Oracle® Fusion Middleware C++ API Reference for Oracle Coherence: ConditionalExtractor Class Reference

Detailed Description

IndexAwareExtractor

coherence::util::ConditionalIndex

Note: the underlying ValueExtractor is used for value extraction during index creation and is the extractor that is associated with the created coherence::util::ConditionalIndex in the given index map. Using the ConditionalExtractor to extract values is not supported.

Author:

tb/lh 2010.08.31

Since:

Coherence 3.6

Public Types

typedef spec::Handle

Handle

ConditionalExtractor Handle definition.

typedef spec::View

View

ConditionalExtractor View definition.

typedef spec::Holder

Holder

ConditionalExtractor Holder definition.

Public Member Functions

virtual MapIndex::Handle

createIndex (bool fOrdered, Comparator::View vComparator, Map::Handle hMapIndex) const

Create an index and associate it with the corresponding extractor.

Important: it is a responsibility of this method's implementations to place the necessary <ValueExtractor, MapIndex> entry into the given map of indexes.

Parameters:

	fOrdered	true iff the contents of the indexed information should be ordered; false otherwise
	vComparator	the Comparator object which imposes an ordering of entries in the index contents; or `NULL` if the entries' values natural ordering should be used
	hMapIndex	a Map of ValueExtractor to MapIndex to be updated with the created index

Returns:: the created index; NULL if the index has not been created

virtual MapIndex::Handle

destroyIndex (Map::Handle hMapIndex) const

Destroy an existing index and remove it from the given map of indexes.

Parameters:

hMapIndex

a Map of ValueExtractor to MapIndex to be updated by removing the index being destroyed

Returns:: the destroyed index; NULL if the index does not exist

virtual Object::Holder

extract (Object::Holder ohTarget) const

Using a ConditionalExtractor to extract values in not supported.

virtual void

readExternal (PofReader::Handle hIn)

virtual void

writeExternal (PofWriter::Handle hOut) const

virtual TypedHandle
< const String >

toString () const

Output a human-readable description of this Object to the given stream.

Note that when overriding this method the return type must be TypedHandle<const String> rather then String::View. These two types are assignment compatible but not equivalent and declaring the override with String::View will not be a compatible override.

coherence::lang::operator<<(std::ostream, Object::View) is defined and will call into the toString 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 and is generally how toString() will be implemented.

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

 String::View vs = COH_TO_STRING(vKey << " = " << vValue);

The COH_TO_STRING macro is also the most common way to implement the toString method. For example:

 virtual TypedHandle<const String> Person::toString() const
     {
     return COH_TO_STRING("Name: " << f_sName << " SSN: " << f_nSSN);
     }

Returns:: a string representation of this object

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

Protected Member Functions

ConditionalExtractor ()

Construct the ConditionalExtractor.

ConditionalExtractor (Filter::View vFilter, ValueExtractor::View vExtractor, bool fForwardIndex)

Construct the ConditionalExtractor.

Protected Attributes

FinalView< Filter >

f_vFilter

The filter used by this extractor.

FinalView
< ValueExtractor >

f_vExtractor

The underlying extractor.

bool

m_fForwardIndex

Specifies whether or not this extractor will create a coherence::util::ConditionalIndex that supports a forward index.

Constructor & Destructor Documentation

ConditionalExtractor	(	Filter::View	vFilter,
		ValueExtractor::View	vExtractor,
		bool	fForwardIndex
	)			`[protected]`

Construct the ConditionalExtractor.

Parameters:

	vFilter	the filter used by this extractor to create a ConditionalIndex; must not be NULL
	vExtractor	the extractor used by this extractor to create a ConditionalIndex; Note that the created index will be associated with this extractor in the given index map; must not be NULL
	fForwardIndex	specifies whether or not this extractor will create a ConditionalIndex that supports a forward map

Member Function Documentation

virtual Object::Holder extract ( Object::Holder ohTarget ) const [virtual]

Using a ConditionalExtractor to extract values in not supported.

Exceptions:

UnsupportedOperationException

always

Reimplemented from AbstractExtractor.