diff options
Diffstat (limited to 'serde_v8/src/magic/zero_copy_buf.rs')
-rw-r--r-- | serde_v8/src/magic/zero_copy_buf.rs | 102 |
1 files changed, 0 insertions, 102 deletions
diff --git a/serde_v8/src/magic/zero_copy_buf.rs b/serde_v8/src/magic/zero_copy_buf.rs deleted file mode 100644 index 1f07292ba..000000000 --- a/serde_v8/src/magic/zero_copy_buf.rs +++ /dev/null @@ -1,102 +0,0 @@ -// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license. - -use rusty_v8 as v8; -use std::cell::Cell; -use std::ops::Deref; -use std::ops::DerefMut; - -/// A ZeroCopyBuf encapsulates a slice that's been borrowed from a JavaScript -/// ArrayBuffer object. JavaScript objects can normally be garbage collected, -/// but the existence of a ZeroCopyBuf inhibits this until it is dropped. It -/// behaves much like an Arc<[u8]>. -/// -/// # Cloning -/// Cloning a ZeroCopyBuf does not clone the contents of the buffer, -/// it creates a new reference to that buffer. -/// -/// To actually clone the contents of the buffer do -/// `let copy = Vec::from(&*zero_copy_buf);` -#[derive(Clone)] -pub struct ZeroCopyBuf { - backing_store: v8::SharedRef<v8::BackingStore>, - byte_offset: usize, - byte_length: usize, -} - -unsafe impl Send for ZeroCopyBuf {} - -impl ZeroCopyBuf { - pub fn new<'s>( - scope: &mut v8::HandleScope<'s>, - view: v8::Local<v8::ArrayBufferView>, - ) -> Self { - let backing_store = view.buffer(scope).unwrap().get_backing_store(); - let byte_offset = view.byte_offset(); - let byte_length = view.byte_length(); - Self { - backing_store, - byte_offset, - byte_length, - } - } -} - -impl Deref for ZeroCopyBuf { - type Target = [u8]; - fn deref(&self) -> &[u8] { - unsafe { - get_backing_store_slice( - &self.backing_store, - self.byte_offset, - self.byte_length, - ) - } - } -} - -impl DerefMut for ZeroCopyBuf { - fn deref_mut(&mut self) -> &mut [u8] { - unsafe { - get_backing_store_slice_mut( - &self.backing_store, - self.byte_offset, - self.byte_length, - ) - } - } -} - -impl AsRef<[u8]> for ZeroCopyBuf { - fn as_ref(&self) -> &[u8] { - &*self - } -} - -impl AsMut<[u8]> for ZeroCopyBuf { - fn as_mut(&mut self) -> &mut [u8] { - &mut *self - } -} - -unsafe fn get_backing_store_slice( - backing_store: &v8::SharedRef<v8::BackingStore>, - byte_offset: usize, - byte_length: usize, -) -> &[u8] { - let cells: *const [Cell<u8>] = - &backing_store[byte_offset..byte_offset + byte_length]; - let bytes = cells as *const [u8]; - &*bytes -} - -#[allow(clippy::mut_from_ref)] -unsafe fn get_backing_store_slice_mut( - backing_store: &v8::SharedRef<v8::BackingStore>, - byte_offset: usize, - byte_length: usize, -) -> &mut [u8] { - let cells: *const [Cell<u8>] = - &backing_store[byte_offset..byte_offset + byte_length]; - let bytes = cells as *const _ as *mut [u8]; - &mut *bytes -} |