Avoid duplicate database errors when storing the conversations

diff --git a/include/items.php b/include/items.php
index 5eb254b1e2534d1990cb8fd156a0ccefd2b2021c..1e11c08c4b7da185a0307cbc705020f95841f4a5 100644 (file)
--- a/include/items.php
+++ b/include/items.php
@@ -6,6 +6,7 @@
 
 use Friendica\App;
 use Friendica\ParseUrl;
+use Friendica\Util\Lock;
 
 require_once 'include/bbcode.php';
 require_once 'include/oembed.php';
@@ -444,6 +445,15 @@ function store_conversation($arr) {
                        $conversation['source'] = $arr['source'];
                }
 
+               if (!Lock::set('store_conversation')) {
+                       // When using semaphores, this case never can't happen
+                       unset($arr['conversation-uri']);
+                       unset($arr['conversation-href']);
+                       unset($arr['protocol']);
+                       unset($arr['source']);
+                       return $arr;
+               }
+
                $old_conv = dba::fetch_first("SELECT `item-uri`, `reply-to-uri`, `conversation-uri`, `conversation-href`, `protocol`, `source`
                                FROM `conversation` WHERE `item-uri` = ?", $conversation['item-uri']);
                if (dbm::is_result($old_conv)) {
@@ -465,6 +475,7 @@ function store_conversation($arr) {
                                logger('Conversation: insert for '.$conversation['item-uri'].' (protocol '.$conversation['protocol'].') failed', LOGGER_DEBUG);
                        }
                }
+               Lock::remove('store_conversation');
        }
 
        unset($arr['conversation-uri']);
@@ -2317,7 +2328,7 @@ function drop_item($id, $interactive = true) {
 
 }
 
-
+/// @todo: This query seems to be really slow
 function first_post_date($uid, $wall = false) {
        $r = q("SELECT `id`, `created` FROM `item`
                WHERE `uid` = %d AND `wall` = %d AND `deleted` = 0 AND `visible` = 1 AND `moderated` = 0