| /* |
| * Copyright 1999,2004 The Apache Software Foundation. |
| * |
| * 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 org.apache.jasper.runtime; |
| |
| import java.util.Enumeration; |
| import java.util.Vector; |
| |
| import javax.servlet.ServletConfig; |
| import javax.servlet.jsp.JspException; |
| import javax.servlet.jsp.tagext.Tag; |
| |
| import org.apache.jasper.Constants; |
| |
| /** |
| * Thread-local based pool of tag handlers that can be reused. |
| * |
| * @author Jan Luehe |
| * @author Costin Manolache |
| */ |
| public class PerThreadTagHandlerPool extends TagHandlerPool { |
| |
| private int maxSize; |
| |
| // For cleanup |
| private Vector perThreadDataVector; |
| |
| private ThreadLocal perThread; |
| |
| private static class PerThreadData { |
| Tag handlers[]; |
| int current; |
| } |
| |
| /** |
| * Constructs a tag handler pool with the default capacity. |
| */ |
| public PerThreadTagHandlerPool() { |
| super(); |
| perThreadDataVector = new Vector(); |
| } |
| |
| protected void init(ServletConfig config) { |
| maxSize = Constants.MAX_POOL_SIZE; |
| String maxSizeS = getOption(config, OPTION_MAXSIZE, null); |
| if (maxSizeS != null) { |
| maxSize = Integer.parseInt(maxSizeS); |
| if (maxSize < 0) { |
| maxSize = Constants.MAX_POOL_SIZE; |
| } |
| } |
| |
| perThread = new ThreadLocal() { |
| protected Object initialValue() { |
| PerThreadData ptd = new PerThreadData(); |
| ptd.handlers = new Tag[maxSize]; |
| ptd.current = -1; |
| perThreadDataVector.addElement(ptd); |
| return ptd; |
| } |
| }; |
| } |
| |
| /** |
| * Gets the next available tag handler from this tag handler pool, |
| * instantiating one if this tag handler pool is empty. |
| * |
| * @param handlerClass Tag handler class |
| * |
| * @return Reused or newly instantiated tag handler |
| * |
| * @throws JspException if a tag handler cannot be instantiated |
| */ |
| public Tag get(Class handlerClass) throws JspException { |
| PerThreadData ptd = (PerThreadData)perThread.get(); |
| if(ptd.current >=0 ) { |
| return ptd.handlers[ptd.current--]; |
| } else { |
| try { |
| return (Tag) handlerClass.newInstance(); |
| } catch (Exception e) { |
| throw new JspException(e.getMessage(), e); |
| } |
| } |
| } |
| |
| /** |
| * Adds the given tag handler to this tag handler pool, unless this tag |
| * handler pool has already reached its capacity, in which case the tag |
| * handler's release() method is called. |
| * |
| * @param handler Tag handler to add to this tag handler pool |
| */ |
| public void reuse(Tag handler) { |
| PerThreadData ptd=(PerThreadData)perThread.get(); |
| if (ptd.current < (ptd.handlers.length - 1)) { |
| ptd.handlers[++ptd.current] = handler; |
| } else { |
| handler.release(); |
| } |
| } |
| |
| /** |
| * Calls the release() method of all tag handlers in this tag handler pool. |
| */ |
| public void release() { |
| Enumeration enumeration = perThreadDataVector.elements(); |
| while (enumeration.hasMoreElements()) { |
| PerThreadData ptd = (PerThreadData)enumeration.nextElement(); |
| if (ptd.handlers != null) { |
| for (int i=ptd.current; i>=0; i--) { |
| if (ptd.handlers[i] != null) { |
| ptd.handlers[i].release(); |
| } |
| } |
| } |
| } |
| } |
| } |
| |