Minor attempts to further reduce creation of unnecessary temp buffers for Reflection (on readers)

Author: cowtowncoder

jr-objects/src/main/java/com/fasterxml/jackson/jr/ob/api/MapBuilder.java

@@ -163,7 +163,8 @@ private final Map<String, Object> _map(int initialSize) {
             if (_mapType != null) {
                 try {
                     @SuppressWarnings("unchecked")
-                    Map<String,Object> m = (Map<String,Object>) _mapType.getDeclaredConstructor().newInstance();
+                    Map<String,Object> m = (Map<String,Object>)
+                        _mapType.getDeclaredConstructor().newInstance((Object[]) null);
                     return m;
                 } catch (Exception e) {
                     Throwable t = e;

jr-objects/src/main/java/com/fasterxml/jackson/jr/ob/impl/BeanPropertyReader.java

@@ -69,19 +69,21 @@ public Class<?> rawSetterType() {
     public ValueReader getReader() { return _valueReader; }
     public String getName() { return _name; }
 
-    public void setValueFor(Object bean, Object value) throws IOException
+    public void setValueFor(Object bean, Object[] valueBuf)
+        throws IOException
     {
         try {
             if (_setter == null) {
-                _field.set(bean, value);
+                _field.set(bean, valueBuf[0]);
             } else {
-                _setter.invoke(bean, value);
+                _setter.invoke(bean, valueBuf);
             }
         } catch (Exception e) {
             Throwable t = e;
             if (t instanceof InvocationTargetException) {
                 t = t.getCause();
             }
+            final Object value = valueBuf[0];
             final String valueTypeDesc = (value == null) ? "NULL" : value.getClass().getName();
             throw new JSONObjectException(String.format(
                     "Failed to set property '%s' (raw type %s) to value of type %s; exception (%s): %s",

jr-objects/src/main/java/com/fasterxml/jackson/jr/ob/impl/BeanReader.java

@@ -93,6 +93,7 @@ public Object readNext(JSONReader r, JsonParser p) throws IOException
             case START_OBJECT:
                 {
                     Object bean = create();
+                    final Object[] valueBuf = r._setterBuffer;
                     String propName;
 
                     for (; (propName = p.nextFieldName()) != null; ) {
@@ -101,14 +102,13 @@ public Object readNext(JSONReader r, JsonParser p) throws IOException
                             handleUnknown(r, p, propName);
                             continue;
                         }
-                        ValueReader vr = prop.getReader();
-                        prop.setValueFor(bean, vr.readNext(r, p));
+                        valueBuf[0] = prop.getReader().readNext(r, p);
+                        prop.setValueFor(bean, valueBuf);
                     }
                     // also verify we are not confused...
                     if (!p.hasToken(JsonToken.END_OBJECT)) {
                         throw _reportProblem(p);
                     }                    
-                    
                     return bean;
                 }
             default:
@@ -145,15 +145,16 @@ public Object read(JSONReader r, JsonParser p) throws IOException
                 {
                     Object bean = create();
                     String propName;
+                    final Object[] valueBuf = r._setterBuffer;
 
                     for (; (propName = p.nextFieldName()) != null; ) {
                         BeanPropertyReader prop = findProperty(propName);
                         if (prop == null) {
                             handleUnknown(r, p, propName);
                             continue;
                         }
-                        final Object value = prop.getReader().readNext(r, p);
-                        prop.setValueFor(bean, value);
+                        valueBuf[0] = prop.getReader().readNext(r, p);
+                        prop.setValueFor(bean, valueBuf);
                     }
                     // also verify we are not confused...
                     if (!p.hasToken(JsonToken.END_OBJECT)) {
@@ -179,7 +180,7 @@ protected Object create() throws Exception {
         if (_defaultCtor == null) {
             throw new IllegalStateException("Class "+_valueType.getName()+" does not have default constructor to use");
         }
-        return _defaultCtor.newInstance();
+        return _defaultCtor.newInstance((Object[]) null);
     }
 
     protected Object create(String str) throws Exception {

jr-objects/src/main/java/com/fasterxml/jackson/jr/ob/impl/JSONReader.java

@@ -39,7 +39,7 @@ public class JSONReader
      * Handler that takes care of constructing {@link java.util.Map}s as needed
      */
     protected final CollectionBuilder _collectionBuilder;
-    
+
     /*
     /**********************************************************************
     /* Instance config, state
@@ -64,6 +64,14 @@ public class JSONReader
      */
     protected final JsonParser _parser;
 
+    /**
+     * Minor performance optimization: {@code Object[1]} reused to avoid
+     * Reflection having to allocate it for every "setter" call.
+     *
+     * @since 2.13
+     */
+    protected final Object[] _setterBuffer;
+
     /*
     /**********************************************************************
     /* Blueprint construction
@@ -81,6 +89,7 @@ public JSONReader(CollectionBuilder lb, MapBuilder mb)
         _collectionBuilder = lb;
         _mapBuilder = mb;
         _parser = null;
+        _setterBuffer = null; // should NOT  be used on blueprint
     }
 
     /**
@@ -96,6 +105,7 @@ protected JSONReader(JSONReader base, int features,
         _collectionBuilder = base._collectionBuilder.newBuilder(features);
         _mapBuilder = base._mapBuilder.newBuilder(features);
         _parser = p;
+        _setterBuffer = new Object[1];
     }
 
     /*