{"id":24310,"url":"https://patchwork.libcamera.org/api/1.1/patches/24310/?format=json","web_url":"https://patchwork.libcamera.org/patch/24310/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/1.1/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20250911092945.16517-4-mzamazal@redhat.com>","date":"2025-09-11T09:29:33","name":"[v17,03/12] config: Add configuration retrieval helpers","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"f40054046bb58923283991f941f6b401c15ba3ae","submitter":{"id":177,"url":"https://patchwork.libcamera.org/api/1.1/people/177/?format=json","name":"Milan Zamazal","email":"mzamazal@redhat.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/24310/mbox/","series":[{"id":5431,"url":"https://patchwork.libcamera.org/api/1.1/series/5431/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5431","date":"2025-09-11T09:29:30","name":"Add global configuration file","version":17,"mbox":"https://patchwork.libcamera.org/series/5431/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/24310/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/24310/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id E0600C324E\n\tfor ;\n\tThu, 11 Sep 2025 09:30:11 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 9317B69376;\n\tThu, 11 Sep 2025 11:30:11 +0200 (CEST)","from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.129.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 1B0616935A\n\tfor ;\n\tThu, 11 Sep 2025 11:30:10 +0200 (CEST)","from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com\n\t(ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63])\n\tby relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3,\n\tcipher=TLS_AES_256_GCM_SHA384) id us-mta-223-VYKxYmA5Ni2maVBAwqA23Q-1;\n\tThu, 11 Sep 2025 05:30:03 -0400","from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com\n\t(mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com\n\t[10.30.177.12])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\tkey-exchange X25519 server-signature RSA-PSS (2048 bits)\n\tserver-digest SHA256) (No client certificate requested)\n\tby mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix)\n\twith ESMTPS id A19BA1977538; Thu, 11 Sep 2025 09:30:02 +0000 (UTC)","from mzamazal-thinkpadp1gen7.tpbc.com (unknown [10.44.34.98])\n\tby mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix)\n\twith ESMTP id 44C8119560B1; Thu, 11 Sep 2025 09:29:59 +0000 (UTC)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=redhat.com header.i=@redhat.com\n\theader.b=\"O7muSoGA\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n\ts=mimecast20190719; t=1757583009;\n\th=from:from:reply-to:subject:subject:date:date:message-id:message-id:\n\tto:to:cc:cc:mime-version:mime-version:content-type:content-type:\n\tcontent-transfer-encoding:content-transfer-encoding:\n\tin-reply-to:in-reply-to:references:references;\n\tbh=Bw52UuO45FOFbwiN3BUPbA2UWTY2YDEcEO8Nrj9Nmi4=;\n\tb=O7muSoGApASjhCtnVxJvWrI+splWzAcBmA+FvfQs1XFZ+3GfkjShb/57W7sZceEeF0jr+i\n\tuKkT2LpG9uLtYwiZhxL2DthqtIQIkmg5IcqPO5ND3wWALvgg6HFNJrCP/2LlvYM0uVQwkK\n\t/jgQM393q3LqfyilsSbaz9HiFqt2a3Y=","X-MC-Unique":"VYKxYmA5Ni2maVBAwqA23Q-1","X-Mimecast-MFC-AGG-ID":"VYKxYmA5Ni2maVBAwqA23Q_1757583002","From":"Milan Zamazal ","To":"libcamera-devel@lists.libcamera.org","Cc":"Milan Zamazal , Kieran Bingham\n\t, =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?=\n\t, Laurent Pinchart\n\t, Paul Elder\n\t","Subject":"[PATCH v17 03/12] config: Add configuration retrieval helpers","Date":"Thu, 11 Sep 2025 11:29:33 +0200","Message-ID":"<20250911092945.16517-4-mzamazal@redhat.com>","In-Reply-To":"<20250911092945.16517-1-mzamazal@redhat.com>","References":"<20250911092945.16517-1-mzamazal@redhat.com>","MIME-Version":"1.0","X-Scanned-By":"MIMEDefang 3.0 on 10.30.177.12","X-Mimecast-Spam-Score":"0","X-Mimecast-MFC-PROC-ID":"82JVeA8pAu4Kd0pUHMrke0WZoU-2ZBDkZaheAqjZnRs_1757583002","X-Mimecast-Originator":"redhat.com","Content-Transfer-Encoding":"8bit","content-type":"text/plain; charset=\"US-ASCII\"; x-default=true","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"Let's add some helpers to make accessing simple configuration values\nsimpler. The helpers are used in the followup patches.\n\nGlobalConfiguration::option ensures that no value is returned rather\nthan a value of YamlObject::empty.\n\nSigned-off-by: Milan Zamazal \n---\n .../libcamera/internal/global_configuration.h | 28 ++++++\n src/libcamera/global_configuration.cpp | 99 +++++++++++++++++++\n 2 files changed, 127 insertions(+)","diff":"diff --git a/include/libcamera/internal/global_configuration.h b/include/libcamera/internal/global_configuration.h\nindex f695498c4..8d09517ed 100644\n--- a/include/libcamera/internal/global_configuration.h\n+++ b/include/libcamera/internal/global_configuration.h\n@@ -8,6 +8,11 @@\n #pragma once\n \n #include \n+#include \n+#include \n+#include \n+\n+#include \n \n #include \"libcamera/internal/yaml_parser.h\"\n \n@@ -23,6 +28,29 @@ public:\n \tunsigned int version() const;\n \tConfiguration configuration() const;\n \n+\ttemplate\n+\tstd::optional option(\n+\t\tconst std::initializer_list confPath) const\n+\t{\n+\t\tconst YamlObject *c = &configuration();\n+\t\tfor (auto part : confPath) {\n+\t\t\tc = &(*c)[part];\n+\t\t\tif (!*c)\n+\t\t\t\treturn {};\n+\t\t}\n+\t\treturn c->get();\n+\t}\n+\n+\tstd::optional> listOption(\n+\t\tconst std::initializer_list confPath) const;\n+\tstd::optional envOption(\n+\t\tconst char *const envVariable,\n+\t\tconst std::initializer_list confPath) const;\n+\tstd::optional> envListOption(\n+\t\tconst char *const envVariable,\n+\t\tconst std::initializer_list confPath,\n+\t\tconst std::string delimiter = \":\") const;\n+\n private:\n \tbool loadFile(const std::filesystem::path &fileName);\n \tvoid load();\ndiff --git a/src/libcamera/global_configuration.cpp b/src/libcamera/global_configuration.cpp\nindex d02668111..592edcf30 100644\n--- a/src/libcamera/global_configuration.cpp\n+++ b/src/libcamera/global_configuration.cpp\n@@ -8,8 +8,12 @@\n #include \"libcamera/internal/global_configuration.h\"\n \n #include \n+#include \n+#include \n+#include \n #include \n #include \n+#include \n \n #include \n #include \n@@ -43,6 +47,12 @@ LOG_DEFINE_CATEGORY(Configuration)\n * If the first found configuration file cannot be opened or parsed, an error is\n * reported and no configuration file is used. This is to prevent libcamera from\n * using an unintended configuration file.\n+ *\n+ * The configuration can be accessed using the provided helpers. Namely\n+ * GlobalConfiguration::option(), GlobalConfiguration::envOption(),\n+ * GlobalConfiguration::listOption(), and GlobalConfiguration::envListOption()\n+ * to access individual options, or GlobalConfiguration::configuration() to\n+ * access the whole configuration.\n */\n \n bool GlobalConfiguration::loadFile(const std::filesystem::path &fileName)\n@@ -110,6 +120,95 @@ GlobalConfiguration::GlobalConfiguration()\n * the underlying type.\n */\n \n+/**\n+ * \\fn std::optional GlobalConfiguration::option(const std::initializer_list &confPath) const\n+ * \\brief Return value of the configuration option identified by \\a confPath\n+ * \\param[in] confPath Sequence of the YAML section names (excluding\n+ * `configuration') leading to the requested option\n+ * \\return The value of the configuration item corresponding to \\a confPath if\n+ * it exists in the configuration file, or no value otherwise\n+ */\n+\n+/**\n+ * \\brief Return values of the configuration option identified by \\a confPath\n+ * \\tparam T The type of the retrieved configuration value\n+ * \\param[in] confPath Sequence of the YAML section names (excluding\n+ * `configuration') leading to the requested list option, separated by dots\n+ * \\return A vector of strings or no value if not found\n+ */\n+std::optional> GlobalConfiguration::listOption(\n+\tconst std::initializer_list confPath) const\n+{\n+\tconst YamlObject *c = &configuration();\n+\tfor (auto part : confPath) {\n+\t\tc = &(*c)[part];\n+\t\tif (!*c)\n+\t\t\treturn {};\n+\t}\n+\treturn c->getList();\n+}\n+\n+/**\n+ * \\brief Return value of environment variable with a fallback on the configuration file\n+ * \\param[in] envVariable Environment variable to get the value from\n+ * \\param[in] confPath The sequence of YAML section names to fall back on when\n+ * \\a envVariable is unavailable\n+ *\n+ * This helper looks first at the given environment variable and if it is\n+ * defined then it returns its value (even if it is empty). Otherwise it looks\n+ * for \\a confPath the same way as in GlobalConfiguration::option. Only string\n+ * values are supported.\n+ *\n+ * \\note Support for using environment variables to configure libcamera behavior\n+ * is provided here mostly for backward compatibility reasons. Introducing new\n+ * configuration environment variables is discouraged.\n+ *\n+ * \\return The value retrieved from the given environment if it is set,\n+ * otherwise the value from the configuration file if it exists, or no value if\n+ * it does not\n+ */\n+std::optional GlobalConfiguration::envOption(\n+\tconst char *envVariable,\n+\tconst std::initializer_list confPath) const\n+{\n+\tconst char *envValue = utils::secure_getenv(envVariable);\n+\tif (envValue)\n+\t\treturn std::optional{ std::string{ envValue } };\n+\treturn option(confPath);\n+}\n+\n+/**\n+ * \\brief Return values of the configuration option from a file or environment\n+ * \\param[in] envVariable Environment variable to get the value from\n+ * \\param[in] confPath The same as in GlobalConfiguration::option\n+ * \\param[in] delimiter Items separator in the environment variable\n+ *\n+ * This helper looks first at the given environment variable and if it is\n+ * defined (even if it is empty) then it splits its value by semicolons and\n+ * returns the resulting list of strings. Otherwise it looks for \\a confPath the\n+ * same way as in GlobalConfiguration::option, value of which must be a list of\n+ * strings.\n+ *\n+ * \\note Support for using environment variables to configure libcamera behavior\n+ * is provided here mostly for backward compatibility reasons. Introducing new\n+ * configuration environment variables is discouraged.\n+ *\n+ * \\return A vector of strings retrieved from the given environment option or\n+ * configuration file or no value if not found; the vector may be empty\n+ */\n+std::optional> GlobalConfiguration::envListOption(\n+\tconst char *const envVariable,\n+\tconst std::initializer_list confPath,\n+\tconst std::string delimiter) const\n+{\n+\tconst char *envValue = utils::secure_getenv(envVariable);\n+\tif (envValue) {\n+\t\tauto items = utils::split(envValue, delimiter);\n+\t\treturn std::vector(items.begin(), items.end());\n+\t}\n+\treturn listOption(confPath);\n+}\n+\n /**\n * \\brief Return configuration version\n *\n","prefixes":["v17","03/12"]}