Oracle Coherence for C++ API


FilterTrigger Class Reference

#include <coherence/util/filter/FilterTrigger.hpp>

Inherits Object, PortableObject, and MapTrigger.

List of all members.

Detailed Description

A generic Filter-based MapTrigger implementation.

If an evaluation of the coherence::util::MapTrigger::Entry object representing a pending change fails (returns false), then one of the following actions is taken:

Note: This trigger never prevents entries from being removed.

djl 2008.05.22

Public Types

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

Public Member Functions

virtual void process (MapTrigger::Entry::Handle vEntry)
 This method is called before the result of a mutating operation represented by the specified Entry object is committed into the underlying map.

An implementation of this method can evaluate the change by analyzing the original and the new value, and can perform any of the following:

  • override the requested change by calling Entry::setValue with a different value;
  • undo the pending change by resetting the entry value to the original value obtained from Entry::getOriginalValue;
  • remove the entry from the underlying map by calling Entry::remove;
  • reject the pending change by throwing a RuntimeException, which will prevent any changes from being committed, and will result in the exception being thrown from the operation that attempted to modify the map; or
  • do nothing, thus allowing the pending change to be committed to the underlying map.

vEntry a Entry object that represents the pending change to be committed to the map, as well as the original state of the Entry

virtual void readExternal (PofReader::Handle hIn)
virtual void writeExternal (PofWriter::Handle hOut) const
virtual bool equals (Object::View v) const
 Compare the FilterTrigger with another object to determine equality.
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.

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);

out the stream used to output the description

virtual Filter::View getFilter () const
 Obtain the underlying Filter.
virtual int32_t getAction () const
 Obtain the action code for this FilterTrigger.

Static Public Attributes

static const int32_t action_rollback
 Evaluation failure results in an IllegalArgumentException thrown by the trigger.
static const int32_t action_ignore
 Evaluation failure results in restoring the original Entry's value.
static const int32_t action_remove
 Evaluation failure results in a removal of the entry.

Protected Member Functions

 FilterTrigger ()
 Default constructor (necessary for the PortableObject interface).
 FilterTrigger (Filter::View vFilter, int32_t nAction=action_rollback)
 Construct a FilterTrigger based on the specified Filter object and the action constant.

Protected Attributes

MemberView< Filterm_vFilter
 The underlying filter.
int32_t m_nAction
 The action code.

Constructor & Destructor Documentation

FilterTrigger ( Filter::View  vFilter,
int32_t  nAction = action_rollback 
) [protected]

Construct a FilterTrigger based on the specified Filter object and the action constant.

vFilter the underlying Filter
nAction one of the ACTION_* constants, default is action_rollback

Member Function Documentation

virtual bool equals ( Object::View  v  )  const [virtual]

Compare the FilterTrigger with another object to determine equality.

Two FilterTrigger objects are considered equal iff the wrapped filters and action codes are equal.

true iff this FilterTrigger and the passed object are equivalent FilterTrigger objects

virtual Filter::View getFilter (  )  const [virtual]

Obtain the underlying Filter.

the underlying Filter object

virtual int32_t getAction (  )  const [virtual]

Obtain the action code for this FilterTrigger.

one of the ACTION_* constants

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