com.goldencode.p2j.util

Class LazyUndoable

java.lang.Object

com.goldencode.p2j.util.LazyUndoable

All Implemented Interfaces:

Undoable

Direct Known Subclasses:

Accumulator, BaseDataType, RecordBuffer.LightweightUndoable

public abstract class LazyUndoable
extends java.lang.Object
implements Undoable

Defines behaviour for objects which can be rolled back at runtime.

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	changed Flag indicating if this instance was changed.
private boolean	global Flag indicating if this resource was defined as a NEW GLOBAL SHARED.
private boolean	rollingBack Flag indicating if this instance is currently rolling back.
private int	transLevel This is the transaction nesting level, where the undoable was last changed.
private boolean	undoable Flag indicating if this instance is undoable.
private TransactionManager.UndoableHelper	undoableHelper Helper object to access context-local data in the TransactionManager.

Constructor Summary

Constructors

Constructor and Description
LazyUndoable()

Method Summary

Modifier and Type	Method and Description
protected boolean	changed() Check if this variable has changed.
protected void	checkUndoable(boolean changed) Check if this undoable has changed; if so, and we are in a transaction block (and not rolling back), then register this instance with all blocks up the stack, which were started after the object's last save transaction level.
protected void	checkUndoable(java.util.function.Supplier<Undoable> newValue) Check if this undoable has changed; if so, and we are in a transaction block (and not rolling back), then register this instance with all blocks up the stack, which were started after the object's last save transaction level.
protected void	checkUndoable(Undoable newValue) Check if this undoable has changed; if so, and we are in a transaction block (and not rolling back), then register this instance with all blocks up the stack, which were started after the object's last save transaction level.
private void	checkUndoable(Undoable nv1, java.util.function.Supplier<Undoable> nv2, boolean force) Check if this undoable has changed; if so, and we are in a transaction block (and not rolling back), then register this instance with all blocks up the stack, which were started after the object's last save transaction level.
(package private) int	getTransLevel() Get the transaction level at which this instance was last registered.
protected boolean	isGlobal() Get this undoable's global state.
protected boolean	isUndoable() Check if this instance is undoable.
protected void	markUndoable(int transLevel) Mark this instance as undoable and save the transaction level where it was created.
protected void	popBlock() Notification that a transaction block was finished.
protected void	rollback(Undoable copy) Rollback this instance to the state in the given copy.
protected void	setGlobal(boolean global) Set this undoable as defined via a NEW GLOBAL SHARED statement.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.goldencode.p2j.util.Undoable

assign, deepCopy

Field Detail

undoable

private transient boolean undoable

Flag indicating if this instance is undoable.

changed

private transient boolean changed

Flag indicating if this instance was changed.

rollingBack

private transient boolean rollingBack

Flag indicating if this instance is currently rolling back.

global

private transient boolean global

Flag indicating if this resource was defined as a NEW GLOBAL SHARED.

transLevel

private transient int transLevel

This is the transaction nesting level, where the undoable was last changed. When exiting a tx block, this value gets decremented - this number will reflect the last block (inclusive) where the object was registered. When registering, it goes up the stack and registers only with tx blocks with a tx level greater than this value.

undoableHelper

private transient TransactionManager.UndoableHelper undoableHelper

Helper object to access context-local data in the TransactionManager.

Constructor Detail

LazyUndoable

public LazyUndoable()

Method Detail

setGlobal

protected final void setGlobal(boolean global)

Set this undoable as defined via a NEW GLOBAL SHARED statement.

Parameters:

global - true to indicate a global resource.

isGlobal

protected final boolean isGlobal()

Get this undoable's global state.

Returns:

the global flag.

popBlock

protected final void popBlock()

Notification that a transaction block was finished.

changed

protected final boolean changed()

Check if this variable has changed. This check resets the changed flag.

Returns:

The state of the changed flag.

rollback

protected final void rollback(Undoable copy)

Rollback this instance to the state in the given copy.

Parameters:

copy - The state to which the instance is rolledback.

isUndoable

protected boolean isUndoable()

Check if this instance is undoable.

Returns:

The undoable flag state.

markUndoable

protected final void markUndoable(int transLevel)

Mark this instance as undoable and save the transaction level where it was created.

Parameters:

transLevel - The transaction nesting level where this instance was created.

checkUndoable

protected void checkUndoable(boolean changed)

Check if this undoable has changed; if so, and we are in a transaction block (and not rolling back), then register this instance with all blocks up the stack, which were started after the object's last save transaction level.

Parameters:

changed - Flag indicating if this undoable has changed or not.

checkUndoable

protected void checkUndoable(Undoable newValue)

Check if this undoable has changed; if so, and we are in a transaction block (and not rolling back), then register this instance with all blocks up the stack, which were started after the object's last save transaction level.

Parameters:

newValue - To value to compare against, when deciding if this undoable is changed.

checkUndoable

protected void checkUndoable(java.util.function.Supplier<Undoable> newValue)

Check if this undoable has changed; if so, and we are in a transaction block (and not rolling back), then register this instance with all blocks up the stack, which were started after the object's last save transaction level.

Parameters:

newValue - To value to compare against, when deciding if this undoable is changed.

getTransLevel

int getTransLevel()

Get the transaction level at which this instance was last registered.

Returns:

The transLevel.

checkUndoable

private void checkUndoable(Undoable nv1,
                           java.util.function.Supplier<Undoable> nv2,
                           boolean force)

Check if this undoable has changed; if so, and we are in a transaction block (and not rolling back), then register this instance with all blocks up the stack, which were started after the object's last save transaction level.

If the changed argument is true, then the nv1 and nv2 arguments are ignored; otherwise, if nv2 is not-null, then this will be used to compare against, while nv1 is used in the last case.

Parameters:

nv1 - To value to compare against, when deciding if this undoable is changed.

nv2 - To value to compare against, when deciding if this undoable is changed, wrapped in a supplier, to avoid instantiating a new object.

force - When true, ignore the previous two arguments and force the undoable registration.