Allow manual rescan

[arnuschky]

btcwallet is currently missing a way to manually trigger a full rescan of the wallet (similar to bitcoin core's --rescan command line parameter).

A full rescan of all addresses at once might be simplest, but feature-wise a RPC call that allows to select addresses to rescan and optionally accepts a starting height would be great.

[jrick]

On master (which uses the old txstore package) this can be triggered by closing wallet, deleting the file ~/.btcwallet/{main,test,sim}net/tx.bin, and restarting. Once #234 lands and transaction history is recorded in the same database as keys, another tool (dropwtxmgr) in the cmd directory will need to be used.

I'm hesitant to add non-hacky ways to do this for all addresses from the wallet, since the rescan is likely necessary because of another bug which should be fixed instead. Rescanning for individual addresses is better, but if it's just imported addresses from batch imports that need rescanning, than a batch import should be added, or delay the rescan of all imported addresses until all of them have been imported.

[arnuschky]

Thanks for the workaround.

Regarding bulk import, I agree. Regarding individual address rescan, once you use a tool for deleting from the common database, wouldn't it be easy to remove the transactions of an individual address?

[jrick]

When would you need individual address rescan for a non-imported address?

[arnuschky]

Err, good point - especially if the overhead of rescanning all addresses at once is low. (We're coming from bitcoin core, where rescan is so slow that we cooked up all kinds of techniques to speed it up...)

[arnuschky]

For the record: #234 has been merged, thus deleting tx.bin does not trigger a rescan anymore.

Instead, use dropwtxmgr --db=/path/to/btcwallet/testnet/wallet.db