Partially flatten arrow-buffer (#2737)

* Partially flatten arrow-buffer

* Format

arrow-buffer/src/lib.rs

@@ -19,6 +19,11 @@
 
 pub mod alloc;
 pub mod buffer;
+pub use buffer::{Buffer, MutableBuffer};
+
 mod bytes;
-pub mod native;
-pub mod util;
+mod native;
+
+pub use native::*;
+mod util;
+pub use util::*;

arrow/src/bitmap.rs

@@ -17,12 +17,11 @@
 
 //! Defines [Bitmap] for tracking validity bitmaps
 
-use crate::buffer::Buffer;
 use crate::error::{ArrowError, Result};
 use crate::util::bit_util;
 use std::mem;
 
-use arrow_buffer::buffer::{buffer_bin_and, buffer_bin_or};
+use arrow_buffer::buffer::{buffer_bin_and, buffer_bin_or, Buffer};
 use std::ops::{BitAnd, BitOr};
 
 #[derive(Debug, Clone)]

arrow/src/datatypes/native.rs

@@ -16,7 +16,7 @@
 // under the License.
 
 use super::DataType;
-pub use arrow_buffer::native::{ArrowNativeType, ToByteSlice};
+pub use arrow_buffer::{ArrowNativeType, ToByteSlice};
 use half::f16;
 
 /// Trait bridging the dynamic-typed nature of Arrow (via [`DataType`]) with the

arrow/src/util/mod.rs

@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-pub use arrow_buffer::util::{bit_chunk_iterator, bit_util};
+pub use arrow_buffer::{bit_chunk_iterator, bit_util};
 
 #[cfg(feature = "test_utils")]
 pub mod bench_util;