/*
* 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.catalina.session;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.IOException;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import org.apache.catalina.Container;
import org.apache.catalina.Context;
import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.LifecycleListener;
import org.apache.catalina.Session;
import org.apache.catalina.Store;
import org.apache.catalina.util.LifecycleSupport;
import org.apache.catalina.security.SecurityUtil;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
/**
* Extends the <b>ManagerBase</b> class to implement most of the
* functionality required by a Manager which supports any kind of
* persistence, even if onlyfor restarts.
* <p>
* <b>IMPLEMENTATION NOTE</b>: Correct behavior of session storing and
* reloading depends upon external calls to the <code>start()</code> and
* <code>stop()</code> methods of this class at the correct times.
*
* @author Craig R. McClanahan
* @author Jean-Francois Arcand
* @version $Revision: 467222 $ $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
*/
public abstract class PersistentManagerBase
extends ManagerBase
implements Lifecycle, PropertyChangeListener {
private static Log log = LogFactory.getLog(PersistentManagerBase.class);
// ---------------------------------------------------- Security Classes
private class PrivilegedStoreClear
implements PrivilegedExceptionAction {
PrivilegedStoreClear() {
}
public Object run() throws Exception{
store.clear();
return null;
}
}
private class PrivilegedStoreRemove
implements PrivilegedExceptionAction {
private String id;
PrivilegedStoreRemove(String id) {
this.id = id;
}
public Object run() throws Exception{
store.remove(id);
return null;
}
}
private class PrivilegedStoreLoad
implements PrivilegedExceptionAction {
private String id;
PrivilegedStoreLoad(String id) {
this.id = id;
}
public Object run() throws Exception{
return store.load(id);
}
}
private class PrivilegedStoreSave
implements PrivilegedExceptionAction {
private Session session;
PrivilegedStoreSave(Session session) {
this.session = session;
}
public Object run() throws Exception{
store.save(session);
return null;
}
}
private class PrivilegedStoreKeys
implements PrivilegedExceptionAction {
PrivilegedStoreKeys() {
}
public Object run() throws Exception{
return store.keys();
}
}
// ----------------------------------------------------- Instance Variables
/**
* The descriptive information about this implementation.
*/
private static final String info = "PersistentManagerBase/1.1";
/**
* The lifecycle event support for this component.
*/
protected LifecycleSupport lifecycle = new LifecycleSupport(this);
/**
* The maximum number of active Sessions allowed, or -1 for no limit.
*/
protected int maxActiveSessions = -1;
/**
* The descriptive name of this Manager implementation (for logging).
*/
private static String name = "PersistentManagerBase";
/**
* Has this component been started yet?
*/
protected boolean started = false;
/**
* Store object which will manage the Session store.
*/
protected Store store = null;
/**
* Whether to save and reload sessions when the Manager <code>unload</code>
* and <code>load</code> methods are called.
*/
protected boolean saveOnRestart = true;
/**
* How long a session must be idle before it should be backed up.
* -1 means sessions won't be backed up.
*/
protected int maxIdleBackup = -1;
/**
* Minimum time a session must be idle before it is swapped to disk.
* This overrides maxActiveSessions, to prevent thrashing if there are lots
* of active sessions. Setting to -1 means it's ignored.
*/
protected int minIdleSwap = -1;
/**
* The maximum time a session may be idle before it should be swapped
* to file just on general principle. Setting this to -1 means sessions
* should not be forced out.
*/
protected int maxIdleSwap = -1;
/**
* Number of session creations that failed due to maxActiveSessions.
*/
protected int rejectedSessions = 0;
/**
* Processing time during session expiration and passivation.
*/
protected long processingTime = 0;
// ------------------------------------------------------------- Properties
/**
* Indicates how many seconds old a session can get, after its last use in a
* request, before it should be backed up to the store. -1 means sessions
* are not backed up.
*/
public int getMaxIdleBackup() {
return maxIdleBackup;
}
/**
* Sets the option to back sessions up to the Store after they
* are used in a request. Sessions remain available in memory
* after being backed up, so they are not passivated as they are
* when swapped out. The value set indicates how old a session
* may get (since its last use) before it must be backed up: -1
* means sessions are not backed up.
* <p>
* Note that this is not a hard limit: sessions are checked
* against this age limit periodically according to <b>processExpiresFrequency</b>.
* This value should be considered to indicate when a session is
* ripe for backing up.
* <p>
* So it is possible that a session may be idle for maxIdleBackup +
* processExpiresFrequency * engine.backgroundProcessorDelay seconds, plus the time it takes to handle other
* session expiration, swapping, etc. tasks.
*
* @param backup The number of seconds after their last accessed
* time when they should be written to the Store.
*/
public void setMaxIdleBackup (int backup) {
if (backup == this.maxIdleBackup)
return;
int oldBackup = this.maxIdleBackup;
this.maxIdleBackup = backup;
support.firePropertyChange("maxIdleBackup",
new Integer(oldBackup),
new Integer(this.maxIdleBackup));
}
/**
* The time in seconds after which a session should be swapped out of
* memory to disk.
*/
public int getMaxIdleSwap() {
return maxIdleSwap;
}
/**
* Sets the time in seconds after which a session should be swapped out of
* memory to disk.
*/
public void setMaxIdleSwap(int max) {
if (max == this.maxIdleSwap)
return;
int oldMaxIdleSwap = this.maxIdleSwap;
this.maxIdleSwap = max;
support.firePropertyChange("maxIdleSwap",
new Integer(oldMaxIdleSwap),
new Integer(this.maxIdleSwap));
}
/**
* The minimum time in seconds that a session must be idle before
* it can be swapped out of memory, or -1 if it can be swapped out
* at any time.
*/
public int getMinIdleSwap() {
return minIdleSwap;
}
/**
* Sets the minimum time in seconds that a session must be idle before
* it can be swapped out of memory due to maxActiveSession. Set it to -1
* if it can be swapped out at any time.
*/
public void setMinIdleSwap(int min) {
if (this.minIdleSwap == min)
return;
int oldMinIdleSwap = this.minIdleSwap;
this.minIdleSwap = min;
support.firePropertyChange("minIdleSwap",
new Integer(oldMinIdleSwap),
new Integer(this.minIdleSwap));
}
/**
* Set the Container with which this Manager has been associated. If it is a
* Context (the usual case), listen for changes to the session timeout
* property.
*
* @param container
* The associated Container
*/
public void setContainer(Container container) {
// De-register from the old Container (if any)
if ((this.container != null) && (this.container instanceof Context))
((Context) this.container).removePropertyChangeListener(this);
// Default processing provided by our superclass
super.setContainer(container);
// Register with the new Container (if any)
if ((this.container != null) && (this.container instanceof Context)) {
setMaxInactiveInterval
( ((Context) this.container).getSessionTimeout()*60 );
((Context) this.container).addPropertyChangeListener(this);
}
}
/**
* Return descriptive information about this Manager implementation and
* the corresponding version number, in the format
* <code><description>/<version></code>.
*/
public String getInfo() {
return (info);
}
/**
* Return true, if the session id is loaded in memory
* otherwise false is returned
*
* @param id The session id for the session to be searched for
*/
public boolean isLoaded( String id ){
try {
if ( super.findSession(id) != null )
return true;
} catch (IOException e) {
log.error("checking isLoaded for id, " + id + ", "+e.getMessage(), e);
}
return false;
}
/**
* Return the maximum number of active Sessions allowed, or -1 for
* no limit.
*/
public int getMaxActiveSessions() {
return (this.maxActiveSessions);
}
/**
* Set the maximum number of actives Sessions allowed, or -1 for
* no limit.
*
* @param max The new maximum number of sessions
*/
public void setMaxActiveSessions(int max) {
int oldMaxActiveSessions = this.maxActiveSessions;
this.maxActiveSessions = max;
support.firePropertyChange("maxActiveSessions",
new Integer(oldMaxActiveSessions),
new Integer(this.maxActiveSessions));
}
/**
* Number of session creations that failed due to maxActiveSessions.
*
* @return The count
*/
public int getRejectedSessions() {
return rejectedSessions;
}
public void setRejectedSessions(int rejectedSessions) {
this.rejectedSessions = rejectedSessions;
}
/**
* Return the descriptive short name of this Manager implementation.
*/
public String getName() {
return (name);
}
/**
* Get the started status.
*/
protected boolean isStarted() {
return started;
}
/**
* Set the started flag
*/
protected void setStarted(boolean started) {
this.started = started;
}
/**
* Set the Store object which will manage persistent Session
* storage for this Manager.
*
* @param store the associated Store
*/
public void setStore(Store store) {
this.store = store;
store.setManager(this);
}
/**
* Return the Store object which manages persistent Session
* storage for this Manager.
*/
public Store getStore() {
return (this.store);
}
/**
* Indicates whether sessions are saved when the Manager is shut down
* properly. This requires the unload() method to be called.
*/
public boolean getSaveOnRestart() {
return saveOnRestart;
}
/**
* Set the option to save sessions to the Store when the Manager is
* shut down, then loaded when the Manager starts again. If set to
* false, any sessions found in the Store may still be picked up when
* the Manager is started again.
*
* @param saveOnRestart true if sessions should be saved on restart, false if
* they should be ignored.
*/
public void setSaveOnRestart(boolean saveOnRestart) {
if (saveOnRestart == this.saveOnRestart)
return;
boolean oldSaveOnRestart = this.saveOnRestart;
this.saveOnRestart = saveOnRestart;
support.firePropertyChange("saveOnRestart",
new Boolean(oldSaveOnRestart),
new Boolean(this.saveOnRestart));
}
// --------------------------------------------------------- Public Methods
/**
* Clear all sessions from the Store.
*/
public void clearStore() {
if (store == null)
return;
try {
if (SecurityUtil.isPackageProtectionEnabled()){
try{
AccessController.doPrivileged(new PrivilegedStoreClear());
}catch(PrivilegedActionException ex){
Exception exception = ex.getException();
log.error("Exception clearing the Store: " + exception);
exception.printStackTrace();
}
} else {
store.clear();
}
} catch (IOException e) {
log.error("Exception clearing the Store: " + e);
e.printStackTrace();
}
}
/**
* Implements the Manager interface, direct call to processExpires and processPersistenceChecks
*/
public void processExpires() {
long timeNow = System.currentTimeMillis();
Session sessions[] = findSessions();
int expireHere = 0 ;
if(log.isDebugEnabled())
log.debug("Start expire sessions " + getName() + " at " + timeNow + " sessioncount " + sessions.length);
for (int i = 0; i < sessions.length; i++) {
if (!sessions[i].isValid()) {
expiredSessions++;
expireHere++;
}
}
processPersistenceChecks();
if ((getStore() != null) && (getStore() instanceof StoreBase)) {
((StoreBase) getStore()).processExpires();
}
long timeEnd = System.currentTimeMillis();
if(log.isDebugEnabled())
log.debug("End expire sessions " + getName() + " processingTime " + (timeEnd - timeNow) + " expired sessions: " + expireHere);
processingTime += (timeEnd - timeNow);
}
/**
* Called by the background thread after active sessions have been checked
* for expiration, to allow sessions to be swapped out, backed up, etc.
*/
public void processPersistenceChecks() {
processMaxIdleSwaps();
processMaxActiveSwaps();
processMaxIdleBackups();
}
/**
* Return the active Session, associated with this Manager, with the
* specified session id (if any); otherwise return <code>null</code>.
* This method checks the persistence store if persistence is enabled,
* otherwise just uses the functionality from ManagerBase.
*
* @param id The session id for the session to be returned
*
* @exception IllegalStateException if a new session cannot be
* instantiated for any reason
* @exception IOException if an input/output error occurs while
* processing this request
*/
public Session findSession(String id) throws IOException {
Session session = super.findSession(id);
if (session != null)
return (session);
// See if the Session is in the Store
session = swapIn(id);
return (session);
}
/**
* Remove this Session from the active Sessions for this Manager,
* but not from the Store. (Used by the PersistentValve)
*
* @param session Session to be removed
*/
public void removeSuper(Session session) {
super.remove (session);
}
/**
* Load all sessions found in the persistence mechanism, assuming
* they are marked as valid and have not passed their expiration
* limit. If persistence is not supported, this method returns
* without doing anything.
* <p>
* Note that by default, this method is not called by the MiddleManager
* class. In order to use it, a subclass must specifically call it,
* for example in the start() and/or processPersistenceChecks() methods.
*/
public void load() {
// Initialize our internal data structures
sessions.clear();
if (store == null)
return;
String[] ids = null;
try {
if (SecurityUtil.isPackageProtectionEnabled()){
try{
ids = (String[])
AccessController.doPrivileged(new PrivilegedStoreKeys());
}catch(PrivilegedActionException ex){
Exception exception = ex.getException();
log.error("Exception in the Store during load: "
+ exception);
exception.printStackTrace();
}
} else {
ids = store.keys();
}
} catch (IOException e) {
log.error("Can't load sessions from store, " + e.getMessage(), e);
return;
}
int n = ids.length;
if (n == 0)
return;
if (log.isDebugEnabled())
log.debug(sm.getString("persistentManager.loading", String.valueOf(n)));
for (int i = 0; i < n; i++)
try {
swapIn(ids[i]);
} catch (IOException e) {
log.error("Failed load session from store, " + e.getMessage(), e);
}
}
/**
* Remove this Session from the active Sessions for this Manager,
* and from the Store.
*
* @param session Session to be removed
*/
public void remove(Session session) {
super.remove (session);
if (store != null){
removeSession(session.getIdInternal());
}
}
/**
* Remove this Session from the active Sessions for this Manager,
* and from the Store.
*
* @param id Session's id to be removed
*/
protected void removeSession(String id){
try {
if (SecurityUtil.isPackageProtectionEnabled()){
try{
AccessController.doPrivileged(new PrivilegedStoreRemove(id));
}catch(PrivilegedActionException ex){
Exception exception = ex.getException();
log.error("Exception in the Store during removeSession: "
+ exception);
exception.printStackTrace();
}
} else {
store.remove(id);
}
} catch (IOException e) {
log.error("Exception removing session " + e.getMessage());
e.printStackTrace();
}
}
/**
* Save all currently active sessions in the appropriate persistence
* mechanism, if any. If persistence is not supported, this method
* returns without doing anything.
* <p>
* Note that by default, this method is not called by the MiddleManager
* class. In order to use it, a subclass must specifically call it,
* for example in the stop() and/or processPersistenceChecks() methods.
*/
public void unload() {
if (store == null)
return;
Session sessions[] = findSessions();
int n = sessions.length;
if (n == 0)
return;
if (log.isDebugEnabled())
log.debug(sm.getString("persistentManager.unloading",
String.valueOf(n)));
for (int i = 0; i < n; i++)
try {
swapOut(sessions[i]);
} catch (IOException e) {
; // This is logged in writeSession()
}
}
// ------------------------------------------------------ Protected Methods
/**
* Look for a session in the Store and, if found, restore
* it in the Manager's list of active sessions if appropriate.
* The session will be removed from the Store after swapping
* in, but will not be added to the active session list if it
* is invalid or past its expiration.
*/
protected Session swapIn(String id) throws IOException {
if (store == null)
return null;
Session session = null;
try {
if (SecurityUtil.isPackageProtectionEnabled()){
try{
session = (Session)
AccessController.doPrivileged(new PrivilegedStoreLoad(id));
}catch(PrivilegedActionException ex){
Exception exception = ex.getException();
log.error("Exception in the Store during swapIn: "
+ exception);
if (exception instanceof IOException){
throw (IOException)exception;
} else if (exception instanceof ClassNotFoundException) {
throw (ClassNotFoundException)exception;
}
}
} else {
session = store.load(id);
}
} catch (ClassNotFoundException e) {
log.error(sm.getString("persistentManager.deserializeError", id, e));
throw new IllegalStateException
(sm.getString("persistentManager.deserializeError", id, e));
}
if (session == null)
return (null);
if (!session.isValid()) {
log.error("session swapped in is invalid or expired");
session.expire();
removeSession(id);
return (null);
}
if(log.isDebugEnabled())
log.debug(sm.getString("persistentManager.swapIn", id));
session.setManager(this);
// make sure the listeners know about it.
((StandardSession)session).tellNew();
add(session);
((StandardSession)session).activate();
session.endAccess();
return (session);
}
/**
* Remove the session from the Manager's list of active
* sessions and write it out to the Store. If the session
* is past its expiration or invalid, this method does
* nothing.
*
* @param session The Session to write out.
*/
protected void swapOut(Session session) throws IOException {
if (store == null || !session.isValid()) {
return;
}
((StandardSession)session).passivate();
writeSession(session);
super.remove(session);
session.recycle();
}
/**
* Write the provided session to the Store without modifying
* the copy in memory or triggering passivation events. Does
* nothing if the session is invalid or past its expiration.
*/
protected void writeSession(Session session) throws IOException {
if (store == null || !session.isValid()) {
return;
}
try {
if (SecurityUtil.isPackageProtectionEnabled()){
try{
AccessController.doPrivileged(new PrivilegedStoreSave(session));
}catch(PrivilegedActionException ex){
Exception exception = ex.getException();
log.error("Exception in the Store during writeSession: "
+ exception);
exception.printStackTrace();
}
} else {
store.save(session);
}
} catch (IOException e) {
log.error(sm.getString
("persistentManager.serializeError", session.getIdInternal(), e));
throw e;
}
}
// ------------------------------------------------------ Lifecycle Methods
/**
* Add a lifecycle event listener to this component.
*
* @param listener The listener to add
*/
public void addLifecycleListener(LifecycleListener listener) {
lifecycle.addLifecycleListener(listener);
}
/**
* Get the lifecycle listeners associated with this lifecycle. If this
* Lifecycle has no listeners registered, a zero-length array is returned.
*/
public LifecycleListener[] findLifecycleListeners() {
return lifecycle.findLifecycleListeners();
}
/**
* Remove a lifecycle event listener from this component.
*
* @param listener The listener to remove
*/
public void removeLifecycleListener(LifecycleListener listener) {
lifecycle.removeLifecycleListener(listener);
}
/**
* Prepare for the beginning of active use of the public methods of this
* component. This method should be called after <code>configure()</code>,
* and before any of the public methods of the component are utilized.
*
* @exception LifecycleException if this component detects a fatal error
* that prevents this component from being used
*/
public void start() throws LifecycleException {
// Validate and update our current component state
if (started) {
log.info(sm.getString("standardManager.alreadyStarted"));
return;
}
if( ! initialized )
init();
lifecycle.fireLifecycleEvent(START_EVENT, null);
started = true;
// Force initialization of the random number generator
if (log.isDebugEnabled())
log.debug("Force random number initialization starting");
String dummy = generateSessionId();
if (log.isDebugEnabled())
log.debug("Force random number initialization completed");
if (store == null)
log.error("No Store configured, persistence disabled");
else if (store instanceof Lifecycle)
((Lifecycle)store).start();
}
/**
* Gracefully terminate the active use of the public methods of this
* component. This method should be the last one called on a given
* instance of this component.
*
* @exception LifecycleException if this component detects a fatal error
* that needs to be reported
*/
public void stop() throws LifecycleException {
if (log.isDebugEnabled())
log.debug("Stopping");
// Validate and update our current component state
if (!isStarted()) {
log.info(sm.getString("standardManager.notStarted"));
return;
}
lifecycle.fireLifecycleEvent(STOP_EVENT, null);
setStarted(false);
if (getStore() != null && saveOnRestart) {
unload();
} else {
// Expire all active sessions
Session sessions[] = findSessions();
for (int i = 0; i < sessions.length; i++) {
StandardSession session = (StandardSession) sessions[i];
if (!session.isValid())
continue;
session.expire();
}
}
if (getStore() != null && getStore() instanceof Lifecycle)
((Lifecycle)getStore()).stop();
// Require a new random number generator if we are restarted
this.random = null;
if( initialized )
destroy();
}
// ----------------------------------------- PropertyChangeListener Methods
/**
* Process property change events from our associated Context.
*
* @param event The property change event that has occurred
*/
public void propertyChange(PropertyChangeEvent event) {
// Validate the source of this event
if (!(event.getSource() instanceof Context))
return;
Context context = (Context) event.getSource();
// Process a relevant property change
if (event.getPropertyName().equals("sessionTimeout")) {
try {
setMaxInactiveInterval
( ((Integer) event.getNewValue()).intValue()*60 );
} catch (NumberFormatException e) {
log.error(sm.getString("standardManager.sessionTimeout",
event.getNewValue().toString()));
}
}
}
// ------------------------------------------------------ Protected Methods
/**
* Swap idle sessions out to Store if they are idle too long.
*/
protected void processMaxIdleSwaps() {
if (!isStarted() || maxIdleSwap < 0)
return;
Session sessions[] = findSessions();
long timeNow = System.currentTimeMillis();
// Swap out all sessions idle longer than maxIdleSwap
// FIXME: What's preventing us from mangling a session during
// a request?
if (maxIdleSwap >= 0) {
for (int i = 0; i < sessions.length; i++) {
StandardSession session = (StandardSession) sessions[i];
if (!session.isValid())
continue;
int timeIdle = // Truncate, do not round up
(int) ((timeNow - session.getLastAccessedTime()) / 1000L);
if (timeIdle > maxIdleSwap && timeIdle > minIdleSwap) {
if (log.isDebugEnabled())
log.debug(sm.getString
("persistentManager.swapMaxIdle",
session.getIdInternal(), new Integer(timeIdle)));
try {
swapOut(session);
} catch (IOException e) {
; // This is logged in writeSession()
}
}
}
}
}
/**
* Swap idle sessions out to Store if too many are active
*/
protected void processMaxActiveSwaps() {
if (!isStarted() || getMaxActiveSessions() < 0)
return;
Session sessions[] = findSessions();
// FIXME: Smarter algorithm (LRU)
if (getMaxActiveSessions() >= sessions.length)
return;
if(log.isDebugEnabled())
log.debug(sm.getString
("persistentManager.tooManyActive",
new Integer(sessions.length)));
int toswap = sessions.length - getMaxActiveSessions();
long timeNow = System.currentTimeMillis();
for (int i = 0; i < sessions.length && toswap > 0; i++) {
int timeIdle = // Truncate, do not round up
(int) ((timeNow - sessions[i].getLastAccessedTime()) / 1000L);
if (timeIdle > minIdleSwap) {
if(log.isDebugEnabled())
log.debug(sm.getString
("persistentManager.swapTooManyActive",
sessions[i].getIdInternal(), new Integer(timeIdle)));
try {
swapOut(sessions[i]);
} catch (IOException e) {
; // This is logged in writeSession()
}
toswap--;
}
}
}
/**
* Back up idle sessions.
*/
protected void processMaxIdleBackups() {
if (!isStarted() || maxIdleBackup < 0)
return;
Session sessions[] = findSessions();
long timeNow = System.currentTimeMillis();
// Back up all sessions idle longer than maxIdleBackup
if (maxIdleBackup >= 0) {
for (int i = 0; i < sessions.length; i++) {
StandardSession session = (StandardSession) sessions[i];
if (!session.isValid())
continue;
int timeIdle = // Truncate, do not round up
(int) ((timeNow - session.getLastAccessedTime()) / 1000L);
if (timeIdle > maxIdleBackup) {
if (log.isDebugEnabled())
log.debug(sm.getString
("persistentManager.backupMaxIdle",
session.getIdInternal(), new Integer(timeIdle)));
try {
writeSession(session);
} catch (IOException e) {
; // This is logged in writeSession()
}
}
}
}
}
}
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