From 220359916d7d5ad5cb28428a8fe0996e5b19d372 Mon Sep 17 00:00:00 2001
From: Lingfeng Zhang <zhanglingfeng04@meituan.com>
Date: Mon, 18 Nov 2024 20:01:33 +0800
Subject: [PATCH] update

---
 cpp/core/shuffle/Utils.cc | 6 +-----
 cpp/core/shuffle/Utils.h  | 5 ++++-
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/cpp/core/shuffle/Utils.cc b/cpp/core/shuffle/Utils.cc
index 8965288beeeda..157c100a1f6f8 100644
--- a/cpp/core/shuffle/Utils.cc
+++ b/cpp/core/shuffle/Utils.cc
@@ -227,11 +227,7 @@ arrow::Result<std::shared_ptr<MmapFileStream>> MmapFileStream::open(const std::s
     return arrow::Status::IOError("Memory mapping file failed: ", ::arrow::internal::ErrnoMessage(errno));
   }
 
-  auto fstream = std::shared_ptr<MmapFileStream>(new MmapFileStream());
-  fstream->fd_ = std::move(fd);
-  fstream->data_ = static_cast<uint8_t*>(result);
-  fstream->size_ = size;
-  return fstream;
+  return std::make_shared<MmapFileStream>(std::move(fd), static_cast<uint8_t*>(result), size);
 }
 
 void MmapFileStream::advance(int64_t length) {
diff --git a/cpp/core/shuffle/Utils.h b/cpp/core/shuffle/Utils.h
index 5d6f07707a733..41b0d5160445e 100644
--- a/cpp/core/shuffle/Utils.h
+++ b/cpp/core/shuffle/Utils.h
@@ -72,8 +72,12 @@ arrow::Result<std::shared_ptr<arrow::RecordBatch>> makeUncompressedRecordBatch(
 
 std::shared_ptr<arrow::Buffer> zeroLengthNullBuffer();
 
+// MmapFileStream is used to optimize sequential file reading. It uses madvise
+// to prefetch and release memory timely.
 class MmapFileStream : public arrow::io::InputStream {
  public:
+  MmapFileStream(arrow::internal::FileDescriptor fd, uint8_t* data, int64_t size)
+      : fd_(std::move(fd)), data_(data), size_(size){};
   static arrow::Result<std::shared_ptr<MmapFileStream>> open(const std::string& path);
   arrow::Result<int64_t> Tell() const override;
   arrow::Status Close() override;
@@ -99,7 +103,6 @@ class MmapFileStream : public arrow::io::InputStream {
   int64_t size_;
   int64_t pos_ = 0;
   int64_t posRetain_ = 0;
-  MmapFileStream() = default;
 };
 
 } // namespace gluten