From ce30f3933fcb31cb0e7b6ac0956c1c8e64fedba3 Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Thu, 30 Nov 2023 11:41:00 +0000
Subject: git: share unlinked pack checking code with gcf2

It saves some code in case we keep libgit2 around.
---
 lib/PublicInbox/Gcf2.pm | 16 ++++------------
 lib/PublicInbox/Git.pm  | 27 ++++++++++++++-------------
 2 files changed, 18 insertions(+), 25 deletions(-)

diff --git a/lib/PublicInbox/Gcf2.pm b/lib/PublicInbox/Gcf2.pm
index dcbb201d..78392990 100644
--- a/lib/PublicInbox/Gcf2.pm
+++ b/lib/PublicInbox/Gcf2.pm
@@ -9,7 +9,7 @@ use PublicInbox::Spawn qw(which run_qx); # may set PERL_INLINE_DIRECTORY
 use Fcntl qw(SEEK_SET);
 use Time::HiRes qw(clock_gettime CLOCK_MONOTONIC);
 use IO::Handle; # autoflush
-use PublicInbox::Git;
+use PublicInbox::Git qw($ck_unlinked_packs);
 use PublicInbox::Lock;
 use autodie qw(close open seek truncate);
 
@@ -86,16 +86,6 @@ sub add_alt ($$) {
 	1;
 }
 
-sub have_unlinked_files () {
-	# FIXME: port gcf2-like over to git.git so we won't need to
-	# deal with libgit2
-	return 1 if $^O ne 'linux';
-	if (my $s = PublicInbox::IO::try_cat("/proc/$$/maps")) {
-		return 1 if /\.(?:idx|pack) \(deleted\)/s;
-	}
-	undef;
-}
-
 # Usage: $^X -MPublicInbox::Gcf2 -e PublicInbox::Gcf2::loop [EXPIRE-TIMEOUT]
 # (see lib/PublicInbox/Gcf2Client.pm)
 sub loop (;$) {
@@ -104,6 +94,7 @@ sub loop (;$) {
 	my (%seen, $check_at);
 	STDERR->autoflush(1);
 	STDOUT->autoflush(1);
+	my $pid = $$;
 
 	while (<STDIN>) {
 		chomp;
@@ -130,7 +121,8 @@ sub loop (;$) {
 			$check_at //= $now + $exp;
 			if ($now > $check_at) {
 				undef $check_at;
-				if (have_unlinked_files()) {
+				if (!$ck_unlinked_packs ||
+						$ck_unlinked_packs->($pid)) {
 					$gcf2 = new();
 					%seen = ();
 				}
diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index 235a35cd..9c4d938e 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -24,7 +24,8 @@ use Carp qw(croak carp);
 use PublicInbox::SHA qw(sha_all);
 our %HEXLEN2SHA = (40 => 1, 64 => 256);
 our %OFMT2HEXLEN = (sha1 => 40, sha256 => 64);
-our @EXPORT_OK = qw(git_unquote git_quote %HEXLEN2SHA %OFMT2HEXLEN);
+our @EXPORT_OK = qw(git_unquote git_quote %HEXLEN2SHA %OFMT2HEXLEN
+			$ck_unlinked_packs);
 our $in_cleanup;
 our $async_warn; # true in read-only daemons
 
@@ -597,27 +598,27 @@ sub manifest_entry {
 	$ent;
 }
 
+our $ck_unlinked_packs = $^O eq 'linux' ? sub {
+	# FIXME: port gcf2-like over to git.git so we won't need to
+	# deal with libgit2
+	my $s = try_cat "/proc/$_[0]/maps";
+	$s =~ /\.(?:idx|pack) \(deleted\)/s ? 1 : undef;
+} : undef;
+
 # returns true if there are pending cat-file processes
 sub cleanup_if_unlinked {
 	my ($self) = @_;
-	return cleanup($self, 1) if $^O ne 'linux';
+	$ck_unlinked_packs or return cleanup($self, 1);
 	# Linux-specific /proc/$PID/maps access
 	# TODO: support this inside git.git
-	my $ret = 0;
+	my $nr_live = 0;
 	for my $obj ($self, ($self->{ck} // ())) {
 		my $sock = $obj->{sock} // next;
 		my $pid = $sock->attached_pid // next;
-		open my $fh, '<', "/proc/$pid/maps" or return cleanup($self, 1);
-		while (<$fh>) {
-			# n.b. we do not restart for unlinked multi-pack-index
-			# since it's not too huge, and the startup cost may
-			# be higher.
-			/\.(?:idx|pack) \(deleted\)$/ and
-				return cleanup($self, 1);
-		}
-		++$ret;
+		$ck_unlinked_packs->($pid) and return cleanup($self, 1);
+		++$nr_live;
 	}
-	$ret;
+	$nr_live;
 }
 
 sub event_step {
-- 
cgit v1.2.3-24-ge0c7