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1   package org.apache.velocity.runtime;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.    
20   */
21  
22  import org.apache.velocity.runtime.parser.Parser;
23  import org.apache.velocity.util.SimplePool;
24  
25  
26  /**
27   * This wraps the original parser SimplePool class.  It also handles
28   * instantiating ad-hoc parsers if none are available.
29   *
30   * @author <a href="mailto:sergek@lokitech.com">Serge Knystautas</a>
31   * @version $Id: RuntimeInstance.java 384374 2006-03-08 23:19:30Z nbubna $
32   */
33  public class ParserPoolImpl implements ParserPool {
34  
35      RuntimeServices rsvc = null;
36      SimplePool pool = null;
37      int max = RuntimeConstants.NUMBER_OF_PARSERS;
38  
39      /**
40       * Create the underlying "pool".
41       * @param rsvc
42       */
43      public void initialize(RuntimeServices rsvc)
44      {
45          this.rsvc = rsvc;
46          max = rsvc.getInt(RuntimeConstants.PARSER_POOL_SIZE, RuntimeConstants.NUMBER_OF_PARSERS);
47          pool = new SimplePool(max);
48  
49          for (int i = 0; i < max; i++)
50          {
51              pool.put(rsvc.createNewParser());
52          }
53  
54          if (rsvc.getLog().isDebugEnabled())
55          {
56              rsvc.getLog().debug("Created '" + max + "' parsers.");
57          }
58      }
59  
60      /**
61       * Call the wrapped pool.  If none are available, it will create a new
62       * temporary one.
63       * @return A parser Object.
64       */
65      public Parser get()
66      {
67          Parser parser = (Parser) pool.get();
68          if (parser == null)
69          {
70              rsvc.getLog().debug("Created new " +
71                      "parser (pool exhausted).  Consider " +
72                      "increasing pool size.");
73              parser = rsvc.createNewParser();
74          }
75          return parser;
76      }
77  
78      /**
79       * Call the wrapped pool.
80       * @param parser
81       */
82      public void put(Parser parser)
83      {
84          pool.put(parser);
85      }
86  }