1 | #pragma once |
2 | #include <Processors/ISimpleTransform.h> |
3 | #include <Core/SortDescription.h> |
4 | #include <Interpreters/FillingRow.h> |
5 | |
6 | namespace DB |
7 | { |
8 | |
9 | /** Implements modifier WITH FILL of ORDER BY clause. |
10 | * It fills gaps in data stream by rows with missing values in columns with set WITH FILL and deafult values in other columns. |
11 | * Optionally FROM, TO and STEP values can be specified. |
12 | */ |
13 | class FillingTransform : public ISimpleTransform |
14 | { |
15 | public: |
16 | FillingTransform(const Block & , const SortDescription & fill_description_); |
17 | |
18 | String getName() const override { return "FillingTransform" ; } |
19 | |
20 | Status prepare() override; |
21 | |
22 | protected: |
23 | void transform(Chunk & Chunk) override; |
24 | |
25 | private: |
26 | void setResultColumns(Chunk & chunk, MutableColumns & fill_columns, MutableColumns & other_columns) const; |
27 | |
28 | const SortDescription sort_description; /// Contains only rows with WITH FILL. |
29 | FillingRow filling_row; /// Current row, which is used to fill gaps. |
30 | FillingRow next_row; /// Row to which we need to generate filling rows. |
31 | |
32 | using Positions = std::vector<size_t>; |
33 | Positions fill_column_positions; |
34 | Positions other_column_positions; |
35 | bool first = true; |
36 | bool generate_suffix = false; |
37 | |
38 | /// Determines should we insert filling row before start generating next rows. |
39 | bool should_insert_first = false; |
40 | }; |
41 | |
42 | } |
43 | |