[libcamera-devel] [PATCH v6 1/3] libcamera: Introduce YamlParser as a helper to parse yaml files
Han-Lin Chen
hanlinchen at chromium.org
Wed Apr 27 16:09:27 CEST 2022
Introduce YamlParser as a helper to convert contents of a yaml file to
a tree based structure for easier reading, and to avoid writing parser
with raw yaml tokens. The class is based on libyaml, and only support
reading but not writing a yaml file.
The interface is inspired by Json::Value class from jsoncpp:
http://jsoncpp.sourceforge.net/class_json_1_1_value.html
Signed-off-by: Han-Lin Chen <hanlinchen at chromium.org>
---
README.rst | 4 +-
include/libcamera/internal/meson.build | 1 +
include/libcamera/internal/yaml_parser.h | 87 +++
src/libcamera/meson.build | 3 +
src/libcamera/yaml_parser.cpp | 679 +++++++++++++++++++++++
5 files changed, 772 insertions(+), 2 deletions(-)
create mode 100644 include/libcamera/internal/yaml_parser.h
create mode 100644 src/libcamera/yaml_parser.cpp
diff --git a/README.rst b/README.rst
index aae6b79f..b5a2d448 100644
--- a/README.rst
+++ b/README.rst
@@ -60,7 +60,7 @@ Meson Build system: [required]
pip3 install --user --upgrade meson
for the libcamera core: [required]
- python3-yaml python3-ply python3-jinja2
+ libyaml-dev python3-yaml python3-ply python3-jinja2
for IPA module signing: [required]
libgnutls28-dev openssl
@@ -98,7 +98,7 @@ for tracing with lttng: [optional]
liblttng-ust-dev python3-jinja2 lttng-tools
for android: [optional]
- libexif-dev libjpeg-dev libyaml-dev
+ libexif-dev libjpeg-dev
for lc-compliance: [optional]
libevent-dev
diff --git a/include/libcamera/internal/meson.build b/include/libcamera/internal/meson.build
index c9e055d4..7a780d48 100644
--- a/include/libcamera/internal/meson.build
+++ b/include/libcamera/internal/meson.build
@@ -42,4 +42,5 @@ libcamera_internal_headers = files([
'v4l2_pixelformat.h',
'v4l2_subdevice.h',
'v4l2_videodevice.h',
+ 'yaml_parser.h',
])
diff --git a/include/libcamera/internal/yaml_parser.h b/include/libcamera/internal/yaml_parser.h
new file mode 100644
index 00000000..3a4f3052
--- /dev/null
+++ b/include/libcamera/internal/yaml_parser.h
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2022, Google Inc.
+ *
+ * yaml_parser.h - libcamera YAML parsing helper
+ */
+
+#pragma once
+
+#include <cstdio>
+#include <map>
+#include <string>
+#include <vector>
+
+#include <libcamera/base/class.h>
+
+#include <libcamera/geometry.h>
+
+namespace libcamera {
+
+class YamlParserContext;
+
+class YamlObject
+{
+public:
+ YamlObject();
+ ~YamlObject();
+
+ bool isValue() const
+ {
+ return type_ == Value;
+ }
+ bool isList() const
+ {
+ return type_ == List;
+ }
+ bool isDictionary() const
+ {
+ return type_ == Dictionary;
+ }
+
+#ifndef __DOXYGEN__
+ template<typename T,
+ typename std::enable_if_t<
+ std::is_same<bool, T>::value ||
+ std::is_same<double, T>::value ||
+ std::is_same<int32_t, T>::value ||
+ std::is_same<uint32_t, T>::value ||
+ std::is_same<std::string, T>::value ||
+ std::is_same<Size, T>::value> * = nullptr>
+#else
+ template<typename T>
+#endif
+ T get(const T &defaultValue, bool *ok = nullptr) const;
+
+ std::size_t size() const;
+ const YamlObject &operator[](std::size_t index) const;
+
+ bool contains(const std::string &key) const;
+ const YamlObject &operator[](const std::string &key) const;
+ std::vector<std::string> memberNames() const;
+
+private:
+ LIBCAMERA_DISABLE_COPY_AND_MOVE(YamlObject)
+
+ friend class YamlParserContext;
+
+ enum Type {
+ Dictionary,
+ List,
+ Value,
+ };
+
+ Type type_;
+
+ std::string value_;
+ std::vector<std::unique_ptr<YamlObject>> list_;
+ std::map<const std::string, std::unique_ptr<YamlObject>> dictionary_;
+};
+
+class YamlParser final
+{
+public:
+ static std::unique_ptr<YamlObject> parse(std::FILE *fh);
+};
+
+} /* namespace libcamera */
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index 26912ca1..f8e18e03 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -46,6 +46,7 @@ libcamera_sources = files([
'v4l2_pixelformat.cpp',
'v4l2_subdevice.cpp',
'v4l2_videodevice.cpp',
+ 'yaml_parser.cpp',
])
libcamera_sources += libcamera_public_headers
@@ -66,6 +67,7 @@ subdir('proxy')
libdl = cc.find_library('dl')
libgnutls = cc.find_library('gnutls', required : true)
libudev = dependency('libudev', required : false)
+libyaml = dependency('yaml-0.1', required : true)
if libgnutls.found()
config_h.set('HAVE_GNUTLS', 1)
@@ -126,6 +128,7 @@ libcamera_deps = [
libgnutls,
liblttng,
libudev,
+ libyaml,
]
# We add '/' to the build_rpath as a 'safe' path to act as a boolean flag.
diff --git a/src/libcamera/yaml_parser.cpp b/src/libcamera/yaml_parser.cpp
new file mode 100644
index 00000000..4a047494
--- /dev/null
+++ b/src/libcamera/yaml_parser.cpp
@@ -0,0 +1,679 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2022, Google Inc.
+ *
+ * yaml_parser.cpp - libcamera YAML parsing helper
+ */
+
+#include "libcamera/internal/yaml_parser.h"
+
+#include <cerrno>
+#include <cstdlib>
+
+#include <libcamera/base/log.h>
+
+#include <yaml.h>
+
+/**
+ * \file libcamera/internal/yaml_parser.h
+ * \brief A YAML parser helper
+ */
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(YamlParser)
+
+namespace {
+
+/* Empty static YamlObject as a safe result for invalid operations */
+static const YamlObject empty;
+
+void setOk(bool *ok, bool result)
+{
+ if (ok)
+ *ok = result;
+}
+
+} /* namespace */
+
+/**
+ * \class YamlObject
+ * \brief A class representing the tree structure of the YAML content
+ *
+ * The YamlObject class represents the tree structure of YAML content. A
+ * YamlObject can be a dictionary or list of YamlObjects or a value if a tree
+ * leaf.
+ */
+
+YamlObject::YamlObject()
+ : type_(Value)
+{
+}
+
+YamlObject::~YamlObject() = default;
+
+/**
+ * \fn YamlObject::isValue()
+ * \brief Return whether the YamlObject is a value
+ *
+ * \return True if the YamlObject is a value, false otherwise
+ */
+
+/**
+ * \fn YamlObject::isList()
+ * \brief Return whether the YamlObject is a list
+ *
+ * \return True if the YamlObject is a list, false otherwise
+ */
+
+/**
+ * \fn YamlObject::isDictionary()
+ * \brief Return whether the YamlObject is a dictionary
+ *
+ * \return True if the YamlObject is a dictionary, false otherwise
+ */
+
+/**
+ * \fn template<typename T> YamlObject::get<T>(
+ * const T &defaultValue, bool *ok) const
+ * \brief Parse the YamlObject as a \a T value
+ * \param[in] defaultValue The default value when failing to parse
+ * \param[out] ok The result of whether the parse succeeded
+ *
+ * This function parses the value of the YamlObject as a \a T object, and
+ * returns the value. If parsing fails (usually because the YamlObject doesn't
+ * store a \a T value), the \a defaultValue is returned, and \a ok is set to
+ * false. Otherwise, the YamlObject value is returned, and \a ok is set to true.
+ *
+ * The \a ok pointer is optional and can be a nullptr if the caller doesn't
+ * need to know if parsing succeeded.
+ *
+ * \return Value as a bool type
+ */
+
+#ifndef __DOXYGEN__
+
+template<>
+bool YamlObject::get(const bool &defaultValue, bool *ok) const
+{
+ setOk(ok, false);
+
+ if (type_ != Value)
+ return defaultValue;
+
+ if (value_ == "true") {
+ setOk(ok, true);
+ return true;
+ } else if (value_ == "false") {
+ setOk(ok, true);
+ return false;
+ }
+
+ return defaultValue;
+}
+
+template<>
+int32_t YamlObject::get(const int32_t &defaultValue, bool *ok) const
+{
+ setOk(ok, false);
+
+ if (type_ != Value)
+ return defaultValue;
+
+ if (value_ == "")
+ return defaultValue;
+
+ char *end;
+
+ errno = 0;
+ int32_t value = std::strtol(value_.c_str(), &end, 10);
+
+ if ('\0' != *end || errno == ERANGE)
+ return defaultValue;
+
+ setOk(ok, true);
+ return value;
+}
+
+template<>
+uint32_t YamlObject::get(const uint32_t &defaultValue, bool *ok) const
+{
+ setOk(ok, false);
+
+ if (type_ != Value)
+ return defaultValue;
+
+ if (value_ == "")
+ return defaultValue;
+
+ /*
+ * libyaml parses all scalar values as strings. When a string has
+ * leading spaces before a minus sign, for example " -10", strtoul
+ * skips leading spaces, accepts the leading minus sign, and the
+ * calculated digits are negated as if by unary minus. Rule it out in
+ * case the user gets a large number when the value is negative.
+ */
+ std::size_t found = value_.find_first_not_of(" \t");
+ if (found != std::string::npos && value_[found] == '-')
+ return defaultValue;
+
+ char *end;
+
+ errno = 0;
+ uint32_t value = std::strtoul(value_.c_str(), &end, 10);
+
+ if ('\0' != *end || errno == ERANGE)
+ return defaultValue;
+
+ setOk(ok, true);
+ return value;
+}
+
+template<>
+double YamlObject::get(const double &defaultValue, bool *ok) const
+{
+ setOk(ok, false);
+
+ if (type_ != Value)
+ return defaultValue;
+
+ if (value_ == "")
+ return defaultValue;
+
+ char *end;
+
+ errno = 0;
+ double value = std::strtod(value_.c_str(), &end);
+
+ if ('\0' != *end || errno == ERANGE)
+ return defaultValue;
+
+ setOk(ok, true);
+ return value;
+}
+
+template<>
+std::string YamlObject::get(const std::string &defaultValue, bool *ok) const
+{
+ setOk(ok, false);
+
+ if (type_ != Value)
+ return defaultValue;
+
+ setOk(ok, true);
+ return value_;
+}
+
+template<>
+Size YamlObject::get(const Size &defaultValue, bool *ok) const
+{
+ setOk(ok, false);
+
+ if (type_ != List)
+ return defaultValue;
+
+ if (list_.size() != 2)
+ return defaultValue;
+
+ /*
+ * Add a local variable to validate each dimension in case
+ * that ok == nullptr.
+ */
+ bool valid;
+ uint32_t width = list_[0]->get<uint32_t>(0, &valid);
+ if (!valid)
+ return defaultValue;
+
+ uint32_t height = list_[1]->get<uint32_t>(0, &valid);
+ if (!valid)
+ return defaultValue;
+
+ setOk(ok, true);
+ return Size(width, height);
+}
+
+#endif /* __DOXYGEN__ */
+
+/**
+ * \fn YamlObject::size()
+ * \brief Retrieve the number of elements in a list YamlObject
+ *
+ * This function retrieves the size of the YamlObject, defined as the number of
+ * child elements it contains. Only YamlObject instances of List type have a
+ * size, calling this function on other types of instances is invalid and
+ * results in undefined behaviour.
+ *
+ * \return The size of the YamlObject
+ */
+std::size_t YamlObject::size() const
+{
+ if (type_ != List)
+ return 0;
+
+ return list_.size();
+}
+
+/**
+ * \fn YamlObject::operator[](std::size_t index) const
+ * \brief Retrieve the element from list YamlObject by index
+ *
+ * This function retrieves an element of the YamlObject. Only YamlObject
+ * instances of List type associate elements with index, calling this function
+ * on other types of instances is invalid and results in undefined behaviour.
+ *
+ * \return The YamlObject as an element of the list
+ */
+const YamlObject &YamlObject::operator[](std::size_t index) const
+{
+ if (type_ != List || index >= size())
+ return empty;
+
+ return *list_[index];
+}
+
+/**
+ * \fn YamlObject::contains()
+ * \brief Check if an element of a dictionary exists
+ *
+ * This function check if the YamlObject contains an element. Only YamlObject
+ * instances of Dictionary type associate elements with names, calling this
+ * function on other types of instances is invalid and results in undefined
+ * behaviour.
+ *
+ * \return True if an element exists, false otherwise
+ */
+bool YamlObject::contains(const std::string &key) const
+{
+ if (dictionary_.find(key) == dictionary_.end())
+ return false;
+
+ return true;
+}
+
+/**
+ * \fn YamlObject::memberNames()
+ * \brief Retrieve all member names of the dictionary
+ *
+ * This function retrieve member names of a YamlObject. Only YamlObject
+ * instances of Dictionary type associate elements with names, calling this
+ * function on other types of instances is invalid and results in undefined
+ * behaviour.
+ *
+ * \todo Replace this function with an iterator-based API
+ *
+ * \return A vector of string as the member names
+ */
+std::vector<std::string> YamlObject::memberNames() const
+{
+ std::vector<std::string> memberNames;
+ for (auto &[key, _] : dictionary_)
+ memberNames.push_back(key);
+
+ return memberNames;
+}
+
+/**
+ * \fn YamlObject::operator[](const std::string &key) const
+ * \brief Retrieve a member by name from the dictionary
+ *
+ * This function retrieve a member of a YamlObject by name. Only YamlObject
+ * instances of Dictionary type associate elements with names, calling this
+ * function on other types of instances is invalid and results in undefined
+ * behaviour.
+ *
+ * \return The YamlObject corresponding to the \a key member
+ */
+const YamlObject &YamlObject::operator[](const std::string &key) const
+{
+ if (type_ != Dictionary || !contains(key))
+ return empty;
+
+ auto iter = dictionary_.find(key);
+ return *iter->second;
+}
+
+#ifndef __DOXYGEN__
+
+class YamlParserContext
+{
+public:
+ YamlParserContext();
+ ~YamlParserContext();
+
+ int init(std::FILE *fh);
+ int parseContent(YamlObject &yamlObject);
+
+private:
+ struct EventDeleter {
+ void operator()(yaml_event_t *event) const
+ {
+ yaml_event_delete(event);
+ delete event;
+ }
+ };
+ using EventPtr = std::unique_ptr<yaml_event_t, EventDeleter>;
+
+ EventPtr nextEvent();
+
+ void readValue(std::string &value, EventPtr event);
+ int parseDictionaryOrList(YamlObject::Type type,
+ const std::function<int(EventPtr event)> &parseItem);
+ int parseNextYamlObject(YamlObject &yamlObject, EventPtr event);
+
+ bool parserValid_;
+ yaml_parser_t parser_;
+};
+
+/**
+ * \class YamlParserContext
+ * \brief Class for YamlParser parsing and context data
+ *
+ * The YamlParserContext class stores the internal yaml_parser_t and provides
+ * helper functions to do event-based parsing for YAML files.
+ */
+YamlParserContext::YamlParserContext()
+ : parserValid_(false)
+{
+}
+
+/**
+ * \class YamlParserContext
+ * \brief Destructor of YamlParserContext
+ */
+YamlParserContext::~YamlParserContext()
+{
+ if (parserValid_) {
+ yaml_parser_delete(&parser_);
+ parserValid_ = false;
+ }
+}
+
+/**
+ * \fn YamlParserContext::init()
+ * \brief Initialize a parser with an opened file for parsing
+ * \param[in] fh The YAML file to parse
+ *
+ * Prior to parsing the YAML content, the YamlParserContext must be initialized
+ * with an opened FILE to create an internal parser. The FILE needs to stay
+ * valid during the process.
+ *
+ * \return 0 on success or a negative error code otherwise
+ * \retval -EINVAL The parser has failed to initialize
+ */
+int YamlParserContext::init(std::FILE *fh)
+{
+ /* yaml_parser_initialize returns 1 when it succeededs */
+ if (!yaml_parser_initialize(&parser_)) {
+ LOG(YamlParser, Error) << "Failed to initialize YAML parser";
+ return -EINVAL;
+ }
+ parserValid_ = true;
+ yaml_parser_set_input_file(&parser_, fh);
+
+ return 0;
+}
+
+/**
+ * \fn YamlParserContext::nextEvent()
+ * \brief Get the next event
+ *
+ * Get the next event in the current YAML event stream, and return nullptr when
+ * there is no more event.
+ *
+ * \return The next event on success or nullptr otherwise
+ */
+YamlParserContext::EventPtr YamlParserContext::nextEvent()
+{
+ EventPtr event(new yaml_event_t);
+
+ /* yaml_parser_parse returns 1 when it succeeds */
+ if (!yaml_parser_parse(&parser_, event.get()))
+ return nullptr;
+
+ return event;
+}
+
+/**
+ * \fn YamlParserContext::parseContent()
+ * \brief Parse the content of a YAML document
+ * \param[in] yamlObject The result of YamlObject
+ *
+ * Check YAML start and end events of a YAML document, and parse the root object
+ * of the YAML document into a YamlObject.
+ *
+ * \return 0 on success or a negative error code otherwise
+ * \retval -EINVAL The parser has failed to validate end of a YAML file
+ */
+int YamlParserContext::parseContent(YamlObject &yamlObject)
+{
+ /* Check start of the YAML file. */
+ EventPtr event = nextEvent();
+ if (!event || event->type != YAML_STREAM_START_EVENT)
+ return -EINVAL;
+
+ event = nextEvent();
+ if (!event || event->type != YAML_DOCUMENT_START_EVENT)
+ return -EINVAL;
+
+ /* Parse the root object. */
+ event = nextEvent();
+ if (parseNextYamlObject(yamlObject, std::move(event)))
+ return -EINVAL;
+
+ /* Check end of the YAML file. */
+ event = nextEvent();
+ if (!event || event->type != YAML_DOCUMENT_END_EVENT)
+ return -EINVAL;
+
+ event = nextEvent();
+ if (!event || event->type != YAML_STREAM_END_EVENT)
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * \fn YamlParserContext::readValue()
+ * \brief Parse event scalar and fill its content into a string
+ * \param[in] value The string reference to fill value
+ *
+ * A helper function to parse a scalar event as string. The caller needs to
+ * guarantee the event is of scaler type.
+ */
+void YamlParserContext::readValue(std::string &value, EventPtr event)
+{
+ value.assign(reinterpret_cast<char *>(event->data.scalar.value),
+ event->data.scalar.length);
+}
+
+/**
+ * \fn YamlParserContext::parseDictionaryOrList()
+ * \brief A helper function to abstract the common part of parsing dictionary or list
+ *
+ * \param[in] isDictionary True for parsing a dictionary, and false for a list
+ * \param[in] parseItem The callback to handle an item
+ *
+ * A helper function to abstract parsing an item from a dictionary or a list.
+ * The differences of them in a YAML event stream are:
+ *
+ * 1. The start and end event types are different
+ * 2. There is a leading scalar string as key in the items of a dictionary
+ *
+ * The caller should handle the leading key string in its callback parseItem
+ * when it's a dictionary.
+ *
+ * \return 0 on success or a negative error code otherwise
+ * \retval -EINVAL The parser is failed to initialize
+ */
+int YamlParserContext::parseDictionaryOrList(YamlObject::Type type,
+ const std::function<int(EventPtr event)> &parseItem)
+{
+ yaml_event_type_t endEventType = YAML_SEQUENCE_END_EVENT;
+ if (type == YamlObject::Dictionary)
+ endEventType = YAML_MAPPING_END_EVENT;
+
+ /*
+ * Add a safety counter to make sure we don't loop indefinitely in case
+ * the YAML file is malformed.
+ */
+ for (unsigned int sentinel = 1000; sentinel; sentinel--) {
+ auto evt = nextEvent();
+ if (!evt)
+ return -EINVAL;
+
+ if (evt->type == endEventType)
+ return 0;
+
+ int ret = parseItem(std::move(evt));
+ if (ret)
+ return ret;
+ }
+
+ LOG(YamlParser, Error) << "The YAML file contains a List or Dictionary"
+ " whose size exceeding the parser's limit(1000)";
+
+ return -EINVAL;
+}
+
+/**
+ * \fn YamlParserContext::parseNextYamlObject()
+ * \brief Parse next YAML event and read it as a YamlObject
+ * \param[in] yamlObject The result of YamlObject
+ * \param[in] event The leading event of the object
+ *
+ * Parse next YAML object separately as a value, list or dictionary.
+ *
+ * \return 0 on success or a negative error code otherwise
+ * \retval -EINVAL Fail to parse the YAML file.
+ */
+int YamlParserContext::parseNextYamlObject(YamlObject &yamlObject, EventPtr event)
+{
+ if (!event)
+ return -EINVAL;
+
+ switch (event->type) {
+ case YAML_SCALAR_EVENT:
+ yamlObject.type_ = YamlObject::Value;
+ readValue(yamlObject.value_, std::move(event));
+ return 0;
+
+ case YAML_SEQUENCE_START_EVENT: {
+ yamlObject.type_ = YamlObject::List;
+ auto &list = yamlObject.list_;
+ auto handler = [this, &list](EventPtr evt) {
+ list.emplace_back(new YamlObject());
+ return parseNextYamlObject(*list.back(), std::move(evt));
+ };
+ return parseDictionaryOrList(YamlObject::List, handler);
+ }
+
+ case YAML_MAPPING_START_EVENT: {
+ yamlObject.type_ = YamlObject::Dictionary;
+ auto &dictionary = yamlObject.dictionary_;
+ auto handler = [this, &dictionary](EventPtr evtKey) {
+ /* Parse key */
+ if (evtKey->type != YAML_SCALAR_EVENT) {
+ LOG(YamlParser, Error) << "Expect key at line: "
+ << evtKey->start_mark.line
+ << " column: "
+ << evtKey->start_mark.column;
+ return -EINVAL;
+ }
+
+ std::string key;
+ readValue(key, std::move(evtKey));
+
+ /* Parse value */
+ EventPtr evtValue = nextEvent();
+ if (!evtValue)
+ return -EINVAL;
+
+ auto elem = dictionary.emplace(key, std::make_unique<YamlObject>());
+ return parseNextYamlObject(*elem.first->second.get(), std::move(evtValue));
+ };
+ return parseDictionaryOrList(YamlObject::Dictionary, handler);
+ }
+ default:
+ LOG(YamlParser, Error) << "Invalid YAML file";
+ return -EINVAL;
+ }
+}
+
+#endif /* __DOXYGEN__ */
+
+/**
+ * \class YamlParser
+ * \brief A helper class for parsing a YAML file
+ *
+ * The YamlParser class provides an easy interface to parse the contents of a
+ * YAML file into a tree of YamlObject instances.
+ *
+ * Example usage:
+ *
+ * \code{.unparsed}
+ *
+ * name:
+ * "John"
+ * numbers:
+ * - 1
+ * - 2
+ *
+ * \endcode
+ *
+ * The following code illustrates how to parse the above YAML file:
+ *
+ * \code{.cpp}
+ *
+ * std::unique_ptr<YamlObject> root = YamlParser::parse(fh);
+ * if (!root)
+ * return;
+ *
+ * if (!root->isDictionary())
+ * return;
+ *
+ * const YamlObject &name = (*root)["name"];
+ * std::cout << name.get<std::string>("") << std::endl;
+ *
+ * const YamlObject &numbers = (*root)["numbers"];
+ * if (!numbers.isList())
+ * return;
+ *
+ * for (std::size_t i = 0; i < numbers.size(); i++)
+ * std::cout << numbers[i].get<int32_t>(0) << std::endl;
+ *
+ * \endcode
+ *
+ * The YamlParser::parse() function takes an open FILE, parses its contents, and
+ * returns a pointer to a YamlObject corresponding to the root node of the YAML
+ * document.
+ */
+
+/**
+ * \fn YamlParser::parse()
+ * \brief Parse a YAML file as a YamlObject
+ * \param[in] fh The YAML file to parse
+ *
+ * The YamlParser::parse() function takes an open FILE, parses its contents, and
+ * returns a pointer to a YamlObject corresponding to the root node of the YAML
+ * document. The caller is responsible for closing the file.
+ *
+ * \return Pointer to result YamlObject on success or nullptr otherwise
+ */
+std::unique_ptr<YamlObject> YamlParser::parse(std::FILE *fh)
+{
+ YamlParserContext context;
+
+ if (context.init(fh))
+ return nullptr;
+
+ std::unique_ptr<YamlObject> root(new YamlObject());
+
+ if (context.parseContent(*root)) {
+ LOG(YamlParser, Error) << "Failed to parse YAML content";
+ return nullptr;
+ }
+
+ return root;
+}
+
+} /* namespace libcamera */
--
2.36.0.rc2.479.g8af0fa9b8e-goog
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