01: /*
02: * <copyright>
03: *
04: * Copyright 1997-2004 BBNT Solutions, LLC
05: * under sponsorship of the Defense Advanced Research Projects
06: * Agency (DARPA).
07: *
08: * You can redistribute this software and/or modify it under the
09: * terms of the Cougaar Open Source License as published on the
10: * Cougaar Open Source Website (www.cougaar.org).
11: *
12: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
13: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
14: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
15: * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
16: * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
17: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
18: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
22: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23: *
24: * </copyright>
25: */
26:
27: package org.cougaar.core.blackboard;
28:
29: import java.util.Iterator;
30:
31: import org.cougaar.core.agent.service.MessageSwitchService;
32:
33: /**
34: * A message acknowledgement manager used by the {@link
35: * org.cougaar.core.blackboard.Distributor}'s non-lazy persistence
36: * mode to ensure that unacknowledged messages are persisted.
37: */
38: public interface MessageManager {
39: int OK = 0;
40: int RESTART = 4;
41: int IGNORE = 8;
42: int DUPLICATE = IGNORE + 1;
43: int FUTURE = IGNORE + 2;
44: int PRESENT = OK;
45:
46: /**
47: * Start the message manager running. The message manager should be
48: * inactive until this method is called because it does know know
49: * the identity of the agent it is in.
50: */
51: void start(MessageSwitchService msgSwitch, boolean didRehydrate);
52:
53: /**
54: * Stop the message manager, halting any internal activity.
55: */
56: void stop();
57:
58: /**
59: * Add a set of messages to the queue of messages waiting to be
60: * transmitted. When persistence is enabled, the messages are held
61: * until the end of the epoch.
62: */
63: void sendMessages(Iterator messages);
64:
65: /**
66: * Incorporate a directive message into the message manager's state.
67: * @return Normally, the message is returned, but duplicate and from
68: * the future messages are ignored by returning null.
69: */
70: int receiveMessage(DirectiveMessage aMessage);
71:
72: /**
73: * Incorporate a directive acknowledgement into the message
74: * manager's state. The acknowledged messages are removed from the
75: * retransmission queues.
76: */
77: int receiveAck(AckDirectiveMessage theAck);
78:
79: /**
80: * Prepare to acknowledge a list of directive messages. The
81: * acknowledgements are not actually sent until the end of the
82: * epoch.
83: */
84: void acknowledgeMessages(Iterator messagesToAck);
85:
86: /**
87: * Advance epoch. Bring the current epoch to an end in preparation
88: * for a persistence delta.
89: * @return true if the message manager actually requires the epoch to advance
90: */
91: void advanceEpoch();
92:
93: boolean needAdvanceEpoch();
94: }
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