300 BTC Coding Contest: Distributed Exchange (MasterCoin Developer Thread)

[Tachikoma]

I'm getting this  transaction as invalid
8d47449b082ffe6f6b2adad327591778c43bf984e84062fb1cb13320b47ccbbd

TMSC

Date: 11/10/2013 9:22:18 AM      
Remarks: Sender 16rAwebBXhJAM9ALf3fLFbaHKz24r2o3UN doesn't have 1.337 TMSC. Bal:1.1583 Sale:0.002 Pend:0      

11/8/2013 6:44:20 AM   1NHVAzYT2jQ8roRddYXhvZtiVjuMwuWBGn .1337   6890  
11/7/2013 8:15:22 AM   1NHVAzYT2jQ8roRddYXhvZtiVjuMwuWBGn .808   6866  
11/2/2013 10:15:26 PM   1F73UPD5xBKgTSRd8q6QhuncVmDnJAHxYV .1   6727  
11/2/2013 10:15:22 AM   18xEZx3po1iJWP5H2aM3Do11dCGQyaebnT .2 .003232 6736  
10/28/2013 8:13:38 AM 2.4 1NHVAzYT2jQ8roRddYXhvZtiVjuMwuWBGn     6708  

Yeah the problem is I have been messing with the DEx for two months now and it's really about time I do a full reimport because some of these transactions got imported with the old logic. I will make some time over the weekend to create a development database and see the consensus between the old and new. Until that time please assume you implementation is the correct one

Grazcoin: Could you take a look at a1b5d7c73e9ec345075eb2357c4dbfced610bdac63808f2f0d05fa431e266795? It appears you are using the change address as recipient for this transaction.

[1714979514]

1714979514

[1714979514]

1714979514

[1714979514]

1714979514

[1714979514]

1714979514

[grazcoin]

The guys from engine.co found a potential race condition where the user could accidentally create a new sell order when they were trying to change an old one, because the old one had already been bought.

At my suggestion, Marv made this pull request to add a 2-confirmation time limit after a sale is complete before that address can initiate a new sell offer: https://github.com/mastercoin-MSC/spec/pull/38

I'm posting here because not respecting the time limit will lead to consensus divergence, so I want to make sure everybody is aware of it.

Thanks!

Perhaps it's the lack of sleep but I don't like the fact that this has been merged already, up till now everything we did was democratic. Shouldn't we discuss such a major change in the protocol before merging it? I would appreciate it if at least some examples could be given in how this is suppose to work before and after the merge.

I also think this pull request should be open for discussion like any other pull request.
my opinion:
I don't think this solution really solves this race condition, e.g. due to difference in fee amount and inputs complexity of the buy/sell change transactions, the sell offer change can still get merged 2 confirmations later, and then we're in the same race condition state.

Alternative solution would be to keep only the option to cancel the offer (amount zero), and omit the option to change it.
If one wants to make a change, he can first cancel the old offer, and then create a new one.

EDIT: it would be also much easier to implement, and reduce complexity.

[Bitoy]

Updated the Dex engine.

http://www.mymastercoins.com/Orders.aspx?CurrencyID=2

[Tachikoma]

My DEx transactions are getting stuck in a verification loop, don't mind any of my output at the moment.

[ukbitco.in]

Hiya,

As things start to heat up (cool!) - it's clear you require help testing - i'd like to be involved. Is there any clear plan or list of tasks that one should accomplish?

Thanks for all the hard work.

[jakecnn]

Is there a way to speed up the transactions? Or is it usual to have 8 hours until 1st confirmation?
Do many miners reject multisig transaction?

Edit: Nevermind, second transaction was quickly processed.

[mastream]

Hey guys,

It's great to see so much progress lately on this awesome project.
I'd like to help with testing the DEx, could I get some Test MSC for that?
The Testnet address is mkXFVEDn8rf5L4k9dw1rKBgU1Ceu69rrsn, BTC address is 1B4dzdSTt8p1qfMba4MTPUvABDXDYTHT2S, thanks.
Also, if I try adding the address to the masterchain wallet as described here https://masterchain.info/downloads/masterchain_tutorial.pdf
it just shows me an empty wallet page with no addresses in it after clicking on "Add to wallet". I tried several times with different addresses but it doesn't seem to work for me. I'm using Chrome on Windows 8 if that's important.

I hope I can be of help,
Best wishes

[Tachikoma]

The guys from engine.co found a potential race condition where the user could accidentally create a new sell order when they were trying to change an old one, because the old one had already been bought.

At my suggestion, Marv made this pull request to add a 2-confirmation time limit after a sale is complete before that address can initiate a new sell offer: https://github.com/mastercoin-MSC/spec/pull/38

I'm posting here because not respecting the time limit will lead to consensus divergence, so I want to make sure everybody is aware of it.

Thanks!

Perhaps it's the lack of sleep but I don't like the fact that this has been merged already, up till now everything we did was democratic. Shouldn't we discuss such a major change in the protocol before merging it? I would appreciate it if at least some examples could be given in how this is suppose to work before and after the merge.

I also think this pull request should be open for discussion like any other pull request.
my opinion:
I don't think this solution really solves this race condition, e.g. due to difference in fee amount and inputs complexity of the buy/sell change transactions, the sell offer change can still get merged 2 confirmations later, and then we're in the same race condition state.

Alternative solution would be to keep only the option to cancel the offer (amount zero), and omit the option to change it.
If one wants to make a change, he can first cancel the old offer, and then create a new one.

EDIT: it would be also much easier to implement, and reduce complexity.

My plus 1 for this idea. Separate messages make a lot of sense to me.

[jakecnn]

Masterchain.info/HybridWebWallet:
I'm getting ERROR in the source script field when I prepare a simple send of TMSC or a sell offer. I've verified the address before and got an OK.

[grazcoin]

Masterchain.info/HybridWebWallet:
I'm getting ERROR in the source script field when I prepare a simple send of TMSC or a sell offer. I've verified the address before and got an OK.

The exact errors from the server are not yet shown on the html page, and it will be fixed soon (you could still see the server's output that contains the errors with chrome developer tools).
I assume there were no available bitcoin funds on that address ("zero inputs" error), so no valid transaction could be contracted - am I right?
If not, please give me more details of which address/time it was (or simply reproduce the same error), and I could check the logs.

[jakecnn]

Yep, zero inputs error, works now. Thanks.

[grazcoin]

quote from mastercoin-tools:

Available new docs on http://masterchain.info/downloads

Testing format suggestion (partially done):
https://masterchain.info/downloads/DEx_test_plan.pdf

screenshot:


and icons list (lexicon):
https://masterchain.info/downloads/masterchain_icons_list.pdf

You are welcome to extend this document (pptx files on downloads directory), and fill in tests.
Grazcoin

[mastream]

@grazcoin looks great, I like your site and would love to participate, but I can't seem to get it to work.
Whenever I try to add an address to the wallet, I end up with an empty wallet with no addresses in it.

[jakecnn]

I couldnt get Bitoy's MyMscWallet to work. I get 'Exception thrown:File not found' every time I run the executable.
I've tried it on a 32bit and 64bit system, getting the same problem.
When I update the settings(which seems to work, since the values are persistent), I get the same error twice.

[jakecnn]

@grazcoin looks great, I like your site and would love to participate, but I can't seem to get it to work.
Whenever I try to add an address to the wallet, I end up with an empty wallet with no addresses in it.

I think you can only add addresses that received MSC or TMSC.

[mastream]

@grazcoin looks great, I like your site and would love to participate, but I can't seem to get it to work.
Whenever I try to add an address to the wallet, I end up with an empty wallet with no addresses in it.

I think you can only add addresses that received MSC or TMSC.

thanks, I thought so too but i got the same effect when trying to add an address with MSC in it.

edit:
I see now that I can still try to use the DEx functions and I dont really need to have the address in my wallet.
the effect should be the same, right?

[aTriz]

I couldnt get Bitoy's MyMscWallet to work. I get 'Exception thrown:File not found' every time I run the executable.
I've tried it on a 32bit and 64bit system, getting the same problem.
When I update the settings(which seems to work, since the values are persistent), I get the same error twice.

Bitoy will be able to help you better but just a few pages back I had issues and found..

-Make sure you have none of you're files in your MyMastercoins folder set to read only! (You can do this by Right Click: Properties and make sure the box is un-checked) (Additionally make sure you have Full Control as an Administrator, you can do this as well by Right Click: Properties: Security make sure you have "Full Control")

Though that shouldn't have anything to do with Exception thrown: File not found.

I had a issue with the main setup.exe so I actually go into the MyMastercoinsTCW_1_0_0_1 folder and run MyMastercoinsTCW (Application).

[Bitoy]

I couldnt get Bitoy's MyMscWallet to work. I get 'Exception thrown:File not found' every time I run the executable.
I've tried it on a 32bit and 64bit system, getting the same problem.
When I update the settings(which seems to work, since the values are persistent), I get the same error twice.

Hi jakecnn

Please post a screen shot of the error to
https://bitcointalk.org/index.php?topic=355739.0

After updating, close then try to restart the program.


(When I post the files directly to github, the setup doesn't work something to do with file checksum.  So I zipped it before sending  to github.)

[grazcoin]

@grazcoin looks great, I like your site and would love to participate, but I can't seem to get it to work.
Whenever I try to add an address to the wallet, I end up with an empty wallet with no addresses in it.

I think you can only add addresses that received MSC or TMSC.

Indeed. For now, a wallet can only have addresses that already received MSC/TMSC.
If you want to work with an address that *doesn't have yet* MSC/TMSC, you should first send MSC/TMSC to that address (using a wallet of an address that does have such coins, and the button send).
Once you have MSC/TMSC on that address, you can add it to a wallet.

[grazcoin]

@grazcoin looks great, I like your site and would love to participate, but I can't seem to get it to work.
Whenever I try to add an address to the wallet, I end up with an empty wallet with no addresses in it.

I think you can only add addresses that received MSC or TMSC.

thanks, I thought so too but i got the same effect when trying to add an address with MSC in it.

edit:
I see now that I can still try to use the DEx functions and I dont really need to have the address in my wallet.
the effect should be the same, right?

right.
the wallet is only for convenience - it lists your addresses and balances, and suggest these addresses whenever you click "send here" or "accept". The functionality of DEx (as well as simple send) is identical with and without wallet.