DelegateStateHandler (IBM Streams Java Operator API)

java.lang.Object
- com.ibm.streams.operator.state.DelegateStateHandler<T>

Type Parameters:

T -

All Implemented Interfaces:

StateHandler, java.io.Closeable, java.lang.AutoCloseable
```
public class DelegateStateHandler<T extends StateHandler>
extends java.lang.Object
implements StateHandler
```
TODO

Since:

InfoSphere® Streams Version 4.0

Field Summary

Fields
Modifier and Type Field and Description

static java.lang.String IBM_COPYRIGHT

Fields
Modifier and Type	Field and Description
`static java.lang.String`	`IBM_COPYRIGHT`

Constructor Summary

Constructors
Constructor and Description

DelegateStateHandler(T handler)

Constructors
Constructor and Description
`DelegateStateHandler(T handler)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`checkpoint(Checkpoint checkpoint)` Checkpoint the operator state to support resetting of its state to the saved state, using `StateHandler.reset(Checkpoint)`.
`void`	`close()`
`void`	`drain()` Drain any outstanding processing.
`T`	`getDelegateHandler()`
`void`	`prepareForNonBlockingCheckpoint(long id)` Called to prepare for non-blocking checkpoint.
`void`	`regionCheckpointed(long id)` Called when the whole consistent region has been drained and checkpointed.
`void`	`reset(Checkpoint checkpoint)` Reset the operator to a previous state defined by `checkpoint`.
`void`	`resetToInitialState()` Reset the operator to its initial state.
`void`	`retireCheckpoint(long id)` Called when a checkpoint can be retired.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - IBM_COPYRIGHT
```
public static final java.lang.String IBM_COPYRIGHT
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - DelegateStateHandler
```
public DelegateStateHandler(T handler)
```
- Method Detail
  - getDelegateHandler
```
public T getDelegateHandler()
```
  - close
```
public void close()
           throws java.io.IOException
```
    Specified by:
    
    close in interface java.io.Closeable
    
    Specified by:
    
    close in interface java.lang.AutoCloseable
    
    Throws:
    
    java.io.IOException
  - drain
```
public void drain()
           throws java.lang.Exception
```
    Description copied from interface: StateHandler
    Drain any outstanding processing. Once this method returns, the operator is indicating that it has drained all outstanding processing for all input ports.
    The method may:
    - Submit tuples to output ports.
    - Interact with external systems
    - Wait for background activity to drain outstanding work
    For a consistent region:
    - This method is called once all tuples and marks for the current cut for all data (non-control) input ports in the region have been processed, meaning the process and processPunctuation have returned for all tuples and marks.
    - A permit is implicitly acquired before the method is called, and released once it returns.
    - This method is not called concurrently with tuple or mark processing for any data (non-control) input ports in the region.
    - This method is may be called concurrently with tuple or mark or mark processing for any autonomous input ports
    Specified by:
    
    drain in interface StateHandler
    
    Throws:
    
    java.lang.Exception - Exception attempting to drain state.
  - reset
```
public void reset(Checkpoint checkpoint)
           throws java.lang.Exception
```
    Description copied from interface: StateHandler
    
    Reset the operator to a previous state defined by checkpoint.
    When in a consistent region checkpoint corresponds to the a previous successful drain and checkpoint cut cycle for the entire region. state.
    
    Specified by:
    
    reset in interface StateHandler
    
    Throws:
    
    java.lang.Exception - Exception attempting to reset state.
  - checkpoint
```
public void checkpoint(Checkpoint checkpoint)
                throws java.lang.Exception
```
    Description copied from interface: StateHandler
    Checkpoint the operator state to support resetting of its state to the saved state, using StateHandler.reset(Checkpoint).
    For a consistent region this method is called when:
    - StateHandler.drain() has completed
    - All background threads have released processing permits.
    - All control input ports (if any) have been drained.
    Specified by:
    
    checkpoint in interface StateHandler
    
    Throws:
    
    java.lang.Exception - Exception attempting to checkpoint state.
  - retireCheckpoint
```
public void retireCheckpoint(long id)
                      throws java.lang.Exception
```
    Description copied from interface: StateHandler
    
    Called when a checkpoint can be retired.
    
    Specified by:
    
    retireCheckpoint in interface StateHandler
    
    Parameters:
    
    id - Id of checkpoint.
    
    Throws:
    
    java.lang.Exception - Exception attempting to retire a checkpoint state.
  - resetToInitialState
```
public void resetToInitialState()
                         throws java.lang.Exception
```
    Description copied from interface: StateHandler
    
    Reset the operator to its initial state.
    If the operator is in a consistent region then this is called if a reset occurs prior to the first successful completion of drain and checkpoint cycle for the region.
    This method is not called when the operator first initializes.
    
    Specified by:
    
    resetToInitialState in interface StateHandler
    
    Throws:
    
    java.lang.Exception - Exception attempting to retire a checkpoint state.
  - prepareForNonBlockingCheckpoint
```
public void prepareForNonBlockingCheckpoint(long id)
                                     throws java.lang.Exception
```
    Description copied from interface: StateHandler
    
    Called to prepare for non-blocking checkpoint.
    This method is executed only when the operator enables non-blocking checkpointing with the ConsistentRegionContext.enableNonBlockingCheckpoint() method. This method is guaranteed to execute after StateHandler.drain() and before StateHandler.checkpoint(Checkpoint). It is also guaranteed to execute before the consistent region resumes tuple processing.
    This method was added after the interface was released in Version 4.0. It is defined as a default method for compatibility reasons. The default implementation is sufficient if the operator does not support non-blocking checkpoint.
    
    Specified by:
    
    prepareForNonBlockingCheckpoint in interface StateHandler
    
    Parameters:
    
    id - Id of checkpoint.
    
    Throws:
    
    java.lang.Exception - Exception attempting to prepare for non-blocking checkpoint.
  - regionCheckpointed
```
public void regionCheckpointed(long id)
                        throws java.lang.Exception
```
    Description copied from interface: StateHandler
    
    Called when the whole consistent region has been drained and checkpointed.
    When all operators in a consistent region have finished checkpointing (including non-blocking checkpointing), this method is called to notify start operator(s) of the region. This method is called only for start operator(s) of a consistent region.
    This method was added after the interface was released in Version 4.0. It is defined as a default method for compatibility reasons.
    
    Specified by:
    
    regionCheckpointed in interface StateHandler
    
    Parameters:
    
    id - Id of checkpoint.
    
    Throws:
    
    java.lang.Exception - Exception attempting to notify start operator that the region has been drained and checkpointed.

Methods inherited from class java.lang.Object

IBM_COPYRIGHT

DelegateStateHandler

getDelegateHandler

close

drain

reset

checkpoint

retireCheckpoint

resetToInitialState

prepareForNonBlockingCheckpoint

regionCheckpointed