Make flac.NewSeek() use a buffered reader too

[MarkKremer]

For one of the users of Beep, I discovered that flac.NewSeek() is very slow and caused stuttering. After inspection, flac.NewSeek() didn't seem to use a buffered reader (bufio.Reader) like it's brother flac.New() does. This caused millions of relatively slow syscalls.

Unfortunately bufio doesn't have a io.ReadSeeker, so I wrote my own based on bufio.Reader.

Let me know if I need to unit test this in some way.

[mewmew]

Great work!

For practical non-stuttering use of seek, having an underlying buffer is definitely needed. Great to see you spear-heading this Mark.

Let me know if I need to unit test this in some way.

As for unit tests, it would definitely be good to have a few unit tests related to the added seek support in your adaptation of the *bufio.Reader.

My suggestion would be to add a internal/bufseekio/test_readseeker.go unit test e.g. func TestSeek(t *testing.T) { ... }.

Try to ensure that subsequent seek calls "land" on the right offset, and that subsequent reads give the intended bytes. Also, try to check extremes, e.g. seek with negative offsets, seek at end/after end of buffer.

Cheers,
Robin

[MarkKremer]

Here ya go!

Edit: actually, I would like to see if I can improve them somewhat. The tests seem verbose & I think the out of range parts can be tested more. Let me have another stab at it.

[MarkKremer]

OK, I think I'm happy with it. :)

[mewmew]

LGTM.