ddl/codec/static_codec.h

/**
 * @file
 * Implementation of the ADTF default media description.
 *
 * @copyright
 * @verbatim
   Copyright @ 2017 Audi Electronics Venture GmbH. All rights reserved.

       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 https://mozilla.org/MPL/2.0/.

   If it is not possible or desirable to put the notice in a particular file, then
   You may include the notice in a location (such as a LICENSE file in a
   relevant directory) where a recipient would be likely to look for such a notice.

   You may add additional accurate notices of copyright ownership.
   @endverbatim
 */

#ifndef DDL_STATIC_CODEC_CLASS_HEADER
#define DDL_STATIC_CODEC_CLASS_HEADER

#include "a_util/result.h"
#include "a_util/variant.h"
#include "a_util/memory.h"

#include "struct_element.h"

namespace ddl
{

class StructLayout;
class ElementAccessor;

/**
 * Decoder for static structures defined by a DDL definition.
 */
class StaticDecoder
{
    public:
        /**
         * Noncopyable
         */
        StaticDecoder(const StaticDecoder&) = delete;

        /**
         * Noncopyable
         */
        StaticDecoder& operator=(const StaticDecoder&) = delete;

        /**
         * Move constructor.
         */
        StaticDecoder(StaticDecoder&&) = default;

        /**
         * Move assignment operator.
         */
        StaticDecoder& operator=(StaticDecoder&&) = default;

        /**
         * @return Whether or not the decoder is valid.
         * @retval ERR_INVALID_ARG The passed data is not large enough.
         */
        virtual a_util::result::Result isValid() const;

        /**
         * @return The amount of elements contained in the data structure.
         */
        virtual size_t getElementCount() const;

        /**
         * Access information about an element.
         * @param[in] index The index of the element.
         * @param[out] element Pointer that will be updated to point to the element information.
         * @retval ERR_INVALID_INDEX Invalid element index.
         */
        a_util::result::Result getElement(size_t index, const StructElement*& element) const;

        /**
         * Returns the current value of the given element by copying its data
         * to the passed-in location.
         * @param[in] index The index of the element.
         * @param[out] value The location where the value should be copied to.
         * @retval ERR_INVALID_INDEX Invalid element index.
         */
        a_util::result::Result getElementValue(size_t index, void* value) const;

        /**
         * Returns the current value of the given element as a variant.
         * @param[in] index The index of the element.
         * @param[out] value The will be set to the current value.
         * @retval ERR_INVALID_INDEX Invalid element index.
         */
        a_util::result::Result getElementValue(size_t index, a_util::variant::Variant& value) const;

        /**
         * @param[in] index The index of the element.
         * @return A pointer to the element or NULL in case of an error.
         */
        const void* getElementAddress(size_t index) const;

        /**
         * @param[in] rep The data representation for which the buffer size should be returned.
         * @return The size of the structure in the requested data representation.
         */
        size_t getStaticBufferSize(DataRepresentation rep = deserialized) const;

        /**
         * @return The data representation which this decoder handles.
         */
        DataRepresentation getRepresentation() const;

    protected:
        friend class CodecFactory;

        /// For internal use only. @internal
        StaticDecoder(a_util::memory::shared_ptr<const StructLayout> layout,
                       const void* data, size_t data_size,
                       DataRepresentation rep);
        /// For internal use only. @internal
        virtual const StructLayoutElement* getLayoutElement(size_t index) const;

    protected:
        /// For internal use only. @internal
        a_util::memory::shared_ptr<const StructLayout> _layout;
        /// For internal use only. @internal
        const void* _data;
        /// For internal use only. @internal
        size_t _data_size;
        /// For internal use only. @internal
        const ElementAccessor* _element_accessor;
};

/**
 * Codec for static structures defined by a DDL definition.
 */
class StaticCodec: public StaticDecoder
{
    public:
        /**
         * Sets the current value of the given element by copying its data
         * from the passed-in location.
         * @param[in] index The index of the element.
         * @param[in] value The location where the data should be copied from.
         * @retval ERR_INVALID_INDEX Invalid element index.
         */
        a_util::result::Result setElementValue(size_t index, const void* value);

        /**
         * Sets the current value of the given element to the given value.
         * @param[in] index The index of the element.
         * @param[in] value The value.
         * @retval ERR_INVALID_INDEX Invalid element index.
         */
        a_util::result::Result setElementValue(size_t index, const a_util::variant::Variant& value);

        /**
         * @param[in] index The index of the element.
         * @return A pointer to the element or NULL in case of an error.
         */
        void* getElementAddress(size_t index);
        using StaticDecoder::getElementAddress;

        /**
         * Sets all elements to their constant values defined in the DDL.
         * @return Standard result.
         */
        a_util::result::Result setConstants();

    private:
        friend class CodecFactory;
        /// For internal use only. @internal
        StaticCodec(a_util::memory::shared_ptr<const StructLayout> layout, void* data, size_t data_size,
                     DataRepresentation rep);
};

}

#endif