com.espertech.esper.epl.variable

Class VariableReader

java.lang.Object

com.espertech.esper.epl.variable.VariableReader

public class VariableReader
extends Object

Reads and writes variable values.

Works closely with VariableService in determining the version to read.

Constructor Summary

Constructors

Constructor and Description
VariableReader(VariableMetaData variableMetaData, VariableVersionThreadLocal versionThreadLocal, VersionedValueList<Object> versionsLow)

Method Summary

Modifier and Type	Method and Description
Object	getValue() Returns the value of a variable.
VariableMetaData	getVariableMetaData()
VersionedValueList<Object>	getVersionsLow()
void	setVersionsHigh(VersionedValueList<Object> versionsHigh) For roll-over (overflow) in version numbers, sets a new collection of versioned-values for the variable to use when requests over the version rollover boundary are made.
void	setVersionsLow(VersionedValueList<Object> versionsLow) Sets a new list of versioned-values to inquire against, for use when version numbers roll-over.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VariableReader

public VariableReader(VariableMetaData variableMetaData,
                      VariableVersionThreadLocal versionThreadLocal,
                      VersionedValueList<Object> versionsLow)

Method Detail

setVersionsHigh

public void setVersionsHigh(VersionedValueList<Object> versionsHigh)

For roll-over (overflow) in version numbers, sets a new collection of versioned-values for the variable to use when requests over the version rollover boundary are made.

Parameters:

versionsHigh - the list of versions for roll-over

setVersionsLow

public void setVersionsLow(VersionedValueList<Object> versionsLow)

Sets a new list of versioned-values to inquire against, for use when version numbers roll-over.

Parameters:

versionsLow - the list of versions for read

getValue

public Object getValue()

Returns the value of a variable.

Considers the version set via thread-local for the thread's atomic read of variable values.

Returns:

value of variable at the version applicable for the thead

getVariableMetaData

public VariableMetaData getVariableMetaData()

getVersionsLow

public VersionedValueList<Object> getVersionsLow()