Refactor generator TypeSubTypeMeta to use SubTypeRequest

Refactoring to reduce method arguments passed around, by
introducing SubTypeRequest. Also means we can hide the
frequency and common name maps to be internal to SubTypeRequest

Author: rbygrave

jsonb-generator/src/main/java/io/avaje/jsonb/generator/ClassReader.java

@@ -406,10 +406,11 @@ private void writeFromJsonWithSubTypes(Append writer) {
     }
     // another frequency map to append numbers to the subtype constructor params
     final Map<String, Integer> frequencyMap2 = new HashMap<>();
+    final var req = new SubTypeRequest(typeVar, this, useSwitch, useEnum, frequencyMap2, isCommonFieldMap);
 
     for (final TypeSubTypeMeta subTypeMeta : typeReader.subTypes()) {
       final var varName = Util.initLower(Util.shortName(subTypeMeta.type()));
-         subTypeMeta.writeFromJsonBuild(writer, typeVar, varName, this, useSwitch, useEnum, frequencyMap2, isCommonFieldMap);
+      subTypeMeta.writeFromJsonBuild(writer, varName, req);
     }
     if (useSwitch) {
       writer.append("      default").appendSwitchCase().eol().append("    ");

jsonb-generator/src/main/java/io/avaje/jsonb/generator/SubTypeRequest.java

@@ -0,0 +1,47 @@
+package io.avaje.jsonb.generator;
+
+import java.util.Map;
+
+final class SubTypeRequest {
+
+  private final String typeVar;
+  private final ClassReader beanReader;
+  private final boolean useSwitch;
+  private final boolean useEnum;
+  private final Map<String, Integer> frequencyMap;
+  private final Map<String, Boolean> commonFieldMap;
+
+  SubTypeRequest(String typeVar, ClassReader beanReader, boolean useSwitch, boolean useEnum, Map<String, Integer> frequencyMap, Map<String, Boolean> commonFieldMap) {
+    this.typeVar = typeVar;
+    this.beanReader = beanReader;
+    this.useSwitch = useSwitch;
+    this.useEnum = useEnum;
+    this.frequencyMap = frequencyMap;
+    this.commonFieldMap = commonFieldMap;
+  }
+
+  String typeVar() {
+    return typeVar;
+  }
+
+  ClassReader beanReader() {
+    return beanReader;
+  }
+
+  boolean useSwitch() {
+    return useSwitch;
+  }
+
+  boolean useEnum() {
+    return useEnum;
+  }
+
+  boolean isCommonField(String paramName) {
+    return Boolean.TRUE.equals(commonFieldMap.get(paramName));
+  }
+
+  String frequencySuffix(String constructParamName) {
+    var frequency = frequencyMap.compute(constructParamName, (k, v) -> v == null ? 0 : v + 1);
+    return frequency == 0 ? "" : frequency.toString();
+  }
+}

jsonb-generator/src/main/java/io/avaje/jsonb/generator/TypeSubTypeMeta.java

@@ -5,7 +5,6 @@
 import java.util.ArrayList;
 import java.util.LinkedHashSet;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
 
 import javax.lang.model.element.TypeElement;
@@ -18,6 +17,7 @@ final class TypeSubTypeMeta {
   private TypeElement typeElement;
   private boolean defaultPublicConstructor;
   private final List<MethodReader> publicConstructors = new ArrayList<>();
+  private final Set<String> constructorFieldNames = new LinkedHashSet<>();
 
   @Override
   public String toString() {
@@ -56,39 +56,39 @@ void addConstructor(MethodReader methodReader) {
     publicConstructors.add(methodReader);
   }
 
-  void writeFromJsonBuild(Append writer, String typeVar, String varName, ClassReader beanReader, boolean useSwitch, boolean useEnum, Map<String, Integer> frequencyMap2, Map<String, Boolean> isCommonFieldMap) {
-    if (useSwitch) {
-      if (useEnum) {
+  void writeFromJsonBuild(Append writer, String varName, SubTypeRequest req) {
+    if (req.useSwitch()) {
+      if (req.useEnum()) {
         writer.append("      case %s", name()).appendSwitchCase().eol();
       } else {
         writer.append("      case \"%s\"", name()).appendSwitchCase().eol();
       }
       writer.append("  ");
-      writeFromJsonConstructor(writer, varName, beanReader, frequencyMap2,isCommonFieldMap);
-      writeFromJsonSetters(writer, varName, beanReader, useSwitch);
+      writeFromJsonConstructor(writer, varName, req);
+      writeFromJsonSetters(writer, varName, req);
       if (useEnhancedSwitch()) {
         writer.append("        yield _$%s;", varName).eol();
         writer.append("      }").eol();
       } else {
         writer.append("        return _$%s;", varName).eol();
       }
     } else {
-      if (useEnum) {
-        writer.append("    if (%s.equals(%s)) {", name(), typeVar).eol();
+      if (req.useEnum()) {
+        writer.append("    if (%s.equals(%s)) {", name(), req.typeVar()).eol();
       } else {
-        writer.append("    if (\"%s\".equals(%s)) {", name(), typeVar).eol();
+        writer.append("    if (\"%s\".equals(%s)) {", name(), req.typeVar()).eol();
       }
-      writeFromJsonConstructor(writer, varName, beanReader, frequencyMap2, isCommonFieldMap);
-      writeFromJsonSetters(writer, varName, beanReader, useSwitch);
+      writeFromJsonConstructor(writer, varName, req);
+      writeFromJsonSetters(writer, varName, req);
       writer.append("      return _$%s;", varName).eol();
       writer.append("    }").eol();
     }
   }
 
-  private void writeFromJsonSetters(Append writer, String varName, ClassReader beanReader, boolean useSwitch) {
-    for (final FieldReader field : beanReader.allFields()) {
+  private void writeFromJsonSetters(Append writer, String varName, SubTypeRequest req) {
+    for (final FieldReader field : req.beanReader().allFields()) {
       if (isIncludeSetter(field)) {
-        if (useSwitch) {
+        if (req.useSwitch()) {
           writer.append("  ");
         }
         field.writeFromJsonSetter(writer, varName, "  ");
@@ -100,9 +100,8 @@ private boolean isIncludeSetter(FieldReader field) {
     return field.includeFromJson() && !constructorFieldNames.contains(field.fieldName()) && field.includeForType(this);
   }
 
-  private final Set<String> constructorFieldNames = new LinkedHashSet<>();
 
-  private void writeFromJsonConstructor(Append writer, String varName, ClassReader beanReader, Map<String, Integer> frequencyMap2, Map<String, Boolean> isCommonFieldMap) {
+  private void writeFromJsonConstructor(Append writer, String varName, SubTypeRequest req) {
     writer.append("      %s _$%s = new %s(", shortType, varName, shortType);
     final MethodReader constructor = findConstructor();
     if (constructor != null) {
@@ -114,11 +113,10 @@ private void writeFromJsonConstructor(Append writer, String varName, ClassReader
         final var param = params.get(i);
         final String paramName = param.name();
         constructorFieldNames.add(paramName);
-        var constructParamName = beanReader.constructorParamName(paramName);
-        final var writeWithNum = isCommonFieldMap.get(paramName);
-        if (constructParamName.startsWith("_val$") && writeWithNum != null && writeWithNum) {
-          final var frequency = frequencyMap2.compute(constructParamName, (k, v) -> v == null ? 0 : v + 1);
-          constructParamName = constructParamName + (frequency == 0 ? "" : frequency.toString());
+        var constructParamName = req.beanReader().constructorParamName(paramName);
+        if (constructParamName.startsWith("_val$") && req.isCommonField(paramName)) {
+          final var frequencySuffix = req.frequencySuffix(constructParamName);
+          constructParamName = constructParamName + frequencySuffix;
         }
 
         writer.append(constructParamName); // assuming name matches field here?