Bug 172714 – [Readable Streams API] Implement ReadableStreamBYOBReader read()

• Component: WebCore Misc.
• Status: RESOLVED FIXED

[Romain Bellessort]

Implement read() method of ReadableStreamBYOBReader.

[Romain Bellessort]

Created attachment 311692 [details]
Patch

[Romain Bellessort]

Comment on attachment 311692 [details]
Patch

Patch implements read() behavior. Implementation of this patch allowed to reach new code and thus revealed 2 bugs to be fixed distinctly (172716 & 172717). These 2 bugs are responsible for the remaining failures in WPT tests dedicated to readable byte streams.

[youenn fablet]

Comment on attachment 311692 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=311692&action=review

> Source/WebCore/Modules/streams/ReadableByteStreamInternals.js:626
> +        elementSize = view.BYTES_PER_ELEMENT;

BYTES_PER_ELEMENT is attached to the prototype, which may be changed for the given view.
In that case, BYTES_PER_ELEMENT might be set to any value.
Given there is a FIXME below, we should also add one there I guess.

[Romain Bellessort]

(In reply to youenn fablet from comment #3)
> Comment on attachment 311692 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=311692&action=review
> 
> > Source/WebCore/Modules/streams/ReadableByteStreamInternals.js:626
> > +        elementSize = view.BYTES_PER_ELEMENT;
> 
> BYTES_PER_ELEMENT is attached to the prototype, which may be changed for the
> given view.
> In that case, BYTES_PER_ELEMENT might be set to any value.
> Given there is a FIXME below, we should also add one there I guess.

I thought that contrary to constructor property, BYTES_PER_ELEMENT could be safely relied on as it is read-only. Is it in fact not the case?

[youenn fablet]

(In reply to Romain Bellessort from comment #4)
> (In reply to youenn fablet from comment #3)
> > Comment on attachment 311692 [details]
> > Patch
> > 
> > View in context:
> > https://bugs.webkit.org/attachment.cgi?id=311692&action=review
> > 
> > > Source/WebCore/Modules/streams/ReadableByteStreamInternals.js:626
> > > +        elementSize = view.BYTES_PER_ELEMENT;
> > 
> > BYTES_PER_ELEMENT is attached to the prototype, which may be changed for the
> > given view.
> > In that case, BYTES_PER_ELEMENT might be set to any value.
> > Given there is a FIXME below, we should also add one there I guess.
> 
> I thought that contrary to constructor property, BYTES_PER_ELEMENT could be
> safely relied on as it is read-only. Is it in fact not the case?

Can you try to create a view, change its prototype and set a BYTES_PER_ELEMENT property and see what would be the impact on the implementation?

[Romain Bellessort]

(In reply to youenn fablet from comment #5)
> (In reply to Romain Bellessort from comment #4)
> > (In reply to youenn fablet from comment #3)
> > > Comment on attachment 311692 [details]
> > > Patch
> > > 
> > > View in context:
> > > https://bugs.webkit.org/attachment.cgi?id=311692&action=review
> > > 
> > > > Source/WebCore/Modules/streams/ReadableByteStreamInternals.js:626
> > > > +        elementSize = view.BYTES_PER_ELEMENT;
> > > 
> > > BYTES_PER_ELEMENT is attached to the prototype, which may be changed for the
> > > given view.
> > > In that case, BYTES_PER_ELEMENT might be set to any value.
> > > Given there is a FIXME below, we should also add one there I guess.
> > 
> > I thought that contrary to constructor property, BYTES_PER_ELEMENT could be
> > safely relied on as it is read-only. Is it in fact not the case?
> 
> Can you try to create a view, change its prototype and set a
> BYTES_PER_ELEMENT property and see what would be the impact on the
> implementation?

You're right, this allows setting any value. I will update the patch with a FIXME.

[Romain Bellessort]

Created attachment 313597 [details]
Patch

[WebKit Commit Bot]

Comment on attachment 313597 [details]
Patch

Rejecting attachment 313597 [details] from commit-queue.

Failed to run "['/Volumes/Data/EWS/WebKit/Tools/Scripts/webkit-patch', '--status-host=webkit-queues.webkit.org', '--bot-id=webkit-cq-03', 'land-attachment', '--force-clean', '--non-interactive', '--parent-command=commit-queue', 313597, '--port=mac']" exit_code: 2 cwd: /Volumes/Data/EWS/WebKit

Last 500 characters of output:
    -> origin/master
Partial-rebuilding .git/svn/refs/remotes/origin/master/.rev_map.268f45cc-cd09-0410-ab3c-d52691b4dbfc ...
Currently at 218691 = 8da38dae886bcd23bde664d88dbbe517fb30a4e2
r218692 = 385f101ebc73fc9cc38e7da16e98e09b11d22b15
r218693 = c9ce2a0e61f5f952e926419c27f98c78b04eb83d
Done rebuilding .git/svn/refs/remotes/origin/master/.rev_map.268f45cc-cd09-0410-ab3c-d52691b4dbfc
First, rewinding head to replay your work on top of it...
Fast-forwarded master to refs/remotes/origin/master.

Full output: http://webkit-queues.webkit.org/results/3977787

[Romain Bellessort]

Created attachment 313618 [details]
Patch

[WebKit Commit Bot]

Comment on attachment 313618 [details]
Patch

Clearing flags on attachment: 313618

Committed r218701: <http://trac.webkit.org/changeset/218701>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.