| 1 | package net.spy.memcached.protocol.ascii; |
| 2 | |
| 3 | import java.nio.ByteBuffer; |
| 4 | import java.util.Collection; |
| 5 | |
| 6 | import net.spy.memcached.KeyUtil; |
| 7 | import net.spy.memcached.ops.GetOperation; |
| 8 | import net.spy.memcached.ops.GetsOperation; |
| 9 | import net.spy.memcached.ops.OperationCallback; |
| 10 | import net.spy.memcached.ops.OperationState; |
| 11 | import net.spy.memcached.ops.OperationStatus; |
| 12 | |
| 13 | /** |
| 14 | * Base class for get and gets handlers. |
| 15 | */ |
| 16 | abstract class BaseGetOpImpl extends OperationImpl { |
| 17 | |
| 18 | private static final OperationStatus END = new OperationStatus(true, "END"); |
| 19 | private final String cmd; |
| 20 | private final Collection<String> keys; |
| 21 | private String currentKey = null; |
| 22 | private long casValue=0; |
| 23 | private int currentFlags = 0; |
| 24 | private byte[] data = null; |
| 25 | private int readOffset = 0; |
| 26 | private byte lookingFor = '\0'; |
| 27 | |
| 28 | public BaseGetOpImpl(String c, |
| 29 | OperationCallback cb, Collection<String> k) { |
| 30 | super(cb); |
| 31 | cmd=c; |
| 32 | keys=k; |
| 33 | } |
| 34 | |
| 35 | /** |
| 36 | * Get the keys this GetOperation is looking for. |
| 37 | */ |
| 38 | public final Collection<String> getKeys() { |
| 39 | return keys; |
| 40 | } |
| 41 | |
| 42 | @Override |
| 43 | public final void handleLine(String line) { |
| 44 | if(line.equals("END")) { |
| 45 | getLogger().debug("Get complete!"); |
| 46 | getCallback().receivedStatus(END); |
| 47 | transitionState(OperationState.COMPLETE); |
| 48 | data=null; |
| 49 | } else if(line.startsWith("VALUE ")) { |
| 50 | getLogger().debug("Got line %s", line); |
| 51 | String[] stuff=line.split(" "); |
| 52 | assert stuff[0].equals("VALUE"); |
| 53 | currentKey=stuff[1]; |
| 54 | currentFlags=Integer.parseInt(stuff[2]); |
| 55 | data=new byte[Integer.parseInt(stuff[3])]; |
| 56 | if(stuff.length > 4) { |
| 57 | casValue=Long.parseLong(stuff[4]); |
| 58 | } |
| 59 | readOffset=0; |
| 60 | getLogger().debug("Set read type to data"); |
| 61 | setReadType(OperationReadType.DATA); |
| 62 | } else { |
| 63 | assert false : "Unknown line type: " + line; |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | @Override |
| 68 | public final void handleRead(ByteBuffer b) { |
| 69 | assert currentKey != null; |
| 70 | assert data != null; |
| 71 | // This will be the case, because we'll clear them when it's not. |
| 72 | assert readOffset <= data.length |
| 73 | : "readOffset is " + readOffset + " data.length is " + data.length; |
| 74 | |
| 75 | getLogger().debug("readOffset: %d, length: %d", |
| 76 | readOffset, data.length); |
| 77 | // If we're not looking for termination, we're still looking for data |
| 78 | if(lookingFor == '\0') { |
| 79 | int toRead=data.length - readOffset; |
| 80 | int available=b.remaining(); |
| 81 | toRead=Math.min(toRead, available); |
| 82 | getLogger().debug("Reading %d bytes", toRead); |
| 83 | b.get(data, readOffset, toRead); |
| 84 | readOffset+=toRead; |
| 85 | } |
| 86 | // Transition us into a ``looking for \r\n'' kind of state if we've |
| 87 | // read enough and are still in a data state. |
| 88 | if(readOffset == data.length && lookingFor == '\0') { |
| 89 | // The callback is most likely a get callback. If it's not, then |
| 90 | // it's a gets callback. |
| 91 | try { |
| 92 | GetOperation.Callback gcb=(GetOperation.Callback)getCallback(); |
| 93 | gcb.gotData(currentKey, currentFlags, data); |
| 94 | } catch(ClassCastException e) { |
| 95 | GetsOperation.Callback gcb=(GetsOperation.Callback) |
| 96 | getCallback(); |
| 97 | gcb.gotData(currentKey, currentFlags, casValue, data); |
| 98 | } |
| 99 | lookingFor='\r'; |
| 100 | } |
| 101 | // If we're looking for an ending byte, let's go find it. |
| 102 | if(lookingFor != '\0' && b.hasRemaining()) { |
| 103 | do { |
| 104 | byte tmp=b.get(); |
| 105 | assert tmp == lookingFor : "Expecting " + lookingFor + ", got " |
| 106 | + (char)tmp; |
| 107 | switch(lookingFor) { |
| 108 | case '\r': lookingFor='\n'; break; |
| 109 | case '\n': lookingFor='\0'; break; |
| 110 | default: |
| 111 | assert false: "Looking for unexpected char: " |
| 112 | + (char)lookingFor; |
| 113 | } |
| 114 | } while(lookingFor != '\0' && b.hasRemaining()); |
| 115 | // Completed the read, reset stuff. |
| 116 | if(lookingFor == '\0') { |
| 117 | currentKey=null; |
| 118 | data=null; |
| 119 | readOffset=0; |
| 120 | currentFlags=0; |
| 121 | getLogger().debug("Setting read type back to line."); |
| 122 | setReadType(OperationReadType.LINE); |
| 123 | } |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | @Override |
| 128 | public final void initialize() { |
| 129 | // Figure out the length of the request |
| 130 | int size=6; // Enough for gets\r\n |
| 131 | Collection<byte[]> keyBytes=KeyUtil.getKeyBytes(keys); |
| 132 | for(byte[] k : keyBytes) { |
| 133 | size+=k.length; |
| 134 | size++; |
| 135 | } |
| 136 | ByteBuffer b=ByteBuffer.allocate(size); |
| 137 | b.put(cmd.getBytes()); |
| 138 | for(byte[] k : keyBytes) { |
| 139 | b.put((byte)' '); |
| 140 | b.put(k); |
| 141 | } |
| 142 | b.put("\r\n".getBytes()); |
| 143 | b.flip(); |
| 144 | setBuffer(b); |
| 145 | } |
| 146 | |
| 147 | @Override |
| 148 | protected final void wasCancelled() { |
| 149 | getCallback().receivedStatus(CANCELLED); |
| 150 | } |
| 151 | |
| 152 | } |