treewide: reduce $PATH checks for `git' executable

Repeatedly checking $PATH for `git' when we need to call it
multiple times in quick succession doesn't seem useful.  So
avoid some expensive stat(2) syscalls to make things less bad
for systems which require expensive CPU vulnerability
mitigations.

This also saves a bunch of memory allocations since we do the
$PATH lookup in pure Perl to avoid doing the uncacheable lookup
in a vfork-ed child.

1 files changed, 4 insertions, 5 deletions

diff --git a/lib/PublicInbox/LeiBlob.pm b/lib/PublicInbox/LeiBlob.pm
index 00697097..7b2ea434 100644
--- a/lib/PublicInbox/LeiBlob.pm
+++ b/lib/PublicInbox/LeiBlob.pm
@@ -36,14 +36,13 @@ sub solver_user_cb { # called by solver when done
         ref($res) eq 'ARRAY' or return $lei->child_error(0, $$log_buf);
         $lei->qerr($$log_buf);
         my ($git, $oid, $type, $size, $di) = @$res;
-        my $gd = $git->{git_dir};
 
         # don't try to support all the git-show(1) options for non-blob,
         # this is just a convenience:
-        $type ne 'blob' and
-                warn "# $oid is a $type of $size bytes in:\n#\t$gd\n";
-
-        my $cmd = [ 'git', "--git-dir=$gd", 'show', $oid ];
+        $type ne 'blob' and warn <<EOM;
+# $oid is a $type of $size bytes in:\n#\t$git->{git_dir}
+EOM
+        my $cmd = $git->cmd('show', $oid);
         my $rdr = { 1 => $lei->{1}, 2 => $lei->{2} };
         run_wait($cmd, $lei->{env}, $rdr) and $lei->child_error($?);
 }