From 780fd0e3ef3c2718dabc635dfa3853ca7785fd1f Mon Sep 17 00:00:00 2001
From: Tim Otten <totten@civicrm.org>
Date: Fri, 29 Jun 2018 14:07:54 -0700
Subject: [PATCH] (dev/core#217) Add skeletal PrevNextCache service

---
 CRM/Core/PrevNextCache/Interface.php | 36 ++++++++++++++++++++++++++++
 CRM/Core/PrevNextCache/Sql.php       | 34 ++++++++++++++++++++++++++
 Civi/Core/Container.php              |  5 ++++
 3 files changed, 75 insertions(+)
 create mode 100644 CRM/Core/PrevNextCache/Interface.php
 create mode 100644 CRM/Core/PrevNextCache/Sql.php

diff --git a/CRM/Core/PrevNextCache/Interface.php b/CRM/Core/PrevNextCache/Interface.php
new file mode 100644
index 0000000000..3c8867838a
--- /dev/null
+++ b/CRM/Core/PrevNextCache/Interface.php
@@ -0,0 +1,36 @@
+<?php
+/*
+ +--------------------------------------------------------------------+
+ | CiviCRM version 5                                                  |
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC (c) 2004-2018                                |
+ +--------------------------------------------------------------------+
+ | This file is a part of CiviCRM.                                    |
+ |                                                                    |
+ | CiviCRM is free software; you can copy, modify, and distribute it  |
+ | under the terms of the GNU Affero General Public License           |
+ | Version 3, 19 November 2007 and the CiviCRM Licensing Exception.   |
+ |                                                                    |
+ | CiviCRM is distributed in the hope that it will be useful, but     |
+ | WITHOUT ANY WARRANTY; without even the implied warranty of         |
+ | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.               |
+ | See the GNU Affero General Public License for more details.        |
+ |                                                                    |
+ | You should have received a copy of the GNU Affero General Public   |
+ | License and the CiviCRM Licensing Exception along                  |
+ | with this program; if not, contact CiviCRM LLC                     |
+ | at info[AT]civicrm[DOT]org. If you have questions about the        |
+ | GNU Affero General Public License or the licensing of CiviCRM,     |
+ | see the CiviCRM license FAQ at http://civicrm.org/licensing        |
+ +--------------------------------------------------------------------+
+ */
+
+/**
+ * Interface CRM_Core_PrevNextCache_Interface
+ *
+ * The previous/next cache is a service for tracking query results. Results
+ * are stored in a cache, and they may be individually toggled.
+ */
+interface CRM_Core_PrevNextCache_Interface {
+
+}
diff --git a/CRM/Core/PrevNextCache/Sql.php b/CRM/Core/PrevNextCache/Sql.php
new file mode 100644
index 0000000000..b51704e85a
--- /dev/null
+++ b/CRM/Core/PrevNextCache/Sql.php
@@ -0,0 +1,34 @@
+<?php
+/*
+ +--------------------------------------------------------------------+
+ | CiviCRM version 5                                                  |
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC (c) 2004-2018                                |
+ +--------------------------------------------------------------------+
+ | This file is a part of CiviCRM.                                    |
+ |                                                                    |
+ | CiviCRM is free software; you can copy, modify, and distribute it  |
+ | under the terms of the GNU Affero General Public License           |
+ | Version 3, 19 November 2007 and the CiviCRM Licensing Exception.   |
+ |                                                                    |
+ | CiviCRM is distributed in the hope that it will be useful, but     |
+ | WITHOUT ANY WARRANTY; without even the implied warranty of         |
+ | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.               |
+ | See the GNU Affero General Public License for more details.        |
+ |                                                                    |
+ | You should have received a copy of the GNU Affero General Public   |
+ | License and the CiviCRM Licensing Exception along                  |
+ | with this program; if not, contact CiviCRM LLC                     |
+ | at info[AT]civicrm[DOT]org. If you have questions about the        |
+ | GNU Affero General Public License or the licensing of CiviCRM,     |
+ | see the CiviCRM license FAQ at http://civicrm.org/licensing        |
+ +--------------------------------------------------------------------+
+ */
+
+/**
+ * Class CRM_Core_PrevNextCache_Sql
+ *
+ * Store the previous/next cache in a special-purpose SQL table.
+ */
+class CRM_Core_PrevNextCache_Sql implements CRM_Core_PrevNextCache_Interface {
+}
diff --git a/Civi/Core/Container.php b/Civi/Core/Container.php
index 82dc0614de..30107af67b 100644
--- a/Civi/Core/Container.php
+++ b/Civi/Core/Container.php
@@ -214,6 +214,11 @@ class Container {
         ->setFactory(array($class, 'singleton'));
     }
 
+    $container->setDefinition('prevnext', new Definition(
+      'CRM_Core_PrevNextCache_Sql',
+      []
+    ));
+
     $container->setDefinition('civi.mailing.triggers', new Definition(
       'Civi\Core\SqlTrigger\TimestampTriggers',
       array('civicrm_mailing', 'Mailing')
-- 
2.25.1