src/core/thread/indirect_sender_frame_context.hpp

/*
 *  Copyright (c) 2019, The OpenThread Authors.
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 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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/**
 * @file
 *   This file includes definitions of frame context used for indirect transmission.
 */

#ifndef INDIRECT_SENDER_FRAME_CONTETX_HPP_
#define INDIRECT_SENDER_FRAME_CONTETX_HPP_

#include "openthread-core-config.h"

#include <stdint.h>

namespace ot {

/**
 * @addtogroup core-mesh-forwarding
 *
 * @brief
 *   This module includes definitions frame context used by indirect sender.
 *
 * @{
 */

/**
 * This class defines the `FrameContext` type.
 *
 * This is the base class for `IndirectSender`.
 *
 */
class IndirectSenderBase
{
public:
    /**
     * This type defines the frame context used by `IndirectSender`.
     *
     * This type specifies all the info that `IndirectSender` requires to be saved along with a prepared frame for
     * indirect transmission.  `IndirectSender` is designed to contain the common code for handling of indirect
     * transmission to sleepy children and be able to interface to different lower-layer implementation of
     * `DataPollHandler`. While the `FrameContext` is defined by the `IndirectSender` itself, the lower-layer
     * (`DataPollHandler`) is expected to provide the buffer/object for context to be stored (it is provided from the
     * lower-layer callback asking for a frame to be prepared). This model allows different implementations of
     * `DataPollHandler` to adopt different strategies on how to save the context.
     *
     */
    struct FrameContext
    {
        friend class IndirectSender;
        friend class CslTxScheduler;

    private:
        uint16_t mMessageNextOffset; ///< The next offset into the message associated with the prepared frame.
    };
};

/**
 * @}
 *
 */

} // namespace ot

#endif // INDIRECT_SENDER_FRAME_CONTETX_HPP_