Cache serialization (#226)

Author: norberttech

src/Flow/ETL/Cache.php

@@ -2,7 +2,13 @@
 
 namespace Flow\ETL;
 
-interface Cache
+use Flow\Serializer\Serializable;
+
+/**
+ * @template T
+ * @extends Serializable<T>
+ */
+interface Cache extends Serializable
 {
     public function add(string $id, Rows $rows) : void;
 

src/Flow/ETL/Cache/InMemoryCache.php

@@ -7,13 +7,25 @@
 use Flow\ETL\Cache;
 use Flow\ETL\Rows;
 
+/**
+ * @implements Cache<array<mixed>>
+ */
 final class InMemoryCache implements Cache
 {
     /**
      * @var array<string, array<Rows>>
      */
     private array $cache = [];
 
+    public function __serialize() : array
+    {
+        return [];
+    }
+
+    public function __unserialize(array $data) : void
+    {
+    }
+
     public function add(string $id, Rows $rows) : void
     {
         if (!\array_key_exists($id, $this->cache)) {

src/Flow/ETL/Cache/LocalFilesystemCache.php

@@ -10,6 +10,7 @@
 use Flow\Serializer\Serializer;
 
 /**
+ * @implements Cache<array{path: string, serializer: Serializer}>
  * @infection-ignore-all
  */
 final class LocalFilesystemCache implements Cache
@@ -23,6 +24,20 @@ public function __construct(
         }
     }
 
+    public function __serialize() : array
+    {
+        return [
+            'path' => $this->path,
+            'serializer' => $this->serializer,
+        ];
+    }
+
+    public function __unserialize(array $data) : void
+    {
+        $this->path = $data['path'];
+        $this->serializer = $data['serializer'];
+    }
+
     public function add(string $id, Rows $rows) : void
     {
         $cacheStream = \fopen($this->cachePath($id), 'a');

src/Flow/ETL/ConfigBuilder.php

@@ -9,7 +9,6 @@
 use Flow\ETL\ExternalSort\MemorySort;
 use Flow\ETL\Monitoring\Memory\Unit;
 use Flow\Serializer\CompressingSerializer;
-use Flow\Serializer\NativePHPSerializer;
 use Flow\Serializer\Serializer;
 
 final class ConfigBuilder
@@ -39,7 +38,7 @@ public function __construct()
     public function build() : Config
     {
         $this->id ??= \uniqid('flow_php');
-        $this->serializer ??= new CompressingSerializer(new NativePHPSerializer());
+        $this->serializer ??= new CompressingSerializer();
         $this->cache ??= new LocalFilesystemCache(
             \is_string(\getenv(Config::CACHE_DIR_ENV))
                 ? \getenv(Config::CACHE_DIR_ENV)

src/Flow/Serializer/CompressingSerializer.php

@@ -8,10 +8,14 @@
 
 final class CompressingSerializer implements Serializer
 {
-    public function __construct(
-        private readonly Serializer $serializer,
-        private readonly int $compressionLevel = 9
-    ) {
+    private readonly int $compressionLevel;
+
+    private readonly Serializer $serializer;
+
+    public function __construct()
+    {
+        $this->serializer = new NativePHPSerializer();
+        $this->compressionLevel = 9;
     }
 
     public function serialize(Serializable $serializable) : string

src/Flow/Serializer/NativePHPSerializer.php

@@ -8,6 +8,10 @@
 
 final class NativePHPSerializer implements Serializer
 {
+    public function __construct()
+    {
+    }
+
     public function serialize(Serializable $serializable) : string
     {
         return \serialize($serializable);

tests/Flow/ETL/Tests/Double/CacheSpy.php

@@ -7,6 +7,9 @@
 use Flow\ETL\Cache;
 use Flow\ETL\Rows;
 
+/**
+ * @implements Cache<array<mixed>>
+ */
 final class CacheSpy implements Cache
 {
     /**
@@ -28,6 +31,15 @@ public function __construct(private readonly Cache $cache)
     {
     }
 
+    public function __serialize() : array
+    {
+        return [];
+    }
+
+    public function __unserialize(array $data) : void
+    {
+    }
+
     public function add(string $id, Rows $rows) : void
     {
         if (!\array_key_exists($id, $this->writes)) {