From 318e9d7e76c8b52a367a38e446fcacfdfd0b36e0 Mon Sep 17 00:00:00 2001
From: Mateusz Charytoniuk <mateusz.charytoniuk@gmail.com>
Date: Wed, 14 Mar 2018 19:53:18 +0100
Subject: [PATCH] Import CSV rows one at a time (#3450)

Credit @mcharytoniuk.

While importing over 250k records ImportModel kept running into various problems. One of them was too big memory usage - `ImportModel` loaded the complete file upfront (`$reader->fetchAll()`). Simple one-line change to `$reader->fetch()` makes `ImportModel` import CSV file row-by-row and returning an iterator which limits memory usage and allows data to be imported. This change optimizes memory usage and allows much simpler importing of larger files.
---
 modules/backend/models/ImportModel.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/modules/backend/models/ImportModel.php b/modules/backend/models/ImportModel.php
index 55f6512ad..83ac38928 100644
--- a/modules/backend/models/ImportModel.php
+++ b/modules/backend/models/ImportModel.php
@@ -142,7 +142,7 @@ abstract class ImportModel extends Model
         }
 
         $result = [];
-        $contents = $reader->fetchAll();
+        $contents = $reader->fetch();
         foreach ($contents as $row) {
             $result[] = $this->processImportRow($row, $matches);
         }