Oracle Coherence for C++ API
Release 3.7.0.0

E18684-01

CompositeKey Class Reference

#include <coherence/util/CompositeKey.hpp>

Inherits Object, KeyAssociation, and PortableObject.

List of all members.


Detailed Description

Key class that consists of a primary and secondary component.

Two instances of CompositeKey are considered to be equal iff both the primary and secondary components of the two instances are considered equal. Additionally, the hash code of a CompositeKey takes into the consideration the hash codes of its two components. Finally, the CompositeKey class implements KeyAssociation by returning the primary component.

Author:
wl 2010.09.02

Public Types

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

Public Member Functions

virtual Object::View getAssociatedKey () const
 Determine the key object to which this key object is associated.

The key object returned by this method is often referred to as a host key.

Returns:
the host key that for this key object, or NULL if this key has no association.

virtual void readExternal (PofReader::Handle hIn)
 
virtual void writeExternal (PofWriter::Handle hOut) 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 bool equals (Object::View v) const
 
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

virtual Object::View getPrimaryKey () const
 Return the primary key component.
virtual Object::View getSecondaryKey () const
 Return the secondary key component.

Protected Member Functions

 CompositeKey ()
 Default constructor.
 CompositeKey (Object::View voPrimary, Object::View voSecondary)
 Create a new CompositeKey that consists of the given primary and secondary components.

Constructor & Destructor Documentation

CompositeKey ( Object::View  voPrimary,
Object::View  voSecondary 
) [protected]

Create a new CompositeKey that consists of the given primary and secondary components.

Parameters:
voPrimary the primary key component; must not be null. This is also the host key returned by the KeyAssociation implementation
voSecondary the secondary key component; must not be null


Member Function Documentation

virtual Object::View getPrimaryKey (  )  const [virtual]

Return the primary key component.

Returns:
the primary key component

virtual Object::View getSecondaryKey (  )  const [virtual]

Return the secondary key component.

Returns:
the secondary key component


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