Re: Use GhostScript API instead of forking (issue 548030043 by address@hidden)

[Han-Wen Nienhuys]

On Fri, May 1, 2020 at 1:18 PM <address@hidden> wrote:
>
>
> https://codereview.appspot.com/548030043/diff/583830043/lily/general-scheme.cc
> File lily/general-scheme.cc (right):
>
> https://codereview.appspot.com/548030043/diff/583830043/lily/general-scheme.cc#newcode783
> lily/general-scheme.cc:783: command += "(" + ly_scm2string (input) + ")
> run";
> On 2020/05/01 06:42:43, hanwenn wrote:
> > This doesn't hook very deeply into GS internals or how we arrange the
> page.
> > Could we get the same speedup by putting the batching into an
> encompassing .ps
> > file, and calling GS on that file once?
>
> I think this would require substantial refactoring of how LilyPond
> works. As far as I understand, currently each input file is handled
> separately and temporary files are deleted after processing. To get
> similar speedup, we have to reuse the interpreter for the complete run
> of LilyPond.

We can hide it behind a facade, in much the same way that your patch
introduces hidden state. That would only work if we don't postprocess
the GS output after it's generated, but IIRC, we don't do that.

> > Also: is there a GPL'd version of Ghostscript for which this works?
>
> GPL Ghostscript 9.06 from 2012 is apparently the last GPL version. You
> probably don't want to stick with dependencies of that age ;-)




-- 
Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen