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.mts.base;
28:
29: import org.cougaar.mts.std.AttributedMessage;
30: import java.util.Iterator;
31:
32: import org.cougaar.core.component.Component;
33: import org.cougaar.core.component.Service;
34:
35: /**
36: * The selection of a {@link DestinationLink} is handled by this MTS-internal
37: * service, which is accessible only to MTS components. Its one
38: * method is used to select a link for every message processed by
39: * every DestinationQueue.
40: *
41: * The default implementation simply chooses the cheapest valid link,
42: * using the cost and isValid methods. Other policies can be set with
43: * the {@link LinkSelectionProvisionService}.
44: */
45: public interface LinkSelectionPolicy extends Service, Component {
46: /**
47: * Selects a DestinationLink from the given set of candidates for
48: * the given message. This method will be invoked multiple times
49: * on the same message until the DestinationLink it returns
50: * succeeds in processing the message. In these retry situations
51: * the message will always contains the same set of attributes
52: * for every try. Any attributes added in subsequent processing
53: * will be stripped before the retry. The @param failedMessage
54: * parameter can be used to examine the full set of attributes in
55: * this scenario.
56: */
57: DestinationLink selectLink(Iterator candidate_links,
58: AttributedMessage message, AttributedMessage failedMsg,
59: int retryCount, Exception lastException);
60: }
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