Fix#1020 (see more relevant discussion there)
This definitely makes the amount of generics compiler
has to generate by avoding generating the same functions
for `R`, &mut R`, `&mut &mut R` and so on.
old:
```
> ls -al target/release/deps/bitcoin-07a9dabf1f3e0266
-rwxrwxr-x 1 dpc dpc 9947832 Jun 2 22:42 target/release/deps/bitcoin-07a9dabf1f3e0266
> strip target/release/deps/bitcoin-07a9dabf1f3e0266
> ls -al target/release/deps/bitcoin-07a9dabf1f3e0266
-rwxrwxr-x 1 dpc dpc 4463024 Jun 2 22:46 target/release/deps/bitcoin-07a9dabf1f3e0266
```
new:
```
> ls -al target/release/deps/bitcoin-07a9dabf1f3e0266
-rwxrwxr-x 1 dpc dpc 9866800 Jun 2 22:44 target/release/deps/bitcoin-07a9dabf1f3e0266
> strip target/release/deps/bitcoin-07a9dabf1f3e0266
> ls -al target/release/deps/bitcoin-07a9dabf1f3e0266
-rwxrwxr-x 1 dpc dpc 4393392 Jun 2 22:45 target/release/deps/bitcoin-07a9dabf1f3e0266
```
In the unit-test binary itself, it saves ~100KB of data.
I did not expect much performance gains, but turn out I was wrong(*):
old:
```
test blockdata::block::benches::bench_block_deserialize ... bench: 1,072,710 ns/iter (+/- 21,871)
test blockdata::block::benches::bench_block_serialize ... bench: 191,223 ns/iter (+/- 5,833)
test blockdata::block::benches::bench_block_serialize_logic ... bench: 37,543 ns/iter (+/- 732)
test blockdata::block::benches::bench_stream_reader ... bench: 1,872,455 ns/iter (+/- 149,519)
test blockdata::transaction::benches::bench_transaction_deserialize ... bench: 136 ns/iter (+/- 3)
test blockdata::transaction::benches::bench_transaction_serialize ... bench: 51 ns/iter (+/- 8)
test blockdata::transaction::benches::bench_transaction_serialize_logic ... bench: 5 ns/iter (+/- 0)
test blockdata::transaction::benches::bench_transaction_size ... bench: 3 ns/iter (+/- 0)
```
new:
```
test blockdata::block::benches::bench_block_deserialize ... bench: 1,028,574 ns/iter (+/- 10,910)
test blockdata::block::benches::bench_block_serialize ... bench: 162,143 ns/iter (+/- 3,363)
test blockdata::block::benches::bench_block_serialize_logic ... bench: 30,725 ns/iter (+/- 695)
test blockdata::block::benches::bench_stream_reader ... bench: 1,437,071 ns/iter (+/- 53,694)
test blockdata::transaction::benches::bench_transaction_deserialize ... bench: 92 ns/iter (+/- 2)
test blockdata::transaction::benches::bench_transaction_serialize ... bench: 17 ns/iter (+/- 0)
test blockdata::transaction::benches::bench_transaction_serialize_logic ... bench: 5 ns/iter (+/- 0)
test blockdata::transaction::benches::bench_transaction_size ... bench: 4 ns/iter (+/- 0)
```
(*) - I'm benchmarking on a noisy laptop. Take this with a grain of salt. But I think
at least it doesn't make anything slower.
While doing all this manual labor that will probably generate conflicts,
I took a liberty of changing generic type names and variable names to
`r` and `R` (reader) and `w` and `W` for writer.
Features activating external crates are supposed to have same name as
those crates. However we depend on same feature in other crates so we
need a separate feature. After MSRV bump it is possible to rename the
crates and features so we can now fix this inconsistency.
Sadly, derive can't see that the crate was renamed so all derives must
be told to use the other one.
Use cargo to upgrade from edition 2015 to edition 2018.
cargo fix --edition
No manual changes made. The result of the command above is just to fix
all the use statements (add `crate::`) and fix the fully qualified path
formats i.e., `::Foo` -> `crate::Foo`.
The exact code formatting we use is not as important as uniformity.
Since we do not use tooling to control the formatting we have to be
vigilant ourselves. Recently I (Tobin) changed the way default type
parameters were formatted (arbitrarily but uniformly). Turns out I
picked the wrong way, there is already a convention as shown in the rust
documentation online (e.g. [1]).
Use 'conventional' spacing for default type parameters. Make the change
across the whole repository, found using
git grep '\<.* = .*\>'
[1] - https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
In this library we specifically do not use rustfmt and tend to favour
terse statements that do not use extra lines unnecessarily. In order to
help new devs understand the style modify code that seems to use an
unnecessary number of lines.
None of these changes should reduce the readability of the code.
This is the initial step towards using and maybe enforcing clippy.
It does not fix all lints as some are not applicable. They may be
explicitly ignored later.
Docs can always do with a bit of love.
Clean up the module level (`//!`) rustdocs for all public modules.
I claim uniform is better than any specific method/style. I tried to fit
in with what ever was either most sane of most prevalent, therefore
attaining uniformity without unnecessary code churn (one exception being
the changes to headings described below).
Notes:
* Headings - use heading as a regular sentence for all modules e.g.,
```
//! Bitcoin network messages.
```
as opposed to
```
//! # Bitcoin Network Messages
```
It was not clear which style to use so I picked a 'random' mature
project and copied their style.
* Added 'This module' in _most_ places as the start of the module
description, however I was not religious about this one.
* Fixed line length if necessary since most of our code seems to follow
short (80 char) line lengths for comments anyways.
* Added periods and fixed obvious (and sometimes not so obvious)
grammatically errors.
* Added a trailing `//!` to every block since this was almost universal
already. I don't really like this one but I'm guessing it is Andrew's
preferred style since its on the copyright notices as well.
Based on the original work by Justin Moon.
*MSRV unchanged from 1.29.0.*
When `std` is off, `no-std` must be on, and we use the [`alloc`](https://doc.rust-lang.org/alloc/) and core2 crates. The `alloc` crate requires the user define a global allocator.
* Import from `core` and `alloc` instead of `std`
* `alloc` only used if `no-std` is on
* Create `std` feature
* Create `no-std` feature which adds a core2 dependency to polyfill `std::io` features. This is an experimental feature and should be
used with caution.
* CI runs tests `no-std`
* MSRV for `no-std` is 1.51 or so
This is instead of encode::Errors because the encoders should
not be allowed to return errors that don't originate in the writer
they are writing into.
This is a part of the method definition that has been relied upon for a
while already.