in dart:io, need to be able to flush data out of StringInputStream.

[DartBot]

This issue was originally filed by zundel@google.com

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Process p = ...
StringInputStream s = new StringInputStream(p.stderr);
...
p.stderr.available() returns value > 0
s.readLine() returns null;
s.read() returns null;

How do I get the data out?

See my workaround in:
http://codereview.chromium.org/9538009/

After looking at string_stream.dart, maybe the solution is to call _readData() at the top of StringInputStream.read() and .readLine();

Another thought is to add a flush() call, but then I'm not sure how to tell when the lineHandler() and dataHandler() methods are finished.

[DartBot]

This comment was originally written by zundel@google.com

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may be a dup of issue #1407.

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Set owner to @sgjesse.
Added Area-IO, Triaged labels.

[madsager]

You cannot flush input. That doesn't make sense. When you have an input stream you have to register a data OR a line handler. Then you can only read out either data with read in a data handler or lines with readLine in the line handler. You should not use the stream in any other way.

For the dartc batch runner I think we need a token in both stdout and stderr so we can know when we have seen all output from both and only then move on. The changelist above should not be needed and I think we should revert and rework this.

[madsager]

Added WontFix label.

[DartBot]

This comment was originally written by zundel@google.com

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Adding a flush is just the second suggestion, and I agree, it is dumb.

The underlying question I have is, "why is it that we have to wait to go back to the event loop just to copy data from the underlying InputStream to the StringInputStream?" The documentation for StringInputStream.read() implies that it will give you all the data, or null if there is none, but now there is a catch. Emily looked at the code too and wondered how things could get into that state.

[madsager]

read should only be used with onData and readLine should only be used with onLine. Mixing that does not work. We should probably make it an error to call read if onLine has ever been set to make it more explicit.

[kevmoo]

Removed Area-IO label.
Added Area-Library, Library-IO labels.