From cb6b2d0cbf7eb178f1c7fe9746d4bd043ab52fe1 Mon Sep 17 00:00:00 2001
From: Jacek Ablewicz <abl@biblos.pk.edu.pl>
Date: Wed, 30 Mar 2016 12:21:03 +0200
Subject: [PATCH] Bug 16168: Eliminate unneeded C4::Context->dbh calls in
 C4/Biblio.pm

Right now, ->dbh calls are actually quite expensive (they involve
DB connection health checks, each and every time). Some speed-sensitive
subroutines inside C4/Biblio.pm (GetMarcStructure, GetAuthorisedValueDesc)
have this statement

    my $dbh = C4::Context->dbh;

on top of the code, but they don't always/don't usually need DB
handle - not at that stage at least. This trivial patch eliminates
unneeded ->dbh calls in those subroutines. With it, average
GetMarcStructure() running time goes down from 14 miliseconds
to 9 miliseconds (on top of Bug 16166), it also makes catalogue
search profiling a bit easier.

Test plan:

1) apply patch
2) ensure that catalogue searches are still working
3) run t/*Biblio* tests
---
 C4/Biblio.pm |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/C4/Biblio.pm b/C4/Biblio.pm
index 188870c..75afaa1 100644
--- a/C4/Biblio.pm
+++ b/C4/Biblio.pm
@@ -1114,7 +1114,6 @@ $frameworkcode : the framework code to read
 
 sub GetMarcStructure {
     my ( $forlibrarian, $frameworkcode ) = @_;
-    my $dbh = C4::Context->dbh;
     $frameworkcode = "" unless $frameworkcode;
 
     $forlibrarian = $forlibrarian ? 1 : 0;
@@ -1123,6 +1122,7 @@ sub GetMarcStructure {
     my $cached = $cache->get_from_cache($cache_key);
     return $cached if $cached;
 
+    my $dbh = C4::Context->dbh;
     my $sth = $dbh->prepare(
         "SELECT tagfield,liblibrarian,libopac,mandatory,repeatable 
         FROM marc_tag_structure 
@@ -1667,7 +1667,6 @@ descriptions rather than normal ones when they exist.
 
 sub GetAuthorisedValueDesc {
     my ( $tag, $subfield, $value, $framework, $tagslib, $category, $opac ) = @_;
-    my $dbh = C4::Context->dbh;
 
     if ( !$category ) {
 
@@ -1687,6 +1686,7 @@ sub GetAuthorisedValueDesc {
         $category = $tagslib->{$tag}->{$subfield}->{'authorised_value'};
     }
 
+    my $dbh = C4::Context->dbh;
     if ( $category ne "" ) {
         my $sth = $dbh->prepare( "SELECT lib, lib_opac FROM authorised_values WHERE category = ? AND authorised_value = ?" );
         $sth->execute( $category, $value );
@@ -2618,6 +2618,7 @@ hash_ref
 
 sub TransformMarcToKoha {
     my ( $dbh, $record, $frameworkcode, $limit_table ) = @_;
+    ## FIXME: $dbh parameter is never used inside this subroutine ???
 
     my $result = {};
     if (!defined $record) {
-- 
1.7.10.4