org.exist.xupdate
Class Modification

java.lang.Object
  org.exist.xupdate.Modification

Direct Known Subclasses:

Append, Conditional, Insert, Remove, Rename, Replace, Update

public abstract class Modification

extends java.lang.Object

Base class for all XUpdate modifications.

Author:

Wolfgang Meier

Field Summary

protected DBBroker	broker
protected org.w3c.dom.NodeList	content NodeList to keep track of created document fragments within the currently processed XUpdate modification.
protected DocumentSet	docs Documents concerned by this XUpdate modification, i.e.
protected DocumentSet	lockedDocuments
protected static Logger	LOG
protected java.util.Map	namespaces
protected java.lang.String	selectStmt select Statement in the current XUpdate definition; defines the set of nodes to which this XUpdate might apply.
protected java.util.Map	variables

Constructor Summary

Modification(DBBroker broker, DocumentSet docs, java.lang.String selectStmt, java.util.Map namespaces, java.util.Map variables)
Constructor for Modification.

Method Summary

protected void	checkFragmentation(Txn transaction, DocumentSet docs) Check if any of the modified documents needs defragmentation.
protected void	declareNamespaces(XQueryContext context)
protected void	declareVariables(XQueryContext context)
AccessContext	getAccessContext()
abstract java.lang.String	getName()
abstract long	process(Txn transaction) Process the modification.
protected org.w3c.dom.NodeList	select(DocumentSet docs) Evaluate the select expression.
protected StoredNode[]	selectAndLock() Acquire a lock on all documents processed by this modification.
void	setAccessContext(AccessContext accessCtx)
void	setContent(org.w3c.dom.NodeList nodes)
java.lang.String	toString()
protected void	unlockDocuments() Release all acquired document locks; feature trigger_update : at the same time we leverage on the fact that it's called after database modification to call the eventual triggers

Methods inherited from class java.lang.Object

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

Field Detail

LOG

protected static final Logger LOG

selectStmt

protected java.lang.String selectStmt

select Statement in the current XUpdate definition; defines the set of nodes to which this XUpdate might apply.

content

protected org.w3c.dom.NodeList content

NodeList to keep track of created document fragments within the currently processed XUpdate modification. see XUpdateProcessor#contents

broker

protected DBBroker broker

docs

protected DocumentSet docs

Documents concerned by this XUpdate modification, i.e. the set of documents to which this XUpdate might apply.

namespaces

protected java.util.Map namespaces

variables

protected java.util.Map variables

lockedDocuments

protected DocumentSet lockedDocuments

Constructor Detail

Modification

public Modification(DBBroker broker,
                    DocumentSet docs,
                    java.lang.String selectStmt,
                    java.util.Map namespaces,
                    java.util.Map variables)

Constructor for Modification.

Method Detail

setAccessContext

public final void setAccessContext(AccessContext accessCtx)

getAccessContext

public final AccessContext getAccessContext()

process

public abstract long process(Txn transaction)
                      throws PermissionDeniedException,
                             LockException,
                             EXistException,
                             XPathException

Process the modification. This is the main method that has to be implemented by all subclasses.

Returns:

Throws:

PermissionDeniedException

LockException

EXistException

XPathException

getName

public abstract java.lang.String getName()

setContent

public void setContent(org.w3c.dom.NodeList nodes)

select

protected org.w3c.dom.NodeList select(DocumentSet docs)
                               throws PermissionDeniedException,
                                      EXistException,
                                      XPathException

Evaluate the select expression.

Parameters:

docs -

Returns:

Throws:

PermissionDeniedException

EXistException

XPathException

declareVariables

protected void declareVariables(XQueryContext context)
                         throws XPathException

Parameters:

context -

Throws:

XPathException

declareNamespaces

protected void declareNamespaces(XQueryContext context)
                          throws XPathException

Parameters:

context -

Throws:

XPathException

selectAndLock

protected final StoredNode[] selectAndLock()
                                    throws LockException,
                                           PermissionDeniedException,
                                           EXistException,
                                           XPathException

Acquire a lock on all documents processed by this modification. We have to avoid that node positions change during the operation. feature trigger_update : At the same time we leverage on the fact that it's called before database modification to call the eventual triggers.

Returns:

Throws:

LockException

PermissionDeniedException

EXistException

XPathException

unlockDocuments

protected final void unlockDocuments()

Release all acquired document locks; feature trigger_update : at the same time we leverage on the fact that it's called after database modification to call the eventual triggers

checkFragmentation

protected void checkFragmentation(Txn transaction,
                                  DocumentSet docs)
                           throws EXistException

Check if any of the modified documents needs defragmentation. Defragmentation will take place if the number of split pages in the document exceeds the limit defined in the configuration file.

Parameters:

docs -

Throws:

EXistException

toString

public java.lang.String toString()