org.modeshape.jcr.cache.document.LazyCachedNode Maven / Gradle / Ivy
/*
* ModeShape (http://www.modeshape.org)
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
* See the AUTHORS.txt file in the distribution for a full listing of
* individual contributors.
*
* ModeShape is free software. Unless otherwise indicated, all code in ModeShape
* is licensed to you under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* ModeShape is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.modeshape.jcr.cache.document;
import java.io.Serializable;
import java.lang.ref.WeakReference;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import org.infinispan.schematic.document.Document;
import org.modeshape.common.annotation.Immutable;
import org.modeshape.jcr.JcrLexicon;
import org.modeshape.jcr.cache.CachedNode;
import org.modeshape.jcr.cache.ChildReference;
import org.modeshape.jcr.cache.ChildReferences;
import org.modeshape.jcr.cache.NodeCache;
import org.modeshape.jcr.cache.NodeKey;
import org.modeshape.jcr.cache.NodeNotFoundException;
import org.modeshape.jcr.cache.NodeNotFoundInParentException;
import org.modeshape.jcr.cache.PathCache;
import org.modeshape.jcr.value.Name;
import org.modeshape.jcr.value.NameFactory;
import org.modeshape.jcr.value.NamespaceRegistry;
import org.modeshape.jcr.value.Path;
import org.modeshape.jcr.value.Path.Segment;
import org.modeshape.jcr.value.Property;
/**
* This is an immutable {@link CachedNode} implementation that lazily loads its content. Technically each instance modifies its
* internal state, but all the state is based upon a single Document that is read-in only once and never changed again. And thus
* externally each instance appears to be immutable and invariant.
*/
@Immutable
public class LazyCachedNode implements CachedNode, Serializable {
private static final long serialVersionUID = 1L;
private final NodeKey key;
private Document document;
private transient Map properties;
private transient NodeKey parent;
private transient Set additionalParents;
/**
* cached reference of the parent node towards this (child) node
*/
private transient ChildReference parentReferenceToSelf;
/**
* the reference of the parent set when the above reference is set/changed. Needs to be kept in sync to detect stale SNS data
* (see MODE-1613 for more information). Also, to avoid memory leaks, this should not be a strong reference.
*/
private transient WeakReference parentReferenceToSelfParentRef;
private transient boolean propertiesFullyLoaded = false;
private transient ChildReferences childReferences;
public LazyCachedNode( NodeKey key,
Document document ) {
this.key = key;
this.document = document;
}
protected final WorkspaceCache workspaceCache( NodeCache cache ) {
return ((DocumentCache)cache).workspaceCache();
}
/**
* Get the {@link Document} that represents this node.
*
* @param cache the cache to which this node belongs, required in case this node needs to use the cache; may not be null
* @return the document; never null
* @throws NodeNotFoundException if this node no longer exists
*/
protected Document document( WorkspaceCache cache ) {
if (document == null) {
// Fetch from the cache ...
document = cache.documentFor(key);
if (document == null) {
throw new NodeNotFoundException(key);
}
}
return document;
}
@Override
public NodeKey getParentKey( NodeCache cache ) {
if (parent == null) {
WorkspaceCache wsCache = workspaceCache(cache);
parent = wsCache.translator().getParentKey(document(wsCache), wsCache.getWorkspaceKey(), key.getWorkspaceKey());
}
return parent;
}
@Override
public NodeKey getParentKeyInAnyWorkspace( NodeCache cache ) {
WorkspaceCache wsCache = workspaceCache(cache);
return wsCache.translator().getParentKey(document(wsCache), key.getWorkspaceKey(), key.getWorkspaceKey());
}
@Override
public Set getAdditionalParentKeys( NodeCache cache ) {
if (additionalParents == null) {
WorkspaceCache wsCache = workspaceCache(cache);
Set additionalParents = wsCache.translator().getParentKeys(document(wsCache),
wsCache.getWorkspaceKey(),
key.getWorkspaceKey());
this.additionalParents = additionalParents.isEmpty() ? additionalParents : Collections.unmodifiableSet(additionalParents);
}
return additionalParents;
}
@Override
public boolean isAtOrBelow( NodeCache cache,
Path path ) {
Path aPath = getPath(cache);
if (path.isAtOrAbove(aPath)) return true;
Set additionalParents = getAdditionalParentKeys(cache);
if (!additionalParents.isEmpty()) {
Path parentOfPath = path.getParent();
for (NodeKey parentKey : additionalParents) {
CachedNode parent = cache.getNode(parentKey);
if (parent.getPath(cache).isAtOrBelow(parentOfPath)) {
ChildReference ref = parent.getChildReferences(cache).getChild(key);
if (ref != null && ref.getSegment().equals(path.getLastSegment())) return true;
}
}
}
return false;
}
protected CachedNode parent( WorkspaceCache cache ) {
NodeKey parentKey = getParentKey(cache);
if (parentKey == null) {
return null;
}
CachedNode parent = cache.getNode(parentKey);
if (parent == null) {
throw new NodeNotFoundException(parentKey);
}
return parent;
}
/**
* Get the parent node's child reference to this node.
*
* @param cache the cache
* @return the child reference; never null (even for the root node)
* @throws NodeNotFoundInParentException if this node is no longer referenced by its parent as a child of the parent node
* (which can happen if this node is used while in the midst of being (re)moved.
*/
protected ChildReference parentReferenceToSelf( WorkspaceCache cache ) {
if (parentReferenceToSelfParentRef == null || parentReferenceToSelfParentRef.get() == null) {
// either we don't have a parent reference at all yet, or it has been reclaimed by the GC so we need to reset
// parentRefToSelf
parentReferenceToSelf = null;
} else if (parentReferenceToSelf != null) {
// we have a cached child reference and a parent reference, but we need to check that the reference isn't stale (it
// could happen for SNS)
CachedNode parentFromCache = parent(cache);
CachedNode parentReferenceToSelfParent = parentReferenceToSelfParentRef.get();
if (parentReferenceToSelfParent != parentFromCache) {
// the parent coming from the ws cache (possibly the "db") is different that what we have cached, so we need to
// retrieve it again
parentReferenceToSelf = null;
}
}
if (parentReferenceToSelf == null) {
CachedNode parent = parent(cache);
if (parent == null) {
// This should be the root node ...
parentReferenceToSelf = cache.childReferenceForRoot();
} else {
ChildReferences references = parent.getChildReferences(cache);
if (references.supportsGetChildReferenceByKey()) {
parentReferenceToSelf = references.getChild(key);
} else {
// Directly look up the ChildReference by going to the cache (and possibly connector) ...
NodeKey parentKey = getParentKey(cache);
parentReferenceToSelf = cache.getChildReference(parentKey, key);
}
parentReferenceToSelfParentRef = new WeakReference(parent);
}
}
if (parentReferenceToSelf == null) {
// This node references a parent, but that parent no longer has a child reference to this node. Perhaps this node is
// in the midst of being moved or removed. Either way, we don't have much choice but to throw an exception about
// us not being found...
throw new NodeNotFoundInParentException(key, getParentKey(cache));
}
return parentReferenceToSelf;
}
protected Map properties() {
if (properties == null) {
properties = new ConcurrentHashMap();
}
return properties;
}
@Override
public NodeKey getKey() {
return key;
}
@Override
public Name getName( NodeCache cache ) {
return parentReferenceToSelf(workspaceCache(cache)).getName();
}
@Override
public Segment getSegment( NodeCache cache ) {
return parentReferenceToSelf(workspaceCache(cache)).getSegment();
}
/**
* Get the name for this node, without any same-name-sibiling (SNS) index.
*
* @param cache the workspace cache to which this node belongs, required in case this node needs to use the cache; may not be
* null
* @return the name; never null, but the root node will have a zero-length name
* @throws NodeNotFoundInParentException if this node no longer exists
* @see #getSegment(NodeCache)
* @see #getPath(NodeCache)
*/
protected Segment getSegment( WorkspaceCache cache ) {
return parentReferenceToSelf(cache).getSegment();
}
@Override
public Path getPath( NodeCache cache ) {
WorkspaceCache wsCache = workspaceCache(cache);
CachedNode parent = parent(wsCache);
if (parent != null) {
Path parentPath = parent.getPath(wsCache);
return wsCache.pathFactory().create(parentPath, getSegment(wsCache));
}
// check that the node hasn't been removed in the meantime
if (wsCache.getNode(key) == null) {
throw new NodeNotFoundException(key);
}
// This is the root node ...
return wsCache.rootPath();
}
@Override
public Path getPath( PathCache pathCache ) throws NodeNotFoundException {
NodeCache cache = pathCache.getCache();
WorkspaceCache wsCache = workspaceCache(cache);
CachedNode parent = parent(wsCache);
if (parent != null) {
Path parentPath = pathCache.getPath(parent);
return wsCache.pathFactory().create(parentPath, getSegment(wsCache));
}
// check that the node hasn't been removed in the meantime
if (wsCache.getNode(key) == null) {
throw new NodeNotFoundException(key);
}
// This is the root node ...
return wsCache.rootPath();
}
@Override
public Name getPrimaryType( NodeCache cache ) {
Property prop = getProperty(JcrLexicon.PRIMARY_TYPE, cache);
assert prop != null;
WorkspaceCache wsCache = workspaceCache(cache);
return wsCache.nameFactory().create(prop.getFirstValue());
}
@Override
public Set getMixinTypes( NodeCache cache ) {
Property prop = getProperty(JcrLexicon.MIXIN_TYPES, cache);
if (prop == null || prop.size() == 0) return Collections.emptySet();
final NameFactory nameFactory = workspaceCache(cache).nameFactory();
if (prop.size() == 1) {
Name name = nameFactory.create(prop.getFirstValue());
return Collections.singleton(name);
}
Set names = new HashSet();
for (Object value : prop) {
Name name = nameFactory.create(value);
names.add(name);
}
return names;
}
@Override
public int getPropertyCount( NodeCache cache ) {
if (propertiesFullyLoaded) return properties().size();
WorkspaceCache wsCache = workspaceCache(cache);
return wsCache.translator().countProperties(document(wsCache));
}
@Override
public boolean hasProperties( NodeCache cache ) {
Map props = properties();
if (!props.isEmpty()) return true;
if (propertiesFullyLoaded) return false;
WorkspaceCache wsCache = workspaceCache(cache);
return wsCache.translator().hasProperties(document(wsCache));
}
@Override
public boolean hasProperty( Name name,
NodeCache cache ) {
Map props = properties();
if (props.containsKey(name)) return true;
if (propertiesFullyLoaded) return false;
WorkspaceCache wsCache = workspaceCache(cache);
return wsCache.translator().hasProperty(document(wsCache), name);
}
@Override
public Property getProperty( Name name,
NodeCache cache ) {
Map props = properties();
Property property = props.get(name);
if (property == null && !propertiesFullyLoaded) {
WorkspaceCache wsCache = workspaceCache(cache);
property = wsCache.translator().getProperty(document(wsCache), name);
if (property != null) {
props.put(name, property);
}
}
return property;
}
@Override
public Iterator getProperties( NodeCache cache ) {
if (!propertiesFullyLoaded) {
WorkspaceCache wsCache = workspaceCache(cache);
wsCache.translator().getProperties(document(wsCache), properties());
this.propertiesFullyLoaded = true;
}
return properties().values().iterator();
}
@Override
public Iterator getProperties( Collection namePatterns,
NodeCache cache ) {
WorkspaceCache wsCache = workspaceCache(cache);
final NamespaceRegistry registry = wsCache.context().getNamespaceRegistry();
return new PatternIterator(getProperties(wsCache), namePatterns) {
@Override
protected String matchable( Property value ) {
return value.getName().getString(registry);
}
};
}
@Override
public ChildReferences getChildReferences( NodeCache cache ) {
if (childReferences == null) {
WorkspaceCache wsCache = workspaceCache(cache);
childReferences = wsCache.translator().getChildReferences(wsCache, document(wsCache));
}
return childReferences;
}
@Override
public Set getReferrers( NodeCache cache,
ReferenceType type ) {
// Get the referrers ...
WorkspaceCache wsCache = workspaceCache(cache);
return wsCache.translator().getReferrers(document(wsCache), type);
}
@Override
public boolean isQueryable( NodeCache cache ) {
WorkspaceCache wsCache = workspaceCache(cache);
return wsCache.translator().isQueryable(document(wsCache));
}
@Override
public int hashCode() {
return key.hashCode();
}
@Override
public boolean equals( Object obj ) {
if (obj == this) return true;
if (obj instanceof CachedNode) {
CachedNode that = (CachedNode)obj;
return this.getKey().equals(that.getKey());
}
return false;
}
@Override
public String toString() {
return getString(null);
}
public String getString( NamespaceRegistry registry ) {
StringBuilder sb = new StringBuilder();
sb.append("Node ").append(key).append(": ");
if (document != null) sb.append(document);
else sb.append(" ");
return sb.toString();
}
}
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