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Diffstat (limited to 'src/lib/yang/adaptor.h')
| -rw-r--r-- | src/lib/yang/adaptor.h | 133 |
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diff --git a/src/lib/yang/adaptor.h b/src/lib/yang/adaptor.h new file mode 100644 index 0000000..8d1fdf3 --- /dev/null +++ b/src/lib/yang/adaptor.h @@ -0,0 +1,133 @@ +// Copyright (C) 2018-2022 Internet Systems Consortium, Inc. ("ISC") +// +// This Source Code Form is subject to the terms of the Mozilla Public +// License, v. 2.0. If a copy of the MPL was not distributed with this +// file, You can obtain one at http://mozilla.org/MPL/2.0/. + +#ifndef ISC_ADAPTOR_H +#define ISC_ADAPTOR_H 1 + +#include <exceptions/exceptions.h> +#include <cc/data.h> + +namespace isc { +namespace yang { + +/// @brief Missing key error. +class MissingKey : public isc::Exception { +public: + MissingKey(const char* file, size_t line, const char* what) : + isc::Exception(file, line, what) + {} +}; + +/// @brief JSON adaptor between canonical Kea and YANG models. +/// +/// An adaptor slightly modifies a JSON configuration between canonical Kea +/// what required or rendered by a YANG model, e.g. moving a parameter +/// to/from a parent. +/// The basic adaptor provides a set of tools. +class Adaptor { +public: + + /// @brief Constructor. + Adaptor(); + + /// @brief Destructor. + virtual ~Adaptor(); + + /// @brief Get user context. + /// + /// Get user-context and/or comment and return it with the comment + /// if exists moved inside the user-context (without checking if + /// there is already a comment as it should never be the case). + /// + /// This behavior is used to handle comments. For historical purposes + /// Kea allows to define comments in some scopes. Once the user-context + /// has been introduced, the comment (as a separate text field) + /// disappeared and was moved to comment key within user-context. + /// Nevertheless, the old syntax is still supported. + static isc::data::ConstElementPtr + getContext(isc::data::ConstElementPtr parent); + + /// @brief Moves a parameter from parent to a list of children. + /// + /// Move a parameter from the parent to each item in a list. + /// If the parameter exists in a child, it is skipped for this + /// particular child, not overridden. + /// + /// @param name The parameter name. + /// @param parent The parent element. + /// @param list The children list. + static void fromParent(const std::string& name, + isc::data::ConstElementPtr parent, + isc::data::ConstElementPtr list); + + /// @brief Moves a parameter to a parent. + /// + /// Move a parameter from children to the parent. All children + /// on the list must have the parameter specified and it has to have + /// the same value. + /// + /// @param name The parameter name. + /// @param parent The parent element. + /// @param list The children list. + static void toParent(const std::string& name, + isc::data::ElementPtr parent, + isc::data::ConstElementPtr list); + + /// @brief Modify a configuration in its JSON element format. + /// + /// Smart merging tool, e.g. completing a from yang configuration. + /// + /// A modification is a path and actions: + /// - path item can be: + /// * a string: current scope is a map, go down following the string + /// as a key. + /// * a number: current scope is a list, go down the number as an index. + /// * special value -1: current scope is a list, apply to all items. + /// * map { "<key>": <value> }: current scope is a list, go down to + /// the item using the key / value pair. + /// - an action can be: insert, replace or delete: + /// * insert adds a value at a key: + /// . in a map the key is the new entry key + /// . in a list an integer key is the new element index + /// . in a list a map key is the key / value pair the to-be-modified + /// element contains + /// * replace adds or replaces if it already exists a value at + /// an entry key in a map. + /// * delete removes a value designed by a key + /// + /// For instance to add a control-socket entry in a configuration + /// from a generic (vs Kea) model: + /// @code + /// path := [ ] + /// actions := [ { + /// "action": "insert", + /// "key": "Dhcp4", + /// "value": + /// { + /// "control-socket": + /// { + /// "socket-type": "unix", + /// "socket-name": "/tmp/kea4-ctrl-socket" + /// } + /// } + /// } + /// @endcode + /// + /// @param path The search list to follow down to the place to + /// apply the action list. + /// @param actions The action list + /// @param config The configuration (JSON map) to modify. + /// @note modify does not throw but returns on unexpected conditions. + static void modify(isc::data::ConstElementPtr path, + isc::data::ConstElementPtr actions, + isc::data::ElementPtr config); + +}; + +} // end of namespace isc::yang +} // end of namespace isc + +#endif // ISC_ADAPTOR_H |