ITXPNode

All Known Subinterfaces:

IJavaActionActor

All Known Implementing Classes:

AbstractActionActorTXPNode, AbstractJavaActionActor, AbstractTXPNode, DatabaseActionTXPNode, TestJavaActionActor
```
public interface ITXPNode
```
The ITXPNode interface abstracts a unit of work in a transactional process. The interface is used by the ITXProcess implementation the node is associated with and its ITXPCoordinator implementation. The process is itself guided by the ITXPCoordinator. The coordinator can be seen as enforcing a policy.

Author:

Freggle

Nested Class Summary

Nested Classes
Modifier and Type Interface and Description

static class ITXPNode.State
State enum for a ITXPNode.

Nested Classes
Modifier and Type	Interface and Description
`static class`	`ITXPNode.State` State enum for a `ITXPNode`.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`ITXPNode.State`	`begin(ITXProcess process, ITXPid pid)` Notifies the node it got associated with a transactional process.
`ITXPNode.State`	`commit(ITXProcess process)` Instructs the node to commit the work.
`void`	`forget(ITXProcess process)` Notifies the node it got disassociated from the process ie it can abort, rollback (if needed) and forget about the process.
`ITXPid`	`getPid()` Gets the pid of this node.
`ITXPNode.State`	`getState()` Returns the state of the node.
`long`	`getTimeout()` Gets the time in milliseconds this node will wait for a commit() or rollback() call after it is ready.
`boolean`	`hasProcessTimedOut()` Check if processTimeout has been called
`boolean`	`hasTimedOut()` Check if timeout has been called
`boolean`	`isIdempotent()` Asks if the node is idempotent.
`void`	`processTimeout(ITXProcess process)` Called by a process to indicate it timed out waiting for all nodes to complete the work.
`ITXPNode.State`	`recover(ITXProcess process)` This method instructs an node to recover a process after some sort of system failure.
`ITXPNode.State`	`retry(ITXProcess process)` Instructs the node to retry the work.
`ITXPNode.State`	`rollback(ITXProcess process)` Instructs the node to roll back the work.
`void`	`timeout(ITXProcess process)` Called by a process to indicate it timed out waiting for this node.
`ITXPNode.State`	`undo(ITXProcess process)` Instructs the node to undo the committed work.

- Method Detail
  - getPid
```
ITXPid getPid()
```
    Gets the pid of this node.
    
    Returns:
    
    the pid
  - getState
```
ITXPNode.State getState()
```
    Returns the state of the node.
    
    Returns:
    
    the state
  - isIdempotent
```
boolean isIdempotent()
```
    Asks if the node is idempotent. Idempotent means f(f(x)) = f(x). For instance: if the node turns on a light, turning it on again has the same result: the light is on.
    
    Returns:
    
    true if this node is idempotent, false if not
  - getTimeout
```
long getTimeout()
```
    Gets the time in milliseconds this node will wait for a commit() or rollback() call after it is ready.
    
    Returns:
    
    the timeout in milliseconds
  - begin
```
ITXPNode.State begin(ITXProcess process,
                     ITXPid pid)
```
    Notifies the node it got associated with a transactional process. The node should set up its local transaction context and set and respond with either ITXPNode.State.WORKING or ITXPNode.State.FAILED depending on its state.
    
    Parameters:
    
    process - the process
    
    pid - the pid for this node of the process
    
    Returns:
    
    the state of the node
  - forget
```
void forget(ITXProcess process)
```
    Notifies the node it got disassociated from the process ie it can abort, rollback (if needed) and forget about the process.
    
    Parameters:
    
    process - the process
  - timeout
```
void timeout(ITXProcess process)
```
    Called by a process to indicate it timed out waiting for this node. The node should abandon the work and wait for rollback or return READ_ONLY if it can.
    
    Parameters:
    
    process - the process that timed out
  - processTimeout
```
void processTimeout(ITXProcess process)
```
    Called by a process to indicate it timed out waiting for all nodes to complete the work. The node should abandon the work if it can and wait for rollback or return READ_ONLY if it can.
    
    Parameters:
    
    process - the process that timed out
  - hasTimedOut
```
boolean hasTimedOut()
```
    Check if timeout has been called
    
    Returns:
    
    true if timeout has been called
  - hasProcessTimedOut
```
boolean hasProcessTimedOut()
```
    Check if processTimeout has been called
    
    Returns:
    
    try if processTimeout has been called
  - commit
```
ITXPNode.State commit(ITXProcess process)
```
    Instructs the node to commit the work. The node should set and respond with either ITXPNode.State.COMPLETED or ITXPNode.State.FAILED depending on its state. If a commit failed the node is expected to have rolled back the work.
    
    Parameters:
    
    process - the process
    
    Returns:
    
    the state of the node
  - rollback
```
ITXPNode.State rollback(ITXProcess process)
```
    Instructs the node to roll back the work. The node should set and respond with either ITXPNode.State.COMPLETED or ITXPNode.State.FAILED depending on its state. NOTE if the node failed its work it is already rolled back and will return ITXPNode.State.COMPLETED but remain in state. ITXPNode.State.FAILED
    
    Parameters:
    
    process - the process
    
    Returns:
    
    the state of the node
  - retry
```
ITXPNode.State retry(ITXProcess process)
```
    Instructs the node to retry the work. The node should set and respond with either ITXPNode.State.OK, ITXPNode.State.FAILED or ITXPNode.State.UNABLE depending on its state.
    
    Parameters:
    
    process - the process
    
    Returns:
    
    the state of the node
  - undo
```
ITXPNode.State undo(ITXProcess process)
```
    Instructs the node to undo the committed work. The node should set and respond with either ITXPNode.State.OK, ITXPNode.State.FAILED or ITXPNode.State.UNABLE depending on its state. This is of course the 'crux'. It is the implementation that may or may not be able to undo something. For instance. if the node is a JDBC transaction it may know how to perform a compensating transaction; or not.
    
    Parameters:
    
    process - the process
    
    Returns:
    
    the state of the node
  - recover
```
ITXPNode.State recover(ITXProcess process)
```
    This method instructs an node to recover a process after some sort of system failure. In effect this means restoring the state of the ITXPNode to the last known state with regards to the specified process. The node should set and respond with either ITXPNode.State.OK, ITXPNode.State.FAILED or ITXPNode.State.UNABLE depending on its state. To be able to do this the node needs to log its state durably and use the Processes Pid as a key.
    
    Parameters:
    
    process - the process
    
    Returns:
    
    the state of the node

Interface ITXPNode

Nested Class Summary

Method Summary

Method Detail

getPid

getState

isIdempotent

getTimeout

begin

forget

timeout

processTimeout

hasTimedOut

hasProcessTimedOut

commit

rollback

retry

undo

recover