Cache inner iso in XsiTypeEncoder to avoid redundant iso() calls

Captures $this->encoder->iso($context) once in iso() and passes
the result to the private to() and from() methods. This avoids
rebuilding the inner iso on every encode/decode invocation.

In from(), when xsi:type detection resolves to the same encoder,
the cached iso is reused instead of calling iso() again.

Author: veewee

src/Encoder/XsiTypeEncoder.php

@@ -25,35 +25,37 @@ public function __construct(
      */
     public function iso(Context $context): Iso
     {
+        $innerIso = $this->encoder->iso($context);
+
         return new Iso(
-            function (mixed $value) use ($context) : string {
-                return $this->to($context, $value);
+            function (mixed $value) use ($innerIso) : string {
+                return $this->to($innerIso, $value);
             },
-            function (string|Element $value) use ($context) : mixed {
+            function (string|Element $value) use ($context, $innerIso) : mixed {
                 return $this->from(
                     $context,
+                    $innerIso,
                     ($value instanceof Element ? $value : Element::fromString(non_empty_string()->assert($value)))
                 );
             }
         );
     }
 
-    private function to(Context $context, mixed $value): string
+    private function to(Iso $innerIso, mixed $value): string
     {
-        // There is no way to know what xsi:type to use when encoding any type.
-        // The type defined in the wsdl will always be used to encode the value.
-        // If you want more control over the encoded type, please control how to encode by using the MatchingValueEncoder.
-        return $this->encoder->iso($context)->to($value);
+        return $innerIso->to($value);
     }
 
-    private function from(Context $context, Element $value): mixed
+    private function from(Context $context, Iso $innerIso, Element $value): mixed
     {
         /** @var XmlEncoder<string, mixed> $encoder */
         $encoder = match (true) {
             $this->encoder instanceof Feature\DisregardXsiInformation => $this->encoder,
             default => XsiTypeDetector::detectEncoderFromXmlElement($context, $value->element())->unwrapOr($this->encoder)
         };
 
-        return $encoder->iso($context)->from($value);
+        $iso = $encoder === $this->encoder ? $innerIso : $encoder->iso($context);
+
+        return $iso->from($value);
     }
 }