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

Interface VariableManagementService

All Known Implementing Classes:

VariableManagementServiceImpl

public interface VariableManagementService

Variables service for reading and writing variables, and for setting a version number for the current thread to consider variables for.

See implementation class for further details.

Method Summary

Modifier and Type	Method and Description
void	addVariable(String deploymentId, VariableMetaData metaData, String optionalDeploymentIdContext)
void	allocateVariableState(String deploymentId, String variableName, int agentInstanceId, boolean recovery, NullableObject<Object> initialValue, EventBeanTypedEventFactory eventBeanTypedEventFactory)
void	checkAndWrite(String deploymentId, String variableName, int agentInstanceId, Object newValue) Check type of the value supplied and writes the new variable value.
void	commit() Commits the variable outstanding changes.
void	deallocateVariableState(String deploymentId, String variableName, int agentInstanceId)
void	destroy()
Map<String,VariableDeployment>	getDeploymentsWithVariables()
VariableStateNonConstHandler	getOptionalStateHandler()
VariableReader	getReader(String deploymentId, String variableName, int agentInstanceIdAccessor) Returns a reader that provides access to variable values.
ConcurrentHashMap<Integer,VariableReader>	getReadersPerCP(String deploymentId, String variableName)
ReadWriteLock	getReadWriteLock() Lock for use in atomic writes to the variable space.
Variable	getVariableMetaData(String deploymentId, String variableName)
Map<DeploymentIdNamePair,VariableReader>	getVariableReadersNonCP()
void	registerCallback(String deploymentId, String variableName, int agentInstanceId, VariableChangeCallback variableChangeCallback) Registers a callback invoked when the variable is written with a new value.
void	removeVariableIfFound(String deploymentId, String variableName) Removes a variable.
void	rollback() Rolls back the variable outstanding changes.
void	setLocalVersion() Sets the variable version that subsequent reads consider.
void	traverseVariables(BiConsumer<String,Variable> consumer)
void	unregisterCallback(String deploymentId, String variableName, int agentInstanceId, VariableChangeCallback variableChangeCallback) Removes a callback.
void	write(int variableNumber, int agentInstanceId, Object newValue) Writes a new variable value.

Method Detail

setLocalVersion

void setLocalVersion()

Sets the variable version that subsequent reads consider.

getReadWriteLock

ReadWriteLock getReadWriteLock()

Lock for use in atomic writes to the variable space.

Returns:

read write lock for external coordinated write

addVariable

void addVariable(String deploymentId,
                 VariableMetaData metaData,
                 String optionalDeploymentIdContext)

getReader

VariableReader getReader(String deploymentId,
                         String variableName,
                         int agentInstanceIdAccessor)

Returns a reader that provides access to variable values. The reader considers the version currently set via setLocalVersion.

Parameters:

deploymentId - deployment id

variableName - the variable that the reader should read

agentInstanceIdAccessor - agent instance id of accessor

Returns:

reader

registerCallback

void registerCallback(String deploymentId,
                      String variableName,
                      int agentInstanceId,
                      VariableChangeCallback variableChangeCallback)

Registers a callback invoked when the variable is written with a new value.

Parameters:

deploymentId - deployment id

variableName - variable name

agentInstanceId - agent instance id

variableChangeCallback - a callback

unregisterCallback

void unregisterCallback(String deploymentId,
                        String variableName,
                        int agentInstanceId,
                        VariableChangeCallback variableChangeCallback)

Removes a callback.

Parameters:

deploymentId - deployment id

variableName - variable name

agentInstanceId - agent instance id

variableChangeCallback - a callback

write

void write(int variableNumber,
           int agentInstanceId,
           Object newValue)

Writes a new variable value.

Must be followed by either a commit or rollback.

Parameters:

variableNumber - the index number of the variable to write (from VariableReader)

newValue - the new value

agentInstanceId - agent instance id

checkAndWrite

void checkAndWrite(String deploymentId,
                   String variableName,
                   int agentInstanceId,
                   Object newValue)

Check type of the value supplied and writes the new variable value.

Must be followed by either a commit or rollback.

Parameters:

deploymentId - deployment id

variableName - variable name

agentInstanceId - agent instance id

newValue - the new value

commit

void commit()

Commits the variable outstanding changes.

rollback

void rollback()

Rolls back the variable outstanding changes.

getVariableMetaData

Variable getVariableMetaData(String deploymentId,
                             String variableName)

removeVariableIfFound

void removeVariableIfFound(String deploymentId,
                           String variableName)

Removes a variable.

Parameters:

deploymentId - deployment id

variableName - to remove

destroy

void destroy()

allocateVariableState

void allocateVariableState(String deploymentId,
                           String variableName,
                           int agentInstanceId,
                           boolean recovery,
                           NullableObject<Object> initialValue,
                           EventBeanTypedEventFactory eventBeanTypedEventFactory)

deallocateVariableState

void deallocateVariableState(String deploymentId,
                             String variableName,
                             int agentInstanceId)

getReadersPerCP

ConcurrentHashMap<Integer,VariableReader> getReadersPerCP(String deploymentId,
                                                          String variableName)

getVariableReadersNonCP

Map<DeploymentIdNamePair,VariableReader> getVariableReadersNonCP()

getOptionalStateHandler

VariableStateNonConstHandler getOptionalStateHandler()

getDeploymentsWithVariables

Map<String,VariableDeployment> getDeploymentsWithVariables()

traverseVariables

void traverseVariables(BiConsumer<String,Variable> consumer)