Due: Wednesday, March 19, 2008, 11:59pm

Authors: Adnan Aziz, Gayatri Ramachandran

Keep an eye on the changelog.

In this lab you will build a class that implements a stock quote server.

The server gets two types of requests: updates and queries.

These requests are in the form of text strings, and the response is in the form of text strings.

An update is an offer to sell or buy a certain quantity of stock at a certain price, or a change in the quantity of stock for an existing offer. The update format is timestamp id type symbol quantity unit-price

• Buy: 1232111 131 B GOOG 1000 270.12 is an offer to buy 1000 shares of Google (GOOG) at $270.12 a share.
• Sell: 2212313 246 S IBM 100 111.01 is an offer to sell 100 shares of IBM (IBM) at $111.01 a share.
• Update: 1411001 131 U GOOG 900 270.01 is an update to the order with id 131 indicating that there are now only 900 shares on offer at a price of $270.01
• Withdraw: 1507981 131 W says that the order with id 131 has been withdrawn
• Halt: 89123123 812312 H tells the server to halt operation and recover all allocated memory

IMPORTANT The server is not matching buyers and sellers. In particular, if 1232111 131 S GOOG 1000 270.12 is followed by 1232112 132 B GOOG 1000 270.12, the two do not cancel out - both are active. Think of the code you are writing as targeting a trader who wants to observe the state of the market. (If the two orders are matched by the market, then your server will get two withdraw updates, one for each offer.)

A query is specified as a string. The format is timestamp id type symbol quantity unit-price

The timestamp, id, symbol, quantity, and price fields are as before.

• 1232131 34 QB GOOG 100 0 queries the best price to buy 100 shares of Google
• 1402122 777 QBM GOOG 100 271.11 queries the best price to buy 100 shares of Google, without paying more than $271.11 a share
• 1412313 1231 QBT GOOG 100 271.11 track the best price to buy 100 shares of Google, without paying more than $271.11 a share
• 2231112 1231 QBTO stop tracking query with id 1231

For each buy query, there is an analogous sell query.

While tracking a query, you should not output a response after each update. You need to output the tracking result only after something has happened related to the stock you are tracking. For instance, if we are tracking a sell for GOOG, then the result for this will be output only after there is an addition, update or withdraw related to a buy request for GOOG.

You will need to handle two kinds of errors for this lab:

• Duplicate id error : This error occurs when we try to add a B, S, QB, QBM, QBT, QS, QSM or QST request with the same id as another active request. In this case, the server should print the message, Error: Duplicate id, and discard the request.
• Invalid id error : When this error occurs, the server should print the message, Error: Invalid id, and discard the message. This error occurs under the following conditions:
  • When the server receives a U or W request for an id which does not correspond to an active B or S request.
  • When the server receives a QBTO request for an id which does not correspond to an active QBT request.
  • When the server receives a QSTO request for an id which does not correspond to an active QST request.

Assume that the server is reading queries and updates one per line from stdin and writing its output to stdout The format of the output is given below. Lines starting with —- are the lines on standard output, and the text from the # symbol to the end of the line is a comment that will not be present in the actual running.

1 1 QB GOOG 100 0 
-- NA                    # indicates that 100 shares are not available
21 2 S GOOG 1000 271.01
37 3 S GOOG 100 270.00
44 5 QB GOOG 200 0
-- 54101.00              # 100 shares at 270.00 and 100 shares at 271.01
55 3 W
79 12 QB GOOG 200 0
-- 54202.00              # 200 shares at 271.01 
121 15 S GOOG 1000 270.50
180 19 QBM GOOG 500 270.80
-- Yes                   # can fulfill such an order
201 27 QBT GOOG 1000 270.51
-- 27 Yes                # can be fulfilled
270 31 B GOOG 1000 269.97
336 15 U GOOG 500 270.50 # only 500 shares are being offered now
-- 27 No                 # cannot be fulfilled now
412 37 S IBM 700 170.02
512 41 S GOOG 700 269.11
-- 27 Yes                # from the orders with id 41 and 15
661 27 QBTO
1243 1231 H              # halt operations

1 1 B ATT 100 123.21
45 2 S ATT 100 123.21
50 3 QB ATT 200 0
-- NA                    #only 100 shares are available
234 4 QB ATT 50 0
-- 6160.50               #50 shares at 123.21
300 5 QB ATT 100 0
-- 12321.00              #100 shares at 123.21
334 6 QB ATT 100 0       #to show that queries do not update the server
-- 12321.00
434 7 QB GOOG 50 0
-- NA
1000 8 B ATT 100 123.21
2431 9 B ATT 50 123.21   #to show that buyers and sellers aren’t matched up
1243 2 H                 #halt operations. id is a don't care

Note: (by Adnan) - the withdraws for id 1 at time 800 onwards should also be flagging an error

100 1 S IBM 500 543.21
110 1 B GOOG 45 676.97
-- Error: Duplicate id
200 1 S GOOG 50 680.86
-- Error: Duplicate id
242 1 QB IBM 500 0
-- Error: Duplicate id
246 1 QBM IBM 100 543.22
-- Error: Duplicate id
300 1 QBT IBM 150 543.20
-- Error: Duplicate id
310 1 W
330 1 B IBM 500 543.21
379 1 S IBM 500 543.21
-- Error: Duplicate id
400 1 W
489 1 S IBM 500 543.21
578 1 W
780 1 QB IBM 500 0
-- NA
800 1 W
-- Error: Invalid id
810 1 QB IBM 500 32.53    #price is a don’t care
-- NA
850 1 W
-- Error: Invalid id
880 1 QBM IBM 500 544.00
-- No
900 1 W
-- Error: Invalid id
923 1 QBT IBM 500 543.21
-- 1 No
940 2 S IBM 500 543.20
-- 1 Yes
945 2 W
-- 1 No
940 2 S IBM 500 543.20
-- 1 Yes
950 3 QBM IBM 500 544.00
-- Yes
960 4 QB IBM 500 543.00   #price is a don’t care
-- 271600.00              #500 shares at 543.20
970 5 QB GOOG 500 0
-- NA
987 123 H                 #id is a don’t care

154 1 B YHOO 1000 122.12
176 2 S GOOG 500 653.23
190 3 QB IBM 2000 234.53
-- NA
213 4 QBM YHOO 500 123.00
-- No
234 5 QBT GOOG 500 653.25
-- 5 Yes
256 1 U GOOG 500 652.50
320 2 U GOOG 100 650.50
-- 5 No
336 2 U GOOG 500 653.23
-- 5 Yes
367 3 U IBM 200 250.50
-- Error: Invalid id
390 4 U IBM 100 243.00
-- Error: Invalid id
425 5 U YHOO 300 132.50
-- Error: Invalid id
456 1 QBTO
-- Error: Invalid id
466 2 QBTO
-- Error: Invalid id
576 3 QBTO
-- Error: Invalid id
588 4 QBTO
-- Error: Invalid id
599 1 W
611 2 W
-- 5 No
624 5 QBTO
643 3 W
-- Error: Invalid id
657 4 W
-- Error: Invalid id
667 5 W
-- Error: Invalid id
682 1 U GOOG 500 650.50
-- Error: Invalid id
698 2 U GOOG 500 650.50
-- Error: Invalid id
762 5 QBTO
-- Error: Invalid id
764 1 W
-- Error: Invalid id 
790 2 W
-- Error: Invalid id
853 2 S GOOG 500 653.23
890 1 H

100 1 B ATT 100 123.70
107 2 S ATT 100 120.70
202 3 S ATT 100 124.70
222 4 QS ATT 50 123.21    #price is a don’t care
-- 6185.00                #50 shares at 123.70
257 5 B ATT 100 122.70
298 6 QS ATT 150 0
-- 18505.00               #100 shares at 123.70 and 50 shares at 122.70
456 7 QSM ATT 150 123.50
-- No
486 8 QSM ATT 50 123.50
-- Yes
568 9 QSM GOOG 50 121.23
-- No
708 11 QSM ATT 150 123.35
-- Yes                    #100 shares at 123.70 and 50 shares at 122.70
764 12 QS IBM 150 0
-- NA
769 13 QST ATT 200 123.10
-- 13 Yes
864 1 W
-- 13 No
890 1 B ATT 100 123.70
-- 13 Yes
894 13 QSTO
904 1 W
978 56 H

100 1 QB ATT 100 0
-- NA
101 1 QBM ATT 100 120.00
-- No
164 1 QS GOOG 100 0
-- NA
207 1 QSM ATT 100 120.00
-- No
242 1 QBT ATT 100 121.00
-- 1 No
276 1 QBTO
342 1 QST ATT 100 121.00
-- 1 No
376 1 QSTO
399 1 S ATT 100 118.00
415 2 B ATT 100 120.00
424 3 QBT ATT 100 119.00
-- 3 Yes
456 4 QBT ATT 100 117.00
-- 4 No
466 8 QST GOOG 100 120.00
-- 8 No
476 5 QST ATT 100 119.00
-- 5 Yes
487 6 QST ATT 100 121.00
-- 6 No
490 7 S ATT 100 117.00
-- 3 Yes
-- 4 Yes
499 2 U GOOG 100 120.00
-- 5 No
-- 6 No
-- 8 Yes
500 2 U GOOG 100 119.00
-- 8 No
512 9 B GOOG 100 120.00
-- 8 Yes
523 10 QSM GOOG 150 119.70
-- No
524 10 QSM GOOG 150 119.60
-- Yes
525 10 QBM ATT 150 117.30
-- No
529 10 QBM ATT 150 117.40
-- Yes
567 125 H

399 1 S ATT 200 118.00
486 2 S ATT 100 118.00
543 3 B ATT 100 118.00
568 4 B ATT 50 118.00
586 5 QBM ATT 300 118.00
-- Yes
597 5 QSM ATT 150 118.00
-- Yes
654 5 QBT ATT 300 118.00
-- 5 Yes
676 6 QBT ATT 400 118.00
-- 6 No
712 7 QBT ATT 200 118.00
-- 7 Yes
743 2 W
-- 5 No
-- 6 No
-- 7 Yes
754 8 QST ATT 150 118.00
-- 8 Yes
764 9 QST ATT 100 118.00
-- 9 Yes
875 10 QST ATT 200 118.00
-- 10 No
878 4 W
-- 8 No
-- 9 Yes
-- 10 No
888 21 H

You are to code the class Qs implementing the server. It should have the following methods:

• void Start() - begin in interactive mode, i.e., read queries and updates from stdin, write results to stdout
• void Stop() - stop processing, call the class destructors to recover memory (this method should be called when the update is of type halt H)
• void NonInteractive() - this tells the server not to take inputs from stdin and write to stdout (by default, the server should be in interactive mode)
• String Request(String aRequest) - this tells the server to process the request in aRequest (this method will be called only when the server is in non-interactive mode). The method should return the string that would ordinarily be printed to stdout in interactive mode (this string may span multiple lines, in which case your result should have '\n's in the approriate places)

• QsMain.java
• Qs.java

• qsMain.cpp
• qs.h

The inputs and outputs of the examples are given below. You could copy them into your directory and use redirection instead of typing in the inputs each time.

If you are working on a Linux machine, you could do the following to read in all the inputs from Input1 and print the output into my_output1:
java Qs < Input1 > my_output1

After this is done, you could type the command
diff my_output1 Output1
to check if you get the expected output.

You should base your implementation on BSTs - you can use any standard implementation (e.g., STL or the Java Collections API). You will likely need to augment the data structure to achieve reasonable performance.

• You have to work on this lab individually.
• You need to submit only one file for this lab – Qs.java or qs.h.
• Please confirm that your file compiles by running ‘java QsMain’ or 'g++ -ansi -Wall qsMain.cpp' on any LRC Linux/Unix machine before submitting your program. Please do not wait until the last moment to do this.
• In order to help us assign you the grades, please make sure that you put your names and ECE logins on the top of all the files that you submit in the following format, as a comment:
  

/********************************************************************************
@file <filename>
<Description>
@author Fullname1(ECE login1)
@date
*******************************************************************************/

Example:

 
/********************************************************************************
@file Qs.java
Implementing Simple Hash Map
@author Adnan Aziz(adnan)
@date 03/10/2008
*******************************************************************************/

• Where and how to submit – You have to submit your source files online on the Blackboard. Either submit all your files as a single zipped folder or compress it into a tar ball. Go to the assignments section on your course page, click on the link to assignment3 and follow the instructions. If you have a valid reason for not being able to submit the file online on the blackboard, you could email your compressed file to along with your reason. You should also submit a 2-3 page writeup on the design of your algorithm.
• Breakdown: 60% for passing all functional tests; 10% for adhering to coding guidelines; 20% for performance; 10% for design and 1% penalty for each warning (upto 10%).
• You can submit anytime starting now until two days after the deadline, after which no submissions will be accepted, for any reason.

• If you enjoyed this lab, check out TradeStation
• This programming assignment is based on an example posted at RGM Advisers, a trading firm that uses science and computing to make investment decisions

1. 2.25.2008 - initial release.
2. 2.26.2008 - changed halt from halt on a newline to be more like queries and updates.
3. 3.3.2008 - added starter code.
4. 3.4.2008 - clarified that server is not matching buyers and sellers.
5. 3.4.2008 - added an example to show that the server is not matching buyers and sellers.
6. 3.5.2008 - added examples to illustrate error handling.
7. 3.10.2008 - added note about error handling for id 1 after time 800 for examples.
8. 3.14.2008 - added example for the sell queries.
9. 3.14.2008 - clarified that a tracking query does not need to output the result after each update, and made changes to examples accordingly.
10. 3.15.2008 - modified the error handling section to include the sell analogies of the queries too.
11. 3.16.2008 - added inputs and outputs to the sample test case section.
12. 3.17.2008 - added another example to the example section and the sample test case section.
13. 3.17.2008 - modified QsMain.java and qsMain.cpp to show how the non-interactive mode will be tested.
14. 3.18.2008 - added an example with same unit_price for multiple requests.