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
Validating a block's proof-of-work involves computing the block hash.
Returning it from BlockHeader::validate_pow avoids having callers
recompute the block hash if it is needed.
Taking an external dependency just to convert ints to byte arrays
is somewhat of a waste, especially when Rust isn't very aggressive
about doing cross-crate LTO.
Note that the latest LLVM pattern-matches this, and while I haven't
tested it, that should mean this means no loss of optimization.
The protocol has a bug where a 0u8 is pushed at the end of each
block header on the wire in headers messages. WHy this bug came
about is unrealted and shouldn't impact API design.
- Move network::encodable::* to consensus::encode::*
- Rename Consensus{En,De}codable to {En,De}codable (now under
consensus::encode)
- Move network::serialize::Error to consensus::encode::Error
- Remove Raw{En,De}coder, implement {En,De}coder for T: {Write,Read}
instead
- Move network::serialize::Simple{En,De}coder to
consensus::encode::{En,De}coder
- Rename util::Error::Serialize to util::Error::Encode
- Modify comments to refer to new names
- Modify files to refer to new names
- Expose {En,De}cod{able,er}, {de,}serialize, Params
- Do not return Result for serialize{,_hex} as serializing to a Vec
should never fail
Addresses #96.
Turns out it was being used for hex encoding/decoding, so replaced that with the `hex` crate.
i chose to import the `decode` method as:
```
use hex::decode as hex_decode
```
so that it is clear to the reader what is being decoded when it is called. "decode" is such a generic sounding function name that it would get confusing otherwise.