In this commit, we refactor the wallet's syncing logic with
syncWithChain to use the newer, simpler methods: syncToBirthday and
recovery. Along the way, we also fix a bug within the wallet where it
was possible to sync past the birthday, but not sync to tip completely
and restart, which would lead to us starting a rescan from the latest
synced height, rather than from the birthday stamp.
This commit slightly changes the wallet's syncing behavior to the
following:
1. Ensure the wallet is synced to its birthday.
2. Perform a recovery if requested.
3. Check for chain reorgs.
4. Dispatch a rescan from the current synced height.
Co-authored-by: Roei Erez <roeierez@gmail.com>
In this commit, we add a new recovery method to the wallet. This method
attempts to recover any unspent outputs which pay to any of the wallet's
addresses. Most of the logic found within it is heavily borrowed from
the existing syncWithChain method. This method is currently unused, but
it will end up replacing some of the existing sync logic in a later
commit.
In this commit, we add a new syncToBirthday method to the wallet. This
method intends to sync the wallet's point of the view of the chain until
finding its birthday. Most of the logic found within it is heavily
borrowed from the existing syncWithChain method. This method is
currently unused, but it will end up replacing some of the existing sync
logic in a later commit.
Co-authored-by: Roei Erez <roeierez@gmail.com>
In this commit, we extend the BitcoindClient to properly detect the
spend of an arbitrary script on-chain. This is possible by looking at a
transaction's input and re-deriving the PkScript, from its signature
script/witness, of the output it's attempting to spend. Upon detecting
the spend, a chain.RelevantTx will be dispatched.
In this commit, we modify the dropwtxmgr tool to force a rescan upon
restart from the wallet's birthday block, rather than the chain's
genesis block. We can safely do this as we expect that no on-chain
events relevant to the wallet should happen before this block. For
older wallets which do not have their birthday block set, the rescan
should start from the genesis block.
In this commit, we address an issue that would cause users to be stuck
in an infinite loop by fetching the same candidate birthday block due to
its height not being updated if the sanity check was attempting to fix
an estimate in the future. We fix this by setting the new candidate
height so that new candidate blocks can be fetched and tested.
In this commit, we remove the wallet dependency from the
birthdaySanityCheck function. Every interaction with the wallet is now
backed by two interfaces, birthdayStore and chainConn. These interfaces
will allow us to increase the test coverage of the birthdaySanityCheck
as now we'll only need to mock out only the necessary functionality.
In this commit, we prevent any further sanity check attempts by the
wallet if its correctness has previously been verified. We do this to
ensure we don't unnecessarily attempt to find a new candidate.
In this commit, we add a new key/value pair to the waddrmgr's sync
bucket to store the verification status of the birthday block. This
verification status determines whether the wallet has verified the
correctness of its birthday block through its sanity check on startup.
In this commit, we address an issue with the wallet where it would
always request a rescan from the birthday block. This is very crucial
for older wallets, as it'll potentially go through thousands of blocks.
To address this, we'll now only request a rescan from our birthday if
we're recovering our wallet from our seed, the birthday block was rolled
back, or if we're performing our initial sync. Otherwise, we'll request
a rescan from tip.
In this commit, we follow up our previous migration to reset our synced
block to our birthday block with another migration to drop our
transaction history. We'll need to do this to ensure that the
transaction store matches the exact state of our outputs on-chain to
prevent inadvertently crafting any invalid transactions.
In this commit, we add a migration to force a rescan of users' wallets
starting from their birthday block to ensure that their balance is
reflected correctly as it is on-chain. This was inspired by the recent
bug discovered where the wallet would not watch for the confirmation of
a relevant transaction.
In this commit, we address a slight regression within the wallet
that was introduced in a previous commit. When attempting to send coins
on-chain, we would never ask the chain backend to notify us of the
transaction upon confirmation. This, along with the rebroadcast of
unconfirmed transactions logic, would result in the wallet becoming out
of sync with the chain.
Below is an example of how this could have happened:
1. Send funds on-chain.
2. Wallet doesn't ask to be notified of the confirmation.
3. Since the wallet is not notified of the confirmation, the
transaction remains in the unconfirmed bucket, even though it might
have already confirmed on-chain.
4. Restart and trigger the rebroadcast of unconfirmed transactions.
5. The unconfirmed transaction is removed from the unconfirmed bucket
due to it already existing on-chain, without it being moved to the
confirmed bucket. Moving to the confirmed bucket would require the
block at which it confirmed, which we don't have at this point.
In this commit, we add a sanity check for the wallet's birthday block
before syncing as a result of the migration that populated it for
existing wallets. This is done as the second part to the migration to
ensure we do not miss any relevant events throughout rescans.
The sanity check performs two main checks: whether the birthday block
timestamp reflects a time before the birthday timestamp and whether the
delta between these two timestamps is a reasonable amount. The birthday
block is then found as the first candidate that satisfies both of these
conditions.
In this commit, we add a new migration to the waddrmgr to populate the
birthday block for existing wallets. This will deem useful when
performing rescans for whatever reason, as we'll now be able to start
from this point rather than the genesis block, incurring a longer
rescan.
The migration is not as reliable since we do not store block timestamps,
so we'll need to estimate our height by looking at the genesis timestamp
and assuming a block occurs every 10 minutes. This can be unsafe, and
cause us to actually miss on-chain events, so a sanity check will be
added before the wallet attempts to sync itself in a later commit.
In this commit, we add a new key/value pair within the waddrmgr's
syncBucket that will represent the birthday block of the wallet. This
can then be used to force rescans from this point, rather than from the
genesis block.
