Very rough first cut

supports int32, double, strings.

parquet/parquet_cursor.h

@@ -0,0 +1,52 @@
+#ifndef PARQUET_CURSOR_H
+#define PARQUET_CURSOR_H
+
+#include "parquet_table.h"
+#include "parquet/api/reader.h"
+
+class ParquetCursor {
+
+  ParquetTable* table;
+  std::unique_ptr<parquet::ParquetFileReader> reader;
+  std::unique_ptr<parquet::RowGroupMetaData> rowGroupMetadata;
+  std::shared_ptr<parquet::RowGroupReader> rowGroup;
+  std::vector<std::shared_ptr<parquet::Scanner>> scanners;
+  std::vector<parquet::Type::type> types;
+
+  std::vector<int> colRows;
+  std::vector<bool> colNulls;
+  std::vector<uintptr_t> colIntValues;
+  std::vector<double> colDoubleValues;
+  std::vector<parquet::ByteArray> colByteArrayValues;
+
+  int rowId;
+  int rowGroupId;
+  int numRows;
+  int numRowGroups;
+  int rowsLeftInRowGroup;
+
+  void nextRowGroup();
+
+public:
+  ParquetCursor(ParquetTable* table);
+  int getRowId();
+  void next();
+  bool eof();
+
+  void ensureColumn(int col);
+  bool isNull(int col);
+  int getInt(int col);
+  double getDouble(int col);
+  parquet::ByteArray* getByteArray(int col);
+  parquet::Type::type getPhysicalType(int col);
+  /*
+  sqlite3_result_double()
+  sqlite3_result_int()
+  sqlite3_result_int64()
+  sqlite3_result_null()
+  sqlite3_result_text()
+  */
+};
+
+#endif
+