Oracle Coherence for C++ API
Release 3.7.0.0

E18684-01

SemiLiteEventTransformer Class Reference

#include <coherence/util/transformer/SemiLiteEventTransformer.hpp>

Inherits Object, PortableObject, and MapEventTransformer.

List of all members.


Detailed Description

SemiLiteEventTransformer is a special purpose MapEventTransformer implementation that removes an OldValue from the MapEvent object for the purpose of reducing the amount of data that has to be sent over the network to event consumers.

Usage example:

    cache->addMapListener(listener, MapEventTransformerFilter::create(NULL,
        SemiLiteEventTransformer::getInstance(), false);
 

Author:
djl 2008.06.17

Public Types

typedef spec::Handle Handle
 SemiLiteEventTransformer Handle definition.
typedef spec::View View
 SemiLiteEventTransformer View definition.
typedef spec::Holder Holder
 SemiLiteEventTransformer Holder definition.

Public Member Functions

virtual MapEvent::Handle transform (MapEvent::Handle hEvent) const
 Transform the specified MapEvent.

The values contained by the returned MapEvent object will be the ones given (sent) to the corresponding listener.

Parameters:
hEvent the original MapEvent object
Returns:
modified MapEvent object or NULL to discard the event

virtual void readExternal (PofReader::Handle hIn)
 
virtual void writeExternal (PofWriter::Handle hOut) const
 
virtual bool equals (Object::View v) const
 
virtual size32_t hashCode () const
 Return a hash code value for the Object.

This method is supported for the benefit of hash-based containers.

The general contract of hashCode is:

  • Whenever it is invoked on the same Object more than once during an execution of an application, the hashCode method must consistently return the same value, provided no information used in equals comparisons on the object is modified. This value need not remain consistent from one execution of an application to another execution of the same application.
  • If two Objects are equal according to the equals method, then calling the hashCode method on each of the two Objects must produce the same value.
  • It is not required that if two Objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct results. However, the programmer should be aware that producing distinct results for unequal objects may improve the performance of hash-based containers.

The default implementation is identity based.

Returns:
a hash code value for this Object

virtual void toStream (std::ostream &out) const
 Output a human-readable description of this Object to the given stream.

coherence::lang::operator<<(std::ostream, Object::View) is defined and will call into the toStream method, to output Objects. If a managed String object is desired, the COH_TO_STRING macro can be used to build up a String from streamable contents.

 Object::View vKey   = ...
 Object::View vValue = ...
 std::cout << vKey << " = " << vValue << std::endl;

 String::Handle hs = COH_TO_STRING(vKey << " = " << vValue);

Parameters:
out the stream used to output the description


Static Public Member Functions

static
SemiLiteEventTransformer::Handle 
getInstance ()
 The SemiLiteEventTransformer singleton.

Protected Member Functions

 SemiLiteEventTransformer ()
 Default constructor (necessary for the PortableObject interface).

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