8ccfb412c1 Improve documentation of `hash_newtype!` (Martin Habovstiak)
58876e2be9 Remove unused macro (Martin Habovstiak)
Pull request description:
Removed unused macro and improved documentation to address review of #1659 - see commits. I also added a note about recursion.
ACKs for top commit:
apoelstra:
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tcharding:
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Tree-SHA512: 3b4b0c4ffc8a5166619110d9dcb51affd5cafbb2af84a55dd540a815e4702514d99c71dc1c54aca27fb91970e7e7189d1dffb4f7da7951b0f71336ef6f32d30b
The macro is non-trivial, so documenting it well is very useful. This
change improves both user-facing and developer-facing code with
appropriate warnings about the limitations of the code and Rust macro
system.
Currently we have an associated type on hash types `Inner` with
accompanying methods `into_inner`, `from_inner`, `as_inner`. Also, we
provide a way to create new wrapped hash types. The use of 'inner'
becomes ambiguous with the addition of wrapped types because the inner
could be the inner hash type or the `Inner` byte array of the inner
wrapped hash type.
In an effort to make the API more clear and uniform do the following:
- Rename `Inner` -> `Bytes`
- Rename `*_inner` -> `*_byte_array`
- Rename the inner hash to/from methods to `*_raw_hash`
Correct method prefix `into_` -> `to_` because theses methods convert
owned `Copy` types.
Add the trait Bound `Copy` to the `Bytes` type because we rely on this
trait bound for the conversion methods to be correctly named according
to convention.
Because of the dependency hole created by `secp256k1` this patch changes
the secp dependency to a git tag dependency that includes changes to the
hashes calls required so that we can get green lights on CI in this
repo.
The API guidelines say macro input should be evocative of the output.
`hash_newtype` didn't have this property.
This change makes it look exactly like the resulting struct, `$len`
parameter was removed since it's not needed, reversing is controlled
using an attribute. The macro is also better documented and ready to be
extended in the future.
The tagged SHA256 newtype is not yet modified because it has a more
complicated input parameters.
Closes#1648
a121e19e94 hashes: Implement AsRef for fixed size arrays (Tobin C. Harding)
Pull request description:
Implement `AsRef<[u8; X]>` for hash types including wrapped hash types. Doing so means at times the compiler can no longer infer the type because we have `AsRef<[u8]` implemented also but we can use `into_inner` and `as_inner` to get the inner array if needed.
Fix: #1462
## Note
This touches code that will likely be changed by #1577 and when we do #1491 but I believe its a step forward.
ACKs for top commit:
arturomf94:
ACK [`a121e19`](a121e19e94)
apoelstra:
ACK a121e19e94
Kixunil:
ACK a121e19e94
Tree-SHA512: 257c44826c7649db25bb3a6f023f68b2f17b70c546a056afad044bc8a16bf61f654c3846222505aaf5e6f9a0ad1d2113272d61317b407d0ac83702e41060a1ee
Remove `FromHex` from hash and script types
- Remove the `FromHex` implementation from hash types and `ScriptBuf`
- Remove the `FromStr` implementation from `ScriptBuf` because it does not
roundtrip with `Display`.
- Implement a method `from_hex` on `ScriptBuf`.
- Implement `FromStr` on hash types using a fixed size array.
This leaves `FromHex` implementations only on `Vec` and fixed size arrays.
Implement `AsRef<[u8; X]>` for hash types including wrapped hash types.
Doing so means at times the compiler can no longer infer the type because we have
`AsRef<[u8]` implemented also but we can use `into_inner` and `as_inner`
to get the inner array if needed.
`bitcoin-internals` contains a more performant implementation of hex
encoding than what `bitcoin_hashes` uses internally. This switches the
implementations for formatting trait implementations as a step towards
moving over completely.
The public macros are also changed to delegate to inner type which is
technically a breaking change but we will break the API anyway and the
consuers should only call the macro on the actual hash newtypes where
the inner types already have the appropriate implementations.
Apart from removing reliance on internal hex from public API this
reduces duplicated code generated and compiled. E.g. if you created 10
hash newtypes of SHA256 the formatting implementation would be
instantiated 11 times despite being the same.
To do all this some other changes were required to the hex
infrastructure. Mainly modifying `put_bytes` to accept iterator (so that
`iter().rev()` can be used) and adding a new `DisplayArray` type. The
iterator idea was invented by Tobin C. Harding, this commit just adds a
bound check and generalizes over `u8` and `&u8` returning iterators.
While it may seem that `DisplayByteSlice` would suffice it'd create and
initialize a large array even for small arrays wasting performance.
Knowing the exact length `DisplayArray` fixes this.
Another part of refactoring is changing from returning `impl Display` to
return `impl LowerHex + UpperHex`. This makes selecting casing less
annoying since the consumer no longer needs to import `Case` without
cluttering the API with convenience methods.
Currently we implement `Deref` for hashes. From the docs [0]
> Deref should only be implemented for smart pointers to avoid confusion
Furthermore because we implement `Deref` as well as implement
`internals::hex::display::DisplayHex` for slices hashes get coerced into
slices and `to_lower_hex_string` can be called on them, this is
incorrect because `DisplayHex` does not account for hashes that display
backwards so we end up with the wrong string.
[0] https://doc.rust-lang.org/std/ops/trait.Deref.html
We would like to bring the `bitcoin_hashes` crate into the
`rust-bitcoin` repository.
Import `bitcoin_hashes` into `rust-bitocin/hashes`, doing so looses all
the commit history from the original crate but if we archive the
original repository then the history will be preserved. We maintain the
same version number obviously and in the changelog we note the change of
repository.
Commit hash that was tip of `bitcoin_hashes` at time of import:
commit 54c16249e06cc6b7870c7fc07d90f489d82647c7
Includes making `embedded` and `fuzzing` per-crate i.e., move them into
`bitcoin` as hashes includes these also.
NOTE: Does _not_ enable fuzzing for `hashes` in CI.
Notes on CI:
Attempts to merge in the github actions from the hashes crate however reduces
coverage by not running hashes tests for beta toolchain. Some additional
work could be done to improve the CI to increase efficiency without
reducing coverage. Leaving for another day.
Andrew Poelstra
Martin Habovstiak
Tobin C. Harding