lib/PublicInbox/RepoSnapshot.pm | 51 ++++++++++++++++++++-------------------------------
 lib/PublicInbox/RepoTree.pm     |  8 +-------
 lib/PublicInbox/ViewVCS.pm      | 14 ++++++++++++--

diff --git a/lib/PublicInbox/RepoSnapshot.pm b/lib/PublicInbox/RepoSnapshot.pm
index 826392a85a8b02b64263037a660a1a2c634251a1..93ba4db6e332a289afa89b177866201bf8134a43 100644
--- a/lib/PublicInbox/RepoSnapshot.pm
+++ b/lib/PublicInbox/RepoSnapshot.pm
@@ -4,9 +4,8 @@
 # cgit-compatible /snapshot/ endpoint for WWW coderepos
 package PublicInbox::RepoSnapshot;
 use v5.12;
-use PublicInbox::Git;
 use PublicInbox::Qspawn;
-use PublicInbox::GitAsyncCat;
+use PublicInbox::ViewVCS;
 use PublicInbox::WwwStatic qw(r);
 
 # Not using standard mime types since the compressed tarballs are
@@ -42,31 +41,25 @@ 		'Content-Disposition', qq(inline; filename="$fn"),
 		'ETag', qq("$ctx->{etag}") ] ];
 }
 
-sub archive_cb {
-	my ($ctx) = @_;
-	my @cfg;
-	if (my $cmd = $FMT_CFG{$ctx->{snap_fmt}}) {
-		@cfg = ('-c', "tar.$ctx->{snap_fmt}.command=$cmd");
-	}
-	my $qsp = PublicInbox::Qspawn->new(['git', @cfg,
-			"--git-dir=$ctx->{git}->{git_dir}", 'archive',
-			"--prefix=$ctx->{snap_pfx}/",
-			"--format=$ctx->{snap_fmt}", $ctx->{treeish}]);
-	$qsp->psgi_return($ctx->{env}, undef, \&archive_hdr, $ctx);
-}
-
 sub ver_check { # git->check_async callback
 	my ($oid, $type, $size, $ctx) = @_;
-	if ($type eq 'missing') { # try 'v' and 'V' prefixes
-		my $pfx = shift @{$ctx->{try_pfx}} or return
+	return if defined $ctx->{etag};
+	my $treeish = shift @{$ctx->{-try}} // die 'BUG: no {-try}';
+	if ($type eq 'missing') {
+		scalar(@{$ctx->{-try}}) or
 			delete($ctx->{env}->{'qspawn.wcb'})->(r(404));
-		my $v = $ctx->{treeish} = $pfx.$ctx->{snap_ver};
-		return $ctx->{env}->{'pi-httpd.async'} ?
-			async_check($ctx, $v, \&ver_check, $ctx) :
-			$ctx->{git}->check_async($v, \&ver_check, $ctx);
+	} else { # found, done:
+		$ctx->{etag} = $oid;
+		my @cfg;
+		if (my $cmd = $FMT_CFG{$ctx->{snap_fmt}}) {
+			@cfg = ('-c', "tar.$ctx->{snap_fmt}.command=$cmd");
+		}
+		my $qsp = PublicInbox::Qspawn->new(['git', @cfg,
+				"--git-dir=$ctx->{git}->{git_dir}", 'archive',
+				"--prefix=$ctx->{snap_pfx}/",
+				"--format=$ctx->{snap_fmt}", $treeish]);
+		$qsp->psgi_return($ctx->{env}, undef, \&archive_hdr, $ctx);
 	}
-	$ctx->{etag} = $oid;
-	archive_cb($ctx);
 }
 
 sub srv {
@@ -81,16 +74,12 @@ 	($pfx) = ($pfx =~ m!([^/]+)\z!);
 	substr($fn, 0, length($pfx)) eq $pfx or return;
 	$ctx->{snap_pfx} = $fn;
 	my $v = $ctx->{snap_ver} = substr($fn, length($pfx), length($fn));
-	$ctx->{treeish} = $v; # try without [vV] prefix, first
-	@{$ctx->{try_pfx}} = qw(v V); # cf. cgit:ui-snapshot.c
+	# try without [vV] prefix, first
+	my @try = map { "$_$v" } ('', 'v', 'V'); # cf. cgit:ui-snapshot.c
+	@{$ctx->{-try}} = @try;
 	sub {
 		$ctx->{env}->{'qspawn.wcb'} = $_[0];
-		if ($ctx->{env}->{'pi-httpd.async'}) {
-			async_check($ctx, $v, \&ver_check, $ctx);
-		} else {
-			$ctx->{git}->check_async($v, \&ver_check, $ctx);
-			$ctx->{git}->check_async_wait;
-		}
+		PublicInbox::ViewVCS::do_check_async($ctx, \&ver_check, @try);
 	}
 }
 
diff --git a/lib/PublicInbox/RepoTree.pm b/lib/PublicInbox/RepoTree.pm
index 84e2058983027a1ad2c3a5e63682168c3494e930..7434e9b275f08d2dd8f5c19e1333bb0b2b40ff0e 100644
--- a/lib/PublicInbox/RepoTree.pm
+++ b/lib/PublicInbox/RepoTree.pm
@@ -5,7 +5,6 @@ # cgit-compatible $REPO/tree/[PATH]?h=$tip redirector
 package PublicInbox::RepoTree;
 use v5.12;
 use PublicInbox::ViewDiff qw(uri_escape_path);
-use PublicInbox::GitAsyncCat;
 use PublicInbox::WwwStatic qw(r);
 use PublicInbox::Qspawn;
 use PublicInbox::WwwStream qw(html_oneshot);
@@ -78,12 +77,7 @@ 	# legitimate use of "\n" in filenames anyways.
 	return if index($obj, "\n") >= 0;
 	sub {
 		$ctx->{-wcb} = $_[0]; # HTTP::{Chunked,Identity}
-		if ($ctx->{env}->{'pi-httpd.async'}) {
-			async_check($ctx, $obj, \&tree_show, $ctx);
-		} else {
-			$ctx->{git}->check_async($obj, \&tree_show, $ctx);
-			$ctx->{git}->async_wait_all;
-		}
+		PublicInbox::ViewVCS::do_check_async($ctx, \&tree_show, $obj);
 	};
 }
 
diff --git a/lib/PublicInbox/ViewVCS.pm b/lib/PublicInbox/ViewVCS.pm
index eae5b7f416cf88f8c35823dc5647ef01b0c415ca..37b688ed586e4e6ae42837cad03679d5ebb7411b 100644
--- a/lib/PublicInbox/ViewVCS.pm
+++ b/lib/PublicInbox/ViewVCS.pm
@@ -126,13 +126,23 @@ 		cmt_finalize($ctx);
 }
 
 sub do_cat_async {
-	my ($ctx, $cb, @oids) = @_;
+	my ($ctx, $cb, @req) = @_;
 	# favor git(1) over Gcf2 (libgit2) for SHA-256 support
-	$ctx->{git}->cat_async($_, $cb, $ctx) for @oids;
+	$ctx->{git}->cat_async($_, $cb, $ctx) for @req;
 	if ($ctx->{env}->{'pi-httpd.async'}) {
 		PublicInbox::GitAsyncCat::watch_cat($ctx->{git});
 	} else { # synchronous, generic PSGI
 		$ctx->{git}->cat_async_wait;
+	}
+}
+
+sub do_check_async {
+	my ($ctx, $cb, @req) = @_;
+	if ($ctx->{env}->{'pi-httpd.async'}) {
+		async_check($ctx, $_, $cb, $ctx) for @req;
+	} else { # synchronous, generic PSGI
+		$ctx->{git}->check_async($_, $cb, $ctx) for @req;
+		$ctx->{git}->check_async_wait;
 	}
 }