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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.use super::transl8::{FromV8, ToV8};use crate::magic::transl8::impl_magic;use crate::Error;use smallvec::SmallVec;use std::mem::size_of;
const USIZE2X: usize = size_of::<usize>() * 2;
#[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 ByteString(SmallVec<[u8; USIZE2X]>);impl_magic!(ByteString);
// const-assert that Vec<u8> and SmallVec<[u8; size_of::<usize>() * 2]> have a same size.// Note from https://docs.rs/smallvec/latest/smallvec/#union -//   smallvec can still be larger than Vec if the inline buffer is//   larger than two machine words.const _: () =  assert!(size_of::<Vec<u8>>() == size_of::<SmallVec<[u8; USIZE2X]>>());
impl ToV8 for ByteString {  fn to_v8<'a>(    &mut self,    scope: &mut v8::HandleScope<'a>,  ) -> Result<v8::Local<'a, v8::Value>, crate::Error> {    let v =      v8::String::new_from_one_byte(scope, self, v8::NewStringType::Normal)        .unwrap();    Ok(v.into())  }}
impl FromV8 for ByteString {  fn from_v8(    scope: &mut v8::HandleScope,    value: v8::Local<v8::Value>,  ) -> Result<Self, crate::Error> {    let v8str = v8::Local::<v8::String>::try_from(value)      .map_err(|_| Error::ExpectedString)?;    if !v8str.contains_only_onebyte() {      return Err(Error::ExpectedLatin1);    }    let len = v8str.length();    let mut buffer = SmallVec::with_capacity(len);    #[allow(clippy::uninit_vec)]    // SAFETY: we set length == capacity (see previous line),    // before immediately writing into that buffer and sanity check with an assert    unsafe {      buffer.set_len(len);      let written = v8str.write_one_byte(        scope,        &mut buffer,        0,        v8::WriteOptions::NO_NULL_TERMINATION,      );      assert!(written == len);    }    Ok(Self(buffer))  }}
// smallvec does not impl From/Into traits// like Vec<u8> does. So here we are.
impl From<Vec<u8>> for ByteString {  fn from(vec: Vec<u8>) -> Self {    ByteString(SmallVec::from_vec(vec))  }}
#[allow(clippy::from_over_into)]impl Into<Vec<u8>> for ByteString {  fn into(self) -> Vec<u8> {    self.0.into_vec()  }}
impl From<&[u8]> for ByteString {  fn from(s: &[u8]) -> Self {    ByteString(SmallVec::from_slice(s))  }}
impl From<&str> for ByteString {  fn from(s: &str) -> Self {    let v: Vec<u8> = s.into();    ByteString::from(v)  }}
impl From<String> for ByteString {  fn from(s: String) -> Self {    ByteString::from(s.into_bytes())  }}