still need to modify datareader to use netcdf on only one thread

src/hurricanedata/gpubuffer.h

@@ -1,24 +1,31 @@
 #ifndef GPUBUFFER_H
 #define GPUBUFFER_H
 
-#include "fielddata.h"
-
 #include <string>
+#include <memory>
+#include <experimental/propagate_const>
+
+#include "datareader.h"
+
+struct DataHandle {
+    float *d_data;
+    size_t size;
+};
 
 class GPUBuffer {
 public:
-    GPUBuffer(std::string path, std::string variableName);
+    static constexpr size_t numBufferedFiles = 3;
 
-    FieldData nextFieldData();
+    GPUBuffer(DataReader& dataReader);
+
+    void loadFile(size_t fileIndex, size_t bufferIndex); // Async call
+
+    DataHandle getDataHandle(size_t bufferIndex); // Potentially blocking
 
     ~GPUBuffer();
-
-    FieldMetadata *fmd;
 private:
-    // TODO: Implement GPUBuffer
-    std::string path;
-    std::string variableName;
-
+    class impl;
+    std::experimental::propagate_const<std::unique_ptr<impl>> pImpl;
 };
 
 #endif //GPUBUFFER_H