| #ifndef QPID_SESSIONSTATE_H |
| #define QPID_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/SessionId.h> |
| #include <qpid/framing/SequenceNumber.h> |
| #include <qpid/framing/SequenceSet.h> |
| #include <qpid/framing/AMQFrame.h> |
| #include <qpid/framing/FrameHandler.h> |
| #include <boost/operators.hpp> |
| #include <boost/range/iterator_range.hpp> |
| #include <vector> |
| #include <iosfwd> |
| |
| namespace qpid { |
| using framing::SequenceNumber; |
| using framing::SequenceSet; |
| |
| /** A point in the session. Points to command id + offset */ |
| struct SessionPoint : boost::totally_ordered1<SessionPoint> { |
| SessionPoint(SequenceNumber command = 0, uint64_t offset = 0); |
| |
| SequenceNumber command; |
| uint64_t offset; |
| |
| /** Advance past frame f */ |
| void advance(const framing::AMQFrame& f); |
| |
| bool operator<(const SessionPoint&) const; |
| bool operator==(const SessionPoint&) const; |
| }; |
| |
| std::ostream& operator<<(std::ostream&, const SessionPoint&); |
| |
| /** |
| * Support for session idempotence barrier and resume as defined in |
| * AMQP 0-10. |
| * |
| * We only issue/use contiguous confirmations, out-of-order confirmation |
| * is ignored. Out of order completion is fully supported. |
| * |
| * Raises NotImplemented if the command point is set greater than the |
| * max currently received command data, either explicitly via |
| * session.command-point or implicitly via session.gap. |
| * |
| * Partial replay is not supported, replay always begins on a command |
| * boundary, and we never confirm partial commands. |
| * |
| * The SessionPoint data structure does store offsets so this class |
| * could be extended to support partial replay without |
| * source-incompatbile API changes. |
| */ |
| class SessionState { |
| typedef std::vector<framing::AMQFrame> ReplayList; |
| |
| public: |
| |
| typedef boost::iterator_range<ReplayList::iterator> ReplayRange; |
| |
| struct Configuration { |
| Configuration(size_t flush=1024*1024, size_t hard=0); |
| size_t replayFlushLimit; // Flush when the replay list >= N bytes. 0 disables. |
| size_t replayHardLimit; // Kill session if replay list > N bytes. 0 disables. |
| }; |
| |
| SessionState(const SessionId& =SessionId(), const Configuration& =Configuration()); |
| |
| virtual ~SessionState(); |
| |
| bool hasState() const; |
| |
| const SessionId& getId() const { return id; } |
| |
| uint32_t getTimeout() const { return timeout; } |
| void setTimeout(uint32_t seconds) { timeout = seconds; } |
| |
| bool operator==(const SessionId& other) const { return id == other; } |
| bool operator==(const SessionState& other) const { return id == other.id; } |
| |
| // ==== Functions for sender state. |
| |
| /** Record frame f for replay. Should not be called during replay. */ |
| virtual void senderRecord(const framing::AMQFrame& f); |
| |
| /** @return true if we should send flush for confirmed and completed commands. */ |
| virtual bool senderNeedFlush() const; |
| |
| /** Called when flush for confirmed and completed commands is sent to peer. */ |
| virtual void senderRecordFlush(); |
| |
| /** True if we should reply to the next incoming completed command */ |
| virtual bool senderNeedKnownCompleted() const; |
| |
| /** Called when knownCompleted is sent to peer. */ |
| virtual void senderRecordKnownCompleted(); |
| |
| /** Called when the peer confirms up to comfirmed. */ |
| virtual void senderConfirmed(const SessionPoint& confirmed); |
| |
| /** Called when the peer indicates commands completed */ |
| virtual void senderCompleted(const SequenceSet& commands); |
| |
| /** Point from which the next new (not replayed) data will be sent. */ |
| virtual SessionPoint senderGetCommandPoint(); |
| |
| /** Set of outstanding incomplete commands */ |
| virtual SequenceSet senderGetIncomplete() const; |
| |
| /** Point from which we can replay. */ |
| virtual SessionPoint senderGetReplayPoint() const; |
| |
| /** Peer expecting commands from this point. |
| *@return Range of frames to be replayed. |
| */ |
| virtual ReplayRange senderExpected(const SessionPoint& expected); |
| |
| // ==== Functions for receiver state |
| |
| /** Set the command point. */ |
| virtual void receiverSetCommandPoint(const SessionPoint& point); |
| |
| /** Returns true if frame should be be processed, false if it is a duplicate. */ |
| virtual bool receiverRecord(const framing::AMQFrame& f); |
| |
| /** Command completed locally */ |
| virtual void receiverCompleted(SequenceNumber command, bool cumulative=false); |
| |
| /** Peer has indicated commands are known completed */ |
| virtual void receiverKnownCompleted(const SequenceSet& commands); |
| |
| /** True if the next completed control should set the timely-reply argument |
| * to request a knonw-completed response. |
| */ |
| virtual bool receiverNeedKnownCompleted() const; |
| |
| /** Get the incoming command point */ |
| virtual const SessionPoint& receiverGetExpected() const; |
| |
| /** Get the received high-water-mark, may be > getExpected() during replay */ |
| virtual const SessionPoint& receiverGetReceived() const; |
| |
| /** Completed received commands that the peer may not know about. */ |
| virtual const SequenceSet& receiverGetUnknownComplete() const; |
| |
| /** Incomplete received commands. */ |
| virtual const SequenceSet& receiverGetIncomplete() const; |
| |
| /** ID of the command currently being handled. */ |
| virtual SequenceNumber receiverGetCurrent() const; |
| |
| /** Set the state variables, used to create a session that will resume |
| * from some previously established point. |
| */ |
| virtual void setState( |
| const SequenceNumber& replayStart, |
| const SequenceNumber& sendCommandPoint, |
| const SequenceSet& sentIncomplete, |
| const SequenceNumber& expected, |
| const SequenceNumber& received, |
| const SequenceSet& unknownCompleted, |
| const SequenceSet& receivedIncomplete |
| ); |
| |
| private: |
| |
| struct SendState { |
| SendState(); |
| // invariant: replayPoint <= flushPoint <= sendPoint |
| SessionPoint replayPoint; // Can replay from this point |
| SessionPoint flushPoint; // Point of last flush |
| SessionPoint sendPoint; // Send from this point |
| ReplayList replayList; // Starts from replayPoint. |
| size_t unflushedSize; // Un-flushed bytes in replay list. |
| size_t replaySize; // Total bytes in replay list. |
| SequenceSet incomplete; // Commands sent and not yet completed. |
| size_t bytesSinceKnownCompleted; // Bytes sent since we last issued a knownCompleted. |
| } sender; |
| |
| struct ReceiveState { |
| ReceiveState(); |
| SessionPoint expected; // Expected from here |
| SessionPoint received; // Received to here. Invariant: expected <= received. |
| SequenceSet unknownCompleted; // Received & completed, may not not known-complete by peer. |
| SequenceSet incomplete; // Incomplete received commands. |
| size_t bytesSinceKnownCompleted; // Bytes sent since we last issued a knownCompleted. |
| } receiver; |
| |
| SessionId id; |
| uint32_t timeout; |
| Configuration config; |
| bool stateful; |
| }; |
| |
| inline bool operator==(const SessionId& id, const SessionState& s) { return s == id; } |
| |
| } // namespace qpid |
| |
| |
| #endif /*!QPID_SESSIONSTATE_H*/ |