com.espertech.esper.epl.variable

Interface VariableStateHandler

public interface VariableStateHandler

Interface for a plug-in to VariableService to handle variable persistent state.

Method Summary

Modifier and Type	Method and Description
Pair<Boolean,Object>	getHasState(String variableName, int variableNumber, int agentInstanceId, Class type, EventType eventType, StatementExtensionSvcContext statementExtContext, boolean isConstant) Returns the current variable state plus Boolean.TRUE if there is a current state since the variable may have the value of null; returns Boolean.FALSE and null if there is no current state
void	removeState(String variableName, int variableNumber, int agentInstanceId)
void	removeVariable(String name, Set<Integer> cps)
void	setState(String variableName, int variableNumber, int agentInstanceId, Object newValue) Sets the new variable value

Method Detail

getHasState

Pair<Boolean,Object> getHasState(String variableName,
                                 int variableNumber,
                                 int agentInstanceId,
                                 Class type,
                                 EventType eventType,
                                 StatementExtensionSvcContext statementExtContext,
                                 boolean isConstant)

Returns the current variable state plus Boolean.TRUE if there is a current state since the variable may have the value of null; returns Boolean.FALSE and null if there is no current state

Parameters:

variableName - variable name

variableNumber - number of the variable

type - type of the variable

eventType - event type or null if not a variable that represents an event

statementExtContext - for caches etc.

agentInstanceId - agent instance id

isConstant - indicator for constant

Returns:

indicator whether the variable is known and it's state, or whether it doesn't have state (false)

setState

void setState(String variableName,
              int variableNumber,
              int agentInstanceId,
              Object newValue)

Sets the new variable value

Parameters:

variableName - name of the variable

variableNumber - number of the variable

agentInstanceId - agent instance id

newValue - new variable value, null values allowed

removeState

void removeState(String variableName,
                 int variableNumber,
                 int agentInstanceId)

removeVariable

void removeVariable(String name,
                    Set<Integer> cps)