org.datanucleus.store.types.wrappers.backed.ArrayList Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of datanucleus-core Show documentation
Show all versions of datanucleus-core Show documentation
DataNucleus Core provides the primary components of a heterogenous Java persistence solution.
It supports persistence API's being layered on top of the core functionality.
/**********************************************************************
Copyright (c) 2003 Andy Jefferson and others. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Contributors:
...
**********************************************************************/
package org.datanucleus.store.types.wrappers.backed;
import java.io.ObjectStreamException;
import java.util.Collection;
import java.util.Iterator;
import java.util.ListIterator;
import org.datanucleus.ClassLoaderResolver;
import org.datanucleus.ExecutionContext;
import org.datanucleus.exceptions.NucleusDataStoreException;
import org.datanucleus.flush.ListAddAtOperation;
import org.datanucleus.flush.CollectionAddOperation;
import org.datanucleus.flush.CollectionClearOperation;
import org.datanucleus.flush.ListRemoveAtOperation;
import org.datanucleus.flush.CollectionRemoveOperation;
import org.datanucleus.flush.ListSetOperation;
import org.datanucleus.metadata.AbstractMemberMetaData;
import org.datanucleus.metadata.FieldPersistenceModifier;
import org.datanucleus.state.ObjectProvider;
import org.datanucleus.store.BackedSCOStoreManager;
import org.datanucleus.store.scostore.ListStore;
import org.datanucleus.store.scostore.Store;
import org.datanucleus.store.types.SCOListIterator;
import org.datanucleus.store.types.SCOUtils;
import org.datanucleus.util.Localiser;
import org.datanucleus.util.NucleusLogger;
/**
* A mutable second-class ArrayList object.
* This class extends ArrayList, using that class to contain the current objects, and the backing ListStore
* to be the interface to the datastore. A "backing store" is not present for datastores that dont use
* DatastoreClass, or if the container is serialised or non-persistent.
*
* Modes of Operation
* The user can operate the list in 2 modes.
* The cached mode will use an internal cache of the elements (in the "delegate") reading them at
* the first opportunity and then using the cache thereafter.
* The non-cached mode will just go direct to the "backing store" each call.
*
* Mutators
* When the "backing store" is present any updates are passed direct to the datastore as well as to the "delegate".
* If the "backing store" isn't present the changes are made to the "delegate" only.
*
* Accessors
* When any accessor method is invoked, it typically checks whether the container has been loaded from its
* "backing store" (where present) and does this as necessary. Some methods (size()) just check if
* everything is loaded and use the delegate if possible, otherwise going direct to the datastore.
*/
public class ArrayList extends org.datanucleus.store.types.wrappers.ArrayList implements BackedSCO
{
protected transient ListStore backingStore;
protected transient boolean allowNulls = false;
protected transient boolean useCache=true;
protected transient boolean isCacheLoaded=false;
/**
* Constructor, using the ObjectProvider of the "owner" and the field name.
* @param op The owner ObjectProvider
* @param mmd Metadata for the member
*/
public ArrayList(ObjectProvider op, AbstractMemberMetaData mmd)
{
super(op, mmd);
// Set up our delegate
this.delegate = new java.util.ArrayList();
ExecutionContext ec = op.getExecutionContext();
allowNulls = SCOUtils.allowNullsInContainer(allowNulls, mmd);
useCache = SCOUtils.useContainerCache(op, mmd);
if (!SCOUtils.collectionHasSerialisedElements(mmd) && mmd.getPersistenceModifier() == FieldPersistenceModifier.PERSISTENT)
{
ClassLoaderResolver clr = ec.getClassLoaderResolver();
this.backingStore = (ListStore)((BackedSCOStoreManager)op.getStoreManager()).getBackingStoreForField(clr, mmd, java.util.ArrayList.class);
}
if (NucleusLogger.PERSISTENCE.isDebugEnabled())
{
NucleusLogger.PERSISTENCE.debug(SCOUtils.getContainerInfoMessage(op, ownerMmd.getName(), this,
useCache, allowNulls, SCOUtils.useCachedLazyLoading(op, ownerMmd)));
}
}
/* (non-Javadoc)
* @see org.datanucleus.store.types.SCO#initialise(java.lang.Object, java.lang.Object)
*/
public void initialise(java.util.ArrayList newValue, Object oldValue)
{
if (newValue != null)
{
// Check for the case of serialised PC elements, and assign ObjectProviders to the elements without
if (SCOUtils.collectionHasSerialisedElements(ownerMmd) && ownerMmd.getCollection().elementIsPersistent())
{
ExecutionContext ec = ownerOP.getExecutionContext();
Iterator iter = newValue.iterator();
while (iter.hasNext())
{
Object pc = iter.next();
ObjectProvider objOP = ec.findObjectProvider(pc);
if (objOP == null)
{
objOP = ec.getNucleusContext().getObjectProviderFactory().newForEmbedded(ec, pc, false, ownerOP, ownerMmd.getAbsoluteFieldNumber());
}
}
}
if (NucleusLogger.PERSISTENCE.isDebugEnabled())
{
NucleusLogger.PERSISTENCE.debug(Localiser.msg("023008", ownerOP.getObjectAsPrintable(), ownerMmd.getName(), "" + newValue.size()));
}
// TODO This does clear+addAll : Improve this and work out which elements are added and which deleted
if (backingStore != null)
{
if (SCOUtils.useQueuedUpdate(ownerOP))
{
if (ownerOP.isFlushedToDatastore() || !ownerOP.getLifecycleState().isNew())
{
ownerOP.getExecutionContext().addOperationToQueue(new CollectionClearOperation(ownerOP, backingStore));
for (Object element : newValue)
{
ownerOP.getExecutionContext().addOperationToQueue(new CollectionAddOperation(ownerOP, backingStore, element));
}
}
}
else
{
backingStore.clear(ownerOP);
try
{
backingStore.addAll(ownerOP, newValue, (useCache ? 0 : -1));
}
catch (NucleusDataStoreException dse)
{
NucleusLogger.PERSISTENCE.warn(Localiser.msg("023013", "addAll", ownerMmd.getName(), dse));
}
}
}
delegate.addAll(newValue);
isCacheLoaded = true;
makeDirty();
}
}
/**
* Method to initialise the SCO from an existing value.
* @param c The object to set from
*/
public void initialise(java.util.ArrayList c)
{
if (c != null)
{
// Check for the case of serialised PC elements, and assign ObjectProviders to the elements without
if (SCOUtils.collectionHasSerialisedElements(ownerMmd) && ownerMmd.getCollection().elementIsPersistent())
{
ExecutionContext ec = ownerOP.getExecutionContext();
Iterator iter = c.iterator();
while (iter.hasNext())
{
Object pc = iter.next();
ObjectProvider objOP = ec.findObjectProvider(pc);
if (objOP == null)
{
objOP = ec.getNucleusContext().getObjectProviderFactory().newForEmbedded(ec, pc, false, ownerOP, ownerMmd.getAbsoluteFieldNumber());
}
}
}
if (backingStore != null && useCache && !isCacheLoaded)
{
// Mark as loaded so we just use the value
isCacheLoaded = true;
}
if (NucleusLogger.PERSISTENCE.isDebugEnabled())
{
NucleusLogger.PERSISTENCE.debug(Localiser.msg("023007", ownerOP.getObjectAsPrintable(), ownerMmd.getName(), "" + c.size()));
}
delegate.clear();
delegate.addAll(c);
}
}
/**
* Method to initialise the SCO for use.
*/
public void initialise()
{
if (useCache && !SCOUtils.useCachedLazyLoading(ownerOP, ownerMmd))
{
// Load up the collection now if not using lazy loading
loadFromStore();
}
}
// ----------------------- Implementation of SCO methods -------------------
/**
* Accessor for the unwrapped value that we are wrapping.
* @return The unwrapped value
*/
public java.util.ArrayList getValue()
{
loadFromStore();
return super.getValue();
}
/**
* Method to effect the load of the data in the SCO.
* Used when the SCO supports lazy-loading to tell it to load all now.
*/
public void load()
{
if (useCache)
{
loadFromStore();
}
}
/**
* Method to return if the SCO has its contents loaded.
* If the SCO doesn't support lazy loading will just return true.
* @return Whether it is loaded
*/
public boolean isLoaded()
{
return useCache ? isCacheLoaded : false;
}
/**
* Method to load all elements from the "backing store" where appropriate.
*/
protected void loadFromStore()
{
if (backingStore != null && !isCacheLoaded)
{
if (NucleusLogger.PERSISTENCE.isDebugEnabled())
{
NucleusLogger.PERSISTENCE.debug(Localiser.msg("023006",
ownerOP.getObjectAsPrintable(), ownerMmd.getName()));
}
delegate.clear();
Iterator iter = backingStore.iterator(ownerOP);
while (iter.hasNext())
{
delegate.add(iter.next());
}
isCacheLoaded = true;
}
}
/* (non-Javadoc)
* @see org.datanucleus.store.types.backed.BackedSCO#getBackingStore()
*/
public Store getBackingStore()
{
return backingStore;
}
/**
* Method to update an embedded element in this list.
* @param element The element
* @param fieldNumber Number of field in the element
* @param value New value for this field
* @param makeDirty Whether to make the SCO field dirty.
*/
public void updateEmbeddedElement(Object element, int fieldNumber, Object value, boolean makeDirty)
{
if (backingStore != null)
{
backingStore.updateEmbeddedElement(ownerOP, element, fieldNumber, value);
}
}
/**
* Method to unset the owner and backing store information.
*/
public synchronized void unsetOwner()
{
super.unsetOwner();
if (backingStore != null)
{
backingStore = null;
}
}
// ----------------- Implementation of ArrayList methods -------------------
/**
* Clone operator to return a copy of this object.
* Mutable second-class Objects are required to provide a public clone method in order to allow for copying persistable objects.
* In contrast to Object.clone(), this method must not throw a CloneNotSupportedException.
* @return The cloned object
*/
public Object clone()
{
if (useCache)
{
loadFromStore();
}
return delegate.clone();
}
/**
* Method to return if the list contains this element.
* @param element The element
* @return Whether it is contained
**/
public boolean contains(Object element)
{
if (useCache && isCacheLoaded)
{
// If the "delegate" is already loaded, use it
return delegate.contains(element);
}
else if (backingStore != null)
{
return backingStore.contains(ownerOP,element);
}
return delegate.contains(element);
}
/**
* Accessor for whether a collection of elements are contained here.
* @param c The collection of elements.
* @return Whether they are contained.
**/
public synchronized boolean containsAll(java.util.Collection c)
{
if (useCache)
{
loadFromStore();
}
else if (backingStore != null)
{
java.util.HashSet h=new java.util.HashSet(c);
Iterator iter=iterator();
while (iter.hasNext())
{
h.remove(iter.next());
}
return h.isEmpty();
}
return delegate.containsAll(c);
}
/**
* Equality operator.
* @param o The object to compare against.
* @return Whether this object is the same.
**/
public synchronized boolean equals(Object o)
{
if (useCache)
{
loadFromStore();
}
if (o == this)
{
return true;
}
if (!(o instanceof java.util.List))
{
return false;
}
java.util.List l = (java.util.List)o;
if (l.size() != size())
{
return false;
}
Object[] elements = toArray();
Object[] otherElements = l.toArray();
for (int i=0;i