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
101
102
103
104
105
|
/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*
*/
#include "QueueReplica.h"
#include "QueueContext.h"
#include "PrettyId.h"
#include "qpid/broker/Queue.h"
#include "qpid/log/Statement.h"
#include <algorithm>
namespace qpid {
namespace cluster {
QueueReplica::QueueReplica(boost::shared_ptr<broker::Queue> q,
const MemberId& self_)
: queue(q), self(self_), context(QueueContext::get(*q))
{}
struct PrintSubscribers {
const QueueReplica::MemberQueue& mq;
MemberId self;
PrintSubscribers(const QueueReplica::MemberQueue& m, const MemberId& s) : mq(m), self(s) {}
};
std::ostream& operator<<(std::ostream& o, const PrintSubscribers& ps) {
for (QueueReplica::MemberQueue::const_iterator i = ps.mq.begin(); i != ps.mq.end(); ++i)
o << PrettyId(*i, ps.self) << " ";
return o;
}
std::ostream& operator<<(std::ostream& o, QueueOwnership s) {
static char* tags[] = { "UNSUBSCRIBED", "SUBSCRIBED", "SOLE_OWNER", "SHARED_OWNER" };
return o << tags[s];
}
std::ostream& operator<<(std::ostream& o, const QueueReplica& qr) {
o << qr.queue->getName() << "(" << qr.getState() << "): "
<< PrintSubscribers(qr.subscribers, qr.getSelf());
return o;
}
void QueueReplica::subscribe(const MemberId& member) {
QueueOwnership before = getState();
subscribers.push_back(member);
update(before);
}
void QueueReplica::unsubscribe(const MemberId& member) {
QueueOwnership before = getState();
MemberQueue::iterator i = std::remove(subscribers.begin(), subscribers.end(), member);
if (i != subscribers.end()) {
subscribers.erase(i, subscribers.end());
update(before);
}
}
void QueueReplica::resubscribe(const MemberId& member) {
if (member == subscribers.front()) { // FIXME aconway 2011-09-13: should be assert?
QueueOwnership before = getState();
subscribers.pop_front();
subscribers.push_back(member);
update(before);
}
}
void QueueReplica::update(QueueOwnership before) {
QPID_LOG(trace, "cluster: queue replica " << *this << " (was " << before << ")");
QueueOwnership after = getState();
if (before == after) return;
context->replicaState(after);
}
QueueOwnership QueueReplica::getState() const {
if (isOwner())
return (subscribers.size() > 1) ? SHARED_OWNER : SOLE_OWNER;
return (isSubscriber(self)) ? SUBSCRIBED : UNSUBSCRIBED;
}
bool QueueReplica::isOwner() const {
return !subscribers.empty() && subscribers.front() == self;
}
bool QueueReplica::isSubscriber(const MemberId& member) const {
// FIXME aconway 2011-06-27: linear search here, is it a performance issue?
return std::find(subscribers.begin(), subscribers.end(), member) != subscribers.end();
}
}} // namespace qpid::cluster::exp
|