Attachment 32749 Details for Bug 13146 – Bug 13146 Improve GetRecordValue function by caching field mapping

[patch] Bug 13146 Improve GetRecordValue function by caching field mapping

Bug-13146-Improve-GetRecordValue-function-by-cachi.patch (text/plain), 5.10 KB, created by Frédéric Demians on 2014-10-25 21:25:55 UTC

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Creator: Frédéric Demians

Created: 2014-10-25 21:25:55 UTC

Size: 5.10 KB

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>From baa7f22da24daa3bff8a115c7b2501b36473e417 Mon Sep 17 00:00:00 2001
>From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Demians?= <f.demians@tamil.fr>
>Date: Sat, 25 Oct 2014 20:05:29 +0200
>Subject: [PATCH] Bug 13146 Improve GetRecordValue function by caching field
> mapping
>
>GetRecordValue function is called each time a specific field mapping is
>required. For example, bug 12692 display biblio record subtitle for each hold
>awaiting pickup or overdue. As it is implemented now, GetRecordValue queries
>directly the fieldmapping table to determine in which tag/letter a field has to
>be searched. It means, that the same mapping are requested over and over.
>
>This patch uses Koha cache system to store a complete data structure
>representing the field mapping.
>
>TO TEST:
>
>(1) Look at the code! and check that Koha caching system is properly used.
>
>(2) Find out a Koha function where subtitle field mapping is used. Make you
>    choice: sending a basket, tag list, overdues with fines, renew item, etc.
>
>(3) Note that the display of subtitle field hasn't changed.
>
>(4) If you really want to see how less queries are sent to MySQL with this
>    patch, you have to monitor your MySQL log files!
>
>    Suggestion to do it on a Debian box:
>
>    - In MySQL client: SHOW VARIABLES LIKE "general_log%";
>      It gives you MySQL log file path. Usually, /var/run/mysqld/mysqld.log
>    - Enable log, with: SET GLOBAL general_log = 'ON';
>    - Display a page displaying the subtitle field
>    - Compare request send with/withouth this patch. Without the patch, you
>      will see plenty of query like that:
>
>      SELECT fieldcode, subfieldcode FROM fieldmapping
>---
> C4/Biblio.pm | 71 +++++++++++++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 58 insertions(+), 13 deletions(-)
>
>diff --git a/C4/Biblio.pm b/C4/Biblio.pm
>index ec4c71e..58c5562 100644
>--- a/C4/Biblio.pm
>+++ b/C4/Biblio.pm
>@@ -689,26 +689,69 @@ sub GetRecordValue {
>         carp 'GetRecordValue called with undefined record';
>         return;
>     }
>-    my $dbh = C4::Context->dbh;
> 
>-    my $sth = $dbh->prepare('SELECT fieldcode, subfieldcode FROM fieldmapping WHERE frameworkcode = ? AND field = ?');
>-    $sth->execute( $frameworkcode, $field );
>+    # All field mappings are retrieved from cache, or from DB if not already
>+    # cached.
>+    # The mapping is a data structure that looks like that:
>+    # '' => {
>+    #     subtitle => [
>+    #         [ '200', 'e' ],
>+    #         [ '400', 'e' ],
>+    #     },
>+    #     maintitle => [
>+    #         [ '200', 'a' ],
>+    #         [ '400', 'a'Â ],
>+    #     },
>+    #  },
>+    #  MAIN = {
>+    #     subtitle => [
>+    #         [ '200', 'e' ],
>+    #     },
>+    #     maintitle => [
>+    #         [ '200', 'a' ],
>+    #     },
>+    #  },
>+
>+    my $key = 'FieldMapping';
>+    my $cache = Koha::Cache->get_instance();
>+    my $mapping = $cache->get_from_cache($key);
>+    unless ( $mapping ) {
>+        my $sth = C4::Context->dbh->prepare('SELECT * FROM fieldmapping');
>+        $sth->execute;
>+        $mapping = {};
>+        for my $map ( @{ $sth->fetchall_arrayref({}) } ) {
>+            my ($field, $framework, $tag, $letter) = (
>+                $map->{field},
>+                $map->{frameworkcode},
>+                $map->{fieldcode},
>+                $map->{subfieldcode} );
>+            $mapping->{$framework} ||= {};
>+            $mapping->{$framework}->{$field} ||= [];
>+            push @{ $mapping->{$framework}->{$field} }, [ $tag, $letter ];
>+        }
>+        $cache->set_in_cache($key, $mapping);
>+    }
>+
>+    # Does the requested field mapping exists from the framework?
>+    my $maps = $mapping->{$frameworkcode};
>+    return unless $maps;
>+    $maps = $maps->{$field};
>+    return unless $maps;
> 
>     my @result = ();
>-
>-    while ( my $row = $sth->fetchrow_hashref ) {
>-        foreach my $field ( $record->field( $row->{fieldcode} ) ) {
>-            if ( ( $row->{subfieldcode} ne "" && $field->subfield( $row->{subfieldcode} ) ) ) {
>-                foreach my $subfield ( $field->subfield( $row->{subfieldcode} ) ) {
>-                    push @result, { 'subfield' => $subfield };
>+    for my $map (@$maps) {
>+        my ($tag, $letter) = @$map;
>+        foreach my $field ( $record->field($tag) ) {
>+            if ( $letter ) {
>+                if ( my @values = $field->subfield($letter) ) {
>+                    push @result, { subfield => $_ } for @values;
>                 }
>-
>-            } elsif ( $row->{subfieldcode} eq "" ) {
>-                push @result, { 'subfield' => $field->as_string() };
>+            }
>+            else {
>+                push @result, { subfield => $field->as_string() };
>             }
>         }
>     }
>-
>     return \@result;
> }
> 
>@@ -732,6 +775,7 @@ sub SetFieldMapping {
> 
>         $sth->execute( $fieldcode, $subfieldcode, $framework, $field );
>     }
>+    my $cache = Koha::Cache->get_instance()->clear_from_cache('FieldMapping');
> }
> 
> =head2 DeleteFieldMapping
>@@ -748,6 +792,7 @@ sub DeleteFieldMapping {
> 
>     my $sth = $dbh->prepare('DELETE FROM fieldmapping WHERE id = ?');
>     $sth->execute($id);
>+    my $cache = Koha::Cache->get_instance()->clear_from_cache('FieldMapping');
> }
> 
> =head2 GetFieldMapping
>-- 
>2.1.2

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