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comparison src/org/dancres/blitz/entry/TupleLocator.java @ 0:3dc0c5604566

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Initial checkin of blitz 2.0 fcs - no installer yet.
author Dan Creswell <dan.creswell@gmail.com>
date Sat, 21 Mar 2009 11:00:06 +0000
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-1:000000000000 0:3dc0c5604566
1 package org.dancres.blitz.entry;
2
3 import java.io.IOException;
4
5 import org.dancres.blitz.oid.OID;
6
7 /**
8 All searches, whether they are performed in-memory or on-disk, result
9 in TupleLocators which are then used to iterate over the results.
10 Returned results are always UIDImpls which are then used to load
11 an appropriate EntrySleeve via SleeveCache (this ensures correct state is
12 maintained as the request to load a sleeve will make it's way into
13 an ArcCache then the WriteBuffer and then disk storage).
14 */
15 public interface TupleLocator {
16 /**
17 Invoke this to load the next matching Tuple.
18
19 @return <code>true</code> if there was a tuple, <code>false</code>
20 otherwise
21 */
22 boolean fetchNext() throws IOException;
23
24 /**
25 @return the OID of the tuple just fetched with
26 <code>fetchNext</code>
27 */
28 OID getOID();
29
30 /**
31 When you've finished with the TupleLocator instance, call release.
32 */
33 void release() throws IOException;
34 }