Optimized

src/json-rpc/src/Packer/JsonLengthPacker.php

@@ -47,6 +47,9 @@ class JsonLengthPacker implements PackerInterface
     public function unpack(string $data)
     {
         $data = substr($data, $this->length);
+        if (! $data) {
+            return null;
+        }
         return json_decode($data, true);
     }
 }

src/json-rpc/src/RecvTrait.php

@@ -31,7 +31,7 @@ trait RecvTrait
             throw new RecvException('Connection is closed.');
         }
         if ($data === false) {
-            throw new RecvException('Error receiving data, errno=' . $client->errCode);
+            throw new RecvException('Error receiving data, errno=' . $client->errCode . ' errmsg=' . swoole_strerror($client->errCode));
         }
 
         return $data;