Function ConcatenateBitmaps

cpp/src/arrow/array/concatenate.cc:105–128

Allocate a buffer and concatenate bitmaps into it.

// Allocate a buffer and concatenate bitmaps into it.
Status ConcatenateBitmaps(const std::vector<Bitmap>& bitmaps, MemoryPool* pool,
                          std::shared_ptr<Buffer>* out) {
  int64_t out_length = 0;
  for (const auto& bitmap : bitmaps) {
    if (internal::AddWithOverflow(out_length, bitmap.range.length, &out_length)) {
      return Status::Invalid("Length overflow when concatenating arrays");
    }
  }
  ARROW_ASSIGN_OR_RAISE(*out, AllocateBitmap(out_length, pool));
  uint8_t* dst = (*out)->mutable_data();

  int64_t bitmap_offset = 0;
  for (auto bitmap : bitmaps) {
    if (bitmap.AllSet()) {
      bit_util::SetBitsTo(dst, bitmap_offset, bitmap.range.length, true);
    } else {
      internal::CopyBitmap(bitmap.data, bitmap.range.offset, bitmap.range.length, dst,
                           bitmap_offset);
    }
    bitmap_offset += bitmap.range.length;
  }

  return Status::OK();
}

int64_t SumBufferSizesInBytes(const BufferVector& buffers) {
  int64_t size = 0;