order-processing

multithreading-kata concurrency java8

Order events(Transaction)

Transaction Id	Order Id	Version Id	Symbol	Quantity	Operation	Buy/Sell
1	1	1	ABC	100	INSERT	BUY
2	2	2	XYZ	10	UPDATE	SELL
3	2	1	XYZ	10	INSERT	SELL
4	1	3	ABC	10	CANCEL	BUY

Process transaction(example given above) obeying following rules in a multithreaded environment

1. First version of order would always be INSERT
2. Last version of order would always be CANCEL
3. Order versions may come in any order
4. Process them in sequential order version 1,2,3....
5. Final position of every symbol will be calculated by difference between BUY and SELL units, CANCEL will mark order units 0
6. UPDATE operation may update the symbol, units, buy/sell

Output of the above example

Symbol	Units
XYZ	-10
ABC	0