Package com.espertech.esper.common.internal.epl.variable.core

Class VariableReader

java.lang.Object

com.espertech.esper.common.internal.epl.variable.core.VariableReader

public class VariableReader
extends Object

Reads and writes variable values.

Works closely with VariableManagementService in determining the version to read.

Field Summary

Fields

Modifier and Type	Field	Description
static final EPTypeClass	EPTYPE
static final EPTypeClass	EPTYPEARRAY

Constructor Summary

Constructors

Constructor	Description
VariableReader(Variable variable, VariableVersionThreadLocal versionThreadLocal, VersionedValueList<Object> versionsLow)

Method Summary

Modifier and Type	Method	Description
VariableMetaData	getMetaData()
Object	getValue()	Returns the value of a variable.
Variable	getVariable()
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

Field Details

EPTYPE

public static final EPTypeClass EPTYPE

EPTYPEARRAY

public static final EPTypeClass EPTYPEARRAY

Constructor Details

VariableReader

public VariableReader(Variable variable,
 VariableVersionThreadLocal versionThreadLocal,
 VersionedValueList<Object> versionsLow)

Method Details

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

getMetaData

public VariableMetaData getMetaData()

getVersionsLow

public VersionedValueList<Object> getVersionsLow()

getVariable

public Variable getVariable()