Rebase.

src/data/adapter.h

@@ -337,9 +337,6 @@ class CSRArrayAdapterBatch : public detail::NoMetaInfo {
   size_t NumCols() const { return n_features_; }
   size_t Size() const { return this->NumRows(); }
 
-  size_t NumCols() const { return n_features_; }
-  size_t Size() const { return this->NumRows(); }
-
   Line const GetLine(size_t idx) const {
     auto begin_offset = indptr_.GetElement<size_t>(idx, 0);
     auto end_offset = indptr_.GetElement<size_t>(idx + 1, 0);

src/data/file_iterator.h

@@ -16,26 +16,6 @@
 
 namespace xgboost {
 namespace data {
-template <typename T> std::string MakeArrayInterface(T const *data, size_t n) {
-  Json arr{Object{}};
-  arr["data"] = Array(std::vector<Json>{
-      Json{Integer{reinterpret_cast<int64_t>(data)}}, Json{Boolean{false}}});
-  arr["shape"] = Array{std::vector<Json>{Json{Integer{n}}, Json{Integer{1}}}};
-  std::string typestr;
-  if (DMLC_LITTLE_ENDIAN) {
-    typestr.push_back('<');
-  } else {
-    typestr.push_back('>');
-  }
-  typestr.push_back(ArrayInterfaceHandler::TypeChar<T>());
-  typestr += std::to_string(sizeof(T));
-  arr["typestr"] = typestr;
-  arr["version"] = 3;
-  std::string str;
-  Json::Dump(arr, &str);
-  return str;
-}
-
 /**
  * An iterator for implementing external memory support with file inputs.  Users of
  * external memory are encouraged to define their own file parsers/loaders so this one is