1    
2    /* ====================================================================
3     * The Apache Software License, Version 1.1
4     *
5     * Copyright (c) 2002 The Apache Software Foundation.  All rights
6     * reserved.
7     *
8     * Redistribution and use in source and binary forms, with or without
9     * modification, are permitted provided that the following conditions
10    * are met:
11    *
12    * 1. Redistributions of source code must retain the above copyright
13    *    notice, this list of conditions and the following disclaimer.
14    *
15    * 2. Redistributions in binary form must reproduce the above copyright
16    *    notice, this list of conditions and the following disclaimer in
17    *    the documentation and/or other materials provided with the
18    *    distribution.
19    *
20    * 3. The end-user documentation included with the redistribution,
21    *    if any, must include the following acknowledgment:
22    *       "This product includes software developed by the
23    *        Apache Software Foundation (http://www.apache.org/)."
24    *    Alternately, this acknowledgment may appear in the software itself,
25    *    if and wherever such third-party acknowledgments normally appear.
26    *
27    * 4. The names "Apache" and "Apache Software Foundation" and
28    *    "Apache POI" must not be used to endorse or promote products
29    *    derived from this software without prior written permission. For
30    *    written permission, please contact apache@apache.org.
31    *
32    * 5. Products derived from this software may not be called "Apache",
33    *    "Apache POI", nor may "Apache" appear in their name, without
34    *    prior written permission of the Apache Software Foundation.
35    *
36    * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
37    * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
38    * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
39    * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
40    * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41    * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
42    * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
43    * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
44    * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
45    * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
46    * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47    * SUCH DAMAGE.
48    * ====================================================================
49    *
50    * This software consists of voluntary contributions made by many
51    * individuals on behalf of the Apache Software Foundation.  For more
52    * information on the Apache Software Foundation, please see
53    * <http://www.apache.org/>.
54    */
55   
56   package org.apache.poi.poifs.storage;
57   
58   import java.io.*;
59   
60   import java.util.*;
61   
62   /**
63    * A simple implementation of BlockList
64    *
65    * @author Marc Johnson (mjohnson at apache dot org
66    */
67   
68   class BlockListImpl
69       implements BlockList
70   {
71       private ListManagedBlock[]         _blocks;
72       private BlockAllocationTableReader _bat;
73   
74       /**
75        * Constructor BlockListImpl
76        */
77   
78       protected BlockListImpl()
79       {
80           _blocks = new ListManagedBlock[ 0 ];
81           _bat    = null;
82       }
83   
84       /**
85        * provide blocks to manage
86        *
87        * @param blocks blocks to be managed
88        */
89   
90       protected void setBlocks(final ListManagedBlock [] blocks)
91       {
92           _blocks = blocks;
93       }
94   
95       /* ********** START implementation of BlockList ********** */
96   
97       /**
98        * remove the specified block from the list
99        *
100       * @param index the index of the specified block; if the index is
101       *              out of range, that's ok
102       */
103  
104      public void zap(final int index)
105      {
106          if ((index >= 0) && (index < _blocks.length))
107          {
108              _blocks[ index ] = null;
109          }
110      }
111  
112      /**
113       * remove and return the specified block from the list
114       *
115       * @param index the index of the specified block
116       *
117       * @return the specified block
118       *
119       * @exception IOException if the index is out of range or has
120       *            already been removed
121       */
122  
123      public ListManagedBlock remove(final int index)
124          throws IOException
125      {
126          ListManagedBlock result = null;
127  
128          try
129          {
130              result = _blocks[ index ];
131              if (result == null)
132              {
133                  throw new IOException("block[ " + index
134                                        + " ] already removed");
135              }
136              _blocks[ index ] = null;
137          }
138          catch (ArrayIndexOutOfBoundsException ignored)
139          {
140              throw new IOException("Cannot remove block[ " + index
141                                    + " ]; out of range");
142          }
143          return result;
144      }
145  
146      /**
147       * get the blocks making up a particular stream in the list. The
148       * blocks are removed from the list.
149       *
150       * @param startBlock the index of the first block in the stream
151       *
152       * @return the stream as an array of correctly ordered blocks
153       *
154       * @exception IOException if blocks are missing
155       */
156  
157      public ListManagedBlock [] fetchBlocks(final int startBlock)
158          throws IOException
159      {
160          if (_bat == null)
161          {
162              throw new IOException(
163                  "Improperly initialized list: no block allocation table provided");
164          }
165          return _bat.fetchBlocks(startBlock, this);
166      }
167  
168      /**
169       * set the associated BlockAllocationTable
170       *
171       * @param bat the associated BlockAllocationTable
172       *
173       * @exception IOException
174       */
175  
176      public void setBAT(final BlockAllocationTableReader bat)
177          throws IOException
178      {
179          if (_bat != null)
180          {
181              throw new IOException(
182                  "Attempt to replace existing BlockAllocationTable");
183          }
184          _bat = bat;
185      }
186  
187      /* **********  END  implementation of BlockList ********** */
188  }   // end package-scope class BlockListImpl
189  
190