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| Rev | Author | Line No. | Line |
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| 15 | arune | 1 | /* |
| 2 | * MbComponent.java |
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| 3 | * |
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| 4 | * Created on den 23 augusti 2003, 20:56 |
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| 5 | */ |
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| 6 | package Macbeth.System; |
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| 7 | |||
| 8 | /** |
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| 9 | * This class represents a Macbeth component. Components |
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| 10 | * are parts of the Macbeth system, each having its own |
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| 11 | * _unique_ name, a packet queue and a packet queue handler. |
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| 12 | * Extend this class further to create kernels or modules. |
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| 13 | * @author Jimmy |
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| 14 | */ |
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| 15 | abstract public class MbComponent implements MbPacketHandler,MbPacketReceiver { |
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| 16 | //A packet queue in which all packets will be put before they are processed. |
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| 17 | protected MbPacketQueue packetQueue; |
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| 18 | //A packet processor that takes care of packets in the queue. |
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| 19 | protected MbPacketQueueHandler packetQueueHandler; |
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| 20 | //is this component started? |
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| 21 | private boolean started; |
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| 22 | |||
| 23 | /** |
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| 24 | * Creates a new instance of MbComponent. |
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| 25 | */ |
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| 26 | public MbComponent() { |
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| 27 | //create a new packet queue for us |
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| 28 | packetQueue = new MbPacketQueue(); |
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| 29 | //create a handler for the packet queue |
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| 30 | packetQueueHandler = new MbPacketQueueHandler(packetQueue,this); |
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| 31 | //we're not started yet |
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| 32 | started = false; |
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| 33 | } |
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| 34 | |||
| 35 | /** |
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| 36 | * Gets the name of the component. |
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| 37 | * @return The name of the component. |
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| 38 | */ |
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| 39 | abstract public String name(); |
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| 40 | |||
| 41 | /** |
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| 42 | * Gets a short description of the component. This should |
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| 43 | * be kept short (1-2 lines) and should be formatted as |
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| 44 | * plain text. |
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| 45 | * @return A short description of the component. |
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| 46 | */ |
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| 47 | abstract public String description(); |
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| 48 | |||
| 49 | /** |
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| 50 | * Returns true if this component is started. |
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| 51 | * @return true if this component is started. |
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| 52 | */ |
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| 53 | public boolean isStarted() { |
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| 54 | return started; |
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| 55 | } |
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| 56 | |||
| 57 | /** |
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| 58 | * Will be called when this component should start up. Most |
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| 59 | * initialization should be done here (rather than in the |
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| 60 | * component's constructor). |
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| 61 | * @throws MbStartupException When this component couldn't |
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| 62 | * be started up for some reason. |
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| 63 | */ |
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| 64 | public void startup() throws MbStartupException { |
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| 65 | //start packet queue handler (it will be run in a separate thread) |
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| 66 | packetQueueHandler.startWorking(); |
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| 67 | //this component is started now! |
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| 68 | started = true; |
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| 69 | } |
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| 70 | |||
| 71 | /** |
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| 72 | * Will be called when this component should shut down itself. |
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| 73 | * Default behaviour is to shut down immediately, deleting any |
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| 74 | * eventual packets waiting in our queue. If you want to change |
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| 75 | * this behaviour, just override this method. Keep in mind though, |
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| 76 | * that you cannot send any packets to other components here, they |
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| 77 | * might have been shut down already! |
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| 78 | */ |
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| 79 | public void shutdown() { |
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| 80 | //shut down packet queue handler |
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| 81 | packetQueueHandler.stopWorking(); |
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| 82 | //this component is no longer started! |
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| 83 | started = false; |
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| 84 | } |
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| 85 | |||
| 86 | /** |
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| 87 | * Will be called when someone sends a packet to us. Default behaviour |
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| 88 | * is to simply put the packet onto our packet queue. You could override |
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| 89 | * this if you, for instance, want to filter out certain packets before |
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| 90 | * putting them onto the queue. Note that you should not do the actual |
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| 91 | * packet handling here. That's what the handlePacket-method is for. |
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| 92 | * @param p The packet we're receiving. |
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| 93 | */ |
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| 94 | public void packetReceived(MbPacket p) { |
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| 95 | packetQueue.enqueue(p); |
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| 96 | } |
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| 97 | |||
| 98 | /** |
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| 99 | * Checks if packet handler is ready. |
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| 100 | * @return True if we're ready and it's OK to call handlePacket, false otherwise. |
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| 101 | */ |
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| 102 | public boolean canHandlePacket() { |
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| 103 | return true; |
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| 104 | } |
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| 105 | |||
| 106 | /** |
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| 107 | * Will be called by the packet queue handler for each packet it |
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| 108 | * takes off the queue. This means it is time to parse and take |
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| 109 | * care of this packet. |
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| 110 | * @param p The packet we need to handle. |
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| 111 | */ |
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| 112 | abstract public void handlePacket(MbPacket p); |
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| 113 | |||
| 114 | } |