/*
* 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.wicket.page;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;
import org.apache.wicket.pageStore.IPageStore;
/**
*
*/
public class PageStoreManager extends AbstractPageManager
{
/**
* A cache that holds all registered page managers. <br/>
* applicationName -> page manager
*/
private static final ConcurrentMap<String, PageStoreManager> MANAGERS = new ConcurrentHashMap<>();
private static final String ATTRIBUTE_NAME = "wicket:persistentPageManagerData";
private final IPageStore pageStore;
private final String applicationName;
/**
* Construct.
*
* @param applicationName
* @param pageStore
* @param context
*/
public PageStoreManager(final String applicationName, final IPageStore pageStore,
final IPageManagerContext context)
{
super(context);
this.applicationName = applicationName;
this.pageStore = pageStore;
if (MANAGERS.containsKey(applicationName))
{
throw new IllegalStateException("Manager for application with key '" + applicationName
+ "' already exists.");
}
MANAGERS.put(applicationName, this);
}
/**
* Represents entry for single session. This is stored as session attribute and caches pages
* between requests.
*
* @author Matej Knopp
*/
private static class SessionEntry implements Serializable, HttpSessionBindingListener
{
private static final long serialVersionUID = 1L;
private final String applicationName;
/**
* The id handed to the {@link IPageStore} to identify the session.
* <p>
* Note: If the container changes a session's id, this field remains unchanged on its
* initial value.
*/
private final String sessionId;
private transient List<IManageablePage> sessionCache;
private transient List<Object> afterReadObject;
/**
* Construct.
*
* @param applicationName
* @param sessionId
*/
public SessionEntry(String applicationName, String sessionId)
{
this.applicationName = applicationName;
this.sessionId = sessionId;
}
/**
*
* @return page store
*/
private IPageStore getPageStore()
{
PageStoreManager manager = MANAGERS.get(applicationName);
if (manager == null)
{
return null;
}
return manager.pageStore;
}
/**
*
* @param id
* @return null, if not found
*/
private IManageablePage findPage(int id)
{
for (IManageablePage p : sessionCache)
{
if (p.getPageId() == id)
{
return p;
}
}
return null;
}
/**
* Add the page to cached pages if page with same id is not already there
*
* @param page
*/
private void addPage(IManageablePage page)
{
if (page != null)
{
if (findPage(page.getPageId()) != null)
{
return;
}
sessionCache.add(page);
}
}
/**
* If the pages are stored in temporary state (after deserialization) this method convert
* them to list of "real" pages
*/
private void convertAfterReadObjects()
{
if (sessionCache == null)
{
sessionCache = new ArrayList<>();
}
for (Object o : afterReadObject)
{
IManageablePage page = getPageStore().convertToPage(o);
addPage(page);
}
afterReadObject = null;
}
/**
*
* @param id
* @return manageable page
*/
public synchronized IManageablePage getPage(int id)
{
// check if pages are in deserialized state
if (afterReadObject != null && afterReadObject.isEmpty() == false)
{
convertAfterReadObjects();
}
// try to find page with same id
if (sessionCache != null)
{
IManageablePage page = findPage(id);
if (page != null)
{
return page;
}
}
// not found, ask pagestore for the page
return getPageStore().getPage(sessionId, id);
}
/**
* set the list of pages to remember after the request
*
* @param pages
*/
public synchronized void setSessionCache(final List<IManageablePage> pages)
{
sessionCache = new ArrayList<>(pages);
afterReadObject = null;
}
/**
* Serializes all pages in this {@link SessionEntry}. If this is http worker thread then
* there is available {@link IPageStore} which will be asked to prepare the page for
* serialization (see DefaultPageStore$SerializePage). If there is no {@link IPageStore}
* available (session loading/persisting in application initialization/destruction thread)
* then the pages are serialized without any pre-processing
*
* @param s
* @throws IOException
*/
private void writeObject(final ObjectOutputStream s) throws IOException
{
s.defaultWriteObject();
// prepare for serialization and store the pages
List<Serializable> serializedPages = new ArrayList<Serializable>();
if (sessionCache != null)
{
IPageStore pageStore = getPageStore();
for (IManageablePage p : sessionCache)
{
Serializable preparedPage;
if (pageStore != null)
{
preparedPage = pageStore.prepareForSerialization(sessionId, p);
}
else
{
preparedPage = p;
}
if (preparedPage != null)
{
serializedPages.add(preparedPage);
}
}
}
s.writeObject(serializedPages);
}
/**
* Deserializes the pages in this {@link SessionEntry}. If this is http worker thread then
* there is available {@link IPageStore} which will be asked to restore the page from its
* optimized state (see DefaultPageStore$SerializePage). If there is no {@link IPageStore}
* available (session loading/persisting in application initialization/destruction thread)
* then the pages are deserialized without any post-processing
*
* @param s
* @throws IOException
* @throws ClassNotFoundException
*/
@SuppressWarnings("unchecked")
private void readObject(final ObjectInputStream s) throws IOException,
ClassNotFoundException
{
s.defaultReadObject();
afterReadObject = new ArrayList<>();
List<Serializable> l = (List<Serializable>)s.readObject();
// convert to temporary state after deserialization (will need to be processed
// by convertAfterReadObject before the pages can be accessed)
IPageStore pageStore = getPageStore();
for (Serializable ser : l)
{
Object page;
if (pageStore != null)
{
page = pageStore.restoreAfterSerialization(ser);
}
else
{
page = ser;
}
afterReadObject.add(page);
}
}
@Override
public void valueBound(HttpSessionBindingEvent event)
{
}
@Override
public void valueUnbound(HttpSessionBindingEvent event)
{
// WICKET-5164 use the original sessionId
IPageStore store = getPageStore();
// store might be null if destroyed already
if (store != null)
{
store.unbind(sessionId);
}
}
@Override
public boolean equals(Object o)
{
// see https://issues.apache.org/jira/browse/WICKET-5390
return false;
}
}
private String getAttributeName()
{
return ATTRIBUTE_NAME + " - " + applicationName;
}
/**
* {@link RequestAdapter} for {@link PageStoreManager}
*
* @author Matej Knopp
*/
protected class PersistentRequestAdapter extends RequestAdapter
{
/**
* Construct.
*
* @param context
*/
public PersistentRequestAdapter(IPageManagerContext context)
{
super(context);
}
@Override
protected IManageablePage getPage(int id)
{
IManageablePage touchedPage = findPage(id);
if (touchedPage != null)
{
return touchedPage;
}
// try to get session entry for this session
SessionEntry entry = getSessionEntry(false);
if (entry != null)
{
return entry.getPage(id);
}
else
{
return null;
}
}
/**
*
* @param create
* @return Session Entry
*/
private SessionEntry getSessionEntry(boolean create)
{
String attributeName = getAttributeName();
SessionEntry entry = (SessionEntry)getSessionAttribute(attributeName);
if (entry == null && create)
{
bind();
entry = new SessionEntry(applicationName, getSessionId());
setSessionAttribute(attributeName, entry);
}
return entry;
}
@Override
protected void newSessionCreated()
{
// if the session is not temporary bind a session entry to it
if (getSessionId() != null)
{
getSessionEntry(true);
}
}
@Override
protected void storeTouchedPages(final List<IManageablePage> touchedPages)
{
if (!touchedPages.isEmpty())
{
SessionEntry entry = getSessionEntry(true);
entry.setSessionCache(touchedPages);
for (IManageablePage page : touchedPages)
{
// WICKET-5103 use the same sessionId as used in SessionEntry#getPage()
pageStore.storePage(entry.sessionId, page);
}
}
}
}
@Override
protected RequestAdapter newRequestAdapter(IPageManagerContext context)
{
return new PersistentRequestAdapter(context);
}
@Override
public boolean supportsVersioning()
{
return true;
}
@Override
public void clear()
{
RequestAdapter requestAdapter = getRequestAdapter();
String sessionEntryAttributeName = getAttributeName();
Serializable sessionEntry = requestAdapter.getSessionAttribute(sessionEntryAttributeName);
if (sessionEntry instanceof SessionEntry)
{
((SessionEntry)sessionEntry).valueUnbound(null);
}
}
@Override
public void destroy()
{
MANAGERS.remove(applicationName);
pageStore.destroy();
}
}