This adds testing of the `futures` feature to CI. In order to avoid
introducing a dependency on `std`, we switch to using the `futures-util`
crate directly enabling only a subset of features. To this end, we also
switch to using the `select_biased!` macro, which is equivalent to
`select!` except that it doesn't choose ready futures pseudo-randomly
at runtime.
Expand the BlockSource trait to allow filtered blocks now that
chain::Listen supports them (d629a7edb7).
This makes it possible to use BIP 157/158 compact block filters with
lightning-block-sync.
The `chain::Listen` interface provides a block-connection-based
alternative to the `chain::Confirm` interface, which supports
providing transaction data at a time separate from the block
connection time.
For users who are downloading the full headers tree (e.g. from a
node over the Bitcoin P2P protocol) but who are not downloading
full blocks (e.g. because they're using BIP 157/158 filtering)
there is no API that matches exactly their event stream -
`chain::Listen` requries full blocks for each block,
`chain::Confirm` requires breaking each connection event into two
calls.
Given its incredibly trivial to take a `TransactionData` in
addition to a `Block` in `chain::Listen` we do so here, adding a
default-implementation `block_connected` which simply creates the
`TransactionData`, which ultimately all of the `chain::Listen`
implementations currently do anyway.
Closes#1128.
Querying a BlockSource is a logically immutable operation. Use non-mut
references in its interface to reflect this, which allows for users to
hold multiple references if desired.
Users who want to use lightning-block-sync's init module would
be reasonable in wanting to use it in a multithreaded environment,
however because it takes a list of listeners as dyn chain::Listen
without any Send or Sync bound they fail in doing so.
Here we make the type bounds on `chain::Listen` generic across
`chain::Listen + ?Sized`, which the existing bound of `&dyn
chain::Listen` satisfies. Thus, this is strictly less restrictive
and allows for the use of `&dyn chain::Listen + Send + Sync`.
std::io::ErrorKind is a `#[non_exhaustive]` enum as more specific
error types are to be added in the future. It was unclear in the
docs until very recently, however, that this is to be done by
re-defining `ErrorKind::Other` errors to new enum variants. Thus,
our tests which check explicitly for `ErrorKind::Other` as a
result of trying to access a directory as a file were incorrect.
Sadly, these generated no meaningful feedback from rustc at all,
except that they're suddenly failing in rustc beta!
After some back-and-forth, it seems rustc is moving forward
breaking existing code in future versions, so we move to the
"correct" check here, which is to check the raw IO error.
See rust-lang/rust#86442 and rust-lang/rust#85746 for more info.
