1bf885550e Redesign `hex::BufEncoder` to accept owned arrays (Martin Habovstiak)
Pull request description:
Not being able to create an owned `BufEncoder` prevented returning it from functions which need to allocate the buffer on stack. Such is the case in WIP serde via consensus serialzation.
This change refactors `OutBytes` to be unsized, adds an `AsOutBytes` trait and uses that one instead of `Into` to perform the conversion.
Closes#1270
This is meant as potentially mergeable demonstration. Interestingly, it was easier than I expected.
ACKs for top commit:
tcharding:
Except for the question about the `out_bytes` module, ACK 1bf885550e
apoelstra:
ACK 1bf885550e
Tree-SHA512: 39bc48e54ae0e66b988ba5ad6ea7ecbe03e5f4c71792df0f8e2b03aa2e97e2c0fac1cb03e84ecac12ec6f13649554b57e1000710c34c638d17d9bb575d0ac0a1
Not being able to create an owned `BufEncoder` prevented returning it
from functions which need to allocate the buffer on stack. Such is the
case in WIP serde via consensus serialzation.
This change refactors `OutBytes` to be unsized, adds an `AsOutBytes`
trait and uses that one instead of `Into` to perform the conversion.
There's a `hex` module in `bitcoin_hashes` which is a bit out of place
and not very fast - it passes each *digit* through dynamic dispatch not
only adding overhead but also not allowing `String` to make better
allocations.
This change adds basic support for hex encoding using a stack-allocated
buffer which minimizes the overhead of dynamic dispatch. It also
provides a new `DisplayHex` trait designed to replace `ToHex` found in
`bitcoin_hashes`.
Add a new crate `bitcoin-internals` to be used for internal code needed
by multiple soon-to-be-created crates.
Add the `write_err` macro to `bitcoin-internals`, nothing else.
This patch uses a `path` dependency which means `rust-bitcoin` cannot be
released in its current state, will need to be changed once we release
the `bitcoin-internals` crate on `crates.io`.
Tobin C. Harding
Andrew Poelstra
Martin Habovstiak