[v3,18/37] libcamera: value_node: Support adding nested children in one operation

26540 diff mbox series

The GlobalConfiguration class will need to add nested children to a
ValueNode. Add a new overload to the add() function for this purpose.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v2:

- Do not move child if node->add() fails

Changes since v1:

- Documentation improvements
- Replace NULL with nullptr
- Don't move child node if add fails
---
 include/libcamera/internal/value_node.h |  3 ++
 src/libcamera/value_node.cpp            | 58 +++++++++++++++++++++++++
 2 files changed, 61 insertions(+)

2026. 04. 24. 1:00 keltezéssel, Laurent Pinchart írta:
> The GlobalConfiguration class will need to add nested children to a
> ValueNode. Add a new overload to the add() function for this purpose.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
> Changes since v2:
> 
> - Do not move child if node->add() fails
> 
> Changes since v1:
> 
> - Documentation improvements
> - Replace NULL with nullptr
> - Don't move child node if add fails
> ---

Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>


>   include/libcamera/internal/value_node.h |  3 ++
>   src/libcamera/value_node.cpp            | 58 +++++++++++++++++++++++++
>   2 files changed, 61 insertions(+)
> 
> diff --git a/include/libcamera/internal/value_node.h b/include/libcamera/internal/value_node.h
> index da68a74c5e14..578413199df1 100644
> --- a/include/libcamera/internal/value_node.h
> +++ b/include/libcamera/internal/value_node.h
> @@ -8,6 +8,7 @@
> 
>   #pragma once
> 
> +#include <initializer_list>
>   #include <iterator>
>   #include <map>
>   #include <memory>
> @@ -239,6 +240,8 @@ public:
> 
>   	ValueNode *add(std::unique_ptr<ValueNode> &&child);
>   	ValueNode *add(std::string key, std::unique_ptr<ValueNode> &&child);
> +	ValueNode *add(std::initializer_list<std::string_view> path,
> +		       std::unique_ptr<ValueNode> &&child);
> 
>   private:
>   	LIBCAMERA_DISABLE_COPY_AND_MOVE(ValueNode)
> diff --git a/src/libcamera/value_node.cpp b/src/libcamera/value_node.cpp
> index fbf9ac470359..3b4041b7bbf0 100644
> --- a/src/libcamera/value_node.cpp
> +++ b/src/libcamera/value_node.cpp
> @@ -13,6 +13,8 @@
>   #include <string>
>   #include <vector>
> 
> +#include <libcamera/base/log.h>
> +#include <libcamera/base/span.h>
>   #include <libcamera/base/utils.h>
> 
>   /**
> @@ -22,6 +24,8 @@
> 
>   namespace libcamera {
> 
> +LOG_DEFINE_CATEGORY(ValueNode)
> +
>   namespace {
> 
>   /* Empty static ValueNode as a safe result for invalid operations */
> @@ -539,4 +543,58 @@ ValueNode *ValueNode::add(std::string key, std::unique_ptr<ValueNode> &&child)
>   	return list_.emplace_back(it->first, std::move(child)).value.get();
>   }
> 
> +/**
> + * \brief Add a child node at the given path
> + * \param[in] path The path
> + * \param[in] child The child node
> + *
> + * Add the \a child node at the given \a path starting at this node. Missing
> + * nodes are created along the path. Nodes along the path must be empty (in
> + * which case they are converted to the Type::Dictionary type), be a dictionary,
> + * or be missing. Otherwise, the function returns a nullptr and the \a child is
> + * not modified.
> + *
> + * Path elements are unique in the context of a parent node. If a child with the
> + * same \a key already exist at the end of the path, the function returns a
> + * nullptr and the \a child is not modified.
> + *
> + * \note Any node added along the \a path will remain even if this function
> + * returns a failure.
> + *
> + * \return A pointer to the \a child node if successfully added, nullptr
> + * otherwise
> + */
> +ValueNode *ValueNode::add(std::initializer_list<std::string_view> path,
> +			  std::unique_ptr<ValueNode> &&child)
> +{
> +	if (!path.size())
> +		return nullptr;
> +
> +	ValueNode *node = this;
> +
> +	for (const auto [i, name] : utils::enumerate(path)) {
> +		auto iter = node->dictionary_.find(name);
> +		if (iter == node->dictionary_.end()) {
> +			std::unique_ptr<ValueNode> obj;
> +
> +			if (i < path.size() - 1)
> +				obj = std::make_unique<ValueNode>();
> +
> +			node = node->add(std::string{ name },
> +					 obj ? std::move(obj) : std::move(child));
> +			if (!node) {
> +				Span<const std::string_view> pathName{ std::data(path), i + 1 };
> +				LOG(ValueNode, Error)
> +					<< "Failed to populate '"
> +					<< utils::join(pathName, "/") << "'";
> +				return nullptr;
> +			}
> +		} else {
> +			node = iter->second;
> +		}
> +	}
> +
> +	return node;
> +}
> +
>   } /* namespace libcamera */
> --
> Regards,
> 
> Laurent Pinchart
>