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Jeff Nelson

Jeff Nelson

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Code Block
void revert(String key, long record, long timestamp)

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Set

SET key AS value IN record

Code Block
//NOTE: cannot do automatic retry for this method, so caller must handle that
 
boolean set(String key, TObject value, long record){
	AtomicOperation operation = AtomicOperation.start(store);
    Set<TObject> values = operation.fetch(key, record);
	for (TObject value : values){
		operation.remove(key, value, record);
	}
	operation.add(key, value, record);
    return operation.commit();
}


Verify And Swap

See http://en.wikipedia.org/wiki/Compare-and-swap

Verify key AS value1 IN record AND SET AS SWAP WITH value2 

Code Block
boolean verifyAndSet//NOTE: cannot do automatic retry for this method, so caller must handle that
 
boolean verifyAndSwap(String key, TObject expected, long record, TObject replacement){
	AtomicOperation operation = AtomicOperation.start(store);
    if(operation.verify(key, expected, record){
       operation.remove(key, expected, record);
       operation.add(key, replacement, record);
       return operation.commit();
    }
    else{
       return false;
    }
}

Get And Increment

See http://en.wikipedia.org/wiki/Fetch-and-add

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Warning

The first value for key in record (get returns the first value of a fetch) must be a Number, otherwise this method should throw an exception.

TODO: how to handle floats and doubles?

Code Block
Number getAndIncrement(String key,long record)

 

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{
   while(true){
      value = get(key, record);
      if(verifyAndSet(key, value, record, value + 1){
         return value;
      }
   }
}