From 495a2009a1addad341f92052150662ecbb4692a3 Mon Sep 17 00:00:00 2001
From: Blou <blou@inlibro.com>
Date: Wed, 25 Oct 2023 16:54:08 -0400
Subject: [PATCH] Bug 28411: Use lazy loading to reduce memory footprint of
 C4/Context.pm

This simply removes some 'use' declarations at the top of the file to
instead use 'require' later on.

The effect can be validated with a simple one-liner (provided KOHA_CONF
and PERL5LIB being set)

perl -e "use C4::Context; while(1){sleep(1);}"

And monitoring the memoring usage in tools like 'top'
---
 C4/Context.pm | 8 ++++----
 C4/Search.pm  | 1 +
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/C4/Context.pm b/C4/Context.pm
index 091e4783a4..0d8bce7458 100644
--- a/C4/Context.pm
+++ b/C4/Context.pm
@@ -36,12 +36,8 @@ BEGIN {
 };
 
 use Carp qw( carp );
-use DateTime::TimeZone;
 use Encode;
 use File::Spec;
-use POSIX;
-use YAML::XS;
-use ZOOM;
 use List::MoreUtils qw(any);
 
 use Koha::Caches;
@@ -342,6 +338,7 @@ the value cannot be properly decoded as YAML.
 sub yaml_preference {
     my ( $self, $preference ) = @_;
 
+    require YAML::XS;
     my $yaml = eval { YAML::XS::Load( Encode::encode_utf8( $self->preference( $preference ) ) ); };
     if ($@) {
         warn "Unable to parse $preference syspref : $@";
@@ -607,6 +604,7 @@ sub _new_Zconn {
     my $user = $serverinfo->{user};
     my $password = $serverinfo->{password};
     eval {
+        require ZOOM;
         # set options
         my $o = ZOOM::Options->new();
         $o->option(user => $user) if $user && $password;
@@ -873,6 +871,7 @@ sub get_versions {
     my ( %versions, $mysqlVersion );
     $versions{kohaVersion}  = Koha::version();
     $versions{kohaDbVersion} = C4::Context->preference('version');
+    require POSIX;
     $versions{osVersion} = join(" ", POSIX::uname());
     $versions{perlVersion} = $];
 
@@ -904,6 +903,7 @@ sub tz {
     my $self = shift;
     if (!defined $context->{tz}) {
         my $timezone = $context->{config}->timezone;
+        require DateTime::TimeZone;
         $context->{tz} = DateTime::TimeZone->new(name => $timezone);
     }
     return $context->{tz};
diff --git a/C4/Search.pm b/C4/Search.pm
index e2de36571e..6423caa60b 100644
--- a/C4/Search.pm
+++ b/C4/Search.pm
@@ -39,6 +39,7 @@ use URI::Escape;
 use Business::ISBN;
 use MARC::Record;
 use MARC::Field;
+use ZOOM;
 
 our (@ISA, @EXPORT_OK);
 BEGIN {
-- 
2.34.1