com.aspectran.core.component.session.SessionCache Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2019 The Aspectran Project
*
* 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.
*/
package com.aspectran.core.component.session;
import java.util.Set;
/**
* An interface for managing a set of Session objects pertaining to a context in memory.
*
* Created: 2017. 6. 24.
*/
public interface SessionCache {
int NEVER_EVICT = -1;
int EVICT_ON_SESSION_EXIT = 0;
int EVICT_ON_INACTIVITY = 1; // any number equal or greater is time in seconds
boolean isClustered();
int getMaxSessions();
/**
* Sets the maximum number of active sessions allowed in this session cache.
* The number of active sessions exceeds this limit, attempts to create new sessions
* will be rejected.
* If set to 0 (the default), there is no limit.
*
* @param maxSessions the maximum number of active sessions allowed in this session cache
*/
void setMaxSessions(int maxSessions);
int getEvictionIdleSecs();
/**
* Sessions in this cache can be:
*
* - never evicted
* - evicted once the last request exits
* - evicted after a configurable period of inactivity
*
*
* @param policy -1 is never evict; 0 is evict-on-exit; and any other positive
* value is the time in seconds that a session can be idle before it can
* be evicted.
*/
void setEvictionIdleSecs(int policy);
/**
* @return if true the newly created session will be saved immediately
*/
boolean isSaveOnCreate();
/**
* Whether or not a session that is newly created should be
* immediately saved. If false, a session that is created and
* invalidated within a single request is never persisted.
*
* @param saveOnCreate if true, immediately save the newly created session
*/
void setSaveOnCreate(boolean saveOnCreate);
/**
* @return true if the session should be saved before being evicted
*/
boolean isSaveOnInactiveEviction();
/**
* Whether or not a a session that is about to be evicted should
* be saved before being evicted.
*
* @param saveOnEvict if true, save the session before eviction
*/
void setSaveOnInactiveEviction(boolean saveOnEvict);
/**
* @return if true unloadable session will be deleted
*/
boolean isRemoveUnloadableSessions();
/**
* If the data for a session exists but is unreadable,
* the SessionCache can instruct the SessionStore to delete it.
*
* @param removeUnloadableSessions whether or not SessionCache will delete
* session data that can not be loaded from the SessionStore
*/
void setRemoveUnloadableSessions(boolean removeUnloadableSessions);
/**
* Get an existing Session. If necessary, the cache will load the data for
* the session from the configured SessionStore.
*
* @param id the session id
* @return the Session if one exists, null otherwise
* @throws Exception if an error occurs
*/
DefaultSession get(String id) throws Exception;
/**
* Add an entirely new session to the cache.
*
* @param id the session id
* @param time the timestamp of the session creation
* @param maxInactiveInterval the max inactive time in milliseconds
*/
DefaultSession add(String id, long time, long maxInactiveInterval) throws Exception;
/**
* Finish using a Session. This is called by the SessionHandler
* once a request is finished with a Session. SessionCache
* implementations may want to delay writing out Session contents
* until the last request exits a Session.
*
* @param id the session id
* @param session the session object
* @throws Exception if an error occurs
*/
void release(String id, DefaultSession session) throws Exception;
/**
* Check to see if a session exists: WILL consult the
* SessionStore.
*
* @param id the session id
* @return true if the session exists; false otherwise
* @throws Exception if an error occurs
*/
boolean exists(String id) throws Exception;
/**
* Check to see if a Session is in the cache. Does NOT consult
* the SessionStore.
*
* @param id the session id
* @return true if a Session object matching the id is present
* in the cache; false otherwise
* @throws Exception if an error occurs
*/
boolean contains(String id) throws Exception;
/**
* Remove a Session completely: from both this
* cache and the SessionStore.
*
* @param id the session id
* @return the Session that was removed, null otherwise
* @throws Exception if an error occurs when deleting a session
*/
DefaultSession delete(String id) throws Exception;
/**
* Change the id of a Session.
*
* @param oldId the current session id
* @param newId the new session id
* @return the Session after changing its id
* @throws Exception if any error occurred
*/
DefaultSession renewSessionId(String oldId, String newId) throws Exception;
/**
* Check a list of session ids that belong to potentially expired
* sessions. The Session in the cache should be checked,
* but also the SessionStore, as that is the authoritative
* source of all session information.
*
* @param candidates the session ids to check
* @return the set of session ids that have actually expired: this can
* be a superset of the original candidate list.
*/
Set checkExpiration(Set candidates);
/**
* Check a Session to see if it might be appropriate to
* evict or expire.
*
* @param session the session object
*/
void checkInactiveSession(DefaultSession session);
Set getAllSessions();
/**
* @return the number of sessions in the cache
*/
long getActiveSessionCount();
/**
* @return the max number of sessions in the cache
*/
long getHighestSessionCount();
/**
* @return a running total of sessions in the cache
*/
long getCreatedSessionCount();
long getExpiredSessionCount();
long getRejectedSessionCount();
/**
* Resets the running total session count in the cache.
*/
void resetStatistics();
void destroy();
}