Oliver Gould 4f65e3017b

balance: Remove MakeBalance::from_rng (#497) ...

`MakeBalance`'s use of `SmallRng` is problematic: since it clones the
`SmallRng` between `Balance` instances, each instance will have the same
state and produce an identical sequence of values. This probably isn't
_dangerous_, though it is certainly unexpected.

This change removes the `MakeBalance::from_rng` and
`MakeBalanceLayer::from_rng` helpers. The `MakeBalance` service now uses
the default RNG via `Balance::new`. `Balance::new` now creates its
`SmallRng` from the `thread_rng` instead of the default entropy source,
as the default entropy source may use the slower `getrandom`. From the
[`rand` docs][from_entropy]:

> In case the overhead of using getrandom to seed many PRNGs is an
> issue, one may prefer to seed from a local PRNG, e.g.
> from_rng(thread_rng()).unwrap().

Finally, this change updates the balnancer to the most recent version of
`rand`, v0.8.0.

[from_entropy]: https://docs.rs/rand/0.8.0/rand/trait.SeedableRng.html#method.from_entropy

2020-12-28 12:41:35 -08:00

..

Cargo.toml

balance: Remove MakeBalance::from_rng (#497)

2020-12-28 12:41:35 -08:00