Apache Geode Native C++ Reference  1.14.0
apache::geode::client::Delta Class Referenceabstract

This interface is used for delta propagation. More...

Public Member Functions

virtual std::shared_ptr< Deltaclone () const =0
 Creates a copy of the object on which delta is to be applied via notification. More...
 
virtual void fromDelta (DataInput &in)=0
 Reads in delta information to this object in a user-defined format. More...
 
virtual bool hasDelta () const =0
 hasDelta( ) is invoked by Geode during Region::put( std::shared_ptr<CacheableKey>, std::shared_ptr<Cacheable> ) to determine if the object contains a delta. More...
 
virtual void toDelta (DataOutput &out) const =0
 Writes out delta information to out in a user-defined format. More...
 

Detailed Description

This interface is used for delta propagation.

To use delta propagation, an application class must derive from class Delta as well as class Cacheable publicly. The methods hasDelta( ), toDelta( ) and fromDelta( ) must be implemented by the class, as these methods are used by Geode to detect the presence of delta in an object, to serialize the delta, and to apply a serialized delta to an existing object of the class.

Member Function Documentation

◆ clone()

virtual std::shared_ptr<Delta> apache::geode::client::Delta::clone ( ) const
pure virtual

Creates a copy of the object on which delta is to be applied via notification.

The region attribute for cloning must be set to 'true' in order to enable cloning.

◆ fromDelta()

virtual void apache::geode::client::Delta::fromDelta ( DataInput in)
pure virtual

Reads in delta information to this object in a user-defined format.

This is invoked on an existing application object after Geode determines the presence of delta in DataInput instance.

Exceptions
IOException
InvalidDeltaExceptionif the delta in the DataInput instance cannot be applied to this instance (possible causes may include mismatch of Delta version or logic error).

◆ hasDelta()

virtual bool apache::geode::client::Delta::hasDelta ( ) const
pure virtual

hasDelta( ) is invoked by Geode during Region::put( std::shared_ptr<CacheableKey>, std::shared_ptr<Cacheable> ) to determine if the object contains a delta.

If hasDelta( ) returns true, the delta in the object is serialized by invoking Delta::toDelta( DataOutput& ). If hasDelta( ) returns false, the object is serialized by invoking Cacheable::toData( DataOutput& ).

◆ toDelta()

virtual void apache::geode::client::Delta::toDelta ( DataOutput out) const
pure virtual

Writes out delta information to out in a user-defined format.

This is invoked on an application object after Geode determines the presence of delta in it by calling hasDelta() on the object.

Exceptions
IOException

Apache Geode C++ Cache API Documentation