From 5e497a47a218ee7c222c4be02f284353f842113a Mon Sep 17 00:00:00 2001
From: Tomas Cohen Arazi <tomascohen@theke.io>
Date: Wed, 15 Sep 2021 12:12:33 -0300
Subject: [PATCH] Bug 29032: Pre-load ILL backends to speed up response

Bug 22440 will rewrite the route and make it even more efficient by
prefetching the related data instead of performing several queries in
loops.

In the meantime, we can make this controller perform better with a
simple intervention: load backends once, and use the
$request->_backend() setter to pre-set it before using the objects.

To test:
1. Perform any usual ILL requests listing, try having several
=> FAIL: Notice it takes a weird amount of time to load
2. Apply this patch
3. Restart all
4. Repeat 1
=> SUCCESS: It feels fast enough!
5. Sign off :-D

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
---
 Koha/REST/V1/Illrequests.pm | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/Koha/REST/V1/Illrequests.pm b/Koha/REST/V1/Illrequests.pm
index 24f93cbffa..82c5b5dd08 100644
--- a/Koha/REST/V1/Illrequests.pm
+++ b/Koha/REST/V1/Illrequests.pm
@@ -71,6 +71,15 @@ sub list {
         : ()
     })->as_list;
 
+    my $fetch_backends = {};
+    foreach my $request (@requests) {
+        $fetch_backends->{ $request->backend } ||=
+          Koha::Illrequest->new->load_backend( $request->backend );
+    }
+
+    # Pre-load the backend object to avoid useless backend lookup/loads
+    @requests = map { $_->_backend( $fetch_backends->{ $_->backend } ); $_ } @requests;
+
     # Identify patrons & branches that
     # we're going to need and get them
     my $to_fetch = {
@@ -78,7 +87,7 @@ sub list {
         branches     => {},
         capabilities => {}
     };
-    foreach my $req(@requests) {
+    foreach my $req (@requests) {
         $to_fetch->{patrons}->{$req->borrowernumber} = 1 if $embed{patron};
         $to_fetch->{branches}->{$req->branchcode} = 1 if $embed{library};
         $to_fetch->{capabilities}->{$req->backend} = 1 if $embed{capabilities};
@@ -113,8 +122,7 @@ sub list {
         my @backends = keys %{$to_fetch->{capabilities}};
         if (scalar @backends > 0) {
             foreach my $bc(@backends) {
-                my $backend = Koha::Illrequest->new->load_backend($bc);
-                $to_fetch->{$bc} = $backend->capabilities;
+                $to_fetch->{$bc} = $fetch_backends->{$bc}->capabilities;
             }
         }
     }
-- 
2.20.1