hudson
Class BulkChange

java.lang.Object
  hudson.BulkChange

public class BulkChange
extends Object

Transaction-like object that can be used to make a bunch of changes to an object, and defer the Saveable.save() until the end.

The usage of BulkChange needs to follow a specific closure-like pattern, namely:

 BulkChange bc = new BulkChange(someObject);
 try {
    ... make changes to 'someObject'
 } finally {
    bc.commit();
 }
 

... or if you'd like to avoid saving when something bad happens:

 BulkChange bc = new BulkChange(someObject);
 try {
    ... make changes to 'someObject'
    bc.commit();
 } finally {
    bc.abort();
 }
 

Use of this method is optional. If BulkChange is not used, individual mutator will perform the save operation, and things will just run somewhat slower.

Cooperation from Saveable

For this class to work as intended, Saveable implementations need to co-operate. Namely,

1. Mutater methods should invoke this.save() so that if the method is called outside a BulkChange, the result will be saved immediately.
2. In the save() method implementation, use contains(Saveable) and only perform the actual I/O operation when this method returns false.

See Jenkins.save() as an example if you are not sure how to implement Saveable.

Since:

1.249

Author:

Kohsuke Kawaguchi

Field Summary

static Saveable	ALL Magic Saveable instance that can make BulkChange veto all the save operations by making the contains(Saveable) method return true for everything.
Exception	allocator

Constructor Summary

BulkChange(Saveable saveable)

Method Summary

void	abort() Exits the scope of BulkChange without saving the changes.
void	commit() Saves the accumulated changes.
static boolean	contains(Saveable s) Checks if the given Saveable is currently in the bulk change.
static BulkChange	current() Gets the BulkChange instance currently in scope for the current thread.

Methods inherited from class java.lang.Object

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

Field Detail

allocator

public final Exception allocator

ALL

public static final Saveable ALL

Magic Saveable instance that can make BulkChange veto all the save operations by making the contains(Saveable) method return true for everything.

Constructor Detail

BulkChange

public BulkChange(Saveable saveable)

Method Detail

commit

public void commit()
            throws IOException

Saves the accumulated changes.

Throws:

IOException

abort

public void abort()

Exits the scope of BulkChange without saving the changes.

This can be used when a bulk change fails in the middle. Note that unlike a real transaction, this will not roll back the state of the object.

The abort method can be called after the commit method, in which case this method does nothing. This is so that BulkChange can be used naturally in the try/finally block.

current

public static BulkChange current()

Gets the BulkChange instance currently in scope for the current thread.

contains

public static boolean contains(Saveable s)

Checks if the given Saveable is currently in the bulk change.

The expected usage is from the Saveable.save() implementation to check if the actual persistence should happen now or not.