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Java > Open Source Codes > com > db4o > cs > LazyClientIdIterator


1 /* Copyright (C) 2004 - 2006 db4objects Inc. http://www.db4o.com
2
3 This file is part of the db4o open source object database.
4
5 db4o is free software; you can redistribute it and/or modify it under
6 the terms of version 2 of the GNU General Public License as published
7 by the Free Software Foundation and as clarified by db4objects' GPL
8 interpretation policy, available at
9 http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
10 Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
11 Suite 350, San Mateo, CA 94403, USA.
12
13 db4o is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21 package com.db4o.cs;
22
23 import com.db4o.*;
24 import com.db4o.foundation.*;
25
26
27 /**
28  * @exclude
29  */
30 public class LazyClientIdIterator implements IntIterator4{
31     
32     private final LazyClientQueryResult _queryResult;
33     
34     private int _current;
35     
36     private int[] _ids;
37     
38     private final int _batchSize;
39     
40     private int _available;
41     
42     public LazyClientIdIterator(LazyClientQueryResult queryResult){
43         _queryResult = queryResult;
44         _batchSize = queryResult.config().prefetchObjectCount();
45         _ids = new int[_batchSize];
46         _current = -1;
47     }
48
49     public int currentInt() {
50         if(_current < 0){
51             throw new IllegalStateException JavaDoc();
52         }
53         return _ids[_current];
54     }
55
56     public Object JavaDoc current() {
57         return new Integer JavaDoc(currentInt());
58     }
59
60     public boolean moveNext() {
61         if(_available < 0){
62             return false;
63         }
64         if(_available == 0){
65             _queryResult.fetchIDs(_batchSize);
66             _available --;
67             _current = 0;
68             return (_available > 0);
69         }
70         _current++;
71         _available --;
72         return true;
73     }
74
75     public void reset() {
76         _queryResult.reset();
77         _available = 0;
78         _current = -1;
79     }
80
81     public void loadFromIdReader(YapReader reader, int count) {
82         for (int i = 0; i < count; i++) {
83             _ids[i] = reader.readInt();
84         }
85         if(count > 0){
86             _available = count;
87             return;
88         }
89         _available = -1;
90     }
91
92 }
93
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