table_view.hpp
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16 #pragma once
17 
19 #include <cudf/types.hpp>
20 #include <cudf/utilities/export.hpp>
21 
22 #include <algorithm>
23 #include <vector>
24 
36 namespace CUDF_EXPORT cudf {
37 namespace detail {
51 template <typename ColumnView>
53  static_assert(std::is_same_v<ColumnView, column_view> or
54  std::is_same_v<ColumnView, mutable_column_view>,
55  "table_view_base can only be instantiated with column_view or "
56  "column_view_base.");
57 
58  private:
59  std::vector<ColumnView> _columns{};
60  size_type _num_rows{};
61 
62  public:
63  using iterator = decltype(std::begin(_columns));
64  using const_iterator = decltype(std::cbegin(_columns));
65 
82  explicit table_view_base(std::vector<ColumnView> const& cols);
83 
89  iterator begin() noexcept { return std::begin(_columns); }
90 
96  [[nodiscard]] const_iterator begin() const noexcept { return std::begin(_columns); }
97 
106  iterator end() noexcept { return std::end(_columns); }
107 
116  [[nodiscard]] const_iterator end() const noexcept { return std::end(_columns); }
117 
127  [[nodiscard]] ColumnView const& column(size_type column_index) const
128  {
129  return _columns.at(column_index);
130  }
131 
137  [[nodiscard]] size_type num_columns() const noexcept { return _columns.size(); }
138 
144  [[nodiscard]] size_type num_rows() const noexcept { return _num_rows; }
145 
151  [[nodiscard]] size_type is_empty() const noexcept { return num_columns() == 0; }
152 
153  table_view_base() = default;
154 
155  ~table_view_base() = default;
156 
157  table_view_base(table_view_base const&) = default;
158 
172 };
173 
181 
182 } // namespace detail
183 
191 
200 class table_view : public detail::table_view_base<column_view> {
202 
203  public:
205 
206  table_view() = default;
207 
226  table_view(std::vector<table_view> const& views);
227 
239  template <typename InputIterator>
240  [[nodiscard]] table_view select(InputIterator begin, InputIterator end) const
241  {
242  std::vector<column_view> columns(std::distance(begin, end));
243  std::transform(begin, end, columns.begin(), [this](auto index) { return this->column(index); });
244  return table_view(columns);
245  }
246 
257  [[nodiscard]] table_view select(std::vector<size_type> const& column_indices) const;
258 };
259 
268 class mutable_table_view : public detail::table_view_base<mutable_column_view> {
270 
271  public:
273 
274  mutable_table_view() = default;
275 
282  [[nodiscard]] mutable_column_view& column(size_type column_index) const
283  {
284  return const_cast<mutable_column_view&>(table_view_base::column(column_index));
285  }
289  operator table_view();
290 
309  mutable_table_view(std::vector<mutable_table_view> const& views);
310 };
311 
318 bool nullable(table_view const& view);
319 
328 bool has_nulls(table_view const& view);
329 
336 bool has_nested_nulls(table_view const& input);
337 
346 
353 std::vector<column_view> get_nullable_columns(table_view const& table);
354 
369  std::vector<size_type> const& map,
370  table_view const& target);
371 
372 namespace detail {
381 template <typename TableView>
382 bool is_relationally_comparable(TableView const& lhs, TableView const& rhs);
383 // @cond
384 extern template bool is_relationally_comparable<table_view>(table_view const& lhs,
385  table_view const& rhs);
386 extern template bool is_relationally_comparable<mutable_table_view>(mutable_table_view const& lhs,
387  mutable_table_view const& rhs);
388 // @endcond
389 } // namespace detail
390 } // namespace CUDF_EXPORT cudf
A non-owning, immutable view of device data as a column of elements, some of which may be null as ind...
Base class for a table of ColumnViews.
Definition: table_view.hpp:52
table_view_base(std::vector< ColumnView > const &cols)
Construct a table from a vector of column views.
table_view_base(table_view_base &&)=default
Move constructor.
iterator begin() noexcept
Returns an iterator to the first view in the table.
Definition: table_view.hpp:89
ColumnView const & column(size_type column_index) const
Returns a reference to the view of the specified column.
Definition: table_view.hpp:127
const_iterator end() const noexcept
Returns an iterator one past the last column view in the table.
Definition: table_view.hpp:116
table_view_base & operator=(table_view_base &&)=default
Move assignment operator.
size_type num_columns() const noexcept
Returns the number of columns.
Definition: table_view.hpp:137
size_type is_empty() const noexcept
Returns true if num_columns() returns zero, or false otherwise.
Definition: table_view.hpp:151
decltype(std::begin(_columns)) iterator
Iterator type for the table.
Definition: table_view.hpp:63
size_type num_rows() const noexcept
Returns the number of rows.
Definition: table_view.hpp:144
iterator end() noexcept
Returns an iterator one past the last column view in the table.
Definition: table_view.hpp:106
const_iterator begin() const noexcept
Returns an iterator to the first view in the table.
Definition: table_view.hpp:96
decltype(std::cbegin(_columns)) const_iterator
const iterator type for the table
Definition: table_view.hpp:64
table_view_base(table_view_base const &)=default
Copy constructor.
table_view_base & operator=(table_view_base const &)=default
Copy assignment operator.
A non-owning, mutable view of device data as a column of elements, some of which may be null as indic...
A set of mutable_column_views of the same size.
Definition: table_view.hpp:268
mutable_table_view(std::vector< mutable_table_view > const &views)
Construct a table from a vector of table views.
mutable_column_view & column(size_type column_index) const
Returns column at specified index.
Definition: table_view.hpp:282
A set of cudf::column_view's of the same size.
Definition: table_view.hpp:200
table_view select(InputIterator begin, InputIterator end) const
Returns a table_view built from a range of column indices.
Definition: table_view.hpp:240
table_view(std::vector< table_view > const &views)
Construct a table from a vector of table views.
table_view select(std::vector< size_type > const &column_indices) const
Returns a table_view with set of specified columns.
A set of cudf::column's of the same size.
Definition: table.hpp:41
column view class definitions
std::unique_ptr< column > transform(column_view const &input, std::string const &unary_udf, data_type output_type, bool is_ptx, rmm::device_async_resource_ref mr=rmm::mr::get_current_device_resource())
Creates a new column by applying a unary function against every element of an input column.
int32_t size_type
Row index type for columns and tables.
Definition: types.hpp:93
size_type distance(T f, T l)
Similar to std::distance but returns cudf::size_type and performs static_cast
Definition: types.hpp:108
cuDF interfaces
Definition: aggregation.hpp:34
bool nullable(table_view const &view)
Returns True if any of the columns in the table is nullable. (not entire hierarchy)
bool has_nulls(table_view const &view)
Returns True if the table has nulls in any of its columns.
std::vector< column_view > get_nullable_columns(table_view const &table)
The function to collect all nullable columns at all nested levels in a given table.
bool has_nested_columns(table_view const &table)
Determine if any nested columns exist in a given table.
bool has_nested_nullable_columns(table_view const &input)
Returns True if the table has a nullable column at any level of the column hierarchy.
bool has_nested_nulls(table_view const &input)
Returns True if the table has nulls in any of its columns hierarchy.
table_view scatter_columns(table_view const &source, std::vector< size_type > const &map, table_view const &target)
Copy column_views from a table_view into another table_view according to a column indices map.
bool is_relationally_comparable(TableView const &lhs, TableView const &rhs)
Indicates whether respective columns in input tables are relationally comparable.
Type declarations for libcudf.