Use IsDisturbed(ReadableStream)

[yutakahirano]

This fixes #45. The link should be modified after IsDisturbed is specified on the streams spec.

[annevk]

I see, the "passed flag" is a renaming of the "used flag". Perhaps we should call it "obsolete flag"? I don't think "passed" is very clear.

Also, we need to change Request's used predicate, since it needs to check for IsDisturbed.

I also think the "locked flag" can go, since we were going to define an abstract operation in Streams for text() etc. that would mark the stream disturbed immediately.

[yutakahirano]

@annevk Thanks, I uploaded a revised one.

I see, the "passed flag" is a renaming of the "used flag". Perhaps we should call it "obsolete flag"? I don't think "passed" is very clear.

It came from https://github.com/slightlyoff/ServiceWorker/issues/452 and yes that should be renamed. I think it's ok to call it as "used flag".

Also, we need to change Request's used predicate, since it needs to check for IsDisturbed.

We will, but currently Request doesn't have its body stream. used flag emulates the effect. Hence I'm using the flag for now.

I also think the "locked flag" can go, since we were going to define an abstract operation in Streams for text() etc. that would mark the stream disturbed immediately.

Fixed.

[yutakahirano]

I changed my mind: I decoupled disturbed flag from used flag. The former emulates IsDisturbed(stream) and the latter is defined in https://etherpad.mozilla.org/streams-f2f-july L45 and L46.

[yutakahirano]

Addressed review comments. My current understanding is:

• There is no clear distinction between an evident empty stream (i.e. an already closed empty stream) and a maybe empty stream. Both will be disturbed when read() / cancel() is called.
• There is a clear distinction between a null stream and an empty stream. The former cannot be disturbed while the latter can be.

Please correct me if I'm wrong.

[annevk]

That matches my understanding.

[domenic]

Mine as well.