[TxMt] Re: The overhead of 'Pipe text through' ...

[Jacob Rus]

Torsten Grust wrote:
> Dear all,
> 
> I'm hacking on a little project that is somewhat abusing the 
> 'Pipe text through' feature of TextMate's Web Preview window 
> (''abusing'' in the sense that I do not want to preview HTML text). 
> 
> If you open the Web Preview and uncheck the 'Pipe text through' 
> option you can observe how rapidly TextMate can update the 
> preview (set the 'Refresh after change delay' to 0.00s and type 
> away in some plain text -- the update seems almost immediate and 
> you'll have immediate typing response in the editor window). 
> 
> Enabling 'Pipe text through' makes TextMate pipe the current 
> editor window contents into the specified command.  Even if you 
> only specify 'cat >/dev/null' as that command, you will notice 
> that text editing will become sluggish.  I assume that this 
> delay is all due to the overhead of *forking* the specified
> command -- executing 'cat >/dev/null' itself takes no noticable 
> time on files of size <100k on my Powerbook G4.
> 
> I've got two questions here:
> 
> (1) Is there a smarter way to receive live updates of the 
> current editor window contents?  Maybe via the plugin API?
> 
> (2) How about a comptabile change in 'Pipe text through's 
> behavior?  If the file specified in 'Pipe text through' is a 
> named pipe (mkfifo(1)) do not fork any command but simply 
> write the editor window contents into that named pipe. 
> Otherwise, behave as before.
> 
> Item (2) sounds like a moderate change that could get us rid 
> of the forking overhead for at least some applications that 
> need live update.  What are the chances that Allan has open 
> ears for such things?
> 
> Thanks and all the best for the New Year,
>    --Torsten

I'm not exactly sure what Allan's plans are, but as far as I know, all 
of the architecture for that part of the app (as well as just about 
everything else) is being rewritten for TM 2.0, so your best bet is 
probably to wait for that, and then give feedback.  I know that Allan 
wants to do some unification of the regular html preview and the 
commands' html view, etc.

-Jacob