1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131

// Copyright 2019-2020 the Deno authors. All rights reserved. MIT license.

use std::ffi::c_void;
use std::ptr::null_mut;

use crate::array_buffer::backing_store_deleter_callback;
use crate::support::SharedRef;
use crate::support::UniqueRef;
use crate::BackingStore;
use crate::BackingStoreDeleterCallback;
use crate::HandleScope;
use crate::Isolate;
use crate::Local;
use crate::SharedArrayBuffer;

extern "C" {
  fn v8__SharedArrayBuffer__New__with_byte_length(
    isolate: *mut Isolate,
    byte_length: usize,
  ) -> *const SharedArrayBuffer;
  fn v8__SharedArrayBuffer__New__with_backing_store(
    isolate: *mut Isolate,
    backing_store: *const SharedRef<BackingStore>,
  ) -> *const SharedArrayBuffer;
  fn v8__SharedArrayBuffer__ByteLength(this: *const SharedArrayBuffer)
    -> usize;
  fn v8__SharedArrayBuffer__GetBackingStore(
    this: *const SharedArrayBuffer,
  ) -> SharedRef<BackingStore>;
  fn v8__SharedArrayBuffer__NewBackingStore__with_byte_length(
    isolate: *mut Isolate,
    byte_length: usize,
  ) -> *mut BackingStore;
  fn v8__SharedArrayBuffer__NewBackingStore__with_data(
    data: *mut c_void,
    byte_length: usize,
    deleter: BackingStoreDeleterCallback,
    deleter_data: *mut c_void,
  ) -> *mut BackingStore;
}

impl SharedArrayBuffer {
  /// Create a new SharedArrayBuffer. Allocate |byte_length| bytes.
  /// Allocated memory will be owned by a created SharedArrayBuffer and
  /// will be deallocated when it is garbage-collected,
  /// unless the object is externalized.
  pub fn new<'s>(
    scope: &mut HandleScope<'s>,
    byte_length: usize,
  ) -> Option<Local<'s, SharedArrayBuffer>> {
    unsafe {
      scope.cast_local(|sd| {
        v8__SharedArrayBuffer__New__with_byte_length(
          sd.get_isolate_ptr(),
          byte_length,
        )
      })
    }
  }

  pub fn with_backing_store<'s>(
    scope: &mut HandleScope<'s>,
    backing_store: &SharedRef<BackingStore>,
  ) -> Local<'s, SharedArrayBuffer> {
    unsafe {
      scope.cast_local(|sd| {
        v8__SharedArrayBuffer__New__with_backing_store(
          sd.get_isolate_ptr(),
          backing_store,
        )
      })
    }
    .unwrap()
  }

  /// Data length in bytes.
  pub fn byte_length(&self) -> usize {
    unsafe { v8__SharedArrayBuffer__ByteLength(self) }
  }

  /// Get a shared pointer to the backing store of this array buffer. This
  /// pointer coordinates the lifetime management of the internal storage
  /// with any live ArrayBuffers on the heap, even across isolates. The embedder
  /// should not attempt to manage lifetime of the storage through other means.
  pub fn get_backing_store(&self) -> SharedRef<BackingStore> {
    unsafe { v8__SharedArrayBuffer__GetBackingStore(self) }
  }

  /// Returns a new standalone BackingStore that is allocated using the array
  /// buffer allocator of the isolate. The result can be later passed to
  /// ArrayBuffer::New.
  ///
  /// If the allocator returns nullptr, then the function may cause GCs in the
  /// given isolate and re-try the allocation. If GCs do not help, then the
  /// function will crash with an out-of-memory error.
  pub fn new_backing_store(
    scope: &mut Isolate,
    byte_length: usize,
  ) -> UniqueRef<BackingStore> {
    unsafe {
      UniqueRef::from_raw(
        v8__SharedArrayBuffer__NewBackingStore__with_byte_length(
          scope,
          byte_length,
        ),
      )
    }
  }

  /// Returns a new standalone BackingStore that takes over the ownership of
  /// the given buffer.
  ///
  /// The destructor of the BackingStore frees owned buffer memory.
  ///
  /// The result can be later passed to SharedArrayBuffer::New. The raw pointer
  /// to the buffer must not be passed again to any V8 API function.
  pub fn new_backing_store_from_boxed_slice(
    data: Box<[u8]>,
  ) -> UniqueRef<BackingStore> {
    let byte_length = data.len();
    let data_ptr = Box::into_raw(data) as *mut c_void;
    unsafe {
      UniqueRef::from_raw(v8__SharedArrayBuffer__NewBackingStore__with_data(
        data_ptr,
        byte_length,
        backing_store_deleter_callback,
        null_mut(),
      ))
    }
  }
}