From 913348ce9a1a0285ef59ae1731a1bc7ba353f79c Mon Sep 17 00:00:00 2001
From: Moritz Bunkus <m.bunkus@linet-services.de>
Date: Tue, 20 Dec 2016 16:20:49 +0100
Subject: [PATCH] =?utf8?q?SL::DB::Helper::Manager:=20neue=20Funktion=20zum?=
 =?utf8?q?=20Pre-Cachen=20aller=20Eintr=C3=A4ge=20einer=20Tabelle?=
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Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

---
 SL/DB/Helper/Manager.pm | 73 +++++++++++++++++++++++++++++++++++++++++
 SL/DB/Object.pm         |  8 +++++
 2 files changed, 81 insertions(+)

diff --git a/SL/DB/Helper/Manager.pm b/SL/DB/Helper/Manager.pm
index d456e76b0..c44f67953 100644
--- a/SL/DB/Helper/Manager.pm
+++ b/SL/DB/Helper/Manager.pm
@@ -2,6 +2,8 @@ package SL::DB::Helper::Manager;
 
 use strict;
 
+use Carp;
+
 use Rose::DB::Object::Manager;
 use base qw(Rose::DB::Object::Manager);
 
@@ -36,4 +38,75 @@ sub get_first {
   )->[0];
 }
 
+sub cache_all {
+  my $manager_class =  shift;
+  my $class         =  $manager_class;
+  $class            =~ s{Manager::}{};
+
+  croak "Caching can only be used with classes with exactly one primary key column" if 1 != scalar(@{ $class->meta->primary_key_columns });
+
+  my $all_have_been_cached =  $::request->cache("::SL::DB::Manager::cache_all");
+  return if $all_have_been_cached->{$class};
+
+  $all_have_been_cached->{$class} = 1;
+
+  my $item_cache                  = $::request->cache("::SL::DB::Object::object_cache::${class}");
+  my $primary_key                 = $class->meta->primary_key_columns->[0]->name;
+  my $objects                     = $class->_get_manager_class->get_all;
+
+  $item_cache->{$_->$primary_key} = $_ for @{ $objects};
+}
+
 1;
+__END__
+
+=pod
+
+=encoding utf8
+
+=head1 NAME
+
+SL::DB::Helper::Manager - Base class & helper functions for all Rose manager classes
+
+=head1 FUNCTIONS
+
+=over 4
+
+=item C<cache_all>
+
+Pre-caches all items from a table. Use this is you expect to need all
+items from a table. You can retrieve them later with the
+C<load_cached> function from the corresponding Rose DB object class.
+
+For example, if you expect to need all unit objects, you can use
+C<SL::DB::Manager::Unit-E<gt>cache_all> before you start the actual
+work. Later you can use C<SL::DB::Unit-E<gt>load_cached> to retrieve
+individual objects and be sure that they're already cached.
+
+=item C<find_by>
+
+TODO: Describe find_by
+
+=item C<find_by_or_create>
+
+TODO: Describe find_by_or_create
+
+=item C<get_first>
+
+TODO: Describe get_first
+
+=item C<make_manager_methods>
+
+TODO: Describe make_manager_methods
+
+=back
+
+=head1 BUGS
+
+Nothing here yet.
+
+=head1 AUTHOR
+
+Moritz Bunkus E<lt>m.bunkus@linet-services.deE<gt>
+
+=cut
diff --git a/SL/DB/Object.pm b/SL/DB/Object.pm
index 4c3e18439..485fab2ce 100755
--- a/SL/DB/Object.pm
+++ b/SL/DB/Object.pm
@@ -324,6 +324,14 @@ Loads objects from the database which haven't been cached before and
 caches them for the duration of the current request (see
 L<SL::Request/cache>).
 
+If you know in advance that you will likely need all objects of a
+particular type then you can pre-cache them by calling the manager's
+C<cache_all> function. For example, if you expect to need all unit
+objects, you can use C<SL::DB::Manager::Unit-E<gt>cache_all> before
+you start the actual work. Later you can use
+C<SL::DB::Unit-E<gt>load_cached> to retrieve individual objects and be
+sure that they're already cached.
+
 This method can be called both as an instance method and a class
 method. It loads objects for the corresponding class (e.g. both
 C<SL::DB::Part-E<gt>load_cached(…)> and
-- 
2.20.1