On Wed, Aug 31, 2022 at 11:37 PM Rob Landley <r...@landley.net> wrote:
> On 8/31/22 16:55, enh wrote: > > and if i `CONFIG_TOYBOX_NORECURSE=y`, it calls sed and works... > > > > ...though this might be about to come back and bite me. i'm hearing > as-yet > > unconfirmed reports that toybox `tar czf` is a lot slower than gnu tar, > and -- > > given that they're using --transform` while they're assuming it's tar or > gzip, > > i'm wondering whether it's actually the fact that we're forking out to > sed for > > every file? > > > > i've asked for repro steps or a `perf record` i can look at... > > When I said I had more work to do there, part of what I wanted to do was > add a > sed --tar-xform mode with some sort of protocol that would allow a single > persistent sed to get a name and send back a response without exiting. > (That > would also allow me to implement the trailing type indicators.) > > Right now exiting lets you know that it's done processing, even if your sed > invocation included a "d" or something and thus produced no output (so you > wait > forever if it DOESN'T exit). And even if I use -z mode you can include \0 > manually in a substitution and thus force it out of sync. So the > persistent mode > would need some sort of "expect X bytes of output" indicator, probably > just a > decimal number of bytes ending with a newline, followed by the transformed > payload. And of course the type indicator needs the incoming name to be > annotated with type information as part of the call-and-response > protocol... > > It's not perfect, you can always sed ':a;b a' or something if you want to > cause > Horrible Goose levels of trouble. (Tempted to add something like the > symlink > resolution limit so 1 billion jumps in a single sed pattern evaluation > exit with > an error...) > > The downside of doing that is it would require TOYBOX sed. meh, _i_ don't care about that :-) (and, more seriously, does _anyone_ care about using a mixture of toybox and non-toybox? i'd imagine the only people who'd even notice would be people like me [or these kernel guys] trying to switch over, and the only reason i/they are switching over one tool at a time is because we've been running slightly ahead of you, using stuff that's not finished yet. i guess it would affect the toybox _tests_ but i kind of thing that's a bug already --- given that i support systems where everything's from toybox it's a misfeature that the toybox tests _don't_ test toybox-with-toybox [and i get no value from them testing toybox-with-gnu].) > Right now it should > work with the host sed. I vaguely plan to try to launch "sed --tar-xform -e > $PATTERN" and then fall back to the old one at a time logic not > undestanding > suffixes if sed exits with an error, because toybox commands try NOT to > require > other toybox commands. But I can't figure out a better way to do this than > copying half the sed plumbing to lib/sed.c and it really wasn't designed > to be > broken up... > > Rob >
_______________________________________________ Toybox mailing list Toybox@lists.landley.net http://lists.landley.net/listinfo.cgi/toybox-landley.net
