Added memoryUsage() to JsonArray, JsonObject, and JsonVariant

src/ArduinoJson/Array/ArrayRef.hpp

@@ -34,6 +34,10 @@ class ArrayRefBase {
     return VariantConstRef(_data ? _data->get(index) : 0);
   }
 
+  FORCE_INLINE size_t memoryUsage() const {
+    return _data ? _data->memoryUsage() : 0;
+  }
+
   FORCE_INLINE size_t size() const {
     return _data ? _data->size() : 0;
   }

src/ArduinoJson/Collection/CollectionData.hpp

@@ -55,6 +55,7 @@ class CollectionData {
 
   void remove(VariantSlot *slot);
 
+  size_t memoryUsage() const;
   size_t size() const;
 
  private:

src/ArduinoJson/Collection/CollectionImpl.hpp

@@ -138,6 +138,15 @@ inline void CollectionData::remove(size_t index) {
   remove(getSlot(index));
 }
 
+inline size_t CollectionData::memoryUsage() const {
+  size_t total = 0;
+  for (VariantSlot* s = _head; s; s = s->next()) {
+    total += sizeof(VariantSlot) + s->data()->memoryUsage();
+    if (s->ownsKey()) total += strlen(s->key()) + 1;
+  }
+  return total;
+}
+
 inline size_t CollectionData::size() const {
   return slotSize(_head);
 }

src/ArduinoJson/Object/ObjectRef.hpp

@@ -42,6 +42,10 @@ class ObjectRefBase {
     return _data == 0;
   }
 
+  FORCE_INLINE size_t memoryUsage() const {
+    return _data ? _data->memoryUsage() : 0;
+  }
+
   FORCE_INLINE size_t size() const {
     return _data ? _data->size() : 0;
   }

src/ArduinoJson/Variant/VariantData.hpp

@@ -266,6 +266,20 @@ class VariantData {
     return _content.asCollection;
   }
 
+  size_t memoryUsage() const {
+    switch (type()) {
+      case VALUE_IS_OWNED_STRING:
+        return strlen(_content.asString) + 1;
+      case VALUE_IS_OWNED_RAW:
+        return _content.asRaw.size;
+      case VALUE_IS_OBJECT:
+      case VALUE_IS_ARRAY:
+        return _content.asCollection.memoryUsage();
+      default:
+        return 0;
+    }
+  }
+
   size_t size() const {
     if (type() == VALUE_IS_OBJECT || type() == VALUE_IS_ARRAY)
       return _content.asCollection.size();

src/ArduinoJson/Variant/VariantRef.hpp

@@ -95,6 +95,10 @@ class VariantRefBase {
     return variantIsNull(_data);
   }
 
+  FORCE_INLINE size_t memoryUsage() const {
+    return _data ? _data->memoryUsage() : 0;
+  }
+
   size_t size() const {
     return variantSize(_data);
   }