MultiBit

[bitcoinspot.nl]

I really enjoyed the demo and enjoyed our luch together

I still have a few points i would like to bring up concerning the client,
shall i do it here or do you have some kind of list for that somewhere else?

Greetz
Roland.

[jim618]

Hi Roland,

Yes it was good fun the whole conference and great to meet you.

If you have points, add them in here certainly.
If you number the points/ queries that will make it easier for me to answer them one-by-one and other people can add their comments.

[jim618]

To make it easier to see your BTC going in and out of your wallets, I have added a "View | Charts" menu option.
Currently the only one is "Balance over last 30 days". See screenshot:




This uses a third party library called XChart, written by Tim Molter.

Also, you can now drag and drop the MultiBit QR codes to and from your desktop/ file browser, which is quite handy. Screenshot:



(edited) The file name for the PNG file is "[label of address] - [amount] - [bitcoin address]" so that you can identify the QR codes. It works ok in Mac, Win and Linux as long as you have the permissions to write to the target location.


These will go into the next test code which should be later this week and then the next live which will probably be next week.
(The chart is not perfect yet as the dates aren't localised but I wanted to get it out as I mentioned it in my conference talk).

[freemoney458]

1) The charts are cool. Can I view them in fiat currency, too? Maybe this is useful for people who 'invest' in bitcoins.

BTW, one can accomplish the same thing and more once MultiBit is able to export all transaction data together with date/time and exchange rate from the time of the transaction into a CSV file.

You might need to add the exchange rate to every transaction in the wallet file for such a feature, though.

2) I really like the ability to drag and drop QR codes from and to files.

[jim618]

Hi Freemoney,

For the charts in MultiBit I will probably keep them fairly simple. They can be a huge time soak if you are not careful.
We had three full time people at my last code shop working on the 'Analytics" i.e charts and stuff and we could never keep up with user requests.

I am planning to put  an 'Export' button on the Transactions page so that people can export a CSV file as you suggest, yes. Then people can do whatever they like.

I am not sure about putting the exchange rate on the tx actually as "exchange rate" actually needs:
1) actual exchange rate (including exchange currency)
2) the source exchange e.g. Mt Gox, A.N.Other exchange (in the future).
3) the type of exchange rate from that exchange (e.g last, 24 hour rolling exponential mean, whatever).

If people have the raw data they can look up historical exchange rates from the exchange/ datasource they are interested in.

MultiBit is not really meant to be a full blown Sage!   :-)


Yeah - the QR code drag onto the desktop is pretty useful.

[jim618]

I have just been playing around with the QR codes generated when you drag onto the desktop.
If you put the png files in a folder and use coverplay (on a Mac) they look like this:



Experimenting with my phone, only the central QR code scans.
Pretty easy to create a small catalog of QR codes and say, print them out or keep on a handheld device or whatever.

The file name tells you what it is and the price. If someone scans it and sends BTC, it goes straight to your wallet.

I have changed the order so that you can have pngs called:

   Regular coke (330ml) - 0.05 - 12F8uztWoQQRPuZ7XPSnYDkKJ5MnvQZuwC.png  
   Diet coke (330ml) - 0.05 - 1Eb3bi7tpaQJUVdmN9rrCyMKwQSizFhymZ.png

etc

A bit easier to see the price.

[World]

Here is a demonstration of how to use QR code opposite direction
https://www.youtube.com/watch?v=LlFPYBYIayU&feature=youtube_gdata_player

[teste]

1) The charts are cool. Can I view them in fiat currency, too? Maybe this is useful for people who 'invest' in bitcoins.

BTW, one can accomplish the same thing and more once MultiBit is able to export all transaction data together with date/time and exchange rate from the time of the transaction into a CSV file.

You might need to add the exchange rate to every transaction in the wallet file for such a feature, though.

2) I really like the ability to drag and drop QR codes from and to files.

Hi freemoney458

I requested a feature like this for piuk of blockchain.info.info wallet and he said that can be useful. See his reply: https://bitcointalk.org/index.php?topic=40264.msg1203713#msg1203713

I posted on uservoice too, http://blockchain.uservoice.com/forums/152743-general-ideas/suggestions/3173858-show-the-usd-price-of-1-btc-in-the-exact-time-of-s

[Joe200]

Could you please add an option to MultiBit to allow the user to refuse to accept certain coins. If he receives certain coins, he sends them back right away.

Here is the full proposal: https://bitcointalk.org/index.php?topic=110749.0

Thanks.

[DanielVG]

Hey Jim,

I'd like to report something:
During "reset block chain and transactions" the power of my computer went out.  The .wallet files that were updating got destroyed.  Luckily i had backups of my important wallets.
The file size of all wallets was 0 kb when i rebooted my computer. I opened them with texteditor and they were completely empty.
There was one wallet though with a few coins in it that i didn't back up.
You think there is a possibility to recover it?  For what i've seen so far i doubt it actually.

the error message i get when i try to open it is:
cannot read file /tralala/tralala/tralala/multibit.wallet with wallet.
the error is "com.google.protobuf.InvalidProtocolBufferException Message missing required fields: network_identifier"


I'm using mac OSX 10.7.4 with multi bit 0.5.3beta

something else:
I have the feeling it's too hard to find the .wallet file for common users.
I can imagine some people will have problems locating the file.
An option to backup the .wallet files in the menu would be very useful.
Or even an automated backup, so even the most stupid lazy ass people can't loose their wallets when the power goes out.

[jim618]

Hi DanielVG,

When it writes out the wallet MultiBit stores to a temporary file called 'wallet[a random number].tmp', then renames the file to the actual wallet filename. See if you have a file called that and, if so, rename it to the wallet file and try opening it.

Also, have a look in the same directory if you have any files called [myWalletName].wallet.yyyymmddhhmmss

(where the yyyymmddhhmmss is the date when the wallet is saved)
When MultiBit has trouble saving over the original wallet file it will save to a backup filename with a date in it.

Again, if you have a wallet file with that name rename it and try opening it again.

RE: the location of the wallet
The file the wallet is stored in is shown in the title bar of MultiBit so that the user can see it at any time MultiBit is open. It is also shown on screens such as import keys, export keys, reset blockchain. Also, in the Wallets panel if they open the wallet detail panel they can see where the file is stored by hovering over the filename.

Also, I have written up how I normally back up my wallets (by exporting the private keys encrypted) here:
http://multibit.org/help_backupWalletUsingPrivateKeys.html
You can do this completely in the user interface so there is no need to copy files around.

It is a difficult problem to cope with - sudden power loss - which is why the two stage save is in there.

I hope you recover your wallet file/ keys.
Let me know if the wallet file is there (albeit with a different suffix) or not.

Jim

[jim618]

I have had a look at the wallet save code and improved things for DanielVG's scenario of sudden power loss.

In the current code MultiBit now saves like this:

UPDATED BELOW
1) Create a temporary file called [wallet file name]-new-[random number].tmp and write to that.
2) Copy the existing wallet file to [wallet filename]-old-[random number].tmp and check the file sizes match. Delete the existing wallet file if copy went ok.
3) Copy the temporary wallet file to the actual wallet file and check the file sizes match.
4) If everything worked ok, tidy up by deleting the [wallet filename]-old-[random number].tmp and [wallet filename]-new-[random number].tmp. This leaves just the actual wallet file.

It is 3 times the disk IO but the wallets are typically small so it is worth the extra safety.   Should the power just disappear at any stage there is always a fully saved copy of either the old or new wallet.

The filenames used should make it easier for someone in the future to recover their wallet if a similar thing happens.
This change will appear in the next test and live releases.

[garyrowe]

Also, if you find yourself in a situation where you need to do a data recovery, the following article might help you: http://gary-rowe.com/agilestack/2012/08/17/how-to-recover-your-bitcoins-from-a-failed-hard-drive/

[jim618]

I have refined the writing/ backup of wallet files in MultiBit so that it now does the following:

1) Create a backup file called <wallet file name>-<the current date>.wallet and copy the original wallet to that. This is the "new" backup file. Secure delete the original wallet stored with the walletFilename.
2) Write the details of the new wallet to the walletFilename.
3) Lookup in the wallet info file the name of the wallet backup. This is the "old" backup file.
4) Put the "new" backup file in step 1) into the wallet info file and save it.
5) Secure delete the "old" backup file.

This way you always have one wallet backup file and the working files are secure deleted. If the power goes you always have at least one of:
a) The 'old' wallet backup
b) The 'new' wallet backup
c) The actual wallet.

You can see the backup wallet files in this screenshot:

[alocacoc]

Hello

The second time i got the same problem, and i dont know what is exactly happen. After the first time, i did download and extract Multibit from new, and it did works. But now, this procedure dosent help.

After is start Multibit i see my Wallet and the amount. But i get the error message: Unable to load blockchain "multibit.blockchain". The error  was "java.lang.IllegalStateExeption -40".

How i can resolve this?

[alocacoc]

To make it easier to see your BTC going in and out of your wallets, I have added a "View | Charts" menu option.

Are this functions only available for ios, or in a not official version? So far i only use the Win Version of Multibit.

[jim618]

Hi alocacoc,

They are in the MultiBit code at the moment but have not made it into the downloads on the website yet.
The chart will be available in the next release on multibit.org, which will probably be next week.

This will be for Windows, Mac and Linux.

edit: You can follow "MultiBitOrg" on Twitter for tweets of when the code actually gets released.

[jim618]

Hello

The second time i got the same problem, and i dont know what is exactly happen. After the first time, i did download and extract Multibit from new, and it did works. But now, this procedure dosent help.

After is start Multibit i see my Wallet and the amount. But i get the error message: Unable to load blockchain "multibit.blockchain". The error  was "java.lang.IllegalStateExeption -40".

How i can resolve this?

When you reinstall MultiBit it reuses the blockchain file (to save time in redownloading blocks).

You can force it to reuse the one in the installer by:

1) Shutting down multibit
2) Renaming the multibit.blockchain that is in your application data directory (where your default wallets are).

Then if you restart multibit it recopies the one in the install directory.

[jim618]

There is a new test release of MultiBit at:

github.com

Version 0.5.4beta (Encrypted wallets)

Enhancements:
+  Faster bitcoin network connection
+  Rolling wallet backup to mitigate sudden power loss
+  Chart of wallet balance for last 30 days added
+  Drag and drop QR code to desktop
+  Eliminated tab flicker
+  Tab title tooltips now show ok
+  Update to bitcoinj version 0.6-SNAPSHOT
+  Update to XChart 0.2.0


Scan of release checklist


The version of bitcoinj used in this is a couple of days old so is not *quite* the 0.6.0 release that Mike just posted about today - I will fix this next release.

[freemoney458]

Hi Jim,

I just noted an unexpected behaviour in MultiBit-0.5.3beta (on Mac OS X 10.5.8 ):
1. In the 'Request' pane, I can enter a description for a receive address and MultiBit will store this description.
2. If I click on another receive address or use the up/down cursor keys, MultiBit will show the description of the corresponding receive address.
3. If I revisit the receive address from 1) MultiBit shows the correct description.
So far, so good.

4. If I enter an amount in the amount field, e.g. 5, MultiBit does not store this information as belonging to the receive address. The QR-code is updated, though.
5. If I now visit another receive address with the cursor up/down keys or by clicking, MultiBit keeps the amount in the amount field, e.g. 5 and also generates a new QR code for the visited receiving address.
6. After exiting and restarting MultiBit, the amount information seems lost.

My impression is that the amount information is not handled the same like the address description.
This can be confusing, e.g. if you want to use also the amount information for later bookkeeping, say e.g. as a merchant.
Or if you want to regenerate a QR-code, you have to type in the amount again.

So I suggest that MultiBit should handle the amount information the same like the receiving address description.