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Cleanups to typed array manipulation
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We now validate in the public API and then internal methods can assume they are using real array buffer views
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@domenic
domenic committed Mar 10, 2016
1 parent a07ed09 commit c5d63de
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61 changes: 20 additions & 41 deletions index.bs
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Expand Up @@ -1207,6 +1207,8 @@ Instances of <code>ReadableStreamBYOBReader</code> are created with the internal
<emu-alg>
1. If IsReadableStreamBYOBReader(*this*) is *false*, return a promise rejected with a *TypeError* exception.
1. If *this*@[[ownerReadableStream]] is *undefined*, return a promise rejected with a *TypeError* exception.
1. If Type(_view_) is not Object, return a promise rejected with a *TypeError* exception.
1. If _view_ does not have a [[ViewedArrayBuffer]] internal slot, return a promise rejected with a *TypeError* exception.
1. Return ReadableStreamBYOBReaderRead(*this*, _view_).
</emu-alg>

Expand Down Expand Up @@ -1286,15 +1288,11 @@ Instances of <code>ReadableStreamBYOBReader</code> are created with the internal
1. Let _stream_ be _reader_@[[ownerReadableStream]].
1. Assert: _stream_ is not *undefined*.
1. Set _stream_@[[disturbed]] to *true*.
1. If _view_ is *undefined* or ArrayBuffer.isView(_view_) is *false*, return a promise rejected with a *TypeError* exception.
1. Let _ctor_ be _view_'s constructor.
1. Let _elementSize_ be 1.
1. If _ctor_ is `Int16Array` or _ctor_ is `Uint16Array` or _ctor_ is `Int32Array` or _ctor_ is `Uint32Array` or _ctor_ is `Float32Array` or _ctor_ is `Float64Array` or _ctor_ is `Int8Array` or _ctor_ is `Uint8Array` or _ctor_ is `Uint8ClampedArray`, let _elementSize_ be _ctor_.BYTES_PER_ELEMENT.
1. Otherwise,
1. If _ctor_ is not `DataView`, return a promise rejected with a *TypeError* exception.
1. If _view_@[[byteLength]] is 0, return a promise rejected with a *TypeError* exception.
1. If _view_ has a [[TypedArrayName]] internal slot (i.e., it is not a `DataView`), set _elementSize_ to the element size specified in <a href="https://tc39.github.io/ecma262/#table-49">The TypedArray Constructors table</a> for _view_@[[TypedArrayName]].
1. If _view_@[[ByteLength]] is 0, return a promise rejected with a *TypeError* exception.
1. If _stream_@[[state]] is `"errored"`, return a promise rejected with _stream_@[[storedError]].
1. Return ReadableStreamBYOBControllerPullInto(_stream_@[[readableStreamController]], _view_.[[ViewedArrayBuffer]], _view_@[[ByteOffset]], _view_@[[ByteLength]], _ctor_, _elementSize_).
1. Return ReadableStreamBYOBControllerPullInto(_stream_@[[readableStreamController]], _view_@[[ViewedArrayBuffer]], _view_@[[ByteOffset]], _view_@[[ByteLength]], _ctor_, _elementSize_).
</emu-alg>

<h4 id="readable-stream-default-reader-read" aoid="ReadableStreamDefaultReaderRead" nothrow>ReadableStreamDefaultReaderRead ( reader )</h4>
Expand Down Expand Up @@ -1794,6 +1792,8 @@ table:
1. If IsReadableStreamBYOBController(*this*) is *false*, throw a *TypeError* exception.
1. If *this*@[[closeRequested]] is *true*, throw a *TypeError* exception.
1. If *this*@[[controlledReadableStream]]@[[state]] is not `"readable"`, throw a *TypeError* exception.
1. If Type(_chunk_) is not Object, throw a *TypeError* exception.
1. If _chunk_ does not have a [[ViewedArrayBuffer]] internal slot, throw a *TypeError* exception.
1. Return ReadableStreamBYOBControllerEnqueue(*this*, _chunk_).
</emu-alg>

Expand Down Expand Up @@ -1838,7 +1838,7 @@ controllers.
1. Remove _entry_ from *this*@[[queue]], shifting all other elements downward (so that the second becomes the first, and so on).
1. Subtract _entry_.[[byteLength]] from *this*@[[totalQueuedBytes]].
1. Perform ReadableStreamBYOBControllerHandleQueueDrain(*this*).
1. Let _view_ be Construct(`Uint8Array`, «_entry_.[[buffer]], _entry_.[[byteOffset]], _entry_.[[byteLength]]»).
1. Let _view_ be Construct(%Uint8Array%, «_entry_.[[buffer]], _entry_.[[byteOffset]], _entry_.[[byteLength]]»).
1. Return a promise resolved with CreateIterResultObject(_view_, *false*).
1. Let _promise_ be ReadableStreamAddReadRequest(_stream_).
1. Perform ReadableStreamDefaultControllerCallPullIfNeeded(*this*).
Expand Down Expand Up @@ -1919,6 +1919,8 @@ table:
<emu-alg>
1. If IsReadableStreamBYOBRequest(*this*) is *false*, throw a *TypeError* exception.
1. If *this*@[[associatedReadableStreamBYOBController]] is *undefined*, throw a *TypeError* exception.
1. If Type(_chunk_) is not Object, throw a *TypeError* exception.
1. If _view_ does not have a [[ViewedArrayBuffer]] internal slot, throw a *TypeError* exception.
1. Return ReadableStreamBYOBControllerRespondWithNewView(*this*@[[associatedReadableStreamBYOBController]], _view_).
</emu-alg>

Expand Down Expand Up @@ -2056,7 +2058,7 @@ table:
1. Let _e_ be a *TypeError* exception.
1. Perform ReadableStreamBYOBControllerError(_controller_, _e_).
1. Return a promise rejected with _e_.
1. Transfer _pullIntoDescriptor_@[[buffer]] and set _pullIntoDescriptor_.[[buffer]] to the result.
1. Transfer _pullIntoDescriptor_.[[buffer]] and set _pullIntoDescriptor_.[[buffer]] to the result.
1. Append _pullIntoDescriptor_ as the last element of _controller_@[[pendingPullIntos]].
1. Let _promise_ be ReadableStreamAddReadIntoRequest(_stream_, _byteOffset_, _byteLength_, _ctor_, _elementSize_).
1. Perform ReadableStreamBYOBControllerCallPullIfNeeded(_controller_).
Expand Down Expand Up @@ -2099,7 +2101,7 @@ table:
1. If _remainderSize_ &gt; 0,
1. Let _end_ be _pullIntoDescriptor_.[[byteOffset]] + _pullIntoDescriptor_.[[bytesFilled]].
1. Let _remainder_ be a new ArrayBuffer containing the _remainderSize_ bytes of _pullIntoDescriptor_.[[buffer]] at offset _end_ - _remainderSize_.
1. Perform ReadableStreamBYOBControllerEnqueueChunkToQueue(_controller_, _remainder_, 0, _remainder_@[[byteLength]]).
1. Perform ReadableStreamBYOBControllerEnqueueChunkToQueue(_controller_, _remainder_, 0, _remainder_@[[ByteLength]]).
1. Perform ReadableStreamRespondToReadIntoRequest(_controller_@[[controlledReadableStream]], _transferredBuffer_, _pullIntoDescriptor_.[[bytesFilled]] - _remainderSize_).
1. Perform ReadableStreamBYOBControllerRespondToReadIntoRequestsFromQueue(_controller_).
</emu-alg>
Expand Down Expand Up @@ -2164,17 +2166,17 @@ table:
1. Let _stream_ be _controller_@[[controlledReadableStream]].
1. Assert: _controller_@[[closeRequested]] is *false*.
1. Assert: _controller_@[[state]] is `"readable"`.
1. Let _buffer_ be _chunk_@[[buffer]].
1. Let _byteOffset_ be _chunk_@[[byteOffset]].
1. Let _byteLength_ be _chunk_@[[byteLength]].
1. Let _buffer_ be _chunk_@[[ViewedArrayBuffer]].
1. Let _byteOffset_ be _chunk_@[[ByteOffset]].
1. Let _byteLength_ be _chunk_@[[ByteLength]].
1. If ReadableStreamHasReader(_stream_) is *true*
1. If ReadableStreamGetNumReadRequests(_stream_) is 0,
1. Transfer _buffer_ and let _transferredBuffer_ be the result.
1. Perform ReadableStreamBYOBControllerEnqueueChunkToQueue(_controller_, _transferredBuffer_, _byteOffset_, _byteLength_).
1. Otherwise,
1. Assert: _controller_@[[queue]] is empty.
1. Transfer _buffer_ and let _transferredBuffer_ be the result.
1. Let _transferredView_ be Construct(`Uint8Array`, «_transferredBuffer_, _byteOffset_, _byteLength_»).
1. Let _transferredView_ be Construct(%Uint8Array%, «_transferredBuffer_, _byteOffset_, _byteLength_»).
1. Perform ReadableStreamRespondToReadRequest(_stream_, _transferredView_).
1. Otherwise,
1. If ReadableStreamHasBYOBReader(_stream_) is *true*,
Expand Down Expand Up @@ -2218,12 +2220,12 @@ table:
<emu-alg>
1. Assert: _controller_@[[pendingPullIntos]] is not empty.
1. Let _firstDescriptor_ be the first element of _controller_@[[pendingPullIntos]].
1. If _firstDescriptor_.[[byteOffset]] + _firstDescriptor_.[[bytesFilled]] is not _view_@[[byteOffset]],
1. If _firstDescriptor_.[[byteOffset]] + _firstDescriptor_.[[bytesFilled]] is not _view_@[[ByteOffset]],
1. Throw a *RangeError* exception.
1. If _firstDescriptor_.[[byteLength]] is not _view_@[[byteOffset]],
1. If _firstDescriptor_.[[byteLength]] is not _view_@[[ByteOffset]],
1. Throw a *RangeError* exception.
1. Set _firstDescriptor_.[[buffer]] to _view_@[[buffer]].
1. Return ReadableStreamBYOBControllerRespondInternal(_controller_, _view_@[[byteLength]]).
1. Set _firstDescriptor_.[[buffer]] to _view_@[[ViewedArrayBuffer]].
1. Return ReadableStreamBYOBControllerRespondInternal(_controller_, _view_@[[ByteLength]]).
</emu-alg>

<h5 id="readable-stream-byob-request-invalidate" aoid="ReadableStreamBYOBRequestInvalidate" nothrow>ReadableStreamBYOBRequestInvalidate ( request )</h4>
Expand Down Expand Up @@ -2889,29 +2891,6 @@ throughout the rest of this standard.

A few abstract operations are used in this specification for utility purposes. We define them here.

<h4 id="get-viewed-array-buffer" aoid="GetViewedArrayBuffer" throws>GetViewedArrayBuffer ( O )</h4>

<emu-alg>
1. Return the result of the same algorithm as used by the get accessor function of the original value of %TypedArray%.prototype.buffer, with _O_ in place of *this*.
</emu-alg>

<div class="note">
Ideally, this operation and its counterparts <a href="https://bugs.ecmascript.org/show_bug.cgi?id=4369">would be
defined by ECMAScript</a>.
</div>

<h4 id="get-byte-length" aoid="GetByteLength" throws>GetByteLength ( O )</h4>

<emu-alg>
1. Return the result of the same algorithm as used by the get accessor function of the original value of %TypedArray%.prototype.byteLength, with _O_ in place of *this*.
</emu-alg>

<h4 id="get-byte-offset" aoid="GetByteOffset" throws>GetByteOffset ( O )</h4>

<emu-alg>
1. Return the result of the same algorithm as used by the get accessor function of the original value of %TypedArray%.prototype.byteOffset, with _O_ in place of *this*.
</emu-alg>

<h4 id="is-finite-non-negative-number" aoid="IsFiniteNonNegativeNumber" nothrow>IsFiniteNonNegativeNumber ( v )</h4>

<emu-alg>
Expand Down
25 changes: 14 additions & 11 deletions reference-implementation/lib/readable-stream.js
View file
Expand Up @@ -658,6 +658,10 @@ class ReadableStreamBYOBReader {
return Promise.reject(new TypeError('Cannot read from a released reader'));
}

if (!ArrayBuffer.isView(view)) {
return Promise.reject(new TypeError('view must be an array buffer view'));
}

return ReadableStreamBYOBReaderRead(this, view);
}

Expand Down Expand Up @@ -758,18 +762,9 @@ function ReadableStreamBYOBReaderRead(reader, view) {

stream._disturbed = true;

if (view === undefined || ArrayBuffer.isView(view) === false) {
return Promise.reject(new TypeError('Valid view must be provided'));
}

const ctor = view.constructor;
let elementSize = 1;
if (ctor === Int16Array || ctor === Uint16Array || ctor === Int32Array || ctor === Uint32Array ||
ctor === Float32Array || ctor === Float64Array || ctor === Int8Array || ctor === Uint8Array ||
ctor === Uint8ClampedArray) {
elementSize = ctor.BYTES_PER_ELEMENT;
} else if (ctor !== DataView) {
return Promise.reject(new TypeError('view is of an unsupported type'));
if (view.constructor !== DataView) {
elementSize = view.constructor.BYTES_PER_ELEMENT;
}

if (view.byteLength === 0) {
Expand Down Expand Up @@ -1111,6 +1106,10 @@ class ReadableStreamBYOBRequest {
throw new TypeError('This BYOB request has been invalidated');
}

if (!ArrayBuffer.isView(chunk)) {
throw new TypeError('You can only respond with array buffer views');
}

ReadableStreamBYOBControllerRespondWithNewView(this._associatedReadableStreamBYOBController, view);
}

Expand Down Expand Up @@ -1228,6 +1227,10 @@ class ReadableStreamBYOBController {
throw new TypeError('The stream is not in the readable state and cannot be enqueued to');
}

if (!ArrayBuffer.isView(chunk)) {
throw new TypeError('You can only enqueue array buffer views when using a ReadableStreamBYOBController');
}

ReadableStreamBYOBControllerEnqueue(this, chunk);
}

Expand Down

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