Extremely slow

[shirro]

I had an issue with mosh triggering strange behaviour due to a vim plugin that I closed as it was really an issue with my vim setup.

It made me realise how slow mosh-chrome is compared to regular mosh or ssh. I created a test file to open up vim, go into insert, enter a text document, then quit and timed it on a Toshiba Chromebook and a 2009 Macbook Pro. Both running Chrome Beta channel Version 22.0.1750 and current version of mosh chrome. In each case they connected to the same VPS and ran the same test. I averaged out the results roughly in my head but they are close enough.

Obviously there are variations in fonts and window sizes etc so each test was doing a slightly different amount of work. If I make the mosh chrome screen really small it manages it is less than 4s so it isn't like it is slow sending the characters. I would guess it is less efficient updating the screen somehow.

Test	Time
mosh in Chromebook chroot	0.8s
mosh chrome on Chromebook	79s
Chrome SSH on Chromebook	0.5s
mosh in iterm2 on macbook	1.9s
ssh in iterm2 on macbook	0.6s
ssh in terminal on macbook	2.9s
mosh in terminal on macbook	3.2s
mosh chrome on macbook	110s *
Chrome SSH on Macbook	0.4s

• I got a lot of screen corruption with mosh chrome on the mac and I couldn't read the time so it is a rough stopwatch job.

[rpwoodbu]

Thanks for the analysis. I was thinking about this when you last updated issue #34, as slow behavior could affect interpretation of escape sequences. I've noticed that pasting into the window is slow, but I never thought much of it until now. I am naively marshaling characters one-by-one between hterm and mosh (there's even a TODO in the code about this), so I'll see if that's where I can speed things up.

[rpwoodbu]

Oh, and incidentally, the screen corruption on the Mac may be related to issue #20. My working theory is that it is related to Unicode, but if you have found otherwise, please update that issue.

[rpwoodbu]

Fixed in SHA 9862043.

Batching reads from hterm made pasting nearly instantaneous for me. I think this will also address the escape sequence issue. Look for this in the next release. Thanks for the report!

[shirro]

The best thing about timezones is waking up in the morning to find cutting and pasting a doc into a terminal has dropped from over a minute to half a second. Fantastic work.