Fix pipeTo() to ensure all read chunks are written #726
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Previously, the spec wording allowed for immediate shutdown if the readable stream became closed, even if there were outstanding writes which did not yet get written. This fixes that, by requiring any already-read chunks to be written when possible. The reference implementation mostly did not suffer from this, but did in the case where a read completes while a write is ongoing. This was fixed by making its "wait for writes to finish" functionality more robust. Fixes #644.
domenic
added a commit
to web-platform-tests/wpt
that referenced
this pull request
Apr 6, 2017
In particular, data that was read should not be thrown away, but instead should be written. See whatwg/streams#644. Follows whatwg/streams#726.
|
Note: the two steps (write any read chunks; wait for writes to finish) don't apply in all shutdown cases. In particular they only apply when the source errors or closes. This leads to some duplication. However the alternate approach of only putting those steps underneath their corresponding conditions ("Errors must be propagated forward" and "Closing must be propagated forward") meant you also needed to duplicate the shuttingDown set/check under those conditions. So this version seemed cleanest to me. |
ricea
reviewed
Apr 6, 2017
| if (dest._state === 'writable' && WritableStreamCloseQueuedOrInFlight(dest) === false) { | ||
| // Another write may have started while we were waiting on this currentWrite, so we have to be sure to wait | ||
| // for that too. | ||
| const before = currentWrite; |
There was a problem hiding this comment.
I find the name before a little unclear. I don't have strong feelings about it, but maybe oldCurrentWrite would be better?
|
lgtm |
|
lgtm e22b3d8 |
domenic
added a commit
to web-platform-tests/wpt
that referenced
this pull request
Apr 6, 2017
In particular, data that was read should not be thrown away, but instead should be written. See whatwg/streams#644. Follows whatwg/streams#726.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Previously, the spec wording allowed for immediate shutdown if the readable stream became closed, even if there were outstanding writes which did not yet get written. This fixes that, by requiring any already-read chunks to be written when possible.
The reference implementation mostly did not suffer from this, but did in the case where a read completes while a write is ongoing. This was fixed by making its "wait for writes to finish" functionality more robust.
Fixes #644.
Tests: web-platform-tests/wpt#5270