blob-msg.cpp

Go to the documentation of this file.

// License: Apache 2.0. See LICENSE file in root directory.
// Copyright(c) 2023 Intel Corporation. All Rights Reserved.
 
#include <realdds/topics/blob-msg.h>
#include <realdds/topics/blob/blobPubSubTypes.h>
 
#include <realdds/dds-topic.h>
#include <realdds/dds-topic-reader.h>
#include <realdds/dds-topic-writer.h>
#include <realdds/dds-utilities.h>
 
#include <fastdds/dds/subscriber/DataReader.hpp>
#include <fastdds/dds/publisher/DataWriter.hpp>
#include <fastdds/dds/topic/Topic.hpp>
 
 
namespace realdds {
namespace topics {
 
 
/*static*/ std::shared_ptr< dds_topic >
blob_msg::create_topic( std::shared_ptr< dds_participant > const & participant, char const * topic_name )
{
    return std::make_shared< dds_topic >( participant,
                                          eprosima::fastdds::dds::TypeSupport( new blob_msg::type ),
                                          topic_name );
}
 
 
/*static*/ bool
blob_msg::take_next( dds_topic_reader & reader, blob_msg * output, eprosima::fastdds::dds::SampleInfo * info )
{
    eprosima::fastdds::dds::SampleInfo info_;
    if( ! info )
        info = &info_;  // use the local copy if the user hasn't provided their own
    auto status = reader->take_next_sample( static_cast< udds::blob * >( output ), info );
    if( status == ReturnCode_t::RETCODE_OK )
    {
        // We have data
        if( output )
        {
            // Only samples for which valid_data is true should be accessed
            // valid_data indicates that the instance is still ALIVE and the `take` return an
            // updated sample
            if( ! info->valid_data )
                output->invalidate();
        }
        return true;
    }
    if( status == ReturnCode_t::RETCODE_NO_DATA )
    {
        // This is an expected return code and is not an error
        return false;
    }
    DDS_API_CALL_THROW( "blob_msg::take_next", status );
}
 
 
dds_sequence_number blob_msg::write_to( dds_topic_writer & writer ) const
{
    eprosima::fastrtps::rtps::WriteParams params;
    bool success = DDS_API_CALL(
        writer.get()->write( const_cast< udds::blob * >( static_cast< udds::blob const * >( this ) ), params ) );
    if( ! success )
    {
        LOG_ERROR( "Error writing message" );
        return 0;
    }
    // The params will contain, after the write, the sequence number (incremented automatically) for the sample that was
    // sent. The source_timestamp is always INVALID for some reason.
    return params.sample_identity().sequence_number().to64long();
}
 
 
}  // namespace topics
}  // namespace realdds