blob: f3f6d2122f89e4d65153f77e746710f36a83f8f2 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
/*
*
* Copyright (c) 2006 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.qpid.server.txn;
import org.apache.qpid.AMQException;
/**
* This provides the abstraction of an individual operation within a
* transaction. It is used by the TxnBuffer class.
*/
public interface TxnOp
{
/**
* Do the part of the operation that updates persistent state
*/
public void prepare() throws AMQException;
/**
* Complete the operation started by prepare. Can now update in
* memory state or make netork transfers.
*/
public void commit();
/**
* This is not the same as rollback. Unfortunately the use of an
* in memory reference count as a locking mechanism and a test for
* whether a message should be deleted means that as things are,
* handling an acknowledgement unavoidably alters both memory and
* persistent state on prepare. This is needed to 'compensate' or
* undo the in-memory change if the peristent update of later ops
* fails.
*/
public void undoPrepare();
/**
* Rolls back the operation.
*/
public void rollback();
}
|
