Fix running out of memory

Author: jtojnar

composer.json

@@ -43,6 +43,9 @@
         }
     ],
     "autoload": {
+        "files": [
+            "src/helpers/Functions.php"
+        ],
         "psr-4": {
             "Commands\\": "src/Commands/",
             "controllers\\": "src/controllers/",

src/Commands/Database/ExportCommand.php

@@ -57,7 +57,9 @@ protected function execute(InputInterface $input, OutputInterface $output): int
             'items' => $this->items->getRaw(),
         ];
 
-        file_put_contents($input->getArgument('path'), json_encode($data));
+        $encoder = new \Violet\StreamingJsonEncoder\BufferJsonEncoder($data);
+        $stream = new \Violet\StreamingJsonEncoder\JsonStream($encoder);
+        file_put_contents($input->getArgument('path'), $stream);
 
         return self::SUCCESS;
     }

src/daos/mysql/Items.php

@@ -9,6 +9,7 @@
 use DateTime;
 use DateTimeImmutable;
 use helpers\Configuration;
+use function helpers\functions\map;
 use helpers\HtmlString;
 use Monolog\Logger;
 
@@ -690,8 +691,8 @@ public function getRaw(): array {
         $stmt = static::$stmt;
         $items = $this->database->exec('SELECT * FROM ' . $this->configuration->dbPrefix . 'items');
 
-        /** @var array<array{author: string, content: string, datetime: string, icon: string, id: int, lastseen: string, link: string, shared: int, source: int, starred: bool, thumbnail: ?string, title: string, uid: string, unread: bool, updatetime: string}> */
-        $items = array_map(function($row) {
+        /** @var iterable<array{author: string, content: string, datetime: string, icon: string, id: int, lastseen: string, link: string, shared: int, source: int, starred: bool, thumbnail: ?string, title: string, uid: string, unread: bool, updatetime: string}> */
+        $items = map(function($row) {
             // Use ISO 8601 as export format.
             $row['datetime'] = $row['datetime']->format(\DateTimeInterface::ATOM);
             $row['updatetime'] = $row['updatetime']->format(\DateTimeInterface::ATOM);

src/daos/mysql/Sources.php

@@ -7,6 +7,7 @@
 use daos\DatabaseInterface;
 use Exception;
 use helpers\Configuration;
+use function helpers\Functions\map;
 use function json_encode;
 use const JSON_ERROR_NONE;
 use function json_last_error;
@@ -316,7 +317,7 @@ public function getRaw(): array {
         $stmt = static::$stmt;
         $sources = $this->database->exec('SELECT * FROM ' . $this->configuration->dbPrefix . 'sources');
 
-        return array_map(function($row) {
+        return map(function($row) {
             // Stored as UNIX timestamp, use ISO 8601 as export format.
             $row['lastentry'] = (new \DateTime('@' . $row['lastentry']))->format(\DateTimeInterface::ATOM);
             $row['lastupdate'] = (new \DateTime('@' . $row['lastupdate']))->format(\DateTimeInterface::ATOM);

src/helpers/Functions.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace helpers\Functions;
+
+use Generator;
+
+/**
+ * @template T
+ * @template V
+ *
+ * @param callable(T): V $function
+ * @param iterable<T> $collection
+ *
+ * @return Generator<int, V, void, void>
+ */
+function map(callable $function, iterable $collection): Generator {
+    foreach ($collection as $item) {
+        yield $function($item);
+    }
+}