From 401f01125c23fe54e7697b0c22619c4d8e728b12 Mon Sep 17 00:00:00 2001
From: Lari Taskula <lari.taskula@jns.fi>
Date: Thu, 15 Dec 2016 19:31:30 +0200
Subject: [PATCH] Bug 17783: Optimize
 Koha::IssuingRules->get_effective_issuing_rule

This patch modifies method get_effective_issuing_rule in Koha::IssuingRules
aiming to optimize the search for matching issuing rule.

Before this patch, in worst case scenario, we have had to make a SELECT query
eight times. This will have a negative impact on performance where-ever we need
to find matching issuing rule multiple times, if the search is not directly
matching an issuing rule on the first query.

This patch makes get_effective_issuing_rule have a stable performance on both
best and worst case, whereas the old method was really fast on the best case
and really slow on the worst case.

However, this patch slightly lowers the performance for best case, where matching
issuing rule is found instantly before (branchcode, categorycode and itemtype all
are specifically defined in issuing rules). For all other cases this patch offers
a performance improvement.

To test:
1. Run t/db_dependent/Koha/IssuingRules.t and compare the results with previous
   tests.

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
---
 Koha/IssuingRules.pm | 78 +++++++-------------------------------------
 1 file changed, 11 insertions(+), 67 deletions(-)

diff --git a/Koha/IssuingRules.pm b/Koha/IssuingRules.pm
index 3c588f7d44..c0c69be32b 100644
--- a/Koha/IssuingRules.pm
+++ b/Koha/IssuingRules.pm
@@ -44,73 +44,17 @@ sub get_effective_issuing_rule {
     my $itemtype     = $params->{itemtype};
     my $branchcode   = $params->{branchcode};
 
-    my $rule = $self->find($params);
-    return $rule if $rule;
-
-    $rule = $self->find(
-        {
-            categorycode => $categorycode,
-            itemtype     => $default,
-            branchcode   => $branchcode
-        }
-    );
-    return $rule if $rule;
-
-    $rule = $self->find(
-        {
-            categorycode => $default,
-            itemtype     => $itemtype,
-            branchcode   => $branchcode
-        }
-    );
-    return $rule if $rule;
-
-    $rule = $self->find(
-        {
-            categorycode => $default,
-            itemtype     => $default,
-            branchcode   => $branchcode
-        }
-    );
-    return $rule if $rule;
-
-    $rule = $self->find(
-        {
-            categorycode => $categorycode,
-            itemtype     => $itemtype,
-            branchcode   => $default
-        }
-    );
-    return $rule if $rule;
-
-    $rule = $self->find(
-        {
-            categorycode => $categorycode,
-            itemtype     => $default,
-            branchcode   => $default
-        }
-    );
-    return $rule if $rule;
-
-    $rule = $self->find(
-        {
-            categorycode => $default,
-            itemtype     => $itemtype,
-            branchcode   => $default
-        }
-    );
-    return $rule if $rule;
-
-    $rule = $self->find(
-        {
-            categorycode => $default,
-            itemtype     => $default,
-            branchcode   => $default
-        }
-    );
-    return $rule if $rule;
-
-    return;
+    my $rule = $self->search({
+        categorycode => { 'in' => [ $categorycode, $default ] },
+        itemtype     => { 'in' => [ $itemtype,     $default ] },
+        branchcode   => { 'in' => [ $branchcode,   $default ] },
+    }, {
+        order_by => {
+            -desc => ['branchcode', 'categorycode', 'itemtype']
+        },
+        rows => 1,
+    })->single;
+    return $rule;
 }
 
 =head3 type
-- 
2.39.2