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.
The main loop of the background processor has this line:
`peer_manager.process_events(); // Note that this may block on ChannelManager's locking`
which does, indeed, sometimes block waiting on the `ChannelManager`
to finish whatever its doing. Specifically, its the only place in
the background processor loop that we block waiting on the
`ChannelManager`, so if the `ChannelManager` is relatively busy, we
may end up being blocked there most of the time.
This should be fine, except today we had a user who's node was
particularly slow in processing some channel updates, resulting in
the background processor being blocked there (as expected). Then,
when the channel updates were completed (and persisted) the next
thing the background processor did was hand the user events to
process, creating yet more channel updates. Ultimately, the users'
node crashed before finishing the event processing. This left us
with an updated monitor on disk and an outdated manager, and they
lost the channel on startup.
Here we simply move the above quoted line to after the normal event
processing, ensuring the next thing we do after blocking on
`ChannelManager` locks is persist the manager, prior to event
handling.
MAX_FUNDING_SATOSHIS will no longer be accurately named once wumbo is merged.
Also, we'll want to check that wumbo channels don't exceed the total bitcoin supply
`ChannelDetails::outbound_capacity_msat` describes the total amount
available for sending across several HTLCs, basically just our
balance minus the reserve value maintained by our counterparty.
However, when routing we use it to guess the maximum amount we can
send in a single additional HTLC, which it is not.
There are numerous reasons why our balance may not match the amount
we can send in a single HTLC, whether the HTLC in-flight limit, the
channe's HTLC maximum, or our feerate buffer.
This commit splits the `outbound_capacity_msat` field into two -
`outbound_capacity_msat` and `outbound_htlc_limit_msat`, setting us
up for correctly handling our next-HTLC-limit in the future.
This also addresses the first of the reasons why the values may
not match - the max-in-flight limit. The inaccuracy is ultimately
tracked as #1126.
I recently saw the following panic on one of my test nodes:
```
thread 'tokio-runtime-worker' panicked at 'called `Result::unwrap()`
on an `Err` value: Os { code: 107, kind: NotConnected, message:
"Transport endpoint is not connected" }',
rust-lightning/lightning-net-tokio/src/lib.rs:250:38
```
Presumably what happened is somehow the connection was closed in
between us accepting it and us going to start processing it. While
this is a somewhat surprising race, its clearly reachable. The fix
proposed here is quite trivial - simply don't `unwrap` trying to
fetch our peer's socket address, instead treat the peer address as
`None` and discover the disconnection later when we go to read.
Default to creating tlv onions for nodes for which we haven't received
any features through node announcements or which aren't in the
`network_graph`, and where no other features are known such as invoice
features nor features in the init msg for nodes we have channels to.
When we start getting a numerator and divisor particularly close to
each other, the log approximation starts to get very noisy. In
order to avoid applying scores that are basically noise (and can
range upwards of 2x the default per-hop penalty), simply consider
such cases as having a success probability of 100%.
When we send values over channels of rather substantial size, the
imprecision of our log lookup tables creates a rather substantial
non-linearity between values that round up or down one bit.
For example, with the default scoring values, sending 100k sats
over channels with 1m, 2m, 3m, and 4m sats of capacity score
rather drastically differently: 3645, 2512, 500, and 1442 msat.
Here we expand the precision of our log lookup tables rather
substantially by: (a) making the multiplier 2048 instead of 1024,
which still fits inside a u16, and (b) quadrupling the size of the
lookup table to look at the top 6 bits after the most-significant
bit of an input instead of the top 4.
This makes the scores of the same channels substantially more
linear, with values of 3613, 1977, 1474, and 1223 msat.
The same channels would be scored at 3611, 1972, 1464, and 1216
msat with a non-approximating scorer.
Having public types in a private module is somewhat awkward from a
readability standpoint, but, more importantly, the bindings logic
has a relatively rough go of converting them - it doesn't implement
`pub use` as its "implement this function" logic is all within the
context of a module. We'd need to keep a set of re-exported things
to implement them when parsing modules...or we could just move two
enums from `de.rs` to `lib.rs` here, which is substantially less
work.
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.
We generally make no effort to ensure all writes are buffered in
lower-level objects, so wrapping write calls in `BufWriter` may
substantially improve performance in some cases. This is especially
important now that we block the sample node exit until the
`NetworkGraph` has been written out, which includes many small-ish
writes.
With this change, shutdown of the sample node on a relatively
underpowered device went from 15-30 seconds of CPU time to a second
or two, plus IO sync time.
