deflaterSink = DeflaterSink(deflatedBytes, deflater)

  /** Deflates [buffer] in place as described in RFC 7692 section 7.2.1. */
  @Throws(IOException::class)
  fun deflate(buffer: Buffer) {
    require(deflatedBytes.size == 0L)

    if (noContextTakeover) {
      deflater.reset()
    }

### [Fast Fallback](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-ok-http-client/-builder/fast-fallback/)

Since version 5.0, `OkHttpClient` supports fast fallback, which is our implementation of Happy Eyeballs [RFC 6555](https://datatracker.ietf.org/doc/html/rfc6555).

With fast fallback, OkHttp attempts to connect to multiple web servers concurrently. It keeps whichever route connects first and cancels all of the others. Its rules are:

IDN Data
========

In order to implement Nameprep (RFC 3491), OkHttp uses Unicode tables specified in Stringprep
(RFC 3454). Fragments of this RFC are dumped into the files in this directory and parsed by
`StringprepTablesReader` into a model that can be used at runtime.

This format is chosen to make it easy to validate that these tables are consistent with the RFC.

```
cd okhttp/src/test/resources/okhttp3/internal/idn/