X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FGcf2.pm;h=041dffe7d9c7b26396ab0a97f7b7deaf008c6896;hb=0d38f65c490466837ae091afa7a7b6f59d04ce7c;hp=fe76b1fdaaf2a61881d08c51718ba4f680d0a98e;hpb=3750b2e2952e55fe4a04c73fc78f25c5e07d0525;p=public-inbox.git

diff --git a/lib/PublicInbox/Gcf2.pm b/lib/PublicInbox/Gcf2.pm
index fe76b1fd..041dffe7 100644
--- a/lib/PublicInbox/Gcf2.pm
+++ b/lib/PublicInbox/Gcf2.pm
@@ -1,12 +1,13 @@
 # Copyright (C) 2020 all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
-# backend for public-inbox-gcf2(1) (git-cat-file based on libgit2,
-# other libgit2 stuff may go here, too)
+# backend for a git-cat-file-workalike based on libgit2,
+# other libgit2 stuff may go here, too.
 package PublicInbox::Gcf2;
 use strict;
 use PublicInbox::Spawn qw(which popen_rd);
 use Fcntl qw(LOCK_EX);
+use IO::Handle; # autoflush
 my (%CFG, $c_src, $lockfh);
 BEGIN {
 	# PublicInbox::Spawn will set PERL_INLINE_DIRECTORY
@@ -54,4 +55,56 @@ use Inline C => $c_src;
 undef $c_src;
 undef %CFG;
 undef $lockfh;
+
+sub add_alt ($$) {
+	my ($gcf2, $objdir) = @_;
+
+	# libgit2 (tested 0.27.7+dfsg.1-0.2 and 0.28.3+dfsg.1-1~bpo10+1
+	# in Debian) doesn't handle relative epochs properly when nested
+	# multiple levels.  Add all the absolute paths to workaround it,
+	# since $EXTINDEX_DIR/ALL.git/objects/info/alternates uses absolute
+	# paths to reference $V2INBOX_DIR/all.git/objects and
+	# $V2INBOX_DIR/all.git/objects/info/alternates uses relative paths
+	# to refer to $V2INBOX_DIR/git/$EPOCH.git/objects
+	#
+	# See https://bugs.debian.org/975607
+	if (open(my $fh, '<', "$objdir/info/alternates")) {
+		chomp(my @abs_alt = grep(m!^/!, <$fh>));
+		$gcf2->add_alternate($_) for @abs_alt;
+	}
+	$gcf2->add_alternate($objdir);
+}
+
+# Usage: $^X -MPublicInbox::Gcf2 -e 'PublicInbox::Gcf2::loop()'
+# (see lib/PublicInbox/Gcf2Client.pm)
+sub loop {
+	my $gcf2 = new();
+	my %seen;
+	STDERR->autoflush(1);
+	STDOUT->autoflush(1);
+
+	while (<STDIN>) {
+		chomp;
+		my ($oid, $git_dir) = split(/ /, $_, 2);
+		$seen{$git_dir}++ or add_alt($gcf2, "$git_dir/objects");
+		if (!$gcf2->cat_oid(1, $oid)) {
+			# retry once if missing.  We only get unabbreviated OIDs
+			# from SQLite or Xapian DBs, here, so malicious clients
+			# can't trigger excessive retries:
+			warn "I: $$ $oid missing, retrying in $git_dir\n";
+
+			$gcf2 = new();
+			%seen = ($git_dir => 1);
+			add_alt($gcf2, "$git_dir/objects");
+
+			if ($gcf2->cat_oid(1, $oid)) {
+				warn "I: $$ $oid found after retry\n";
+			} else {
+				warn "W: $$ $oid missing after retry\n";
+				print "$oid missing\n"; # mimic git-cat-file
+			}
+		}
+	}
+}
+
 1;