{"id":21657,"url":"https://patchwork.libcamera.org/api/patches/21657/?format=json","web_url":"https://patchwork.libcamera.org/patch/21657/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/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":"<20241017125220.60567-4-jacopo.mondi@ideasonboard.com>","date":"2024-10-17T12:52:18","name":"[RFC,v2,3/4] libcamera: Implement YamlEmitter","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"897098bd994f51799cbdbd6e6e7fa9f01db0e254","submitter":{"id":143,"url":"https://patchwork.libcamera.org/api/people/143/?format=json","name":"Jacopo Mondi","email":"jacopo.mondi@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/21657/mbox/","series":[{"id":4711,"url":"https://patchwork.libcamera.org/api/series/4711/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=4711","date":"2024-10-17T12:52:15","name":"libcamera: Implement YamlEmitter","version":2,"mbox":"https://patchwork.libcamera.org/series/4711/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/21657/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/21657/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 8B912C32FD\n\tfor ;\n\tThu, 17 Oct 2024 12:52:41 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id F30416538C;\n\tThu, 17 Oct 2024 14:52:40 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 6E84B65387\n\tfor ;\n\tThu, 17 Oct 2024 14:52:33 +0200 (CEST)","from ideasonboard.com (unknown [5.77.64.27])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 072DA827;\n\tThu, 17 Oct 2024 14:50:49 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"ZKpRyAlc\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1729169450;\n\tbh=XXHKXPzAfJiudNvP4pazjj/DWrTK6xt/dq4EJHQaHDM=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=ZKpRyAlcb1O+I4wvvPyF0LlZvbz+QWh+ONS//iUhgJWLO86sP1/u8bKiflwhafwV3\n\tmKI9TNy08/NZ9stvmdNOpsD/E73vqdIh6FBQJFzOmjMsBi29BIFpnYgFHyHYQpbjku\n\tEDWNJPrLAD+7apulThUJjyViucK7MzLXfcOiPNWY=","From":"Jacopo Mondi ","To":"libcamera-devel@lists.libcamera.org","Cc":"Jacopo Mondi ","Subject":"[RFC v2 3/4] libcamera: Implement YamlEmitter","Date":"Thu, 17 Oct 2024 14:52:18 +0200","Message-ID":"<20241017125220.60567-4-jacopo.mondi@ideasonboard.com>","X-Mailer":"git-send-email 2.47.0","In-Reply-To":"<20241017125220.60567-1-jacopo.mondi@ideasonboard.com>","References":"<20241017125220.60567-1-jacopo.mondi@ideasonboard.com>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","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":"Signed-off-by: Jacopo Mondi \n---\n include/libcamera/internal/meson.build | 1 +\n include/libcamera/internal/yaml_emitter.h | 162 ++++++++++\n src/libcamera/meson.build | 1 +\n src/libcamera/yaml_emitter.cpp | 362 ++++++++++++++++++++++\n 4 files changed, 526 insertions(+)\n create mode 100644 include/libcamera/internal/yaml_emitter.h\n create mode 100644 src/libcamera/yaml_emitter.cpp","diff":"diff --git a/include/libcamera/internal/meson.build b/include/libcamera/internal/meson.build\nindex 1c5eef9cab80..7533b075fde2 100644\n--- a/include/libcamera/internal/meson.build\n+++ b/include/libcamera/internal/meson.build\n@@ -41,6 +41,7 @@ libcamera_internal_headers = files([\n 'v4l2_pixelformat.h',\n 'v4l2_subdevice.h',\n 'v4l2_videodevice.h',\n+ 'yaml_emitter.h',\n 'yaml_parser.h',\n ])\n \ndiff --git a/include/libcamera/internal/yaml_emitter.h b/include/libcamera/internal/yaml_emitter.h\nnew file mode 100644\nindex 000000000000..e4a0e3b440a5\n--- /dev/null\n+++ b/include/libcamera/internal/yaml_emitter.h\n@@ -0,0 +1,162 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2024, Ideas On Board Oy\n+ *\n+ * libcamera YAML emitter helper\n+ */\n+\n+#pragma once\n+\n+#include \n+#include \n+\n+#include \n+#include \n+#include \n+\n+#include \n+\n+namespace libcamera {\n+\n+class YamlDict;\n+class YamlEvent;\n+class YamlList;\n+class YamlRoot;\n+class YamlScalar;\n+\n+class YamlEmitter final\n+{\n+public:\n+\t~YamlEmitter();\n+\n+\tstatic std::unique_ptr root(std::string_view path);\n+\n+\tint emit();\n+\tyaml_event_t *event() { return &event_; }\n+\n+private:\n+\tLIBCAMERA_DISABLE_COPY(YamlEmitter)\n+\n+\tclass Emitter\n+\t{\n+\tpublic:\n+\t\t~Emitter();\n+\n+\t\tvoid init(File *file);\n+\n+\t\tint emit(yaml_event_t *event);\n+\n+\tprivate:\n+\t\tvoid logError();\n+\n+\t\tyaml_emitter_t emitter_;\n+\t};\n+\n+\tYamlEmitter() = default;\n+\n+\tvoid init();\n+\n+\tstd::unique_ptr file_;\n+\tyaml_event_t event_;\n+\tEmitter emitter_;\n+};\n+\n+class YamlOutput\n+{\n+public:\n+\tvirtual ~YamlOutput() {};\n+\n+\tYamlOutput(YamlOutput &&other)\n+\t{\n+\t\temitter_ = other.emitter_;\n+\t\tother.emitter_ = nullptr;\n+\t}\n+\n+\tYamlScalar scalar();\n+\tstd::unique_ptr dict();\n+\tstd::unique_ptr list();\n+\n+protected:\n+\tYamlOutput(YamlEmitter *emitter)\n+\t\t: emitter_(emitter)\n+\t{\n+\t}\n+\n+\tint emitScalar(std::string_view scalar);\n+\tint emitMappingStart();\n+\tint emitMappingEnd();\n+\tint emitSequenceStart();\n+\tint emitSequenceEnd();\n+\n+\tYamlEmitter *emitter_;\n+\tyaml_event_t event_;\n+};\n+\n+class YamlRoot : public YamlOutput\n+{\n+public:\n+\t~YamlRoot();\n+\n+\tstd::unique_ptr list();\n+\tstd::unique_ptr dict();\n+\tvoid scalar(std::string_view scalar);\n+\n+private:\n+\tfriend class YamlEmitter;\n+\n+\tYamlRoot(YamlEmitter *emitter)\n+\t\t: YamlOutput(emitter)\n+\t{\n+\t\temitterRoot_ = std::unique_ptr(emitter);\n+\t}\n+\n+\tstd::unique_ptr emitterRoot_;\n+};\n+\n+class YamlScalar : public YamlOutput\n+{\n+public:\n+\t~YamlScalar() = default;\n+\n+\tvoid operator=(std::string_view scalar);\n+\n+private:\n+\tfriend class YamlOutput;\n+\n+\tYamlScalar(YamlEmitter *emitter);\n+};\n+\n+class YamlList : public YamlOutput\n+{\n+public:\n+\tYamlList(YamlList &&other) = default;\n+\t~YamlList();\n+\n+\tstd::unique_ptr list();\n+\tstd::unique_ptr dict();\n+\tvoid scalar(std::string_view scalar);\n+\n+private:\n+\tfriend class YamlOutput;\n+\n+\tYamlList(YamlEmitter *emitter);\n+};\n+\n+class YamlDict : public YamlOutput\n+{\n+public:\n+\tYamlDict(YamlDict &&other) = default;\n+\t~YamlDict();\n+\n+\tstd::unique_ptr list(std::string_view key);\n+\tstd::unique_ptr dict(std::string_view key);\n+\n+\tYamlScalar operator[](std::string_view key);\n+\n+private:\n+\tfriend class YamlOutput;\n+\n+\tYamlDict(YamlEmitter *emitter);\n+};\n+\n+} /* namespace libcamera */\ndiff --git a/src/libcamera/meson.build b/src/libcamera/meson.build\nindex aa9ab0291854..5b8af4103085 100644\n--- a/src/libcamera/meson.build\n+++ b/src/libcamera/meson.build\n@@ -51,6 +51,7 @@ libcamera_internal_sources = files([\n 'v4l2_pixelformat.cpp',\n 'v4l2_subdevice.cpp',\n 'v4l2_videodevice.cpp',\n+ 'yaml_emitter.cpp',\n 'yaml_parser.cpp',\n ])\n \ndiff --git a/src/libcamera/yaml_emitter.cpp b/src/libcamera/yaml_emitter.cpp\nnew file mode 100644\nindex 000000000000..f2aaa1c1c1a6\n--- /dev/null\n+++ b/src/libcamera/yaml_emitter.cpp\n@@ -0,0 +1,362 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2024, Ideas On Board Oy\n+ *\n+ * libcamera YAML emitter helper\n+ */\n+\n+#include \"libcamera/internal/yaml_emitter.h\"\n+\n+#include \n+\n+/**\n+ * \\file yaml_emitter.h\n+ * \\brief A YAML emitter helper\n+ *\n+ * The YAML Emitter helpers allows users to emit output in YAML format.\n+ *\n+ * To emit YAML users of this classes should create a root node with\n+ *\n+ * \\code\n+\tstd::string filePath(\"...\");\n+\tauto root = YamlEmitter::root(filePath);\n+ \\endcode\n+ *\n+ * A YamlRoot implements RAII-style handling of YAML sequence and document\n+ * events handling. Creating a YamlRoot emits the STREAM_START and DOC_START\n+ * events. Once a YamlRoot gets deleted the DOC_SEND and STREAM_END events\n+ * gets automatically deleted.\n+ *\n+ * Once a root node has been created it is possible to populate it with\n+ * scalars, list or dictionaries.\n+ *\n+ * YamlList and YamlDict can only be created wrapped in unique_ptr<> instances,\n+ * to implement a RAII-style handling of YAML of lists and dictionaries.\n+ * Creating a YamlList and a YamlDict emits the YAML sequence and mapping start\n+ * events. Once an instance gets deleted, the sequence and mapping gets\n+ * automatically emitted.\n+ *\n+ * A YamlScalar is a simpler object that can be assigned to different types\n+ * to emit them as strings.\n+ */\n+\n+namespace libcamera {\n+\n+LOG_DEFINE_CATEGORY(YamlEmitter)\n+\n+namespace {\n+\n+int yamlWrite(void *data, unsigned char *buffer, size_t size)\n+{\n+\tFile *file = static_cast(data);\n+\n+\tSpan buf{ buffer, size };\n+\tssize_t ret = file->write(buf);\n+\tif (ret < 0) {\n+\t\tret = errno;\n+\t\tLOG(YamlEmitter, Error) << \"Write error : \" << strerror(ret);\n+\t\treturn 0;\n+\t}\n+\n+\treturn 1;\n+}\n+\n+} /* namespace */\n+\n+/**\n+ * \\class YamlEmitter\n+ *\n+ * Yaml Emitter entry point. Allows to create a YamlRoot object that users\n+ * can populate.\n+ */\n+\n+YamlEmitter::~YamlEmitter()\n+{\n+\tyaml_event_delete(&event_);\n+}\n+\n+/**\n+ * \\brief Create a YamlRoot that applications can start populating with YamlOutput\n+ * \\param[in] path The YAML output file path\n+ * \\return A unique pointer to a YamlRoot\n+ */\n+std::unique_ptr YamlEmitter::root(std::string_view path)\n+{\n+\tYamlEmitter *emitter = new YamlEmitter();\n+\n+\tstd::string filePath(path);\n+\temitter->file_ = std::make_unique(filePath);\n+\temitter->file_->open(File::OpenModeFlag::WriteOnly);\n+\n+\temitter->init();\n+\n+\tYamlRoot *root = new YamlRoot(emitter);\n+\treturn std::unique_ptr(root);\n+}\n+\n+/**\n+ * \\brief Emit a yaml event\n+ */\n+int YamlEmitter::emit()\n+{\n+\treturn emitter_.emit(&event_);\n+}\n+\n+void YamlEmitter::init()\n+{\n+\temitter_.init(file_.get());\n+\n+\tyaml_stream_start_event_initialize(&event_, YAML_UTF8_ENCODING);\n+\temitter_.emit(&event_);\n+\n+\tyaml_document_start_event_initialize(&event_, NULL, NULL, NULL, 0);\n+\temitter_.emit(&event_);\n+}\n+\n+/**\n+ * \\class YamlEmitter::Emitter\n+ *\n+ * yaml_emitter_t wrapper. Initialize the yaml_emitter_t on creation allows\n+ * YamlOutput classes to emit events.\n+ */\n+\n+YamlEmitter::Emitter::~Emitter()\n+{\n+\tyaml_emitter_delete(&emitter_);\n+}\n+\n+void YamlEmitter::Emitter::init(File *file)\n+{\n+\tyaml_emitter_initialize(&emitter_);\n+\tyaml_emitter_set_output(&emitter_, yamlWrite, file);\n+}\n+\n+void YamlEmitter::Emitter::logError()\n+{\n+\tswitch (emitter_.error) {\n+\tcase YAML_MEMORY_ERROR:\n+\t\tLOG(YamlEmitter, Error)\n+\t\t\t<< \"Memory error: Not enough memory for emitting\";\n+\t\tbreak;\n+\n+\tcase YAML_WRITER_ERROR:\n+\t\tLOG(YamlEmitter, Error)\n+\t\t\t<< \"Writer error: \" << emitter_.problem;\n+\t\tbreak;\n+\n+\tcase YAML_EMITTER_ERROR:\n+\t\tLOG(YamlEmitter, Error)\n+\t\t\t<< \"Emitter error: \" << emitter_.problem;\n+\t\tbreak;\n+\n+\tdefault:\n+\t\tLOG(YamlEmitter, Error) << \"Internal problem\";\n+\t\tbreak;\n+\t}\n+}\n+\n+int YamlEmitter::Emitter::emit(yaml_event_t *event)\n+{\n+\tint ret = yaml_emitter_emit(&emitter_, event);\n+\tif (!ret) {\n+\t\tlogError();\n+\t\treturn -EINVAL;\n+\t}\n+\n+\treturn 0;\n+}\n+\n+/**\n+ * \\class YamlOutput\n+ *\n+ * The YamlOutput base class. From this class YamlScalar, YamlList and YamlDict\n+ * are derived.\n+ *\n+ * The YamlOutput class provides functions to create a scalar, a list or a\n+ * dictionary.\n+ *\n+ * The class cannot be instantiated directly by applications.\n+ */\n+\n+YamlScalar YamlOutput::scalar()\n+{\n+\treturn YamlScalar(emitter_);\n+}\n+\n+std::unique_ptr YamlOutput::dict()\n+{\n+\tYamlDict dict(emitter_);\n+\n+\treturn std::make_unique(std::move(dict));\n+}\n+\n+std::unique_ptr YamlOutput::list()\n+{\n+\tYamlList list(emitter_);\n+\n+\treturn std::make_unique(std::move(list));\n+}\n+\n+int YamlOutput::emitScalar(std::string_view scalar)\n+{\n+\tconst unsigned char *value = reinterpret_cast\n+\t\t\t\t (scalar.data());\n+\tyaml_scalar_event_initialize(emitter_->event(), NULL, NULL, value,\n+\t\t\t\t scalar.length(), true, false,\n+\t\t\t\t YAML_PLAIN_SCALAR_STYLE);\n+\treturn emitter_->emit();\n+}\n+\n+int YamlOutput::emitMappingStart()\n+{\n+\tyaml_mapping_start_event_initialize(emitter_->event(), NULL, NULL,\n+\t\t\t\t\t true, YAML_BLOCK_MAPPING_STYLE);\n+\treturn emitter_->emit();\n+}\n+\n+int YamlOutput::emitMappingEnd()\n+{\n+\tyaml_mapping_end_event_initialize(emitter_->event());\n+\treturn emitter_->emit();\n+}\n+\n+int YamlOutput::emitSequenceStart()\n+{\n+\tyaml_sequence_start_event_initialize(emitter_->event(), NULL, NULL, true,\n+\t\t\t\t\t YAML_BLOCK_SEQUENCE_STYLE);\n+\treturn emitter_->emit();\n+}\n+\n+int YamlOutput::emitSequenceEnd()\n+{\n+\tyaml_sequence_end_event_initialize(emitter_->event());\n+\treturn emitter_->emit();\n+}\n+\n+/**\n+ * \\class YamlRoot\n+ *\n+ * Yaml root node. A root node can be populated with a scalar, a list or a dict.\n+ */\n+\n+YamlRoot::~YamlRoot()\n+{\n+\tyaml_document_end_event_initialize(emitter_->event(), 0);\n+\temitterRoot_->emit();\n+\n+\tyaml_stream_end_event_initialize(emitter_->event());\n+\temitterRoot_->emit();\n+}\n+\n+std::unique_ptr YamlRoot::dict()\n+{\n+\temitMappingStart();\n+\n+\treturn YamlOutput::dict();\n+}\n+\n+std::unique_ptr YamlRoot::list()\n+{\n+\temitSequenceStart();\n+\n+\treturn YamlOutput::list();\n+}\n+\n+/**\n+ * \\class YamlScalar\n+ *\n+ * A YamlScalar can be assigned to an std::string_view and other libcamera\n+ * types to emit them as YAML scalars.\n+ */\n+\n+YamlScalar::YamlScalar(YamlEmitter *emitter)\n+\t: YamlOutput(emitter)\n+{\n+}\n+\n+void YamlScalar::operator=(std::string_view scalar)\n+{\n+\temitScalar(scalar);\n+}\n+\n+/**\n+ * \\class YamlList\n+ *\n+ * A YamlList can be populated with scalar and allows to create other lists\n+ * and dictionaries.\n+ */\n+\n+YamlList::YamlList(YamlEmitter *emitter)\n+\t: YamlOutput(emitter)\n+{\n+}\n+\n+YamlList::~YamlList()\n+{\n+\tif (emitter_)\n+\t\temitSequenceEnd();\n+}\n+\n+void YamlList::scalar(std::string_view scalar)\n+{\n+\temitScalar(scalar);\n+}\n+\n+std::unique_ptr YamlList::list()\n+{\n+\temitSequenceStart();\n+\n+\treturn YamlOutput::list();\n+}\n+\n+std::unique_ptr YamlList::dict()\n+{\n+\temitMappingStart();\n+\n+\treturn YamlOutput::dict();\n+}\n+\n+/**\n+ * \\class YamlDict\n+ *\n+ * A YamlDict derives an unordered_map that maps strings to YAML scalar.\n+ *\n+ * A YamlDict can be populated with scalars using operator[] and allows to\n+ * create other lists and dictionaries.\n+ */\n+\n+YamlDict::YamlDict(YamlEmitter *emitter)\n+\t: YamlOutput(emitter)\n+{\n+}\n+\n+YamlDict::~YamlDict()\n+{\n+\tif (emitter_)\n+\t\temitMappingEnd();\n+}\n+\n+std::unique_ptr YamlDict::list(std::string_view key)\n+{\n+\temitScalar(key);\n+\temitSequenceStart();\n+\n+\treturn YamlOutput::list();\n+}\n+\n+std::unique_ptr YamlDict::dict(std::string_view key)\n+{\n+\temitScalar(key);\n+\temitMappingStart();\n+\n+\treturn YamlOutput::dict();\n+}\n+\n+YamlScalar YamlDict::operator[](std::string_view key)\n+{\n+\temitScalar(key);\n+\n+\treturn YamlOutput::scalar();\n+}\n+\n+} /* namespace libcamera */\n","prefixes":["RFC","v2","3/4"]}