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Java > Open Source Codes > com > caucho > db > store > XAWriteBlock


1 /*
2  * Copyright (c) 1998-2006 Caucho Technology -- all rights reserved
3  *
4  * This file is part of Resin(R) Open Source
5  *
6  * Each copy or derived work must preserve the copyright notice and this
7  * notice unmodified.
8  *
9  * Resin Open Source is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * Resin Open Source is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17  * of NON-INFRINGEMENT. See the GNU General Public License for more
18  * details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with Resin Open Source; if not, write to the
22  *
23  * Free Software Foundation, Inc.
24  * 59 Temple Place, Suite 330
25  * Boston, MA 02111-1307 USA
26  *
27  * @author Scott Ferguson
28  */
29
30 package com.caucho.db.store;
31
32 import com.caucho.log.Log;
33 import com.caucho.util.L10N;
34
35 import java.io.IOException JavaDoc;
36 import java.util.logging.Logger JavaDoc;
37
38 /**
39  * Represents a write (dirty) block.
40  */
41 public class XAWriteBlock extends WriteBlock {
42   private static final Logger JavaDoc log = Log.open(XAWriteBlock.class);
43   private static final L10N L = new L10N(XAWriteBlock.class);
44
45   private byte []_buffer;
46
47   public XAWriteBlock(Block block)
48     throws IOException JavaDoc
49   {
50     super(block);
51
52     _buffer = _freeBuffers.allocate();
53     if (_buffer == null)
54       _buffer = new byte[Store.BLOCK_SIZE];
55
56     block.read();
57
58     System.arraycopy(block.getBuffer(), 0, getBuffer(), 0, Store.BLOCK_SIZE);
59   }
60   
61   /**
62    * Returns the block's buffer.
63    */
64   public byte []getBuffer()
65   {
66     return _buffer;
67   }
68
69   public void writeImpl(int offset, int length)
70     throws IOException JavaDoc
71   {
72     System.arraycopy(getBuffer(), offset, _block.getBuffer(), offset,
73              length);
74     
75     _block.setDirty(offset, offset + length);
76     // _block.write();
77 }
78
79   /**
80    * Called when the block is removed from the cache.
81    */
82   protected void freeImpl()
83   {
84     synchronized (this) {
85       byte []buffer = _buffer;
86       _buffer = null;
87     
88       if (buffer != null)
89     _freeBuffers.free(buffer);
90     }
91   }
92
93   public String JavaDoc toString()
94   {
95     return "XAWriteBlock[" + getStore() + "," + getBlockId() / Store.BLOCK_SIZE + "]";
96   }
97 }
98
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