Allow to set APP_FETCHING_BUNCH_SIZE env parameter - closes #4343

app/Console/Commands/FetchEmails.php

@@ -260,6 +260,7 @@ public function fetch($mailbox)
             $this->line('['.date('Y-m-d H:i:s').'] Fetching: '.($unseen ? 'UNREAD' : 'ALL'));
         }
 
+        $page_size = (int)config('app.fetching_bunch_size');
         foreach ($folders as $folder) {
             $this->line('['.date('Y-m-d H:i:s').'] Folder: '.($folder->full_name ?? $folder->name));
 
@@ -279,7 +280,7 @@ public function fetch($mailbox)
                     if ($no_charset) {
                         $messages_query->setCharset(null);
                     }
-                    $messages_query->limit(self::PAGE_SIZE, $page);
+                    $messages_query->limit($page_size, $page);
 
                     $messages = $messages_query->get();
 
@@ -332,7 +333,7 @@ public function fetch($mailbox)
                     $this->processMessage($message, $message_id, $dest_mailbox, $this->mailboxes);
                 }
                 $page++;
-            } while (count($messages) == self::PAGE_SIZE);
+            } while (count($messages) == $page_size);
         }
 
         $client->disconnect();

config/app.php

@@ -348,6 +348,17 @@
     */
     'since_without_quotes_on_fetching'    => env('APP_SINCE_WITHOUT_QUOTES_ON_FETCHING', false),
 
+    /*
+    |--------------------------------------------------------------------------
+    | Emails are fetched in bunches. The larger the bunch's size the more chances
+    | to face "Allowed memory size exhausted" error. The smaller its size the more
+    | connections are made to the mail server and the more time fetching takes.
+    | https://github.com/freescout-help-desk/freescout/issues/4343
+    |
+    |-------------------------------------------------------------------------
+    */
+    'fetching_bunch_size'    => env('APP_FETCHING_BUNCH_SIZE', 100),
+
      /*
     |--------------------------------------------------------------------------
     | Dashboard path.