org.mmbase.bridge.implementation
Class BasicTransaction

java.lang.Object
  org.mmbase.bridge.implementation.BasicCloud
      org.mmbase.bridge.implementation.BasicTransaction

All Implemented Interfaces:

Serializable, Cloneable, Comparable<Cloud>, Cloud, Transaction, SizeMeasurable

public class BasicTransaction
extends BasicCloud
implements Transaction

The basic implementation for a Transaction cLoud. A Transaction cloud is a cloud which buffers all changes made to nodes - which means that changes are committed only if you commit the transaction itself. This mechanism allows you to rollback changes if something goes wrong.

Version:

$Id: BasicTransaction.java 41394 2010-03-16 09:13:37Z michiel $

Author:

Pierre van Rooden

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.mmbase.bridge.implementation.BasicCloud

BasicCloud.BasicCloudStarter

Field Summary

protected BasicCloud	parentCloud
protected String	transactionName The id of the transaction for use with the transaction manager.

Fields inherited from class org.mmbase.bridge.implementation.BasicCloud

account, count, description, locale, name, nodeManagerCache, properties, transactions, userContext

Fields inherited from interface org.mmbase.bridge.Cloud

PROP_IGNOREVALIDATION, PROP_REQUEST, PROP_RESPONSE, PROP_SESSIONNAME, PROP_XMLMODE

Constructor Summary

BasicTransaction(String name, BasicCloud cloud)

Method Summary

(package private) int	add(BasicNode node) Marks the given node as 'being edited'.
(package private) void	add(String currentObjectContext) Ignored by basic cloud.
protected void	afterCommit(BasicNode n) This method is called after a of a certain node.
void	cancel() Cancels this transaction.
boolean	commit() Commits this transaction.
(package private) boolean	contains(MMObjectNode node) Checks wether the current transaction contains the given node.
(package private) void	createAlias(BasicNode node, String aliasName)
BasicTransaction	createTransaction(String name, boolean overwrite) Creates a transaction on this cloud with a specified name.
(package private) void	deleteNewNode(int temporaryNodeId, MMObjectNode node)
(package private) void	deleteNode(int temporaryNodeId, MMObjectNode node) Ignored by basic cloud.
protected void	finalize() If this Transaction is scheduled to be garbage collected, the transaction is canceled and cleaned up.
(package private) String	getAccount() The owner to use for the temporary node manager.
String	getCloudName() Returns the name of the cloud this transaction uses
protected Collection<MMObjectNode>	getCoreNodes()
String	getId() Returns the unique ID used for this transaction.
Node	getNode(String nodeNumber) Returns the node with the specified number from this cloud.
NodeList	getNodes()
Cloud	getNonTransactionalCloud() Returns a cloud which is not a Transaction.
Map<Object,Object>	getProperties() Retrieves all properties previously set for this cloud.
Object	getProperty(Object key) Retrieves a property previously set for this cloud.
boolean	hasNode(String nodeNumber) Determines whether a node with the specified number is available from this cloud.
boolean	isCanceled() Returns whether the transaction is canceled
boolean	isCommitted() Returns whether the transaction is committed
(package private) BasicNode	makeNode(MMObjectNode node, String nodeNumber)
protected void	processCommitProcessors(Node n) Calls the commit processor for every field.
protected void	processDeleteProcessors(Node n) Calls the delete processor for every field.
protected void	setValue(BasicNode node, String fieldName, Object value)
String	toString()
(package private) boolean	verify()

Methods inherited from class org.mmbase.bridge.implementation.BasicCloud

_readObject, _writeObject, check, check, checkAlias, checkNodes, compareTo, createAggregatedQuery, createNodeList, createNodeManagerList, createNodeQuery, createQuery, createRelationList, createRelationManagerList, createTransaction, createTransaction, equals, getBasicNodeManager, getBasicNodeManager, getByteSize, getByteSize, getCloudContext, getClusterNodes, getDescription, getFunction, getFunctions, getLastStepList, getList, getList, getLocale, getName, getNode, getNodeByAlias, getNodeManager, getNodeManager, getNodeManagers, getPossibleContexts, getRelation, getRelation, getRelationManager, getRelationManager, getRelationManager, getRelationManager, getRelationManager, getRelationManagers, getRelationManagers, getRelationManagers, getResultNodeList, getSecureList, getTransaction, getUser, hasNode, hasNodeManager, hasRelation, hasRelation, hasRelationManager, hasRelationManager, hasRelationManager, hasRole, isTemporaryId, may, mayRead, mayRead, remove, setLocale, setProperty, setSecurityConstraint, setSecurityConstraint, shutdown, toBasicQuery, uniqueId, verify, verify

Methods inherited from class java.lang.Object

clone, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.mmbase.bridge.Cloud

createAggregatedQuery, createNodeList, createNodeManagerList, createNodeQuery, createQuery, createRelationList, createRelationManagerList, createTransaction, createTransaction, getCloudContext, getDescription, getFunction, getFunctions, getList, getList, getLocale, getName, getNode, getNodeByAlias, getNodeManager, getNodeManager, getNodeManagers, getPossibleContexts, getRelation, getRelation, getRelationManager, getRelationManager, getRelationManager, getRelationManager, getRelationManagers, getRelationManagers, getRelationManagers, getTransaction, getUser, hasNode, hasNodeManager, hasRelation, hasRelation, hasRelationManager, hasRelationManager, hasRelationManager, hasRole, may, mayRead, mayRead, setLocale, setProperty, shutdown

Field Detail

transactionName

protected String transactionName

The id of the transaction for use with the transaction manager. This is the name as speficied by the user, prefixed by the account name.

parentCloud

protected BasicCloud parentCloud

Constructor Detail

BasicTransaction

BasicTransaction(String name,
                 BasicCloud cloud)

Method Detail

getCoreNodes

protected final Collection<MMObjectNode> getCoreNodes()

Since:

MMBase 1.9

getAccount

String getAccount()

Description copied from class: BasicCloud

The owner to use for the temporary node manager.

Overrides:

getAccount in class BasicCloud

Returns:

the account name

getId

public String getId()

Returns the unique ID used for this transaction. The transaction name may not be unique, because different users, may have transactions with the same name.

Since:

MMBase-1.9.3

getNodes

public NodeList getNodes()

Specified by:

getNodes in interface Transaction

Since:

MMBase-1.9

createTransaction

public BasicTransaction createTransaction(String name,
                                          boolean overwrite)
                                   throws AlreadyExistsException

Description copied from interface: Cloud

Creates a transaction on this cloud with a specified name.

Specified by:

createTransaction in interface Cloud

Overrides:

createTransaction in class BasicCloud

Parameters:

name - an unique name to use for the transaction

overwrite - if true, cancels and replaces any existing transaction of this name for the current user

Returns:

a Transaction on this cloud

Throws:

AlreadyExistsException - if a transaction with the specified name allready exists and overwrite is false

verify

boolean verify()

commit

public boolean commit()

Description copied from interface: Transaction

Commits this transaction. This has no effect if the transaction itself was 'nested' in another transaction. In that case, nothing happens until the 'outer' transaction commits. This routine also removes the transaction as an 'active' transaction (it cannot be opened again).

Specified by:

commit in interface Transaction

Returns:

true if the commit succeeded, false otherwise

cancel

public void cancel()

Description copied from interface: Transaction

Cancels this transaction. If the transaction itself was 'nested' in another transaction, that 'outer' transaction is also canceled. This routine also removes the transaction (and all outer transactions) as an 'active' transaction (it cannot be opened again).

Specified by:

cancel in interface Transaction

add

int add(BasicNode node)

Description copied from class: BasicCloud

Marks the given node as 'being edited'. This means that a copy must be made which is going to contain the changes until the node (or the transaction) is committed.

Overrides:

add in class BasicCloud

add

void add(String currentObjectContext)

Description copied from class: BasicCloud

Ignored by basic cloud. See add(String).

Overrides:

add in class BasicCloud

createAlias

void createAlias(BasicNode node,
                 String aliasName)

Overrides:

createAlias in class BasicCloud

deleteNewNode

void deleteNewNode(int temporaryNodeId,
                   MMObjectNode node)

Overrides:

deleteNewNode in class BasicCloud

deleteNode

void deleteNode(int temporaryNodeId,
                MMObjectNode node)

Description copied from class: BasicCloud

Ignored by basic cloud. See delete(String).

Overrides:

deleteNode in class BasicCloud

contains

boolean contains(MMObjectNode node)

Description copied from class: BasicCloud

Checks wether the current transaction contains the given node.

Overrides:

contains in class BasicCloud

makeNode

BasicNode makeNode(MMObjectNode node,
                   String nodeNumber)

Overrides:

makeNode in class BasicCloud

finalize

protected void finalize()

If this Transaction is scheduled to be garbage collected, the transaction is canceled and cleaned up. Unless it has already been committed/canceled, ofcourse, and unless the parentcloud of a transaction is a transaction itself. In that case, the parent transaction should cancel! This means that a transaction is always cleared - if it 'times out', or is not properly removed, it will eventually be removed from the MMBase cache.

Overrides:

finalize in class Object

isCanceled

public boolean isCanceled()

Description copied from interface: Transaction

Returns whether the transaction is canceled

Specified by:

isCanceled in interface Transaction

Returns:

true when canceled

isCommitted

public boolean isCommitted()

Description copied from interface: Transaction

Returns whether the transaction is committed

Specified by:

isCommitted in interface Transaction

Returns:

true when committed

getProperty

public Object getProperty(Object key)

Description copied from interface: Cloud

Retrieves a property previously set for this cloud. If this Cloud has a 'parent' cloud (ie. this Cloud is a Transaction), then this will also mirror properties in this parent cloud.

Specified by:

getProperty in interface Cloud

Overrides:

getProperty in class BasicCloud

Parameters:

key - the key of the property

Returns:

the property value

See Also:

Cloud.setProperty(Object, Object)

getProperties

public Map<Object,Object> getProperties()

Description copied from interface: Cloud

Retrieves all properties previously set for this cloud.

Specified by:

getProperties in interface Cloud

Overrides:

getProperties in class BasicCloud

Returns:

all properties

getCloudName

public String getCloudName()

Description copied from interface: Transaction

Returns the name of the cloud this transaction uses

Specified by:

getCloudName in interface Transaction

Returns:

the name of the cloud

See Also:

Transaction.getCloudName()

toString

public String toString()

Overrides:

toString in class BasicCloud

getNonTransactionalCloud

public Cloud getNonTransactionalCloud()

Description copied from interface: Cloud

Returns a cloud which is not a Transaction.

Specified by:

getNonTransactionalCloud in interface Cloud

Overrides:

getNonTransactionalCloud in class BasicCloud

Returns:

This cloud or a parent cloud if this cloud is a Transaction

processDeleteProcessors

protected void processDeleteProcessors(Node n)

Description copied from class: BasicCloud

Calls the delete processor for every field.

Overrides:

processDeleteProcessors in class BasicCloud

processCommitProcessors

protected void processCommitProcessors(Node n)

Description copied from class: BasicCloud

Calls the commit processor for every field.

Overrides:

processCommitProcessors in class BasicCloud

setValue

protected void setValue(BasicNode node,
                        String fieldName,
                        Object value)

Overrides:

setValue in class BasicCloud

hasNode

public boolean hasNode(String nodeNumber)

Description copied from interface: Cloud

Determines whether a node with the specified number is available from this cloud. If the string passed is not a number, the string is assumed to be an alias. Note that this method does not determine whether you may actually access (read) this node, use Cloud.mayRead(int) to determine this.

Specified by:

hasNode in interface Cloud

Overrides:

hasNode in class BasicCloud

Parameters:

nodeNumber - a string containing the number or alias of the requested node

Returns:

true if the node exists

getNode

public Node getNode(String nodeNumber)
             throws NotFoundException

Description copied from interface: Cloud

Returns the node with the specified number from this cloud. If the string passed is not a number, the string is assumed to be an alias. The returned node is a new instance of Node with a reference to this instance of Cloud.

Specified by:

getNode in interface Cloud

Overrides:

getNode in class BasicCloud

Parameters:

nodeNumber - a string containing the number or alias of the requested node

Returns:

the requested node

Throws:

NotFoundException - if the specified node could not be found

afterCommit

protected void afterCommit(BasicNode n)

Description copied from class: BasicCloud

This method is called after a of a certain node. If we are not in a transaction this performing the actual commit procedure (using the temporary object manager), and calls Object.notifyAll(). This last thing makes it easy to wait for a node to really exist (finished committing)

                synchronized(ntCloud) {
                    while (! ntCloud.hasNode(node)) {
                        ntCloud.wait();
                    }
                }
     

Committing in a transaction goes a bit different, because the actual committing only happens in the , this method will be mostly empty for BasicTransaction.

Overrides:

afterCommit in class BasicCloud