Mercurial > hg > blitz_condensed
annotate src/org/dancres/blitz/entry/TupleLocator.java @ 34:6f68e94c1fb8 default tip
Add CondensedStats monitoring utility, equivalent to vmstat
author | Dominic Cleal <dominic-cleal@cdo2.com> |
---|---|
date | Thu, 05 Aug 2010 11:07:25 +0100 |
parents | 3dc0c5604566 |
children |
rev | line source |
---|---|
0
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
1 package org.dancres.blitz.entry; |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
2 |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
3 import java.io.IOException; |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
4 |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
5 import org.dancres.blitz.oid.OID; |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
6 |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
7 /** |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
8 All searches, whether they are performed in-memory or on-disk, result |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
9 in TupleLocators which are then used to iterate over the results. |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
10 Returned results are always UIDImpls which are then used to load |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
11 an appropriate EntrySleeve via SleeveCache (this ensures correct state is |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
12 maintained as the request to load a sleeve will make it's way into |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
13 an ArcCache then the WriteBuffer and then disk storage). |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
14 */ |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
15 public interface TupleLocator { |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
16 /** |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
17 Invoke this to load the next matching Tuple. |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
18 |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
19 @return <code>true</code> if there was a tuple, <code>false</code> |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
20 otherwise |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
21 */ |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
22 boolean fetchNext() throws IOException; |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
23 |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
24 /** |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
25 @return the OID of the tuple just fetched with |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
26 <code>fetchNext</code> |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
27 */ |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
28 OID getOID(); |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
29 |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
30 /** |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
31 When you've finished with the TupleLocator instance, call release. |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
32 */ |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
33 void release() throws IOException; |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
parents:
diff
changeset
|
34 } |