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

Detailed Description

MapTrigger

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:

action_rollback - an IllegalArgumentException is thrown by the trigger to reject the operation that would result in this change (default);

action_ignore - the change is ignored and the Entry's value is reset to the original value returned by the coherence::util::MapTrigger::Entry::getOriginalValue() method;

action_remove - the entry is removed from the underlying backing map using the coherence::util::InvocableMap::Entry::remove(bool) call.

Note: This trigger never prevents entries from being removed.

Author:

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.

Parameters:

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.

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

virtual Filter::View

getFilter () const

Obtain the underlying Filter.

virtual int32_t

getAction () const

Obtain the action code for this FilterTrigger.