[PATCH 3/6] hlmod: make into a singleton

[Eric Wong <e@80x24.org>]

It turns out there's no point in having multiple instances of
this or having to worry about destruction or destruction
ordering.

This will make it easier to reuse the one instance we have
across different modules.
---
 lib/PublicInbox/HlMod.pm   | 33 +++++++++++++--------------------
 lib/PublicInbox/ViewVCS.pm |  5 -----
 t/hl_mod.t                 | 15 ---------------
 3 files changed, 13 insertions(+), 40 deletions(-)

diff --git a/lib/PublicInbox/HlMod.pm b/lib/PublicInbox/HlMod.pm
index 284e4b1..13f27d1 100644
--- a/lib/PublicInbox/HlMod.pm
+++ b/lib/PublicInbox/HlMod.pm
@@ -16,6 +16,7 @@ package PublicInbox::HlMod;
 use strict;
 use warnings;
 use highlight; # SWIG-generated stuff
+my $hl;
 
 sub _parse_filetypes ($) {
 	my $ft_conf = $_[0]->searchFile('filetypes.conf') or
@@ -52,16 +53,20 @@ sub _parse_filetypes ($) {
 	(\%ext2lang, \@shebang);
 }
 
+# We only need one instance, so we don't need to do
+# highlight::CodeGenerator::deleteInstance
 sub new {
 	my ($class) = @_;
-	my $dir = highlight::DataDir->new;
-	$dir->initSearchDirectories('');
-	my ($ext2lang, $shebang) = _parse_filetypes($dir);
-	bless {
-		-dir => $dir,
-		-ext2lang => $ext2lang,
-		-shebang => $shebang,
-	}, $class;
+	$hl ||= do {
+		my $dir = highlight::DataDir->new;
+		$dir->initSearchDirectories('');
+		my ($ext2lang, $shebang) = _parse_filetypes($dir);
+		bless {
+			-dir => $dir,
+			-ext2lang => $ext2lang,
+			-shebang => $shebang,
+		}, $class;
+	};
 }
 
 sub _shebang2lang ($$) {
@@ -120,16 +125,4 @@ sub do_hl_lang {
 	\$out;
 }
 
-# SWIG instances aren't reference-counted, but $self is;
-# so we need to delete all the CodeGenerator instances manually
-# at our own destruction
-sub DESTROY {
-	my ($self) = @_;
-	foreach my $gen (values %$self) {
-		if (ref($gen) eq 'highlight::CodeGenerator') {
-			highlight::CodeGenerator::deleteInstance($gen);
-		}
-	}
-}
-
 1;
diff --git a/lib/PublicInbox/ViewVCS.pm b/lib/PublicInbox/ViewVCS.pm
index acdd822..0fb6b64 100644
--- a/lib/PublicInbox/ViewVCS.pm
+++ b/lib/PublicInbox/ViewVCS.pm
@@ -25,11 +25,6 @@ my $hl = eval {
 	PublicInbox::HlMod->new;
 };
 
-# we need to trigger highlight::CodeGenerator::deleteInstance
-# in HlMod::DESTROY before the rest of Perl shuts down to avoid
-# a segfault at shutdown
-END { $hl = undef };
-
 my %QP_MAP = ( A => 'oid_a', B => 'oid_b', a => 'path_a', b => 'path_b' );
 my $max_size = 1024 * 1024; # TODO: configurable
 my $BIN_DETECT = 8000; # same as git
diff --git a/t/hl_mod.t b/t/hl_mod.t
index 238f8ec..f2eb5f9 100644
--- a/t/hl_mod.t
+++ b/t/hl_mod.t
@@ -40,19 +40,4 @@ my $orig = $str;
 	}
 }
 
-my $nr = $ENV{TEST_MEMLEAK};
-if ($nr && -r "/proc/$$/status") {
-	my $fh;
-	open $fh, '<', "/proc/$$/status";
-	diag "starting at memtest at ".join('', grep(/VmRSS:/, <$fh>));
-	PublicInbox::HlMod->new->do_hl(\$orig) for (1..$nr);
-	open $fh, '<', "/proc/$$/status";
-	diag "creating $nr instances: ".join('', grep(/VmRSS:/, <$fh>));
-	my $hls = PublicInbox::HlMod->new;
-	$hls->do_hl(\$orig) for (1..$nr);
-	$hls = undef;
-	open $fh, '<', "/proc/$$/status";
-	diag "reused instance $nr times: ".join('', grep(/VmRSS:/, <$fh>));
-}
-
 done_testing;
-- 
EW