decoder: Optimise creating stdClass object

Author: JakubOnderka

src/simdjson_decoder.cpp

@@ -57,18 +57,21 @@ get_key_with_optional_prefix(simdjson::dom::element &doc, std::string_view json_
     return doc.at_pointer(std_pointer);
 }
 
-static zend_always_inline zend_object* simdjson_init_object(zval *zv, uint32_t size) {
+// Initialize stdClass object and return pointer to propertires HashTable
+static zend_always_inline HashTable* simdjson_init_object(zval *zv, uint32_t size) {
 #if PHP_VERSION_ID >= 80300
-    zend_object *object = (zend_object*)emalloc(sizeof(zend_object) + zend_object_properties_size(zend_standard_class_def));
+    size_t properties_size = zend_object_properties_size(zend_standard_class_def);
+    ZEND_ASSERT(properties_size == -16);
+    zend_object *object = (zend_object*)emalloc(sizeof(zend_object) - properties_size);
     zend_object_std_init(object, zend_standard_class_def);
     // Initialize properties array to expected size
     object->properties = zend_new_array(size);
     zend_hash_real_init_mixed(object->properties);
     ZVAL_OBJ(zv, object);
-    return object;
+    return object->properties;
 #else
     object_init(zv);
-    return Z_OBJ_P(zv);
+    return zend_std_get_properties(Z_OBJ_P(zv));
 #endif
 }
 
@@ -540,8 +543,7 @@ static simdjson_php_error_code simdjson_create_object(simdjson::dom::element ele
         }
         case simdjson::dom::element_type::OBJECT : {
             const auto json_object = element.get_object().value_unsafe();
-            zend_object *obj = simdjson_init_object(return_value, json_object.size());
-            HashTable *ht = zend_std_get_properties(obj);
+            HashTable *ht = simdjson_init_object(return_value, json_object.size());
 
             for (simdjson::dom::key_value_pair field : json_object) {
                 const char *data = field.key.data();