Improve: Added duplicate request limiting

Author: Joel-James

src/services/class-service.php

@@ -161,4 +161,31 @@ protected function set_transient( string $key, $value, int $expiration = 0 ): bo
 	protected function delete_transient( string $key ): bool {
 		return delete_site_transient( $this->get_transient_key( $key ) );
 	}
+
+	/**
+	 * Checks if a request is too frequent.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @param string $key Transient key.
+	 *
+	 * @return bool
+	 */
+	protected function is_duplicate_request( string $key ): bool {
+		return $this->get_transient( $key ) ?? false;
+	}
+
+	/**
+	 * Sets a flag for request time.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @param string $key        Transient key.
+	 * @param int    $expiration Expiration.
+	 *
+	 * @return bool
+	 */
+	protected function set_request_time( string $key, $expiration = MINUTE_IN_SECONDS * 5 ): bool {
+		return $this->set_transient( $key, time(), $expiration );
+	}
 }

src/services/class-update.php

@@ -50,15 +50,19 @@ public function __construct( Plugin $plugin ) {
 	 */
 	public function get_update_data() {
 		// On force-check, delete transient.
-		if ( isset( $_GET['force-check'] ) ) {
+		if ( isset( $_GET['force-check'] ) && ! $this->is_duplicate_request( 'update_check' ) ) {
 			$this->delete_transient( 'update_data' );
 		}
 
 		// Save update data to transient if required.
 		$update_data = $this->get_transient( 'update_data' );
 		if ( ! $update_data ) {
 			$update_data = $this->get_remote_latest();
-			$this->set_transient( 'update_data', $update_data, DAY_IN_SECONDS );
+			// To prevent multiple requests for 5 mins.
+			$this->set_request_time( 'update_check' );
+			if ( ! is_wp_error( $update_data ) ) {
+				$this->set_transient( 'update_data', $update_data, DAY_IN_SECONDS );
+			}
 		}
 
 		return $update_data;