mirror of
https://github.com/denoland/deno.git
synced 2024-12-28 18:19:08 -05:00
77 lines
2.2 KiB
Rust
77 lines
2.2 KiB
Rust
// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
|
|
|
|
use smallvec::smallvec;
|
|
use smallvec::SmallVec;
|
|
|
|
use super::transl8::FromV8;
|
|
use super::transl8::ToV8;
|
|
use crate::error::value_to_type_str;
|
|
use crate::magic::transl8::impl_magic;
|
|
use crate::Error;
|
|
|
|
#[derive(
|
|
PartialEq,
|
|
Eq,
|
|
Clone,
|
|
Debug,
|
|
Default,
|
|
derive_more::Deref,
|
|
derive_more::DerefMut,
|
|
derive_more::AsRef,
|
|
derive_more::AsMut,
|
|
)]
|
|
#[as_mut(forward)]
|
|
#[as_ref(forward)]
|
|
pub struct BigInt(num_bigint::BigInt);
|
|
impl_magic!(BigInt);
|
|
|
|
impl ToV8 for BigInt {
|
|
fn to_v8<'a>(
|
|
&mut self,
|
|
scope: &mut v8::HandleScope<'a>,
|
|
) -> Result<v8::Local<'a, v8::Value>, crate::Error> {
|
|
let (sign, words) = self.0.to_u64_digits();
|
|
let sign_bit = sign == num_bigint::Sign::Minus;
|
|
let v = v8::BigInt::new_from_words(scope, sign_bit, &words).unwrap();
|
|
Ok(v.into())
|
|
}
|
|
}
|
|
|
|
impl FromV8 for BigInt {
|
|
fn from_v8(
|
|
_scope: &mut v8::HandleScope,
|
|
value: v8::Local<v8::Value>,
|
|
) -> Result<Self, crate::Error> {
|
|
let v8bigint = v8::Local::<v8::BigInt>::try_from(value)
|
|
.map_err(|_| Error::ExpectedBigInt(value_to_type_str(value)))?;
|
|
let word_count = v8bigint.word_count();
|
|
let mut words: SmallVec<[u64; 1]> = smallvec![0u64; word_count];
|
|
let (sign_bit, _words) = v8bigint.to_words_array(&mut words);
|
|
let sign = match sign_bit {
|
|
true => num_bigint::Sign::Minus,
|
|
false => num_bigint::Sign::Plus,
|
|
};
|
|
// SAFETY: Because the alignment of u64 is 8, the alignment of u32 is 4, and
|
|
// the size of u64 is 8, the size of u32 is 4, the alignment of u32 is a
|
|
// factor of the alignment of u64, and the size of u32 is a factor of the
|
|
// size of u64, we can safely transmute the slice of u64 to a slice of u32.
|
|
let (prefix, slice, suffix) = unsafe { words.align_to::<u32>() };
|
|
assert!(prefix.is_empty());
|
|
assert!(suffix.is_empty());
|
|
assert_eq!(slice.len(), words.len() * 2);
|
|
let big_int = num_bigint::BigInt::from_slice(sign, slice);
|
|
Ok(Self(big_int))
|
|
}
|
|
}
|
|
|
|
impl From<num_bigint::BigInt> for BigInt {
|
|
fn from(big_int: num_bigint::BigInt) -> Self {
|
|
Self(big_int)
|
|
}
|
|
}
|
|
|
|
impl From<BigInt> for num_bigint::BigInt {
|
|
fn from(big_int: BigInt) -> Self {
|
|
big_int.0
|
|
}
|
|
}
|