rust-secp256k1-unsafe-fast/src/macros.rs

129 lines
4.5 KiB
Rust

// Bitcoin secp256k1 bindings
// Written in 2014 by
// Dawid Ciężarkiewicz
// Andrew Poelstra
//
// To the extent possible under law, the author(s) have dedicated all
// copyright and related and neighboring rights to this software to
// the public domain worldwide. This software is distributed without
// any warranty.
//
// You should have received a copy of the CC0 Public Domain Dedication
// along with this software.
// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
//
/// Implement methods and traits for types that contain an inner array.
#[macro_export]
macro_rules! impl_array_newtype {
($thing:ident, $ty:ty, $len:expr) => {
impl AsRef<[$ty; $len]> for $thing {
#[inline]
/// Gets a reference to the underlying array
fn as_ref(&self) -> &[$ty; $len] {
let &$thing(ref dat) = self;
dat
}
}
impl<I> core::ops::Index<I> for $thing
where
[$ty]: core::ops::Index<I>,
{
type Output = <[$ty] as core::ops::Index<I>>::Output;
#[inline]
fn index(&self, index: I) -> &Self::Output { &self.0[index] }
}
impl $crate::ffi::CPtr for $thing {
type Target = $ty;
fn as_c_ptr(&self) -> *const Self::Target {
let &$thing(ref dat) = self;
dat.as_ptr()
}
fn as_mut_c_ptr(&mut self) -> *mut Self::Target {
let &mut $thing(ref mut dat) = self;
dat.as_mut_ptr()
}
}
};
}
macro_rules! impl_pretty_debug {
($thing:ident) => {
impl core::fmt::Debug for $thing {
fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
write!(f, "{}(", stringify!($thing))?;
for i in &self[..] {
write!(f, "{:02x}", i)?;
}
f.write_str(")")
}
}
};
}
macro_rules! impl_non_secure_erase {
($thing:ident, $target:tt, $value:expr) => {
impl $thing {
/// Attempts to erase the contents of the underlying array.
///
/// Note, however, that the compiler is allowed to freely copy or move the
/// contents of this array to other places in memory. Preventing this behavior
/// is very subtle. For more discussion on this, please see the documentation
/// of the [`zeroize`](https://docs.rs/zeroize) crate.
#[inline]
pub fn non_secure_erase(&mut self) {
secp256k1_sys::non_secure_erase_impl(&mut self.$target, $value);
}
}
};
}
/// Formats error. If `std` feature is OFF appends error source (delimited by `: `). We do this
/// because `e.source()` is only available in std builds, without this macro the error source is
/// lost for no-std builds.
macro_rules! write_err {
($writer:expr, $string:literal $(, $args:expr),*; $source:expr) => {
{
#[cfg(feature = "std")]
{
let _ = &$source; // Prevents clippy warnings.
write!($writer, $string $(, $args)*)
}
#[cfg(not(feature = "std"))]
{
write!($writer, concat!($string, ": {}") $(, $args)*, $source)
}
}
}
}
/// Implements fast unstable comparison methods for `$ty`.
macro_rules! impl_fast_comparisons {
($ty:ident) => {
impl $ty {
/// Like `cmp::Cmp` but faster and with no guarantees across library versions.
///
/// The `Cmp` implementation for FFI types is stable but slow because it first
/// serializes `self` and `other` before comparing them. This function provides a faster
/// comparison if you know that your types come from the same library version.
pub fn cmp_fast_unstable(&self, other: &Self) -> core::cmp::Ordering {
self.0.cmp_fast_unstable(&other.0)
}
/// Like `cmp::Eq` but faster and with no guarantees across library versions.
///
/// The `Eq` implementation for FFI types is stable but slow because it first serializes
/// `self` and `other` before comparing them. This function provides a faster equality
/// check if you know that your types come from the same library version.
pub fn eq_fast_unstable(&self, other: &Self) -> bool {
self.0.eq_fast_unstable(&other.0)
}
}
};
}