root / src / Message.java
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| 1 | 3 | up20160792 | import java.net.DatagramPacket; |
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| 2 | import java.net.InetAddress; |
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| 3 | |||
| 4 | public class Message { |
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| 5 | |||
| 6 | private static final String CRLF = "\r\n"; |
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| 7 | |||
| 8 | public String header; |
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| 9 | public byte[] body; |
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| 10 | |||
| 11 | public enum MessageType { |
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| 12 | PUTCHUNK, STORED, GETCHUNK, CHUNK, DELETE, REMOVED |
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| 13 | }; |
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| 14 | |||
| 15 | public MessageType type;
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| 16 | |||
| 17 | public Message() {
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| 18 | } |
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| 19 | |||
| 20 | // Build a message
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| 21 | public Message(MessageType type, String senderId, String fileId, int chunkN, int replicationDeg, byte[] bytes) { |
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| 22 | |||
| 23 | // Reset body
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| 24 | body = new byte[0]; |
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| 25 | |||
| 26 | // Add chunk
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| 27 | body = bytes; |
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| 28 | |||
| 29 | // Assign type
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| 30 | this.type = type;
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| 31 | |||
| 32 | // Prepare type
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| 33 | switch (type) {
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| 34 | case PUTCHUNK:
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| 35 | header = "PUTCHUNK";
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| 36 | break;
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| 37 | case STORED:
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| 38 | header = "STORED";
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| 39 | break;
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| 40 | case GETCHUNK:
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| 41 | header = "GETCHUNK";
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| 42 | break;
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| 43 | case CHUNK:
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| 44 | header = "CHUNK";
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| 45 | break;
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| 46 | case DELETE:
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| 47 | header = "DELETE";
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| 48 | break;
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| 49 | case REMOVED:
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| 50 | header = "REMOVED";
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| 51 | break;
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| 52 | default:
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| 53 | break;
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| 54 | } |
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| 55 | |||
| 56 | // Version, SenderId and FileId are shared
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| 57 | // TODO hardcoded version 1.0
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| 58 | header += " 1.0";
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| 59 | header += " " + senderId;
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| 60 | header += " " + fileId;
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| 61 | |||
| 62 | // Remaining message header
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| 63 | // Technically it would be more efficient to add chunkN to all types and remove
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| 64 | // in DELETE but eh
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| 65 | switch (type) {
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| 66 | case PUTCHUNK:
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| 67 | header += " " + Integer.toString(chunkN); |
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| 68 | header += " " + Integer.toString(replicationDeg); |
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| 69 | break;
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| 70 | case STORED:
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| 71 | header += " " + Integer.toString(chunkN); |
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| 72 | break;
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| 73 | case GETCHUNK:
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| 74 | header += " " + Integer.toString(chunkN); |
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| 75 | break;
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| 76 | case CHUNK:
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| 77 | header += " " + Integer.toString(chunkN); |
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| 78 | break;
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| 79 | case DELETE:
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| 80 | // Nothing to add
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| 81 | break;
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| 82 | case REMOVED:
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| 83 | header += " " + Integer.toString(chunkN); |
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| 84 | break;
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| 85 | default:
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| 86 | break;
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| 87 | } |
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| 88 | |||
| 89 | // Finalize with double CRLF
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| 90 | header += CRLF + CRLF; |
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| 91 | |||
| 92 | } |
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| 93 | |||
| 94 | // Pack a datagram from message
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| 95 | public DatagramPacket packit(InetAddress address, int port) { |
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| 96 | |||
| 97 | byte[] headerBytes = header.getBytes(); |
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| 98 | |||
| 99 | byte[] full = new byte[headerBytes.length + body.length]; |
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| 100 | |||
| 101 | System.arraycopy(headerBytes, 0, full, 0, headerBytes.length); |
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| 102 | System.arraycopy(body, 0, full, headerBytes.length, body.length); |
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| 103 | |||
| 104 | DatagramPacket packet = new DatagramPacket(full, full.length, address, port); |
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| 105 | |||
| 106 | return packet;
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| 107 | |||
| 108 | } |
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| 109 | |||
| 110 | } |