/*

  * Copyright 2004-2011 the Seasar Foundation and the Others.

  *

  * 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 javax.faces.internal.scope;

 import java.util.Collections;

 import java.util.HashMap;

 import java.util.Map;

 import javax.faces.FacesException;

 import javax.faces.context.ExternalContext;

 import javax.faces.context.FacesContext;

 import javax.faces.internal.WindowIdUtil;

 import org.seasar.framework.util.LruHashMap;

 /**

  * @author higa

  *

  */

 public class VariableScope {

     private String key;

     private int windowSize = 20;

     public VariableScope(String key) {

         this.key = key;

     }

     public VariableScope(String key, int windowSize) {

         this.key = key;

         this.windowSize = windowSize;

     }

     public Map getContext(FacesContext context) throws FacesException {

         ExternalContext extCtx = context.getExternalContext();

         Map contexts = getContexts(extCtx);

         String wid = WindowIdUtil.getWindowId(extCtx);

         return (Map) contexts.get(wid);

     }

     public synchronized Map getOrCreateContext(FacesContext context)

             throws FacesException {

         ExternalContext extCtx = context.getExternalContext();

         Map contexts = getContexts(extCtx);

         String wid = WindowIdUtil.getWindowId(extCtx);

         Map ctx = (Map) contexts.get(wid);

         if (ctx == null) {

             ctx = new HashMap();

             contexts.put(wid, ctx);

         }

         return ctx;

     }

     public void removeContext(FacesContext context) throws FacesException {

         ExternalContext extCtx = context.getExternalContext();

         String wid = WindowIdUtil.getWindowId(extCtx);

         removeContext(context, wid);

     }

     public void removeContext(FacesContext context, String wid)

             throws FacesException {

         ExternalContext extCtx = context.getExternalContext();

         Map contexts = getContexts(extCtx);

         contexts.remove(wid);

     }

     public void clearContext(FacesContext context) throws FacesException {

         ExternalContext extCtx = context.getExternalContext();

         String wid = WindowIdUtil.getWindowId(extCtx);

         clearContext(context, wid);

     }

     public void clearContext(FacesContext context, String wid)

             throws FacesException {

         ExternalContext extCtx = context.getExternalContext();

         Map contexts = getContexts(extCtx);

         Map m = (Map) contexts.get(wid);

         if (m != null) {

             m.clear();

         }

     }

     protected synchronized Map getContexts(ExternalContext externalContext)

             throws FacesException {

         Map sessionMap = externalContext.getSessionMap();

         Map contexts = (Map) sessionMap.get(key);

         if (contexts == null) {

             contexts = Collections.synchronizedMap(new LruHashMap(windowSize));

             sessionMap.put(key, contexts);

         }

         return contexts;

     }

 }