## Détails techniques { #technical-details }

FastAPI met en œuvre certaines bonnes pratiques SSE prêtes à l’emploi.

- Envoyer un commentaire **« keep alive » `ping`** toutes les 15 secondes quand aucun message n’a été émis, pour éviter que certains proxys ne ferment la connexion, comme suggéré dans la [Spécification HTML : Server-Sent Events](https://html.spec.whatwg.org/multipage/server-sent-events.html#authoring-notes).

    FluentIterable<TimeUnit> unused = FluentIterable.from(TimeUnit.values()).append(SECONDS);
  }

  public void testFromArrayAndIteratorRemove() {
    FluentIterable<TimeUnit> units = FluentIterable.from(TimeUnit.values());
    assertThrows(UnsupportedOperationException.class, () -> removeIf(units, equalTo(SECONDS)));
  }

  public void testFrom() {
    assertEquals(
        ImmutableList.of(1, 2, 3, 4),

    }

  private var body: Buffer? = null

  var throttleBytesPerPeriod: Long = Long.MAX_VALUE
    private set
  private var throttlePeriodAmount = 1L
  private var throttlePeriodUnit = TimeUnit.SECONDS

  @set:JvmName("socketPolicy")
  var socketPolicy: SocketPolicy = SocketPolicy.KEEP_OPEN

  @set:JvmName("http2ErrorCode")
  var http2ErrorCode: Int = -1

  private var bodyDelayAmount = 0L

## Technical Details { #technical-details }

FastAPI implements some SSE best practices out of the box.

* Send a **"keep alive" `ping` comment** every 15 seconds when there hasn't been any message, to prevent some proxies from closing the connection, as suggested in the [HTML specification: Server-Sent Events](https://html.spec.whatwg.org/multipage/server-sent-events.html#authoring-notes).

    lines.append("")
    lines.append("")
    return "\n".join(lines).encode("utf-8")


# Keep-alive comment, per the SSE spec recommendation
KEEPALIVE_COMMENT = b": ping\n\n"

# Seconds between keep-alive pings when a generator is idle.
# Private but importable so tests can monkeypatch it.

     */
    public long getRetryDelay() {
        switch (severity) {
        case RECOVERABLE:
            return 100; // Immediate retry with small delay
        case TRANSIENT:
            return 5000; // Wait 5 seconds
        default:
            return 0; // No retry
        }
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();

            }
            thread = null;
            try {
                executorService.shutdown();
                executorService.awaitTermination(60, TimeUnit.SECONDS);
            } catch (final InterruptedException e) {
                if (logger.isDebugEnabled()) {
                    logger.debug("Interrupted.", e);
                }
            } finally {

                    }
                } finally {
                    latch.countDown();
                }
            });
        }

        // Then
        assertTrue(latch.await(10, TimeUnit.SECONDS), "All threads should complete");
        executor.shutdown();
        assertEquals(0, collisions.get(), "There should be no nonce collisions");

* `expose_headers` - Indique les en-têtes de réponse qui doivent être accessibles au navigateur. Par défaut `[]`.
* `max_age` - Définit un temps maximum (en secondes) pendant lequel les navigateurs peuvent mettre en cache les réponses CORS. Par défaut `600`.

Le middleware répond à deux types particuliers de requêtes HTTP ...

		avg = l.rttMsSum / float64(l.successRequestCount)
	}
	now := time.Now().UTC()
	return Metrics{
		LastReachableSecs:   now.Sub(o.serviceMetrics.LastCheckSuccess).Seconds(),
		LastUnreachableSecs: now.Sub(o.serviceMetrics.LastCheckFailure).Seconds(),
		TotalRequests:       l.failedRequestCount + l.successRequestCount,
		FailedRequests:      l.failedRequestCount,
		AvgSuccRTTMs:        avg,
		MaxSuccRTTMs:        l.maxRttMs,