BIndex


1   package com.quadcap.sql.index;
2   
3   /* Copyright 1997 - 2003 Quadcap Software.  All rights reserved.
4    *
5    * This software is distributed under the Quadcap Free Software License.
6    * This software may be used or modified for any purpose, personal or
7    * commercial.  Open Source redistributions are permitted.  Commercial
8    * redistribution of larger works derived from, or works which bundle
9    * this software requires a "Commercial Redistribution License"; see
10   * http://www.quadcap.com/purchase.
11   *
12   * Redistributions qualify as "Open Source" under  one of the following terms:
13   *   
14   *    Redistributions are made at no charge beyond the reasonable cost of
15   *    materials and delivery.
16   *
17   *    Redistributions are accompanied by a copy of the Source Code or by an
18   *    irrevocable offer to provide a copy of the Source Code for up to three
19   *    years at the cost of materials and delivery.  Such redistributions
20   *    must allow further use, modification, and redistribution of the Source
21   *    Code under substantially the same terms as this license.
22   *
23   * Redistributions of source code must retain the copyright notices as they
24   * appear in each source code file, these license terms, and the
25   * disclaimer/limitation of liability set forth as paragraph 6 below.
26   *
27   * Redistributions in binary form must reproduce this Copyright Notice,
28   * these license terms, and the disclaimer/limitation of liability set
29   * forth as paragraph 6 below, in the documentation and/or other materials
30   * provided with the distribution.
31   *
32   * The Software is provided on an "AS IS" basis.  No warranty is
33   * provided that the Software is free of defects, or fit for a
34   * particular purpose.  
35   *
36   * Limitation of Liability. Quadcap Software shall not be liable
37   * for any damages suffered by the Licensee or any third party resulting
38   * from use of the Software.
39   */
40  
41  import java.io.IOException  ;
42  import java.util.Enumeration  ;
43  
44  /**
45   * An index is simply a map, with byte arrays as keys.
46   *
47   * @author Stan Bailes
48   */
49  public interface BIndex {
50      /**
51       * Return this index's comparator
52       */
53      public Comparator getComparator();
54  
55      /**
56       * Delete this index
57       */
58      public void free() throws IOException  ;
59  
60      /**
61       * Get the data bytes for the specified key.  If the key is found, return
62       * the length of the data portion and place as many bytes as will fit in the
63       * data array.  If the key isn't found, return -1.
64       */
65      public int get(byte[] key, int len, byte[] data) throws IOException  ;
66  
67      /**
68       * Delete the specified key.  Return true if the key was deleted.
69       */
70      public boolean delete(byte[] key) throws IOException  ;
71  
72      /**
73       * Add a new key.  If the index is a UNIQUE index, then
74       * the new key/data pair will only be added if the key does not already
75       * exist, otherwise, insert will do nothing and return <b>false</b>
76       * The existing value must not exist or an IOException will be thrown.
77       * Otherwise, the new key/data pair is added regardless.
78       */
79      public void insert(byte[] key, int klen,
80                            byte[] data, int off, int len) throws IOException  ;
81  
82      /**
83       * Update the data value for an existing key.  This only works for
84       * UNIQUE indexes, and only if the specified key already exists.
85       *
86       * @exception IOException may be thrown.
87       */
88      public void update(byte[] key, int klen,
89                         byte[] data, int off, int len) throws IOException  ;
90  
91      /**
92       * Set the key/data pair, replacing any any value it may present in
93       * a unique index, inserting a new values, whatever.  Return
94       * true if the key already existed before this operation.
95       */
96      public boolean set(byte[] key, int klen,
97                         byte[] data, int off, int len) throws IOException  ;
98  
99      /**
100      * Obtain a cursor for most wondrously manipulating this index.
101      */
102     public BCursor getCursor(boolean skipSetup) throws IOException  ;
103 
104 //      /**
105 //       * Close this index
106 //       */
107 //      public void close() throws IOException;
108 }
109
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