blob: 0bb6537930922ef25c8e52e2fe1f404991862048 (
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
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
|
/*
*
* 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.queue;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
/**
* Distributes messages among a list of subsscription managers, using their
* weighting.
*
*/
class NestedSubscriptionManager implements SubscriptionManager
{
private final List<WeightedSubscriptionManager> _subscribers = new CopyOnWriteArrayList<WeightedSubscriptionManager>();
private int _iterations;
private int _index;
void addSubscription(WeightedSubscriptionManager s)
{
_subscribers.add(s);
}
void removeSubscription(WeightedSubscriptionManager s)
{
_subscribers.remove(s);
}
public boolean hasActiveSubscribers()
{
for(WeightedSubscriptionManager s : _subscribers)
{
if(s.hasActiveSubscribers())
{
return true;
}
}
return false;
}
public Subscription nextSubscriber(AMQMessage msg)
{
WeightedSubscriptionManager start = current();
for(WeightedSubscriptionManager s = start; s != null; s = next(start))
{
if(hasMore(s))
{
return nextSubscriber(s);
}
}
return null;
}
private Subscription nextSubscriber(WeightedSubscriptionManager s)
{
_iterations++;
return s.nextSubscriber(null);
}
private WeightedSubscriptionManager current()
{
return _subscribers.isEmpty() ? null : _subscribers.get(_index);
}
private boolean hasMore(WeightedSubscriptionManager s)
{
return _iterations < s.getWeight();
}
private WeightedSubscriptionManager next(WeightedSubscriptionManager start)
{
WeightedSubscriptionManager s = next();
return s == start && !hasMore(s) ? null : s;
}
private WeightedSubscriptionManager next()
{
_iterations = 0;
if(++_index >= _subscribers.size())
{
_index = 0;
}
return _subscribers.get(_index);
}
}
|
