refactor: Refactor and comment cleanup of velox/dwio iceberg related files.

Co-authored-by: Ping Liu <ping.liu.ping@gmail.com>

Author: mohsaka

velox/dwio/parquet/common/CMakeLists.txt

@@ -15,9 +15,9 @@
 velox_add_library(
   velox_dwio_parquet_common
   BloomFilter.cpp
-  XxHasher.cpp
   LevelComparison.cpp
   LevelConversion.cpp
+  XxHasher.cpp
   HEADERS
   BitStreamUtilsInternal.h
   BloomFilter.h

velox/dwio/parquet/writer/arrow/ColumnWriter.h

@@ -270,7 +270,7 @@ class TypedColumnWriter : public ColumnWriter {
       int64_t validBitsOffset,
       const T* values) = 0;
 
-  // Estimated size of the values that are not written to a page yet
+  // Estimated size of the values that are not written to a page yet.
   virtual int64_t estimatedBufferedValueBytes() const = 0;
 };
 

velox/dwio/parquet/writer/arrow/FileWriter.h

@@ -53,11 +53,11 @@ class PARQUET_EXPORT RowGroupWriter {
     virtual int currentColumn() const = 0;
     virtual void close() = 0;
 
-    /// \brief Total uncompressed bytes written by the page writer
+    /// \brief Total uncompressed bytes written by the page writer.
     virtual int64_t totalBytesWritten() const = 0;
-    /// \brief Total bytes still compressed but not written by the page writer
+    /// \brief Total bytes still compressed but not written by the page writer.
     virtual int64_t totalCompressedBytes() const = 0;
-    /// \brief Total compressed bytes written by the page writer
+    /// \brief Total compressed bytes written by the page writer.
     virtual int64_t totalCompressedBytesWritten() const = 0;
 
     virtual bool buffered() const = 0;
@@ -98,7 +98,7 @@ class PARQUET_EXPORT RowGroupWriter {
   /// \brief Total bytes still compressed but not written by the page writer.
   /// It will always return 0 from the SerializedPageWriter.
   int64_t totalCompressedBytes() const;
-  /// \brief Total compressed bytes written by the page writer
+  /// \brief Total compressed bytes written by the page writer.
   int64_t totalCompressedBytesWritten() const;
   /// Returns whether the current RowGroupWriter is in the buffered mode and is
   /// created by calling ParquetFileWriter::appendBufferedRowGroup().