Get rid of the 'movement_idx', since we replay events now.
Since we're removing a field from the 'coin_movement' event emission, we
bump the version type.
Changelog-Updated: `coin_movements` events have been revamped and are now on version 2.
The old model of coin movements attempted to compute fees etc and log
amounts, not utxos. This is not as robust, as multi-party opens and dual
funded channels make it hard to account for fees etc correctly.
Instead, we move towards a 'utxo' view of the onchain events. Every
event is either the creation or 'destruction' of a utxo. For cases where
the value of the utxo is not (fully) debited/credited to our account, we
also record the output_value. E.g. channel closings spend a utxo who's
entire value we may not own.
Since we're now tracking UTXOs onchain, we can now do more complex
assertions about the onchain footprint of them. The integration tests
have been updated to now use more 'chain aware' assertions about the
ending state.
We're not going to do 'spend tracks' any more; instead we'll emit an
event whenever an output is included in a broadcast tx
(even if the broadcast fails!!)
v2 channel open uses a different method to derive the channel_id, so now
we save it to the database so that we dont have to remember how to
derive it for each.
includes a migration for existing channels
This moves the notification for our coin spends from when it's
successfully submited to the mempool to when they're confirmed in a
block.
We also add an 'informational' notice tagged as `spend_track` which
can be used to track which transaction a wallet output was spent in.
Previously we were annotating every movement with the blockheight of
lightningd at notification time. Which is lossy in terms of info, and
won't be helpful for reorg reconciliation. Here we switch over to
logging chain moves iff they've been confirmed.
Next PR will fix this up for withdrawals, which are currently tagged
with a blockheight of zero, since we log on successful send.
onchaind is the only daemon that emits coin events, and those are all
onchain (ha!), so the only 'wire' facility we need for coin moves are
for the 'chain' type.
niftynei
Rusty Russell