Merge pull request #9 from taiyang-li/raw_orc_reader

Add interface to get raw orc reader from adapters

(cherry picked from commit ce6b7af)

cpp/src/arrow/adapters/orc/adapter.cc

@@ -222,6 +222,11 @@ class ORCFileReader::Impl {
     return Init();
   }
 
+  virtual liborc::Reader* GetRawORCReader() {
+    return reader_.get();
+  }
+
+
   Status Init() {
     int64_t nstripes = reader_->getNumberOfStripes();
     stripes_.resize(static_cast<size_t>(nstripes));
@@ -548,6 +553,10 @@ class ORCFileReader::Impl {
     return NextStripeReader(batch_size, empty_vec);
   }
 
+  liborc::Reader* ORCFileReader::GetRawORCReader() {
+    return impl_->GetRawORCReader();
+  }
+
  private:
   MemoryPool* pool_;
   std::unique_ptr<liborc::Reader> reader_;

cpp/src/arrow/adapters/orc/adapter.h

@@ -53,6 +53,19 @@ class ARROW_EXPORT ORCFileReader {
  public:
   ~ORCFileReader();
 
+  /// \brief Creates a new ORC reader.
+  ///
+  /// \param[in] file the data source
+  /// \param[in] pool a MemoryPool to use for buffer allocations
+  /// \param[out] reader the returned reader object
+  /// \return Status
+  ARROW_DEPRECATED("Deprecated in 6.0.0. Use Result-returning overload instead.")
+  static Status Open(const std::shared_ptr<io::RandomAccessFile>& file, MemoryPool* pool,
+                     std::unique_ptr<ORCFileReader>* reader);
+
+  /// \brief Get ORC reader from inside.
+  liborc::Reader* GetRawORCReader();
+
   /// \brief Creates a new ORC reader
   ///
   /// \param[in] file the data source