enveloped_msg.cpp

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/*
 * SObjectizer-5
 */
 
/*!
 * \file
 *
 * \brief Stuff related to enveloped messages.
 *
 * \since v.5.5.23
 */
 
#include <so_5/enveloped_msg.hpp>
 
#include <so_5/impl/enveloped_msg_details.hpp>
 
namespace so_5 {
 
namespace enveloped_msg {
 
namespace {
 
#if defined(__clang__)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wnon-virtual-dtor"
#endif
 
//
// payload_access_handler_invoker_t
//
/*!
 * \brief An implementation of handler_invoker interface for
 * extraction of payload because of various reasons.
 *
 * \since v.5.5.23
 */
class payload_access_handler_invoker_t final : public handler_invoker_t
  {
    const access_context_t m_context;
 
    optional< ::so_5::enveloped_msg::payload_info_t > m_payload;
 
  public:
    payload_access_handler_invoker_t(
      access_context_t context )
      : m_context{ context }
      {}
 
    ~payload_access_handler_invoker_t() = default;
 
    void
    invoke(
      const payload_info_t & payload ) noexcept override
      {
        using namespace so_5::enveloped_msg::impl;
 
        switch( message_kind( payload.message() ) )
          {
          case message_t::kind_t::signal : [[fallthrough]];
          case message_t::kind_t::classical_message : [[fallthrough]];
          case message_t::kind_t::user_type_message :
            m_payload = payload;
          break;
 
          case message_t::kind_t::enveloped_msg :
            auto & envelope = message_to_envelope( payload.message() );
            envelope.access_hook( m_context, *this );
          break;
          }
      }
 
    [[nodiscard]]
    optional< so_5::enveloped_msg::payload_info_t >
    try_get_payload(
      const message_ref_t & envelope_to_process ) noexcept
      {
        using namespace so_5::enveloped_msg::impl;
 
        auto & actual_envelope = message_to_envelope( envelope_to_process );
        actual_envelope.access_hook( m_context, *this );
 
        return m_payload;
      }
  };
 
#if defined(__clang__)
#pragma clang diagnostic pop
#endif
 
} /* namespace anonymous */
 
[[nodiscard]]
SO_5_FUNC
optional< payload_info_t >
extract_payload_for_message_transformation(
  const message_ref_t & envelope_to_process )
  {
    return payload_access_handler_invoker_t{
            access_context_t::transformation
        }.try_get_payload( envelope_to_process );
  }
 
[[nodiscard]]
SO_5_FUNC
optional< message_ref_t >
message_to_be_inspected(
  const message_ref_t & msg_or_envelope )
  {
    message_ref_t result = msg_or_envelope;
    switch( message_kind( msg_or_envelope ) )
      {
      case message_t::kind_t::signal: // Already has a value.
      break;
 
      case message_t::kind_t::classical_message: // Already has a value.
      break;
 
      case message_t::kind_t::user_type_message: // Already has a value.
      break;
 
      case message_t::kind_t::enveloped_msg:
        {
          auto opt_payload = payload_access_handler_invoker_t{
                  access_context_t::inspection
              }.try_get_payload( msg_or_envelope );
 
          if( opt_payload )
            result = opt_payload->message();
        }
      break;
      }
 
    return { result };
  }
 
} /* namespace enveloped_msg */
 
} /* namespace so_5 */