Optimize helidon optionals - io.helidon.common.mapper.OptionalValue (#505)

* Optimize helidon optionals
Helidon docs says that `Optional` is expensive and don't use it unless you need to.
In the generator, optionals are more of an implementation detail and null or the default value is returned.
For better performance, this PR replaces optionals with contains / get as Helidon suggests.

* fix build

---------

Co-authored-by: Josiah Noel <[email protected]>

Author: re-thc

http-generator-helidon/src/main/java/io/avaje/http/generator/helidon/nima/ControllerWriter.java

@@ -202,7 +202,11 @@ private void writeClassStart() {
 
     if (reader.isIncludeValidator()) {
       writer.append("  private String language(ServerRequest req) {").eol();
-      writer.append("    return req.headers().first(HEADER_ACCEPT_LANGUAGE).orElse(null);").eol();
+      writer.append("    var headers = req.headers();").eol();
+      writer.append("    if (headers.contains(HEADER_ACCEPT_LANGUAGE)) {").eol();
+      writer.append("      return headers.get(HEADER_ACCEPT_LANGUAGE).get();").eol();
+      writer.append("    }").eol();
+      writer.append("    return null;").eol();
       writer.append("  }").eol().eol();
     }
   }

http-generator-helidon/src/main/java/io/avaje/http/generator/helidon/nima/NimaPlatformAdapter.java

@@ -67,16 +67,16 @@ private void addRoleImports(List<String> roles, ControllerReader controller) {
   @Override
   public void writeReadParameter(Append writer, ParamType paramType, String paramName) {
     switch (paramType) {
-      case PATHPARAM -> writer.append("pathParams.first(\"%s\").get()", paramName);
+      case PATHPARAM -> writer.append("pathParams.contains(\"%s\") ? pathParams.get(\"%s\") : null", paramName, paramName);
 
-      case QUERYPARAM -> writer.append("req.query().first(\"%s\").orElse(null)", paramName);
+      case QUERYPARAM -> writer.append("req.query().contains(\"%s\") ? req.query().get(\"%s\") : null", paramName, paramName);
 
-      case FORMPARAM -> writer.append("formParams.first(\"%s\").orElse(null)", paramName);
+      case FORMPARAM -> writer.append("formParams.contains(\"%s\") ? formParams.get(\"%s\") : null", paramName, paramName);
 
       case HEADER -> writer.append(
           "req.headers().value(HeaderNames.create(\"%s\")).orElse(null)", paramName);
 
-      case COOKIE -> writer.append("req.headers().cookies().first(\"%s\").orElse(null)", paramName);
+      case COOKIE -> writer.append("req.headers().cookies().contains(\"%s\") ? req.headers().cookies().get(\"%s\") : null", paramName, paramName);
 
       default -> writer.append("null // TODO req.%s().param(\"%s\")", paramType.type(), paramName);
     }
@@ -86,19 +86,19 @@ public void writeReadParameter(Append writer, ParamType paramType, String paramN
   public void writeReadParameter(Append writer, ParamType paramType, String paramName, String paramDefault) {
     switch (paramType) {
       case PATHPARAM -> writer.append(
-          "pathParams.first(\"%s\").orElse(\"%s\")", paramName, paramDefault);
+          "pathParams.contains(\"%s\") ? pathParams.get(\"%s\") : \"%s\"", paramName, paramName, paramDefault);
 
       case QUERYPARAM -> writer.append(
-          "req.query().first(\"%s\").orElse(\"%s\")", paramName, paramDefault);
+          "req.query().contains(\"%s\") ? req.query().get(\"%s\") : \"%s\"", paramName, paramName, paramDefault);
 
       case FORMPARAM -> writer.append(
-          "formParams.first(\"%s\").orElse(\"%s\")", paramName, paramDefault);
+          "formParams.contains(\"%s\") ? formParams.get(\"%s\") : \"%s\"", paramName, paramName, paramDefault);
 
       case HEADER -> writer.append(
           "req.headers().value(Http.Header.create(\"%s\").orElse(\"%s\")", paramName, paramDefault);
 
       case COOKIE -> writer.append(
-          "req.headers().cookies().first(\"%s\").orElse(\"%s\")", paramName, paramDefault);
+          "req.headers().cookies().contains(\"%s\") ? req.headers().cookies().get(\"%s\") : \"%s\"", paramName, paramName, paramDefault);
 
       default -> writer.append("null // TODO req.%s().param(\"%s\")", paramType.type(), paramName);
     }