org.drools.core.spi

Interface Accumulator

All Superinterfaces:

Invoker, RuleComponent

All Known Subinterfaces:

MvelAccumulator

All Known Implementing Classes:

Accumulator.SafeAccumulator, CollectAccumulator, JavaAccumulatorFunctionExecutor, MVELAccumulator, MVELAccumulatorFunctionExecutor

public interface Accumulator
extends Invoker

Accumulator Created: 04/06/2006

Version:

$Id$

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Accumulator.SafeAccumulator This class is used as a wrapper delegate when a security policy is in place.

Method Summary

Methods

Modifier and Type	Method and Description
void	accumulate(Object workingMemoryContext, Object context, Tuple leftTuple, InternalFactHandle handle, Declaration[] declarations, Declaration[] innerDeclarations, WorkingMemory workingMemory) Executes the accumulate (action) code for the given fact handle
Serializable	createContext() Creates the context object for an accumulator session.
Object	createWorkingMemoryContext() Creates and return a context object for each working memory instance
Object	getResult(Object workingMemoryContext, Object context, Tuple leftTuple, Declaration[] declarations, WorkingMemory workingMemory) Gets the result of the accummulation
void	init(Object workingMemoryContext, Object context, Tuple leftTuple, Declaration[] declarations, WorkingMemory workingMemory) Executes the initialization block of code
void	reverse(Object workingMemoryContext, Object context, Tuple leftTuple, InternalFactHandle handle, Declaration[] declarations, Declaration[] innerDeclarations, WorkingMemory workingMemory) Reverses the accumulate action for the given fact handle
boolean	supportsReverse() Returns true if this accumulator supports operation reversal

Method Detail

createWorkingMemoryContext

Object createWorkingMemoryContext()

Creates and return a context object for each working memory instance

Returns:

createContext

Serializable createContext()

Creates the context object for an accumulator session. The context is passed as a parameter to every subsequent accumulator method call in the same session.

Returns:

init

void init(Object workingMemoryContext,
        Object context,
        Tuple leftTuple,
        Declaration[] declarations,
        WorkingMemory workingMemory)
          throws Exception

Executes the initialization block of code

Parameters:

leftTuple - tuple causing the rule fire

declarations - previous declarations

workingMemory -

Throws:

Exception

accumulate

void accumulate(Object workingMemoryContext,
              Object context,
              Tuple leftTuple,
              InternalFactHandle handle,
              Declaration[] declarations,
              Declaration[] innerDeclarations,
              WorkingMemory workingMemory)
                throws Exception

Executes the accumulate (action) code for the given fact handle

Parameters:

leftTuple -

handle -

declarations -

innerDeclarations -

workingMemory -

Throws:

Exception

supportsReverse

boolean supportsReverse()

Returns true if this accumulator supports operation reversal

Returns:

reverse

void reverse(Object workingMemoryContext,
           Object context,
           Tuple leftTuple,
           InternalFactHandle handle,
           Declaration[] declarations,
           Declaration[] innerDeclarations,
           WorkingMemory workingMemory)
             throws Exception

Reverses the accumulate action for the given fact handle

Parameters:

context -

leftTuple -

handle -

declarations -

innerDeclarations -

workingMemory -

Throws:

Exception

getResult

Object getResult(Object workingMemoryContext,
               Object context,
               Tuple leftTuple,
               Declaration[] declarations,
               WorkingMemory workingMemory)
                 throws Exception

Gets the result of the accummulation

Parameters:

leftTuple -

declarations -

workingMemory -

Returns:

Throws:

Exception