Oracle Fusion Middleware C++ API Reference for Oracle Coherence: CompositeKey Class Reference

Detailed Description

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