perf(response): Flush requests early to clients

If not, the response will wait for async actions, e.g. HTTP requests from
IClientService, to be finished before returning. This is not desired in
many cases with e.g. with notifications.

Signed-off-by: Joas Schilling <coding@schilljs.com>

Author: nickvergessen

lib/private/AppFramework/App.php

@@ -198,5 +198,13 @@ public static function main(
 				$io->setOutput($output);
 			}
 		}
+
+		if ($response->getFlushEarly()) {
+			fastcgi_finish_request();
+			while (ob_get_level() > 0) {
+				ob_end_flush();
+			}
+			flush();
+		}
 	}
 }

lib/public/AppFramework/Http/Response.php

@@ -64,6 +64,7 @@ class Response {
 
 	/** @var bool */
 	private $throttled = false;
+	private bool $flushEarly = true;
 	/** @var array */
 	private $throttleMetadata = [];
 
@@ -397,4 +398,25 @@ public function getThrottleMetadata() {
 	public function isThrottled() {
 		return $this->throttled;
 	}
+
+	/**
+	 * Request the response should be flushed to the connected client immediately
+	 *
+	 * @since 34.0.0
+	 */
+	public function setFlushEarly(bool $flushEarly): void {
+		$this->flushEarly = $flushEarly;
+	}
+
+	/**
+	 * Whether the response should be flushed to the connected client immediately
+	 *
+	 * If not, the response will wait for async actions, e.g. HTTP requests from
+	 * IClientService, to be finished before returning.
+	 *
+	 * @since 34.0.0
+	 */
+	public function getFlushEarly(): bool {
+		return $this->flushEarly;
+	}
 }