From patchwork Thu Apr 25 15:20:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= X-Patchwork-Id: 19953 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id E464FC3220 for ; Thu, 25 Apr 2024 15:20:23 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id DFDD4633F4; Thu, 25 Apr 2024 17:20:22 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (2048-bit key; unprotected) header.d=protonmail.com header.i=@protonmail.com header.b="g2o14+ww"; dkim-atps=neutral Received: from mail-4316.protonmail.ch (mail-4316.protonmail.ch [185.70.43.16]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 4025661A9B for ; Thu, 25 Apr 2024 17:20:21 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1714058420; x=1714317620; bh=Xlog3F9xxdLvkkP1wpAD1kbY33z7hKEgYRZ6uvwKWnA=; h=Date:To:From:Subject:Message-ID:Feedback-ID:From:To:Cc:Date: Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=g2o14+wwsEgWKLs1i4SuqpuDD4x6K6dlxPh4An6Wzz1rUyX88W7N522Jv/MhSspJz Fn5Rd//loaCmr1QGKdEg+t5W9g/45pHT1cK618bBuOZ2eGfmJBUQ2PLqLGLwVbtXiY YWr7K2PMi4DuEWYNDqxhzBds3eu3CQWeZrcscFDyys1x06oOUK9U46D3HDCzA71W58 3iX08iPYh5q6YRf/Jjw2FFZNkjB0C4fGnOx7/F/32+BpSUt0odQOJEMZumb3NC7Qyb mya7GhXg3ntAgugilqtf54z60AbwjRK7Vwi9iu1AITgI7kWe3uF/qcC0NcUsgMnMwg wKpGjkxYB2T1g== Date: Thu, 25 Apr 2024 15:20:13 +0000 To: libcamera-devel@lists.libcamera.org From: =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= Subject: [PATCH v1] treewide: Query list of cameras just once Message-ID: <20240425152010.313205-1-pobrn@protonmail.com> Feedback-ID: 20568564:user:proton X-Pm-Message-ID: 6daf2752af386938d94b193b76f2e28a588f9d1a MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" This is more efficient since only a single vector will be constructed, and furthermore, it prevents the TOCTOU issue that might arise when the list of cameras changes between the two queries. --- Documentation/guides/application-developer.rst | 8 ++++---- src/apps/cam/camera_session.cpp | 6 ++++-- src/gstreamer/gstlibcamerasrc.cpp | 5 +++-- 3 files changed, 11 insertions(+), 8 deletions(-) base-commit: fb74bb7df66b96dbe28702155cddfc96a1b30f78 diff --git a/Documentation/guides/application-developer.rst b/Documentation/guides/application-developer.rst index 9a9905b1..dfbc268d 100644 --- a/Documentation/guides/application-developer.rst +++ b/Documentation/guides/application-developer.rst @@ -115,20 +115,20 @@ by name from the Camera Manager, after making sure that at least one camera is available. .. code:: cpp - - if (cm->cameras().empty()) { + auto cameras = cm->cameras(); + if (cameras.empty()) { std::cout << "No cameras were identified on the system." << std::endl; cm->stop(); return EXIT_FAILURE; } - std::string cameraId = cm->cameras()[0]->id(); + std::string cameraId = cameras[0]->id(); camera = cm->get(cameraId); /* * Note that is equivalent to: - * camera = cm->cameras()[0]; + * camera = cameras[0]; */ Once a camera has been selected an application needs to acquire an exclusive diff --git a/src/apps/cam/camera_session.cpp b/src/apps/cam/camera_session.cpp index 8447f932..5afd087f 100644 --- a/src/apps/cam/camera_session.cpp +++ b/src/apps/cam/camera_session.cpp @@ -39,8 +39,10 @@ CameraSession::CameraSession(CameraManager *cm, { char *endptr; unsigned long index = strtoul(cameraId.c_str(), &endptr, 10); - if (*endptr == '\0' && index > 0 && index <= cm->cameras().size()) - camera_ = cm->cameras()[index - 1]; + auto cameras = cm->cameras(); + + if (*endptr == '\0' && index > 0 && index <= cameras.size()) + camera_ = std::move(cameras[index - 1]); else camera_ = cm->get(cameraId); diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp index f015c6d2..8613d66d 100644 --- a/src/gstreamer/gstlibcamerasrc.cpp +++ b/src/gstreamer/gstlibcamerasrc.cpp @@ -385,13 +385,14 @@ gst_libcamera_src_open(GstLibcameraSrc *self) return false; } } else { - if (cm->cameras().empty()) { + auto cameras = cm->cameras(); + if (cameras.empty()) { GST_ELEMENT_ERROR(self, RESOURCE, NOT_FOUND, ("Could not find any supported camera on this system."), ("libcamera::CameraMananger::cameras() is empty")); return false; } - cam = cm->cameras()[0]; + cam = std::move(cameras[0]); } GST_INFO_OBJECT(self, "Using camera '%s'", cam->id().c_str());