From b01200039b8195e5bfcc9004a6b28823f884fe1c Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Sun, 12 Feb 2023 23:18:27 +0000
Subject: lei_mirror: further reduce `git config' calls

We can parse the config at once and avoid clobbering variables
which do not need changing.  We'll also do some prep work for
fetch.hideRefs proposal being discussed at
<https://public-inbox.org/git/20230209122857.M669733@dcvr/>
---
 lib/PublicInbox/LeiMirror.pm | 62 +++++++++++++++++++++++++-------------------
 1 file changed, 36 insertions(+), 26 deletions(-)

diff --git a/lib/PublicInbox/LeiMirror.pm b/lib/PublicInbox/LeiMirror.pm
index d959b6b6..dd6356bb 100644
--- a/lib/PublicInbox/LeiMirror.pm
+++ b/lib/PublicInbox/LeiMirror.pm
@@ -401,23 +401,42 @@ sub fgrp_fetch_all {
 	my $opt = {};
 	my @fetch = do {
 		local $self->{lei}->{opt}->{jobs} = 1;
-		(fetch_args($self->{lei}, $opt),
-			qw(--no-tags --multiple));
+		(fetch_args($self->{lei}, $opt), qw(--no-tags --multiple));
 	};
 	push(@fetch, "-j$j") if $j;
 	while (my ($osdir, $fgrpv) = each %$todo) {
 		my $f = "$osdir/config";
 		return if !keep_going($self);
 
+		my $cmd = ['git', "--git-dir=$osdir", qw(config -f), $f ];
 		# clobber group from previous run atomically
-		my $cmd = ['git', "--git-dir=$osdir", qw(config -f),
-				$f, '--unset-all', "remotes.$grp"];
-		$self->{lei}->qerr("# @$cmd");
-		if (!$self->{dry_run}) {
-			my $pid = spawn($cmd, undef, { 2 => $self->{lei}->{2} });
+		for ("remotes.$grp") { # TODO: hideRefs
+			my $c = [ @$cmd, '--unset-all', $_ ];
+			$self->{lei}->qerr("# @$c");
+			next if $self->{dry_run};
+			my $pid = spawn($c, undef, $opt);
 			waitpid($pid, 0) // die "waitpid: $!";
-			die "E: @$cmd: \$?=$?" if ($? && ($? >> 8) != 5);
+			die "E: @$c \$?=$?" if ($? && ($? >> 8) != 5);
+		}
 
+		# permanent configs:
+		my $cfg = PublicInbox::Config->git_config_dump($f);
+		for my $fgrp (@$fgrpv) {
+			my $u = $fgrp->{-uri} // die 'BUG: no {-uri}';
+			my $rn = $fgrp->{-remote} // die 'BUG: no {-remote}';
+			for ("url=$u", "fetch=+refs/*:refs/remotes/$rn/*",
+					'tagopt=--no-tags') {
+				my ($k, $v) = split(/=/, $_, 2);
+				$k = "remote.$rn.$k";
+				next if ($cfg->{$k} // '') eq $v;
+				my $c = [@$cmd, $k, $v];
+				$fgrp->{lei}->qerr("# @$c");
+				next if $fgrp->{dry_run};
+				run_die($c, undef, $opt);
+			}
+		}
+
+		if (!$self->{dry_run}) {
 			# update the config atomically via O_APPEND while
 			# respecting git-config locking
 			sysopen(my $lk, "$f.lock", O_CREAT|O_EXCL|O_WRONLY)
@@ -430,7 +449,6 @@ sub fgrp_fetch_all {
 			close $fh or die "close($f): $!";
 			unlink("$f.lock") or die "unlink($f.lock): $!";
 		}
-
 		$cmd = [ @git, "--git-dir=$osdir", @fetch, $grp ];
 		my $end = PublicInbox::OnDestroy->new($$, \&fgrpv_done, $fgrpv);
 		start_cmd($self, $cmd, $opt, $end);
@@ -446,12 +464,15 @@ sub forkgroup_prep {
 	my $dir = "$os/$fg.git";
 	if (!-d $dir && !$self->{dry_run}) {
 		PublicInbox::Import::init_bare($dir);
-		my @cmd = ('git', "--git-dir=$dir", 'config');
-		my $opt = { 2 => $self->{lei}->{2} };
-		for ('repack.useDeltaIslands=true',
-				'pack.island=refs/remotes/([^/]+)/') {
-			run_die([@cmd, split(/=/, $_, 2)], undef, $opt);
-		}
+		my $f = "$dir/config";
+		open my $fh, '+>>', $f or die "open:($f): $!";
+		print $fh <<EOM or die "print($f): $!";
+[repack]
+	useDeltaIslands = true
+[pack]
+	island = refs/remotes/([^/]+)/
+EOM
+		close $fh or die "close($f): $!";
 	}
 	my $key = $self->{-key} // die 'BUG: no -key';
 	my $rn = substr(sha256_hex($key), 0, 16);
@@ -546,17 +567,6 @@ sub resume_fetch {
 sub fgrp_enqueue {
 	my ($fgrp, $end) = @_; # $end calls fgrp_fetch_all
 	return if !keep_going($fgrp);
-	my $opt = { 2 => $fgrp->{lei}->{2} };
-	# --no-tags is required to avoid conflicts
-	my $u = $fgrp->{-uri} // die 'BUG: no {-uri}';
-	my $rn = $fgrp->{-remote} // die 'BUG: no {-remote}';
-	my @cmd = ('git', "--git-dir=$fgrp->{-osdir}", 'config');
-	for ("url=$u", "fetch=+refs/*:refs/remotes/$rn/*", 'tagopt=--no-tags') {
-		my @kv = split(/=/, $_, 2);
-		$kv[0] = "remote.$rn.$kv[0]";
-		$fgrp->{dry_run} ? $fgrp->{lei}->qerr("# @cmd @kv") :
-				run_die([@cmd, @kv], undef, $opt);
-	}
 	++$fgrp->{chg}->{nr_chg};
 	push @{$FGRP_TODO->{$fgrp->{-osdir}}}, $fgrp;
 }
-- 
cgit v1.2.3-24-ge0c7