/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
package org.apache.jackrabbit.core.state;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.LinkedList;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;
import javax.jcr.InvalidItemStateException;
import javax.jcr.ItemNotFoundException;
import javax.jcr.ReferentialIntegrityException;
import javax.jcr.RepositoryException;
import org.apache.jackrabbit.core.CachingHierarchyManager;
import org.apache.jackrabbit.core.HierarchyManager;
import org.apache.jackrabbit.core.ZombieHierarchyManager;
import org.apache.jackrabbit.core.id.ItemId;
import org.apache.jackrabbit.core.id.NodeId;
import org.apache.jackrabbit.core.id.PropertyId;
import org.apache.jackrabbit.spi.Name;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Item state manager that handles both transient and persistent items.
*/
public class SessionItemStateManager
implements UpdatableItemStateManager, NodeStateListener {
private static Logger log = LoggerFactory.getLogger(SessionItemStateManager.class);
/**
* State manager that allows updates
*/
private final UpdatableItemStateManager stateMgr;
/**
* Hierarchy manager
*/
private CachingHierarchyManager hierMgr;
/**
* map of those states that have been removed transiently
*/
private final Map<ItemId, ItemState> atticStore =
new HashMap<ItemId, ItemState>();
/**
* map of new or modified transient states
*/
private final Map<ItemId, ItemState> transientStore =
new HashMap<ItemId, ItemState>();
/**
* ItemStateManager view of the states in the attic; lazily instantiated
* in {@link #getAttic()}
*/
private AtticItemStateManager attic;
/**
* State change dispatcher.
*/
private final transient StateChangeDispatcher dispatcher = new StateChangeDispatcher();
/**
* Creates a new <code>SessionItemStateManager</code> instance.
*
* @param rootNodeId the root node id
* @param stateMgr the local item state manager
*/
public SessionItemStateManager(
NodeId rootNodeId, LocalItemStateManager stateMgr) {
this.stateMgr = stateMgr;
// create hierarchy manager that uses both transient and persistent state
hierMgr = new CachingHierarchyManager(rootNodeId, this);
addListener(hierMgr);
}
/**
* Returns the hierarchy manager
*
* @return the hierarchy manager
*/
public HierarchyManager getHierarchyMgr() {
return hierMgr;
}
/**
* Returns an attic-aware hierarchy manager, i.e. an hierarchy manager that
* is also able to build/resolve paths of those items that have been moved
* or removed (i.e. moved to the attic).
*
* @return an attic-aware hierarchy manager
*/
public HierarchyManager getAtticAwareHierarchyMgr() {
return new ZombieHierarchyManager(hierMgr, this, getAttic());
}
//--------------------------------------------------------------< Object >
/**
* {@inheritDoc}
*/
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append("SessionItemStateManager (" + super.toString() + ")\n");
builder.append("[transient]\n");
builder.append(transientStore);
builder.append("[attic]\n");
builder.append(atticStore);
return builder.toString();
}
//-----------------------------------------------------< ItemStateManager >
/**
* {@inheritDoc}
*/
public ItemState getItemState(ItemId id)
throws NoSuchItemStateException, ItemStateException {
// first check if the specified item has been transiently removed
if (atticStore.containsKey(id)) {
/**
* check if there's new transient state for the specified item
* (e.g. if a property with name 'x' has been removed and a new
* property with same name has been created);
* this will throw a NoSuchItemStateException if there's no new
* transient state
*/
return getTransientItemState(id);
}
// check if there's transient state for the specified item
if (transientStore.containsKey(id)) {
return getTransientItemState(id);
}
return stateMgr.getItemState(id);
}
/**
* {@inheritDoc}
*/
public boolean hasItemState(ItemId id) {
// first check if the specified item has been transiently removed
if (atticStore.containsKey(id)) {
/**
* check if there's new transient state for the specified item
* (e.g. if a property with name 'x' has been removed and a new
* property with same name has been created);
*/
return transientStore.containsKey(id);
}
// check if there's transient state for the specified item
if (transientStore.containsKey(id)) {
return true;
}
// check if there's persistent state for the specified item
return stateMgr.hasItemState(id);
}
/**
* {@inheritDoc}
*/
public NodeReferences getNodeReferences(NodeId id)
throws NoSuchItemStateException, ItemStateException {
return stateMgr.getNodeReferences(id);
}
/**
* {@inheritDoc}
*/
public boolean hasNodeReferences(NodeId id) {
return stateMgr.hasNodeReferences(id);
}
//--------------------------------------------< UpdatableItemStateManager >
/**
* {@inheritDoc}
*/
public void edit() throws IllegalStateException {
stateMgr.edit();
}
/**
* {@inheritDoc}
*/
public boolean inEditMode() {
return stateMgr.inEditMode();
}
/**
* {@inheritDoc}
*/
public NodeState createNew(NodeId id, Name nodeTypeName,
NodeId parentId)
throws IllegalStateException {
return stateMgr.createNew(id, nodeTypeName, parentId);
}
/**
* Customized variant of {@link #createNew(NodeId, Name, NodeId)} that
* connects the newly created persistent state with the transient state.
*/
public NodeState createNew(NodeState transientState)
throws IllegalStateException {
NodeState persistentState = createNew(transientState.getNodeId(),
transientState.getNodeTypeName(),
transientState.getParentId());
transientState.connect(persistentState);
return persistentState;
}
/**
* {@inheritDoc}
*/
public PropertyState createNew(Name propName, NodeId parentId)
throws IllegalStateException {
return stateMgr.createNew(propName, parentId);
}
/**
* Customized variant of {@link #createNew(Name, NodeId)} that
* connects the newly created persistent state with the transient state.
*/
public PropertyState createNew(PropertyState transientState)
throws IllegalStateException {
PropertyState persistentState = createNew(transientState.getName(),
transientState.getParentId());
transientState.connect(persistentState);
return persistentState;
}
/**
* {@inheritDoc}
*/
public void store(ItemState state) throws IllegalStateException {
stateMgr.store(state);
}
/**
* {@inheritDoc}
*/
public void destroy(ItemState state) throws IllegalStateException {
stateMgr.destroy(state);
}
/**
* {@inheritDoc}
*/
public void cancel() throws IllegalStateException {
stateMgr.cancel();
}
/**
* {@inheritDoc}
*/
public void update()
throws ReferentialIntegrityException, StaleItemStateException,
ItemStateException, IllegalStateException {
stateMgr.update();
}
/**
* {@inheritDoc}
*/
public void dispose() {
// remove hierarchy manager as listener to avoid
// unnecessary work during stateMgr.dispose()
removeListener(hierMgr);
// discard all transient changes
disposeAllTransientItemStates();
}
//< more methods for listing and retrieving transient ItemState instances >
/**
* @param id
* @return
* @throws NoSuchItemStateException
* @throws ItemStateException
*/
public ItemState getTransientItemState(ItemId id)
throws NoSuchItemStateException, ItemStateException {
ItemState state = transientStore.get(id);
if (state != null) {
return state;
} else {
throw new NoSuchItemStateException(id.toString());
}
}
/**
*
* @param id
* @return
*/
public boolean hasTransientItemState(ItemId id) {
return transientStore.containsKey(id);
}
/**
*
* @param id
* @return
*/
public boolean hasTransientItemStateInAttic(ItemId id) {
return atticStore.containsKey(id);
}
/**
* @return <code>true</code> if this manager has any transient state;
* <code>false</code> otherwise.
*/
public boolean hasAnyTransientItemStates() {
return !transientStore.isEmpty();
}
/**
* Returns a collection of those transient item state instances that are
* direct or indirect descendants of the item state with the given parent.
* The transient item state instance with the given identifier itself
* (if there is such) will not be included.
* <p>
* The instances are returned in depth-first tree traversal order.
*
* @param id identifier of the common parent of the transient item state
* instances to be returned
* @return collection of descendant transient item state instances
* @throws InvalidItemStateException if any descendant item state has been
* deleted externally
* @throws RepositoryException if another error occurs
*/
public Collection<ItemState> getDescendantTransientItemStates(ItemId id)
throws InvalidItemStateException, RepositoryException {
try {
return getDescendantItemStates(
id, transientStore, getAtticAwareHierarchyMgr());
} catch (ItemNotFoundException e) {
// one of the parents of the specified item has been
// removed externally; as we don't know its path,
// we can't determine if it is a descendant;
// InvalidItemStateException should only be thrown if
// a descendant is affected;
// => throw InvalidItemStateException for now (FIXME)
// unable to determine relative depth, assume that the item
// (or any of its ancestors) has been removed externally
throw new InvalidItemStateException(
"Item seems to have been removed externally", e);
}
}
/**
* Same as <code>{@link #getDescendantTransientItemStates(ItemId)}</code>
* except that item state instances in the attic are returned.
*
* @param id identifier of the common parent of the transient item state
* instances to be returned
* @return collection of descendant transient item state instances
* in the attic
*/
public Iterable<ItemState> getDescendantTransientItemStatesInAttic(
ItemId id) throws RepositoryException {
return getDescendantItemStates(
id, atticStore,
new ZombieHierarchyManager(hierMgr, this, getAttic()));
}
/**
* Utility method used by the
* {@link #getDescendantTransientItemStates(ItemId)} and
* {@link #getDescendantTransientItemStatesInAttic(ItemId)} methods
* to collect descendant item states from the given item state store.
*
* @param id identifier of the parent item
* @param store item state store
* @param hierarchyManager hierarchy manager associated with the store
* @return descendants of the identified item
* @throws RepositoryException if the descendants could not be accessed
*/
private List<ItemState> getDescendantItemStates(
ItemId id, Map<ItemId, ItemState> store,
HierarchyManager hierarchyManager) throws RepositoryException {
if (id.denotesNode() && !store.isEmpty()) {
// Group the descendants by reverse relative depth
SortedMap<Integer, Collection<ItemState>> statesByReverseDepth =
new TreeMap<Integer, Collection<ItemState>>();
for (ItemState state : store.values()) {
// determine relative depth: > 0 means it's a descendant
int depth = hierarchyManager.getShareRelativeDepth(
(NodeId) id, state.getId());
if (depth > 0) {
Collection<ItemState> statesAtDepth =
statesByReverseDepth.get(-depth);
if (statesAtDepth == null) {
statesAtDepth = new ArrayList<ItemState>();
statesByReverseDepth.put(-depth, statesAtDepth);
}
statesAtDepth.add(state);
}
}
// Collect the descendants in decreasing depth order
List<ItemState> descendants = new ArrayList<ItemState>();
for (Collection<ItemState> statesAtDepth
: statesByReverseDepth.values()) {
descendants.addAll(statesAtDepth);
}
return descendants;
} else {
return Collections.emptyList();
}
}
/**
* Returns the id of the root of the minimal subtree including all
* transient states.
*
* @return id of nearest common ancestor of all transient states or null
* if there's no transient state.
* @throws RepositoryException if an error occurs
*/
public NodeId getIdOfRootTransientNodeState() throws RepositoryException {
if (transientStore.isEmpty()) {
return null;
}
// short cut
if (transientStore.containsKey(hierMgr.getRootNodeId())) {
return hierMgr.getRootNodeId();
}
// the nearest common ancestor of all transient states
// must be either
// a) a node state with STATUS_EXISTING_MODIFIED, or
// b) the parent node of a property state with STATUS_EXISTING_MODIFIED
// collect all candidates based on above criteria
Collection<NodeId> candidateIds = new LinkedList<NodeId>();
try {
HierarchyManager hierMgr = getHierarchyMgr();
for (ItemState state : transientStore.values()) {
if (state.getStatus() == ItemState.STATUS_EXISTING_MODIFIED) {
NodeId nodeId;
if (state.isNode()) {
nodeId = (NodeId) state.getId();
} else {
nodeId = state.getParentId();
}
// remove any descendant candidates
boolean skip = false;
for (Iterator<NodeId> it = candidateIds.iterator(); it.hasNext();) {
NodeId id = it.next();
if (nodeId.equals(id) || hierMgr.isAncestor(id, nodeId)) {
// already a candidate or a descendant thereof
// => skip
skip = true;
break;
}
if (hierMgr.isAncestor(nodeId, id)) {
// candidate is a descendant => remove
it.remove();
}
}
if (!skip) {
// add to candidates
candidateIds.add(nodeId);
}
}
}
if (candidateIds.size() == 1) {
return candidateIds.iterator().next();
}
// pick (any) candidate with shortest path to start with
NodeId candidateId = null;
for (NodeId id : candidateIds) {
if (candidateId == null) {
candidateId = id;
} else {
if (hierMgr.getDepth(id) < hierMgr.getDepth(candidateId)) {
candidateId = id;
}
}
}
// starting with this candidate closest to root, find first parent
// which is an ancestor of all candidates
NodeState state = (NodeState) getItemState(candidateId);
NodeId parentId = state.getParentId();
boolean continueWithParent = false;
while (parentId != null) {
for (NodeId id : candidateIds) {
if (hierMgr.getRelativeDepth(parentId, id) == -1) {
continueWithParent = true;
break;
}
}
if (continueWithParent) {
state = (NodeState) getItemState(parentId);
parentId = state.getParentId();
continueWithParent = false;
} else {
break;
}
}
return parentId;
} catch (ItemStateException e) {
throw new RepositoryException("failed to determine common root of transient changes", e);
}
}
/**
* Return a flag indicating whether the specified item is in the transient
* item state manager's attic space.
*
* @param id item id
* @return <code>true</code> if the item state is in the attic space;
* <code>false</code> otherwise
*/
public boolean isItemStateInAttic(ItemId id) {
return atticStore.containsKey(id);
}
//------< methods for creating & discarding transient ItemState instances >
/**
* @param id
* @param nodeTypeName
* @param parentId
* @param initialStatus
* @return
* @throws ItemStateException
*/
public NodeState createTransientNodeState(NodeId id, Name nodeTypeName, NodeId parentId, int initialStatus)
throws ItemStateException {
// check map; synchronized to ensure an entry is not created twice.
synchronized (transientStore) {
if (transientStore.containsKey(id)) {
String msg = "there's already a node state instance with id " + id;
log.debug(msg);
throw new ItemStateException(msg);
}
NodeState state = new NodeState(id, nodeTypeName, parentId,
initialStatus, true);
// put transient state in the map
transientStore.put(state.getId(), state);
state.setContainer(this);
return state;
}
}
/**
* @param overlayedState
* @param initialStatus
* @return
* @throws ItemStateException
*/
public NodeState createTransientNodeState(NodeState overlayedState, int initialStatus)
throws ItemStateException {
ItemId id = overlayedState.getNodeId();
// check map; synchronized to ensure an entry is not created twice.
synchronized (transientStore) {
if (transientStore.containsKey(id)) {
String msg = "there's already a node state instance with id " + id;
log.debug(msg);
throw new ItemStateException(msg);
}
NodeState state = new NodeState(overlayedState, initialStatus, true);
// put transient state in the map
transientStore.put(id, state);
state.setContainer(this);
return state;
}
}
/**
* @param parentId
* @param propName
* @param initialStatus
* @return
* @throws ItemStateException
*/
public PropertyState createTransientPropertyState(NodeId parentId, Name propName, int initialStatus)
throws ItemStateException {
PropertyId id = new PropertyId(parentId, propName);
// check map; synchronized to ensure an entry is not created twice.
synchronized (transientStore) {
if (transientStore.containsKey(id)) {
String msg = "there's already a property state instance with id " + id;
log.debug(msg);
throw new ItemStateException(msg);
}
PropertyState state = new PropertyState(id, initialStatus, true);
// put transient state in the map
transientStore.put(id, state);
state.setContainer(this);
return state;
}
}
/**
* @param overlayedState
* @param initialStatus
* @return
* @throws ItemStateException
*/
public PropertyState createTransientPropertyState(PropertyState overlayedState, int initialStatus)
throws ItemStateException {
PropertyId id = overlayedState.getPropertyId();
// check map; synchronized to ensure an entry is not created twice.
synchronized (transientStore) {
if (transientStore.containsKey(id)) {
String msg = "there's already a property state instance with id " + id;
log.debug(msg);
throw new ItemStateException(msg);
}
PropertyState state = new PropertyState(overlayedState, initialStatus, true);
// put transient state in the map
transientStore.put(id, state);
state.setContainer(this);
return state;
}
}
/**
* Disconnect a transient item state from its underlying persistent state.
* Notifies the <code>HierarchyManager</code> about the changed identity.
*
* @param state the transient <code>ItemState</code> instance that should
* be disconnected
*/
public void disconnectTransientItemState(ItemState state) {
state.disconnect();
}
/**
* Disposes the specified transient item state instance, i.e. discards it
* and clears it from cache.
*
* @param state the transient <code>ItemState</code> instance that should
* be disposed
* @see ItemState#discard()
*/
public void disposeTransientItemState(ItemState state) {
// discard item state, this will invalidate the wrapping Item
// instance of the transient state
state.discard();
// remove from map
transientStore.remove(state.getId());
// give the instance a chance to prepare to get gc'ed
state.onDisposed();
}
/**
* Transfers the specified transient item state instance from the 'active'
* cache to the attic.
*
* @param state the transient <code>ItemState</code> instance that should
* be moved to the attic
*/
public void moveTransientItemStateToAttic(ItemState state) {
// remove from map
transientStore.remove(state.getId());
// add to attic
atticStore.put(state.getId(), state);
}
/**
* Disposes the specified transient item state instance in the attic, i.e.
* discards it and removes it from the attic.
*
* @param state the transient <code>ItemState</code> instance that should
* be disposed @see ItemState#discard()
*/
public void disposeTransientItemStateInAttic(ItemState state) {
// discard item state, this will invalidate the wrapping Item
// instance of the transient state
state.discard();
// remove from attic
atticStore.remove(state.getId());
// give the instance a chance to prepare to get gc'ed
state.onDisposed();
}
/**
* Disposes all transient item states in the cache and in the attic.
*/
public void disposeAllTransientItemStates() {
// dispose item states in transient map & attic
// (use temp collection to avoid ConcurrentModificationException)
Collection<ItemState> tmp = new ArrayList<ItemState>(transientStore.values());
for (ItemState state : tmp) {
disposeTransientItemState(state);
}
tmp = new ArrayList<ItemState>(atticStore.values());
for (ItemState state : tmp) {
disposeTransientItemStateInAttic(state);
}
}
/**
* Add an <code>ItemStateListener</code>
*
* @param listener the new listener to be informed on modifications
*/
public void addListener(ItemStateListener listener) {
dispatcher.addListener(listener);
}
/**
* Remove an <code>ItemStateListener</code>
*
* @param listener an existing listener
*/
public void removeListener(ItemStateListener listener) {
dispatcher.removeListener(listener);
}
/**
* Return the attic item state provider that holds all items
* moved into the attic.
*
* @return attic
*/
public ItemStateManager getAttic() {
if (attic == null) {
attic = new AtticItemStateManager();
}
return attic;
}
//----------------------------------------------------< ItemStateListener >
/**
* {@inheritDoc}
* <p/>
* Notification handler gets called for both transient states that this state manager
* has created, as well as states that were created by the local state manager
* we're listening to.
*/
public void stateCreated(ItemState created) {
ItemState visibleState = created;
if (created.getContainer() != this) {
// local state was created
ItemState transientState = transientStore.get(created.getId());
if (transientState != null) {
if (transientState.hasOverlayedState()) {
// underlying state has been permanently created
transientState.pull();
transientState.setStatus(ItemState.STATUS_EXISTING);
} else {
// this is a notification from another session
try {
ItemState local = stateMgr.getItemState(created.getId());
transientState.connect(local);
// update mod count
transientState.setModCount(local.getModCount());
transientState.setStatus(ItemState.STATUS_EXISTING_MODIFIED);
} catch (ItemStateException e) {
// something went wrong
transientState.setStatus(ItemState.STATUS_UNDEFINED);
}
}
visibleState = transientState;
}
}
dispatcher.notifyStateCreated(visibleState);
}
/**
* {@inheritDoc}
* <p/>
* Notification handler gets called for both transient states that this state manager
* has created, as well as states that were created by the local state manager
* we're listening to.
*/
public void stateModified(ItemState modified) {
ItemState visibleState = modified;
// JCR-2650: ignore external changes, they will be considered/merged on save().
dispatcher.notifyStateModified(visibleState);
}
/**
* {@inheritDoc}
* <p/>
* Notification handler gets called for both transient states that this state manager
* has created, as well as states that were created by the local state manager
* we're listening to.
*/
public void stateDestroyed(ItemState destroyed) {
ItemState visibleState = destroyed;
if (destroyed.getContainer() != this) {
// local state was destroyed
ItemState transientState = transientStore.get(destroyed.getId());
if (transientState != null) {
transientState.setStatus(ItemState.STATUS_STALE_DESTROYED);
visibleState = transientState;
} else {
// check attic
transientState = atticStore.get(destroyed.getId());
if (transientState != null) {
atticStore.remove(destroyed.getId());
transientState.onDisposed();
}
}
}
dispatcher.notifyStateDestroyed(visibleState);
}
/**
* {@inheritDoc}
* <p/>
* Notification handler gets called for both transient states that this state manager
* has created, as well as states that were created by the local state manager
* we're listening to.
*/
public void stateDiscarded(ItemState discarded) {
ItemState visibleState = discarded;
if (discarded.getContainer() != this) {
// local state was discarded
ItemState transientState = transientStore.get(discarded.getId());
if (transientState != null) {
transientState.setStatus(ItemState.STATUS_UNDEFINED);
visibleState = transientState;
}
}
dispatcher.notifyStateDiscarded(visibleState);
}
/**
* {@inheritDoc}
* <p/>
* Pass notification to listeners if a transient state was modified
* or if the local state is not overlayed.
*/
public void nodeAdded(NodeState state, Name name, int index, NodeId id) {
if (state.getContainer() == this
|| !transientStore.containsKey(state.getId())) {
dispatcher.notifyNodeAdded(state, name, index, id);
}
}
/**
* {@inheritDoc}
* <p/>
* Pass notification to listeners if a transient state was modified
* or if the local state is not overlayed.
*/
public void nodesReplaced(NodeState state) {
if (state.getContainer() == this
|| !transientStore.containsKey(state.getId())) {
dispatcher.notifyNodesReplaced(state);
}
}
/**
* {@inheritDoc}
* <p/>
* Pass notification to listeners if a transient state was modified
* or if the local state is not overlayed.
*/
public void nodeModified(NodeState state) {
if (state.getContainer() == this
|| !transientStore.containsKey(state.getId())) {
dispatcher.notifyNodeModified(state);
}
}
/**
* {@inheritDoc}
* <p/>
* Pass notification to listeners if a transient state was modified
* or if the local state is not overlayed.
*/
public void nodeRemoved(NodeState state, Name name, int index, NodeId id) {
if (state.getContainer() == this
|| !transientStore.containsKey(state.getId())) {
dispatcher.notifyNodeRemoved(state, name, index, id);
}
}
//--------------------------------------------------------< inner classes >
/**
* ItemStateManager view of the states in the attic
*
* @see SessionItemStateManager#getAttic
*/
private class AtticItemStateManager implements ItemStateManager {
/**
* {@inheritDoc}
*/
public ItemState getItemState(ItemId id)
throws NoSuchItemStateException, ItemStateException {
ItemState state = atticStore.get(id);
if (state != null) {
return state;
} else {
throw new NoSuchItemStateException(id.toString());
}
}
/**
* {@inheritDoc}
*/
public boolean hasItemState(ItemId id) {
return atticStore.containsKey(id);
}
/**
* {@inheritDoc}
*/
public NodeReferences getNodeReferences(NodeId id)
throws NoSuchItemStateException, ItemStateException {
// n/a
throw new ItemStateException("getNodeReferences() not implemented");
}
/**
* {@inheritDoc}
*/
public boolean hasNodeReferences(NodeId id) {
// n/a
return false;
}
}
}