From patchwork Thu Apr 23 23:00:41 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 26541 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 6AD58BDCB5 for ; Thu, 23 Apr 2026 23:01:43 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 2159E62FBC; Fri, 24 Apr 2026 01:01:43 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="hdhWFbCs"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id F2DF062FA2 for ; Fri, 24 Apr 2026 01:01:27 +0200 (CEST) Received: from killaraus.ideasonboard.com (2001-14ba-703d-e500--2a1.rev.dnainternet.fi [IPv6:2001:14ba:703d:e500::2a1]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 7E4819A6 for ; Fri, 24 Apr 2026 00:59:48 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1776985188; bh=jYA4ZrmdMuN4fMJyT8ozMO+KYOftW5mwSAAbsLE8jcw=; h=From:To:Subject:Date:In-Reply-To:References:From; b=hdhWFbCsX4W34PtnAo+x+v5RCyuZ97R92Gg9IbUoESiH0YsXl1UYgWrWGh8I3CXTz 34zRjwRdyiZ3tlbEn6GQCjeA16VN30yRcFpXhSEXv8GhxHoSXewfeHTAVvdpNAEMSv g9VJxy60EQxas3DzV2GXMR5ojgLDYe1gTywl2ClU= From: Laurent Pinchart To: libcamera-devel@lists.libcamera.org Subject: [PATCH v3 19/37] libcamera: value_node: Support looking up descendant node by path Date: Fri, 24 Apr 2026 02:00:41 +0300 Message-ID: <20260423230059.3180987-20-laurent.pinchart@ideasonboard.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260423230059.3180987-1-laurent.pinchart@ideasonboard.com> References: <20260423230059.3180987-1-laurent.pinchart@ideasonboard.com> 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" Looking up a descendant node based on a path is a common operation. Add a helper function to do so, to avoid loops in the callers. Signed-off-by: Laurent Pinchart Reviewed-by: Barnabás Pőcze Reviewed-by: Isaac Scott --- Changes since v1: - Use reference in range-based for loop - Improve commit message --- include/libcamera/internal/value_node.h | 1 + src/libcamera/value_node.cpp | 23 +++++++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/include/libcamera/internal/value_node.h b/include/libcamera/internal/value_node.h index 578413199df1..ccae69e25a82 100644 --- a/include/libcamera/internal/value_node.h +++ b/include/libcamera/internal/value_node.h @@ -237,6 +237,7 @@ public: bool contains(std::string_view key) const; ValueNode *at(std::string_view key); const ValueNode &operator[](std::string_view key) const; + const ValueNode &operator[](std::initializer_list path) const; ValueNode *add(std::unique_ptr &&child); ValueNode *add(std::string key, std::unique_ptr &&child); diff --git a/src/libcamera/value_node.cpp b/src/libcamera/value_node.cpp index 3b4041b7bbf0..6ab11009fccc 100644 --- a/src/libcamera/value_node.cpp +++ b/src/libcamera/value_node.cpp @@ -488,6 +488,29 @@ const ValueNode &ValueNode::operator[](std::string_view key) const return *iter->second; } +/** + * \brief Retrieve a descendant node by path + * \param[in] path The path + * + * This function retrieves a descendant of a ValueNode by following a \a path. + * The path is a list of keys that index nested dictionary nodes. If any node + * along the path is not a Dictionary node, an empty node is returned. + * + * \return The ValueNode corresponding to the \a path + */ +const ValueNode &ValueNode::operator[](std::initializer_list path) const +{ + const ValueNode *node = this; + + for (const auto &part : path) { + node = &(*node)[part]; + if (!*node) + return empty; + } + + return *node; +} + /** * \brief Add a child node to a list * \param[in] child The child node