## Version 5.0.0-alpha.4

_2022-02-01_

**This release introduces fast fallback to better support mixed IPv4+IPv6 networks.** Fast fallback
is what we're calling our implementation of Happy Eyeballs, [RFC 8305][rfc_8305]. With this
feature OkHttp will attempt both IPv6 and IPv4 connections concurrently, keeping whichever connects
first. Fast fallback gives IPv6 connections a 250 ms head start so IPv6 is preferred on networks

# FORMAT NOT DOCUMENTED YET (parser is urltestparser.js)

# Based on http://trac.webkit.org/browser/trunk/LayoutTests/fast/url/script-tests/segments.js
http://example\t.\norg http://example.org/foo/bar s:http h:example.org p:/
http://user:pass@foo:21/bar;par?b#c  s:http u:user pass:pass h:foo port:21 p:/bar;par q:?b f:#c
http:foo.com  s:http h:example.org p:/foo/foo.com
\t\s\s\s:foo.com\s\s\s\n  s:http h:example.org p:/foo/:foo.com

Anyway, in any of the cases above, FastAPI will still work asynchronously and be extremely fast.

But by following the steps above, it will be able to do some performance optimizations.

## Technical Details

* <a href="https://docs.withcoherence.com/docs/configuration/frameworks?utm_medium=advertising&utm_source=fastapi&utm_campaign=banner%20january%2024#fast-api-example" class="external-link" target="_blank">Coherence</a>...

 */
package okhttp3

import okio.IOException

/**
 * Listener for connection events. Extend this class to monitor the new connections and closes.
 *
 * All event methods must execute fast, without external locking, cannot throw exceptions,
 * attempt to mutate the event parameters, or be reentrant back into the client.
 * Any IO - writing to files or network should be done asynchronously.
 */
@ExperimentalOkHttpApi

Le fast-food a 8 processeurs (serveurs/cuisiniers) 👨‍🍳👨‍🍳👨‍🍳👨‍🍳👨‍🍳👨‍🍳👨‍🍳👨‍🍳. Alors que le fast-food de burgers concurrents en avait 2 (un serveur et un cuisinier).

Et pourtant l'expérience finale n'est pas meilleure 😞.

---

- [Project Conventions](https://github.com/istio/istio/wiki/Development-Conventions) - describes the conventions we use within the code base
- [Creating Fast and Lean Code](https://github.com/istio/istio/wiki/Writing-Fast-and-Lean-Code) - performance-oriented advice and guidelines for the code base

You'll find many other useful documents on our [Wiki](https://github.com/istio/istio/wiki).

## Introduction

---

FastAPI is a modern, fast (high-performance), web framework for building APIs with Python based on standard Python type hints.

The key features are:

* **Fast**: Very high performance, on par with **NodeJS** and **Go** (thanks to Starlette and Pydantic). [One of the fastest Python frameworks available](#performance).
* **Fast to code**: Increase the speed to develop features by about 200% to 300%. *

 *
 *  3. Attempt plans from prior connect attempts for this call. These occur as either follow-ups to
 *     failed connect attempts (such as trying the next [ConnectionSpec]), or as attempts that lost
 *     a race in fast follow-up.
 *
 *  4. If there's no existing connection, make a list of routes (which may require blocking DNS
 *     lookups) and attempt a new connection them. When failures occur, retries iterate the list of

* <a href="https://docs.withcoherence.com/docs/configuration/frameworks?utm_medium=advertising&utm_source=fastapi&utm_campaign=banner%20january%2024#fast-api-example" class="external-link" target="_blank">Coherence</a>...