feat: ArrayBuffer transfer 三方法与 detach 源拷贝核

This commit is contained in:
2026-09-22 23:42:17 +00:00
parent 7d7a195014
commit 317c940f04
3 changed files with 315 additions and 0 deletions
+153
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@@ -444,6 +444,121 @@ pub fn array_buffer_slice<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
NativeResult::Ok(JsValue::from_js_object(new_array_buffer(vm, data[start..end].to_vec(), 0, proto)))
}
/// transfer 族新缓冲保持性:Preserve 源存储态上限原样拷贝,Fixed 定长,
/// Immutable 定长并置 immutable 标志。
#[derive(Clone, Copy)]
enum TransferKeep {
Preserve,
Fixed,
Immutable,
}
/// `ArrayBufferCopyAndDetach(O, newLength, keep)` 共享核:品牌守卫 →
/// newLength 求值 → detached/immutable 判定 → 界校验 → 前缀拷贝零填充建新
/// 缓冲 → 源 detach。
///
/// # 步骤
/// 1. this 品牌校验(非对象/非 ArrayBuffer → TypeError)。
/// 2. newLength 缺省 → 源当前字节长;在场 → ToIndex 传播式(强转副作用
/// 先于一切守卫观测)。
/// 3. 重取源载荷指针(求值可已晋升/detach/改 immutable),重检状态位:
/// detached → TypeError;immutable → TypeError。
/// 4. 界校验:resizable 源且 newByteLength > 真实上限(重读存储态 − 1)→
/// RangeError;newByteLength > 引擎分配上界 → RangeError。
/// 5. 物化拷贝(载荷指针新鲜,字节借出止于本步)。
/// 6. 新建缓冲(proto 取 %ArrayBuffer.prototype%,保持性按 keep),字节
/// 序列零填充至 newByteLength。
/// 7. 再重取源载荷指针 detach(`data → None`):分配可已晋升源对象,新缓冲
/// 持独立拷贝,源 detach 不影响返回值。
/// 8. 返回新缓冲。
fn array_buffer_copy_and_detach<H: VmHost>(
vm: &mut H, this_reg: u8, new_length: Option<JsValue>, keep: TransferKeep,
) -> NativeResult {
let this_val = vm.reg(this_reg);
let payload_ptr = native_try!(array_buffer_payload(vm, this_val));
// SAFETY: payload_ptr 经 array_buffer_payload 校验为合法 ArrayBuffer 载荷;
// 只读当前字节长,借用即结束,不跨 JS 调用点。
let cur_len = unsafe { &*payload_ptr }.data.as_ref().map_or(0, |d| d.len());
let new_len = match new_length {
None => cur_len,
Some(v) => native_try!(to_index(vm, v)),
};
// 求值可已把本缓冲区晋升进 session、detach 或置 immutable:接收者寄存器
// 与状态位均须重取重检,不得消费求值前快照。
let this_val = vm.reg(this_reg);
let payload_ptr = native_try!(array_buffer_payload(vm, this_val));
// SAFETY: 重取的 payload_ptr 指向存活载荷盒;标量拷出后借用即结束。
let (cur_len, stored_max, immutable, detached) = unsafe {
let p = &*payload_ptr;
(p.data.as_ref().map_or(0, |d| d.len()), p.max_byte_length, p.immutable, p.data.is_none())
};
if detached {
return NativeResult::Err(crate::error::create_type_error(vm, "ArrayBuffer internal state invalid"));
}
if immutable {
return NativeResult::Err(crate::error::create_type_error(vm, "ArrayBuffer is immutable"));
}
// 存储态上限 +1 编码:真实上限 = 存储态 − 1(上限 0 的缓冲只许同长)。
if stored_max != 0 && new_len > stored_max - 1 {
return NativeResult::Err(crate::error::create_range_error(vm, "invalid ArrayBuffer length"));
}
if new_len > MAX_ARRAY_BUFFER_LENGTH {
return NativeResult::Err(crate::error::create_range_error(vm, "invalid ArrayBuffer length"));
}
// SAFETY: 重取的 payload_ptr 指向存活载荷盒;detached 已排除,data 必为
// Some。字节借出止于本语句。
let copy_len = new_len.min(cur_len);
let mut new_data: Vec<u8> = unsafe { &*payload_ptr }
.data
.as_deref()
.map_or_else(Vec::new, |d| d[..copy_len].to_vec());
new_data.resize(new_len, 0);
let (dest_max, dest_immutable) = match keep {
TransferKeep::Preserve => (stored_max, false),
TransferKeep::Fixed => (0, false),
TransferKeep::Immutable => (0, true),
};
let proto = default_array_buffer_proto(vm);
let dest_ptr = new_array_buffer(vm, new_data, dest_max, proto);
// SAFETY: dest_ptr 为 alloc_object 新建对象,载荷盒由 new_array_buffer 建。
if dest_immutable {
let Some(p) = array_buffer_payload_ptr(unsafe { &*dest_ptr }) else {
return type_error(vm, "ArrayBuffer internal state invalid");
};
unsafe { (*p).immutable = true };
}
// 分配可已将源晋升:detach 前再重取指针,免悬垂窗。
let this_val = vm.reg(this_reg);
let payload_ptr = native_try!(array_buffer_payload(vm, this_val));
// SAFETY: 重取的 payload_ptr 指向存活载荷盒。
unsafe { (*payload_ptr).data = None };
NativeResult::Ok(JsValue::from_js_object(dest_ptr))
}
/// `ArrayBuffer.prototype.transfer([newLength])`:拷贝并 detach,保持性
/// 原样(定长→定长,resizable 源→resizable 同上限)。
pub fn array_buffer_transfer<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
let this_reg = if args.is_empty() { 0 } else { args[0] };
let new_length = if args.len() > 1 { Some(vm.reg(args[1])) } else { None };
array_buffer_copy_and_detach(vm, this_reg, new_length, TransferKeep::Preserve)
}
/// `ArrayBuffer.prototype.transferToFixedLength([newLength])`:拷贝并
/// detach,新缓冲恒定长。
pub fn array_buffer_transfer_to_fixed_length<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
let this_reg = if args.is_empty() { 0 } else { args[0] };
let new_length = if args.len() > 1 { Some(vm.reg(args[1])) } else { None };
array_buffer_copy_and_detach(vm, this_reg, new_length, TransferKeep::Fixed)
}
/// `ArrayBuffer.prototype.transferToImmutable([newLength])`:拷贝并
/// detach,新缓冲恒定长且 immutable。
pub fn array_buffer_transfer_to_immutable<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
let this_reg = if args.is_empty() { 0 } else { args[0] };
let new_length = if args.len() > 1 { Some(vm.reg(args[1])) } else { None };
array_buffer_copy_and_detach(vm, this_reg, new_length, TransferKeep::Immutable)
}
/// `ArrayBuffer.isView(value)`:参数是 DataView 或 TypedArray 才返回 true。
pub fn array_buffer_is_view<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
let value = if args.len() > 1 { vm.reg(args[1]) } else { JsValue::undefined() };
@@ -601,6 +716,44 @@ mod tests {
assert_eq!(vm.lookup_str(e).unwrap(), "TypeError");
}
/// transfer 族新缓冲存储态字段表:Preserve 源上限原样(+1 编码不变)、
/// Fixed/Immutable 定长,仅 Immutable 置位;源均 detach。
#[test]
fn transfer_dest_payload_field_table() {
let mut vm = Vm::new();
let r = eval_ab(
&mut vm,
"var src = new ArrayBuffer(4, {maxByteLength: 8}); \
var v = new Uint8Array(src); v[0] = 9; \
var dest = src.transfer(5); \
var a = new Uint8Array(dest)[0]; \
var src1 = new ArrayBuffer(4, {maxByteLength: 8}); \
var d1 = src1.transferToFixedLength(5).maxByteLength; \
var src2 = new ArrayBuffer(4, {maxByteLength: 8}); \
var d2 = src2.transferToImmutable(5); \
var fixed = new ArrayBuffer(3); \
var d3 = fixed.transfer(3).resizable; \
[a, src.detached, d1, d2.immutable, d2.resizable, fixed.detached, d3].join(',')",
)
.unwrap();
assert_eq!(vm.lookup_str(r).unwrap(), "9,true,5,true,false,true,false");
// 载荷存储态直读:transfer 产物 max = 8 + 1(+1 编码),ttf/tti 产物 = 0。
let dest_val = eval_ab(
&mut vm,
"var s = new ArrayBuffer(4, {maxByteLength: 8}); \
globalThis.__d = s.transfer(5); globalThis.__d",
)
.unwrap();
// SAFETY: __d 为已晋升 session 的 ArrayBuffer 对象,借用止于断言、不跨下一次 eval。
let dest_obj = unsafe { &*dest_val.as_js_object_ptr() };
let p = array_buffer_payload_ptr(dest_obj).expect("产物应携带载荷盒");
// SAFETY: p 指向存活载荷盒。
let payload = unsafe { &*p };
assert_eq!(payload.max_byte_length, 9);
assert!(!payload.immutable);
assert_eq!(payload.data.as_ref().expect("产物应附着").len(), 5);
}
/// resize 后置 detach 重检钉:强转调用中途 detach 后按 TypeError 抛,
/// 不触碰已 detach 载荷(现树 expect 臂的 abort 钉改点)。
#[test]
@@ -63,6 +63,21 @@ pub fn bind_array_buffer(core: &Arc<KernelCore>, session: &KernelSession, global
oxide_builtins::array_buffer::array_buffer_mark_immutable::<crate::vm::Vm> as *const (),
0,
),
(
"transfer",
oxide_builtins::array_buffer::array_buffer_transfer::<crate::vm::Vm> as *const (),
0,
),
(
"transferToFixedLength",
oxide_builtins::array_buffer::array_buffer_transfer_to_fixed_length::<crate::vm::Vm> as *const (),
0,
),
(
"transferToImmutable",
oxide_builtins::array_buffer::array_buffer_transfer_to_immutable::<crate::vm::Vm> as *const (),
0,
),
],
);
@@ -671,3 +671,150 @@ fn ab_ta_view_length_detached_zero() {
oxide_builtins::typed_array::TaIndexGate::NumericInvalid
);
}
/// transfer 拷贝/增减/零填充/源 detach 钉:grow 补零、same 原样、shrink
/// 截断;transfer(0) 产物附着 0 长(区别于 detach)。
#[test]
fn ab_transfer_copies_grows_shrinks_and_detaches() {
let mut vm = Vm::new();
let result = eval(
&mut vm,
"function fill(ab) { var v = new Uint8Array(ab); v[0]=1; v[1]=2; v[2]=3; v[3]=4; return ab; } \
var a = new Uint8Array(fill(new ArrayBuffer(4)).transfer(5)); \
a[0]===1 && a[1]===2 && a[2]===3 && a[3]===4 && a[4]===0 \
&& new Uint8Array(fill(new ArrayBuffer(4)).transfer(4)).length === 4 \
&& new Uint8Array(fill(new ArrayBuffer(4)).transfer(2)).join(',') === '1,2' \
&& fill(new ArrayBuffer(4)).transfer(0).detached === false \
&& fill(new ArrayBuffer(4)).transfer(0).byteLength === 0",
)
.unwrap();
assert!(result.as_bool());
let result = eval(
&mut vm,
"var ab = new ArrayBuffer(4); ab.transfer(2); ab.detached === true && ab.byteLength === 0",
)
.unwrap();
assert!(result.as_bool());
}
/// transfer 保持性钉:resizable 源 → 产物 resizable 同上限,产物附着。
#[test]
fn ab_transfer_preserves_resizability() {
let mut vm = Vm::new();
let result = eval(
&mut vm,
"var dest = new ArrayBuffer(4, {maxByteLength: 8}).transfer(5); \
dest.resizable === true && dest.maxByteLength === 8 \
&& dest.detached === false && dest.byteLength === 5",
)
.unwrap();
assert!(result.as_bool());
}
/// transferToFixedLength 钉:resizable 源 → 产物恒定长、源 detach。
#[test]
fn ab_transfer_to_fixed_length_fixed() {
let mut vm = Vm::new();
let result = eval(
&mut vm,
"var ab = new ArrayBuffer(4, {maxByteLength: 8}); \
var dest = ab.transferToFixedLength(6); \
dest.resizable === false && dest.maxByteLength === 6 && dest.byteLength === 6 \
&& ab.detached === true && ab.byteLength === 0",
)
.unwrap();
assert!(result.as_bool());
}
/// transferToImmutable 钉:产物 immutable + 恒定长、源 detach;显式 longer
/// 零填充。
#[test]
fn ab_transfer_to_immutable_sets_flag() {
let mut vm = Vm::new();
let result = eval(
&mut vm,
"var ab = new ArrayBuffer(4); \
var dest = ab.transferToImmutable(); \
dest.immutable === true && dest.resizable === false && ab.detached === true \
&& new Uint8Array(new ArrayBuffer(4).transferToImmutable(9)).length === 9 \
&& new Uint8Array(new ArrayBuffer(4).transferToImmutable(9))[8] === 0",
)
.unwrap();
assert!(result.as_bool());
}
/// newLength 求值序与强转钉:valueOf→toString 序 TypeError、2^53 RangeError、
/// valueOf 内 detach 后走 detached 判定(求值先于守卫)。
#[test]
fn ab_transfer_new_length_order_and_coercion() {
let mut vm = Vm::new();
let result = eval(
&mut vm,
"var log = []; \
var nl = { toString() { log.push('toString'); return {}; }, \
valueOf() { log.push('valueOf'); return {}; } }; \
var t1 = false; \
try { new ArrayBuffer(0).transfer(nl); } catch (e) { t1 = e instanceof TypeError; } \
t1 && log.length === 2 && log[0] === 'valueOf' && log[1] === 'toString' \
&& (function () { var t2 = false; \
try { new ArrayBuffer(0).transfer(2 ** 53); } catch (e) { t2 = e instanceof RangeError; } \
return t2; })() \
&& (function () { var ab = new ArrayBuffer(8); var t3 = false; \
try { ab.transfer({ valueOf() { $262.detachArrayBuffer(ab); return 1; } }); } \
catch (e) { t3 = e instanceof TypeError; } \
return t3; })()",
)
.unwrap();
assert!(result.as_bool());
}
/// detached 源钉:三方法同形 TypeError。
#[test]
fn ab_transfer_detached_source_type_error() {
let mut vm = Vm::new();
let result = eval(
&mut vm,
"var a = new ArrayBuffer(4); a.transfer(); \
var t1 = false, t2 = false, t3 = false; \
try { a.transfer(); } catch (e) { t1 = e instanceof TypeError; } \
try { a.transferToFixedLength(); } catch (e) { t2 = e instanceof TypeError; } \
try { a.transferToImmutable(); } catch (e) { t3 = e instanceof TypeError; } \
t1 && t2 && t3",
)
.unwrap();
assert!(result.as_bool());
}
/// immutable 源钉:三方法同形 TypeError,newLength 读取先于 mutability 守卫。
#[test]
fn ab_transfer_immutable_source_type_error() {
let mut vm = Vm::new();
let result = eval(
&mut vm,
"var iab = new ArrayBuffer(4).transferToImmutable(); \
var calls = []; \
var nl = { valueOf() { calls.push('valueOf'); return 1; } }; \
var t1 = false, t2 = false, t3 = false; \
try { iab.transfer(nl); } catch (e) { t1 = e instanceof TypeError; } \
try { iab.transferToFixedLength(); } catch (e) { t2 = e instanceof TypeError; } \
try { iab.transferToImmutable(); } catch (e) { t3 = e instanceof TypeError; } \
t1 && t2 && t3 && calls.length === 1 && calls[0] === 'valueOf'",
)
.unwrap();
assert!(result.as_bool());
}
/// 界校验钉:resizable 源超真实上限 RangeError、超引擎分配上界 RangeError。
#[test]
fn ab_transfer_range_and_alloc_limits() {
let mut vm = Vm::new();
let result = eval(
&mut vm,
"var t1 = false, t2 = false; \
try { new ArrayBuffer(4, {maxByteLength: 8}).transfer(9); } catch (e) { t1 = e instanceof RangeError; } \
try { new ArrayBuffer(0).transfer(2 ** 32); } catch (e) { t2 = e instanceof RangeError; } \
t1 && t2",
)
.unwrap();
assert!(result.as_bool());
}