dds::sub::LoanedSamples< T > Class Template Reference

This class encapsulates and automates the management of loaned samples. More...

#include "LoanedSamples.hpp"

Public Types
typedef DELEGATE< T >::const_iterator	const_iterator
typedef T	DataType

Public Member Functions
	LoanedSamples ()
	LoanedSamples (const LoanedSamples &other)
	~LoanedSamples ()
const_iterator	begin () const
const_iterator	end () const
uint32_t	length () const

Detailed Description

template<typename T>
class dds::sub::LoanedSamples< T >

This class encapsulates and automates the management of loaned samples.

It is a container which is used to hold samples which have been read or taken by the DataReader. Samples are effectively "loaned" from the DataReader to avoid the need to copy the data. When the LoanedSamples container goes out of scope the loan is automatically returned.

LoanedSamples maintains a ref count so that the loan will only be returned once all copies of the same LoanedSamples have been destroyed.

dds::domain::DomainParticipant participant(org::eclipse::cyclonedds::domain::default_id());
dds::topic::Topic<Foo::Bar> topic(participant, "TopicName");
dds::sub::Subscriber subscriber(participant);
dds::sub::DataReader<Foo::Bar> reader(subscriber, topic);
 
// Assume there is data to read
{
    dds::sub::LoanedSamples<Foo::Bar> samples = reader.read();
    dds::sub::LoanedSamples<Foo::Bar>::const_iterator it;
    for (it = samples.begin(); it != samples.end(); ++it) {
        const dds::sub::Sample<Foo::Bar>& sample = *it;
        const Foo::Bar& data = sample.data();
        const dds::sub::SampleInfo& info = sample.info();
        // Use sample data and meta information.
    }
 
    function(samples);
}
// LoanedSamples out of scope. Whether the loan is returned, depends what the reference
// count of the LoanedSamples is. That again, depends on what the function() did with it.
// Maybe function() stored the LoanedSamples, maybe not. Whatever the case, LoanedSamples
// takes care of the loan and resource handling.

See also

DataSample for more information

SampleInfo for more information

Subscription for more information

Definition at line 87 of file LoanedSamples.hpp.

Member Typedef Documentation

const_iterator

template<typename T>

typedef DELEGATE<T>::const_iterator dds::sub::LoanedSamples< T >::const_iterator

Convenience typedef for the iterator over the loaned samples.

Definition at line 98 of file LoanedSamples.hpp.

DataType

template<typename T>

typedef T dds::sub::LoanedSamples< T >::DataType

Convenience typedef for the type of the data sample.

Definition at line 93 of file LoanedSamples.hpp.

Constructor & Destructor Documentation

LoanedSamples() [1/2]

template<typename T>

dds::sub::LoanedSamples< T >::LoanedSamples

(

)

Constructs a LoanedSamples instance.

~LoanedSamples()

template<typename T>

dds::sub::LoanedSamples< T >::~LoanedSamples

(

)

Implicitly return the loan if this is the last object with a reference to the contained loan.

LoanedSamples() [2/2]

template<typename T>

dds::sub::LoanedSamples< T >::LoanedSamples

(

const LoanedSamples< T > &

other

)

Copies a LoanedSamples instance.

No actual data samples are copied.
Just references and reference counts are updated.

Member Function Documentation

begin()

template<typename T>

const_iterator dds::sub::LoanedSamples< T >::begin

(

)

const

Gets an iterator pointing to the first sample in the LoanedSamples container.

See example.

Returns

an iterator pointing to the first sample

end()

template<typename T>

const_iterator dds::sub::LoanedSamples< T >::end

(

)

const

Gets an iterator pointing to the end of the LoanedSamples container.

See example.

Returns

an iterator pointing to the end of the container

length()

template<typename T>

uint32_t dds::sub::LoanedSamples< T >::length

(

)

const

Gets the number of samples within the LoanedSamples container.

Returns

the number of samples

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The documentation for this class was generated from the following file:

• dds/sub/LoanedSamples.hpp