Merge pull request #452 from shikorism/fix/451-atomic-metadata-resolve

Metadata解決処理をトランザクション内で実行する

app/Services/MetadataResolveService.php

@@ -8,6 +8,7 @@ use App\MetadataResolver\MetadataResolver;
 use App\Tag;
 use App\Utilities\Formatter;
 use GuzzleHttp\Exception\TransferException;
+use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Facades\Log;
 
 class MetadataResolveService
@@ -33,6 +34,7 @@ class MetadataResolveService
             throw new DeniedHostException($url);
         }
 
+        return DB::transaction(function () use ($url) {
             // 無かったら取得
             // TODO: ある程度古かったら再取得とかありだと思う
             $metadata = Metadata::find($url);
@@ -60,5 +62,6 @@ class MetadataResolveService
             }
 
             return $metadata;
+        });
     }
 }