From f46ca1634a2e566f662b19ea4338d1d702714c88 Mon Sep 17 00:00:00 2001
From: Jakub Onderka <jakub.onderka@gmail.com>
Date: Sat, 20 Jun 2020 09:54:32 +0200
Subject: [PATCH] chg: [internal] Use tmp file fro Feed::getCache

---
 app/Lib/Tools/TmpFileTool.php | 34 ++++++++++++++++++++++++++++++++--
 app/Model/Feed.php            | 20 ++++++++++++--------
 2 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/app/Lib/Tools/TmpFileTool.php b/app/Lib/Tools/TmpFileTool.php
index f34fa0445..882668956 100644
--- a/app/Lib/Tools/TmpFileTool.php
+++ b/app/Lib/Tools/TmpFileTool.php
@@ -37,16 +37,34 @@ class TmpFileTool
         }
     }
 
+    /**
+     * @return Generator
+     * @throws Exception
+     */
+    public function lines()
+    {
+        $this->rewind();
+        while (!feof($this->tmpfile)) {
+            $result = fgets($this->tmpfile);
+            if ($result === false) {
+                throw new Exception('Could not read line from temporary file.');
+            }
+            yield $result;
+        }
+        fclose($this->tmpfile);
+        $this->tmpfile = null;
+    }
+
     /**
      * @return string
      * @throws Exception
      */
     public function finish()
     {
-        fseek($this->tmpfile, 0);
+        $this->rewind();
         $final = stream_get_contents($this->tmpfile);
         if ($final === false) {
-            throw new Exception("Could not read from temporary file.");
+            throw new Exception('Could not read from temporary file.');
         }
         fclose($this->tmpfile);
         $this->tmpfile = null;
@@ -61,4 +79,16 @@ class TmpFileTool
     {
         return $this->finish();
     }
+
+    /**
+     * Seek to start of file.
+     *
+     * @throws Exception
+     */
+    private function rewind()
+    {
+        if (fseek($this->tmpfile, 0) === -1) {
+            throw new Exception('Could not seek to start of temporary file.');
+        }
+    }
 }
diff --git a/app/Model/Feed.php b/app/Model/Feed.php
index d1c956859..32f0b4b61 100644
--- a/app/Model/Feed.php
+++ b/app/Model/Feed.php
@@ -1,6 +1,7 @@
 <?php
 App::uses('AppModel', 'Model');
 App::uses('RandomTool', 'Tools');
+App::uses('TmpFileTool', 'Tools');
 
 class Feed extends AppModel
 {
@@ -161,10 +162,10 @@ class Feed extends AppModel
     /**
      * @param array $feed
      * @param HttpSocket $HttpSocket
-     * @return array
+     * @return Generator|array
      * @throws Exception
      */
-    public function getCache($feed, $HttpSocket)
+    public function getCache(array $feed, HttpSocket $HttpSocket)
     {
         $uri = $feed['Feed']['url'] . '/hashes.csv';
         $data = $this->feedGetUri($feed, $uri, $HttpSocket);
@@ -173,13 +174,16 @@ class Feed extends AppModel
             throw new Exception("File '$uri' with hashes for cache filling is empty.");
         }
 
-        $data = trim($data);
-        $data = explode("\n", $data);
-        $result = array();
-        foreach ($data as $v) {
-            $result[] = explode(',', $v);
+        // CSV file can be pretty big to do operations in memory, so we save content to temp and iterate line by line.
+        $tmpFile = new TmpFileTool();
+        $tmpFile->write(trim($data));
+        unset($data);
+
+        foreach ($tmpFile->lines() as $line) {
+            yield explode(',', rtrim($line));
         }
-        return $result;
+
+        return array();
     }
 
     /**