Db/Cache: first step to externalize lookup caches

library/Director/Db/Cache/CustomVariableCache.php

@@ -0,0 +1,65 @@
+<?php
+
+namespace Icinga\Module\Director\Db\Cache;
+
+use Icinga\Module\Director\CustomVariable\CustomVariables;
+use Icinga\Module\Director\Db;
+use Icinga\Module\Director\Objects\IcingaObject;
+
+class CustomVariableCache
+{
+    protected $type;
+
+    protected $rowsById = array();
+
+    protected $varsById = array();
+
+    public function __construct(IcingaObject $object)
+    {
+        $db = $object->getConnection()->getDbAdapter();
+
+        $query = $db->select()->from(
+            array('v' => $object->getVarsTableName()),
+            array(
+                'id'       => sprintf('v.%s', $object->getVarsIdColumn()),
+                'varname'  => 'v.varname',
+                'varvalue' => 'v.varvalue',
+                'format'   => 'v.format',
+            )
+        );
+
+        foreach ($db->fetchAll($query) as $row) {
+
+            $id = $row->id;
+            unset($row->id);
+
+            if (array_key_exists($id, $this->rowsById)) {
+                $this->rowsById[$id][] = $row;
+            } else {
+                $this->rowsById[$id] = array($row);
+            }
+        }
+    }
+
+    public function getVarsForObject(IcingaObject $object)
+    {
+        $id = $object->id;
+
+        if (array_key_exists($id, $this->rowsById)) {
+            if (! array_key_exists($id, $this->varsById)) {
+                $this->varsById[$id] = CustomVariables::forStoredRows(
+                    $this->rowsById[$id]
+                );
+            }
+
+            return $this->varsById[$id];
+        } else {
+            return new CustomVariables();
+        }
+    }
+
+    public function __destruct()
+    {
+        unset($this->db);
+    }
+}

library/Director/Db/Cache/PrefetchCache.php

@@ -0,0 +1,97 @@
+<?php
+
+namespace Icinga\Module\Director\Db\Cache;
+
+use Icinga\Exception\ProgrammingError;
+use Icinga\Module\Director\Db;
+use Icinga\Module\Director\Objects\IcingaObject;
+
+class PrefetchCache
+{
+    protected $db;
+
+    protected static $instance;
+
+    protected $caches = array();
+
+    protected $varsCaches = array();
+
+    protected $groupsCaches = array();
+
+    public static function initialize(Db $db)
+    {
+        self::$instance = new static($db);
+    }
+
+    protected function __construct(Db $db)
+    {
+        $this->db = $db;
+    }
+
+    public static function instance()
+    {
+        if (static::$instance === null) {
+            throw new ProgrammingError('Prefetch cache has not been loaded');
+        }
+
+        return static::$instance;
+    }
+
+    public static function forget()
+    {
+        self::$instance = null;
+    }
+
+    public static function shouldBeUsed()
+    {
+        return self::$instance !== null;
+    }
+
+    public function vars(IcingaObject $object)
+    {
+        return $this->varsCache($object)->getVarsForObject($object);
+    }
+
+    public function groups(IcingaObject $object)
+    {
+        return $this->groupsCache($object)->getGroupsForObject($object);
+    }
+
+    public function byObjectType($type)
+    {
+        if (! array_key_exists($type, $this->caches)) {
+            $this->caches[$type] = new ObjectCache($type);
+        }
+
+        return $this->caches[$type];
+    }
+
+    protected function varsCache(IcingaObject $object)
+    {
+        $key = $object->getShortTableName();
+
+        if (! array_key_exists($key, $this->varsCaches)) {
+            $this->varsCaches[$key] = new CustomVariableCache($object);
+        }
+
+        return $this->varsCaches[$key];
+    }
+
+    protected function groupsCache(IcingaObject $object)
+    {
+        $key = $object->getShortTableName();
+
+        if (! array_key_exists($key, $this->groupsCaches)) {
+            $this->groupsCaches[$key] = new GroupMembershipCache($object);
+        }
+
+        return $this->groupsCaches[$key];
+    }
+
+    public function __destruct()
+    {
+        unset($this->caches);
+        unset($this->groupsCaches);
+        unset($this->varsCaches);
+    }
+}