After joining the two forked chains, it is necessary to ensure they both agree on the same best hash before proceeding to UnsafeStart the notifier.
This is because when the BitcoindClient starts, it retrieves its best known block then calls GetBlockHeaderVerbose on the hash of the retrieved block. This block could be a reorged block if JoinNodes has not completed sync. If it is the case that the best block retrieved has been reorged out of the chain, GetBlockHeaderVerbose errors because bitcoind sets the number of confirmations to -1 on reorged blocks, and the btcd rpc client panics when parsing a block whose number of confirmations is negative.
This parsing error is expected to be fixed, and as a more permanent solution chain backends should ensure that the `best block` they retrieve during startup has not been reorged out of the chain.
In this commit, we extract some of the helper test variables and
functions into their own file and guard them under a build flag. This is
needed as some unit tests will be introduced in a future commit where
most of the same functions within the interface tests are reused. In
order to prevent these variables and functions from being exportable, we
guard them by the "debug" build tag.
Tests for the case where a chain backend skips a series of blocks, such that the notifier's best block is out of date. Also tests the case where a notifier's best block has been reorged out of the chain.
This tests the case where a client registers for block notifications with an outdated best block, to ensure that the client is properly caught up on the blocks that it has missed.
Switches all ChainNotifier parameters to be TestChainNotifiers. This allows access to the extra testing methods provided by the TestChainNotifier interface.
In this commit, we introduce a nice optimization with regards to lnd's
interaction with a bitcoind backend. Within lnd, we currently have three
different subsystems responsible for watching the chain: chainntnfs,
lnwallet, and routing/chainview. Each of these subsystems has an active
RPC and ZMQ connection to the underlying bitcoind node. This would incur
a toll on the underlying bitcoind node and would cause us to miss ZMQ
events, which are crucial to lnd. We remedy this issue by sharing the
same connection to a bitcoind node between the different clients within
lnd.
This commit increases the time we wait for a spend client to notify a
mempool spend from 50ms to 10s. This is done to catch the case where
bitcoind would use up to 7 seconds before notifying about a mempool
spend, which wasn't caught by the test.
This commit extends the test to exercise a scanario that wasn't properly
covered, by registering for a confirmed spend notification for a
historical spend. We also extend the test to make sure it handles buried
spends properly.
This commit changes the chainntnfs tests to adhere to the new
RegisterSpendNtfn signature. It also makes sure that for the test
testSpendNotification, we are only getting notified when a spend is
mined, as previously btcd would notify on mempool inclusion, while
neutrino and bitcoind would notify only on confirmation, and the test
wouldn't catch this.
In this commit, we extend the existing historical dispatch test case to
detect any instances of early dispatches. This catches a class of bug
within a ChainNotifier when the notifier will *always* dispatch early
no matter the number of confirmations. Currently, this test fails for
the neutrino notifier.
This test adds a test for a consumer that registers for a transaction
confirmation but takes some time to check if that confirmation has
occured.
The test reveals a race condition that can cause btcdnotify to add a
confirmation entry to its internal heap twice. If the notification
consumer is not prompt in reading from the confirmation channel, this
can cause the notifier to block indefinitely.
This commit reduces the neutrino.WaitForMoreCFHeaders parameter when
instantiating a neutrino instance as a lower value will allow the tests
to complete more quickly.
This commit adds a new case and proper initialization for the
NeutrinoNotifier implementation, such that it can be tested in-line
with the other implementations for proper behavior conformity.
Due to a delay when btcd sends invs for new blocks, the timeouts for
several of the tests has been extended in order to give enough time for
propagation of the new block.
This commit adds an initial rough implementation father ChainNotifier
interface for neutrino, our new light client implementation. This
implementation largely borrows from the existing BtcdNotifier
implementation. As a result, a follow up commit will perform two
refactoring in order to further consolidate code.
This commit updates two interface-level tests for confirmation
notifications to check the txIndex and blockHeight advertised to serve
as regression tests for the recent bug fix related to properly setting
these two fields.
This commit modifies two of the main methods in the ChainNotifier
interface to be more light client friendly. In order to do so, we now
tack on an extra parameter to the methods: heightHint. This value
represents the earliest known height that the chain should be scanned
when attempting to do a dispatch from historical data.
All tests have also been updated to use these new parameters properly
when excising the expected behavior of each interface implementation.
This commit modifies the btcdnotify implementation of the ChainNotifier
interface to properly include the height in which the watched output
was spent in the SpendDetail sent as a notification.
The set of tests have also been updated to assert that the proper
spending height is included in received notification.
When iterating with the ChainNotifier, it currently isn’t possible to
cancel a non-dispatched yet active notificaiton intent. As a result,
this can be rather wasteful in many parts of lnd which my repeatedly
create a new spend notification depending on if/when a peer is
connected or not.
In order to fix this, we add a new `Cancel func()` field to both the
`BlockEpochEvent` and `SpendEvent` structs. This new closure attribute
allows the caller to cancel the yet-to-be-dispathed event, allowing the
ChainNotifier to free up resources.
This commit makes a large number of minor changes concerning API usage
within the deamon to match the latest version on the upstream btcsuite
libraries.
The major changes are the switch from wire.ShaHash to chainhash.Hash,
and that wire.NewMsgTx() now takes a paramter indicating the version of
the transaction to be created.
This commit modifies the ChainNotifier interface, specifically the
ConfirmationEvent struct to now return additional details concerning
the exact location in the chain that the transaction was confirmed at.
This information will be very useful within the new routing package, as
within the network, channels are identified via their channel-ID which
is a compact encoding of: blockHeight | txIndex | outputIndex
