When we added `Target` and `Work` types we implemented multiplication
and division by anything `Into<u64>`, this is not typically done in the
Rust stdlib and also is semantically incorrect for the types.
Remove `Mul` and `Div` impls from `Target` and `Work`. Also remove
`Mul<T>` for `T: Into<u64>` from the private `U256` type.
The `max_value` and `min_value` functions only exist to be
compatible/uniform with Rust 1.41.1 they will never change and they just
return a constant value. They can therefore be made const functions.
Recently we introduced some mutation testing to the `pow` module but
testing is never done - add more `mutate` attributes and add unit tests
to ensure all mutants are killed.
Of note, the `from_compact` and `to_compact_lossy` functions are not
done, doing so results in a bunch of surviving mutants.
The `ToHex` trait was replaced by either simple `Display`/`LowerHex`
where appropriate or `DisplayHex` from `bitcoin_internals` which is
faster.
This change replaces the usages and removes the trait.
Add kani verification for `U256::mul_u64`, doing so uncovered a bug in
the current implementation due to overflow.
Re-write the `mul_u64` method.
Props to Elichai for the algorithm.
Co-authored-by: Elichai Turkel <elichai.turkel@gmail.com>
Introduce mutation testing by way of mutagen [0]
- Conditionally add the dev-dependency `mutagen` (using `do_mutate`
flag)
This flag is not very well named but `mutagen` and `mutate` are already
taken?
- Mutate all methods of the `U256` struct that do not require additional
unit tests.
Uses `cfg(all(test, do_mutate), mutate)` - I cannot workout why we need
to check on `test` as well i.e., I don't understand why we cannot use
`cfg(do_mutate, mutate)`?
With this applied test can be run as usual with a stable toolchain. To
run mutagen we use `RUSTFLAGS='--cfg=do_mutate' cargo +nightly mutagen`.
[0] https://github.com/llogiq/mutagen
Adds new module `string` to be later converted to its own
crate. The module currently contains the FromHexStr trait and an error
type to be used for implementing hex parsing on types. This change
also adds implementations of FromHexStr for types with a single u32
member such as `Sequence(pub u32)`. All structs that match the
following regex have been given this implementation
`\(u32\)` and `\(pub u32\)`. All implementations have associated
unit tests matching all possible cases. NonStandardSighashType has
been ommitted from this change as it is an error and should not be
constructed using the methods added in this change.
Adds parse::hex_u32 for future use to be made generic to allow
different sizes of integers to be parsed from hex strings.
The error type FromHexError implements required traits such as
Display and std::error::Error
Currently the types in the block module have longer names than
necessary, "header" and "version" identifiers contain the word "block",
this is unnecessary because we can write `block::Header` instead of
`BlockHeader` when context is required. This allows us to use the naked
type `Header` inside the `block` module with no loss of clarity.
We are stuck with `BlockHash` because the type is defined along with all
the other hash types in `hash_types`, leave it as is for now but
re-export it from the `block` module to assist in putting types that are
used together in scope in the same place, making import statements more
ergonomic.
A zero default value for `Target` and `Work` has no significance and/or
usecase, remove the derived `Default` implementation.
Includes making `Target::ZERO` public.
Currently we use the `Uint256` type to represent two proof of work
integers, namely target and difficulty (work).
It would be nice to not have a public integer type that is not fully
implemented (i.e., does not implement arithmetic etc as do integer types
in stdlib). Instead of implementing all the stdlib functions we can
instead add two new wrapper types, since these are not general purpose
integers they do not need to implement anything we do not need to use.
- Add a `pow` module.
- Put a modified version of `Uint256` to `pow`.
- Add two new wrapper types `Target` and `Difficulty`.
- Only implement methods that we use on each type.
Note this patch does not remove the original `Uint256`, that will be
done as a separate patch.
Tobin C. Harding
Martin Habovstiak
connormullett
Jiri Jakes