From 52053f355af6c09db547f1b8d02bb9ae88abcb1c Mon Sep 17 00:00:00 2001
From: Aleksander Machniak <machniak@kolabsys.com>
Date: Sat, 13 Feb 2016 11:33:01 +0100
Subject: [PATCH] Performance: Optimize kolab_storage_folder::get_object() to
 use one sql query instead of two

Before the change to get an object by UID we first resolve UID to IMAP-UID
and then fetch the object data by IMAP-UID - two select queries. Now we
directly select the data by UID.
---
 plugins/libkolab/lib/kolab_storage_cache.php  |  7 +++-
 plugins/libkolab/lib/kolab_storage_folder.php | 33 ++++++++++++++++---
 2 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/plugins/libkolab/lib/kolab_storage_cache.php b/plugins/libkolab/lib/kolab_storage_cache.php
index 162c220d..800195a8 100644
--- a/plugins/libkolab/lib/kolab_storage_cache.php
+++ b/plugins/libkolab/lib/kolab_storage_cache.php
@@ -665,7 +665,12 @@ class kolab_storage_cache
     public function set_order_by($sortcols)
     {
         if (!empty($sortcols)) {
-            $this->order_by = '`' . join('`, `', (array)$sortcols) . '`';
+            $sortcols = array_map(function($v) {
+                list($column, $order) = explode(' ', $v, 2);
+                return "`$column`" . ($order ? " $order" : '');
+            }, (array) $sortcols);
+
+            $this->order_by = join(', ', $sortcols);
         }
         else {
             $this->order_by = null;
diff --git a/plugins/libkolab/lib/kolab_storage_folder.php b/plugins/libkolab/lib/kolab_storage_folder.php
index 44fe6956..99ea7297 100644
--- a/plugins/libkolab/lib/kolab_storage_folder.php
+++ b/plugins/libkolab/lib/kolab_storage_folder.php
@@ -348,6 +348,12 @@ class kolab_storage_folder extends kolab_storage_folder_api
         if ($length !== null) {
             $this->cache->set_limit($length, $offset);
         }
+
+        $this->order_and_limit = array(
+            'cols'   => $sortcols,
+            'limit'  => $length,
+            'offset' => $offset,
+        );
     }
 
     /**
@@ -376,7 +382,6 @@ class kolab_storage_folder extends kolab_storage_folder_api
         return $query;
     }
 
-
     /**
      * Getter for a single Kolab object, identified by its UID
      *
@@ -388,17 +393,35 @@ class kolab_storage_folder extends kolab_storage_folder_api
      */
     public function get_object($uid, $type = null)
     {
-        if (!$this->valid) {
+        if (!$this->valid || !$uid) {
             return false;
         }
 
+        $query = array(array('uid', '=', $uid));
+
+        if ($type) {
+            $query[] = array('type', '=', $type);
+        }
+
         // synchronize caches
         $this->cache->synchronize();
 
-        $msguid = $this->cache->uid2msguid($uid);
+        // we don't use cache->get() here because we don't have msguid
+        // yet, using select() is faster
 
-        if ($msguid && ($object = $this->cache->get($msguid, $type))) {
-            return $object;
+        // set order to make sure we get most recent object version
+        // set limit to skip count query
+        $this->cache->set_order_by('msguid DESC');
+        $this->cache->set_limit(1);
+
+        $list = $this->cache->select($this->_prepare_query($query));
+
+        // set the order/limit back to defined value
+        $this->cache->set_order_by($this->order_and_limit['order']);
+        $this->cache->set_limit($this->order_and_limit['limit'], $this->order_and_limit['offset']);
+
+        if (!empty($list) && !empty($list[0])) {
+            return $list[0];
         }
 
         return false;