parsing slowdown with new features in 1.281 #309
Description
we saw quite a slowdown in parsing times with the latest PPI, especially in our fatter modules (up to a factor of 20)
the slowdown seems to occur in parsing the document during object creation. method calls on the parsed document have similar call times as before
$ perl -MPPI -E 'warn PPI->VERSION'
1.281 at -e line 1.
$ /tmp/ppi_test.pl "/opt/perl-current-live/local-default/lib/perl5/CGI.pm"
loaded in 4.34172 at /tmp/ppi_test.pl line 10.
complete 1 in 0.05063 at /tmp/ppi_test.pl line 14.
incl 19 in 0.04981 at /tmp/ppi_test.pl line 18.
$
$ ## after PPI downgrade
$ perl -MPPI -E 'warn PPI->VERSION'
1.279 at -e line 1.
$ /tmp/ppi_test.pl "/opt/perl-current-live/local-default/lib/perl5/CGI.pm"
loaded in 0.82833 at /tmp/ppi_test.pl line 10.
complete 1 in 0.04924 at /tmp/ppi_test.pl line 14.
incl 19 in 0.05106 at /tmp/ppi_test.pl line 18.
$
$ cat /tmp/ppi_test.pl
#!/usr/bin/env perl
use v5.40;
use PPI;
use Time::HiRes qw/time/;
my $t0 = time;
my $p = PPI::Document->new(shift)
or die "couldnt load";
warn sprintf("loaded in %.5f", time - $t0);
$t0 = time;
my $ok = $p->complete;
warn sprintf("complete %s in %.5f", $ok, time - $t0);
$t0 = time;
my $incl = $p->find("PPI::Statement::Include");
warn sprintf("incl %s in %.5f", scalar @$incl, time - $t0);
$
we use PPI for checking syntax and via perlcritic