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
133
134
135
136
137
138
|
#ifndef QPID_FRAMING_SESSIONSTATE_H
#define QPID_FRAMING_SESSIONSTATE_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 "qpid/framing/SequenceNumber.h"
#include "qpid/framing/Uuid.h"
#include "qpid/framing/AMQFrame.h"
#include "qpid/sys/Mutex.h"
#include <boost/optional.hpp>
#include <deque>
namespace qpid {
namespace framing {
/**
* Session state common to client and broker.
* Stores replay frames, implements session ack/resume protcools.
*
* A SessionState is always associated with an _open_ session (attached or
* suspended) it is destroyed when the session is closed.
*
*/
class SessionState
{
public:
typedef std::vector<AMQFrame> Replay;
/** States of a session. */
enum State {
SUSPENDED, ///< Suspended, detached from any channel.
RESUMING, ///< Resuming: waiting for initial ack from peer.
ATTACHED ///< Attached to channel and operating normally.
};
/**
*Create a newly opened active session.
*@param ackInterval send/solicit an ack whenever N unacked frames
* have been received/sent.
*
* N=0 disables voluntary send/solict ack.
*/
SessionState(uint32_t ackInterval, bool enableReplay = true, const framing::Uuid& id=framing::Uuid(true));
/**
* Create a non-resumable session. Does not store session frames,
* never volunteers ack or solicit-ack.
*/
SessionState(const framing::Uuid& id=framing::Uuid(true));
const framing::Uuid& getId() const { return id; }
State getState() const { return state; }
/** Received incoming L3 frame.
* @return SequenceNumber if an ack should be sent, empty otherwise.
* SessionState assumes that acks are sent whenever it returns
* a seq. number.
*/
boost::optional<SequenceNumber> received(const AMQFrame&);
/** Sent outgoing L3 frame.
*@return true if solicit-ack should be sent. Note the SessionState
*assumes that a solicit-ack is sent every time it returns true.
*/
bool sent(const AMQFrame&);
/** Received normal incoming ack. */
void receivedAck(SequenceNumber);
/** Frames to replay
*@pre getState()==ATTACHED
*/
Replay replay();
/** Suspend the session. */
void suspend();
/** Start resume protocol for the session.
*@returns sequence number to ack immediately. */
SequenceNumber resuming();
/** About to send an unscheduled ack, e.g. to respond to a solicit-ack.
*
* Note: when received() returns a sequence number this function
* should not be called. SessionState assumes that the ack is sent
* every time received() returns a sequence number.
*/
SequenceNumber sendingAck();
SequenceNumber getLastSent() const { return lastSent; }
SequenceNumber getLastReceived() const { return lastReceived; }
private:
typedef std::deque<AMQFrame> Unacked;
bool sendingSolicit();
State state;
framing::Uuid id;
Unacked unackedOut;
SequenceNumber lastReceived;
SequenceNumber lastSent;
uint32_t ackInterval;
SequenceNumber sendAckAt;
SequenceNumber solicitAckAt;
bool ackSolicited;
bool suspending;
bool resumable;
sys::Mutex unackedLock;
};
}} // namespace qpid::common
#endif /*!QPID_FRAMING_SESSIONSTATE_H*/
|
