summaryrefslogtreecommitdiff
path: root/qpid/cpp/src/qpid/ha/ReplicatingSubscription.h
blob: fa2093ac61d9649f779d0de691f23e02984d47aa (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
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
#ifndef QPID_BROKER_REPLICATINGSUBSCRIPTION_H
#define QPID_BROKER_REPLICATINGSUBSCRIPTION_H

/*
 *
 * 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 "QueueReplicator.h"    // For DEQUEUE_EVENT_KEY
#include "qpid/broker/SemanticState.h"
#include "qpid/broker/QueueObserver.h"
#include "qpid/broker/ConsumerFactory.h"
#include <iosfwd>

namespace qpid {

namespace broker {
class Message;
class Queue;
class QueuedMessage;
class OwnershipToken;
}

namespace framing {
class Buffer;
}

namespace ha {

/**
 * A susbcription that represents a backup replicating a queue.
 *
 * Runs on the primary. Delays completion of messages till the backup
 * has acknowledged, informs backup of locally dequeued messages.
 *
 * THREAD SAFE: Used as a consumer in subscription's connection
 * thread, and as a QueueObserver in arbitrary connection threads.
 */
class ReplicatingSubscription : public broker::SemanticState::ConsumerImpl,
                                public broker::QueueObserver
{
  public:
    struct Factory : public broker::ConsumerFactory {
        boost::shared_ptr<broker::SemanticState::ConsumerImpl> create(
            broker::SemanticState* parent,
            const std::string& name, boost::shared_ptr<broker::Queue> ,
            bool ack, bool acquire, bool exclusive, const std::string& tag,
            const std::string& resumeId, uint64_t resumeTtl,
            const framing::FieldTable& arguments);
    };

    // Argument names for consume command.
    static const std::string QPID_REPLICATING_SUBSCRIPTION;

    ReplicatingSubscription(broker::SemanticState* parent,
                            const std::string& name, boost::shared_ptr<broker::Queue> ,
                            bool ack, bool acquire, bool exclusive, const std::string& tag,
                            const std::string& resumeId, uint64_t resumeTtl,
                            const framing::FieldTable& arguments);

    ~ReplicatingSubscription();

    // QueueObserver overrides.
    bool deliver(broker::QueuedMessage& msg);
    void enqueued(const broker::QueuedMessage&);
    void dequeued(const broker::QueuedMessage&);
    void acquired(const broker::QueuedMessage&) {}
    void requeued(const broker::QueuedMessage&) {}

    // Consumer overrides.
    void cancel();
    void acknowledged(const broker::QueuedMessage&);

    bool hideDeletedError();

  protected:
    bool doDispatch();
  private:
    typedef std::map<framing::SequenceNumber, broker::QueuedMessage> Delayed;
    std::string logPrefix;
    boost::shared_ptr<broker::Queue> events;
    boost::shared_ptr<broker::Consumer> consumer;
    Delayed delayed;
    framing::SequenceSet dequeues;
    framing::SequenceNumber backupPosition;

    void complete(const broker::QueuedMessage&, const sys::Mutex::ScopedLock&);
    void cancelComplete(const Delayed::value_type& v, const sys::Mutex::ScopedLock&);
    void sendDequeueEvent(const sys::Mutex::ScopedLock&);
    void sendPositionEvent(framing::SequenceNumber, const sys::Mutex::ScopedLock&);
    void sendEvent(const std::string& key, framing::Buffer&,
                   const sys::Mutex::ScopedLock&);

    class DelegatingConsumer : public Consumer
    {
      public:
        DelegatingConsumer(ReplicatingSubscription&);
        ~DelegatingConsumer();
        bool deliver(broker::QueuedMessage& msg);
        void notify();
        bool filter(boost::intrusive_ptr<broker::Message>);
        bool accept(boost::intrusive_ptr<broker::Message>);
        void cancel() {}
        void acknowledged(const broker::QueuedMessage&) {}

        broker::OwnershipToken* getSession();

      private:
        ReplicatingSubscription& delegate;
    };
};


}} // namespace qpid::broker

#endif  /*!QPID_BROKER_REPLICATINGSUBSCRIPTION_H*/