cloudflare/ClickHouse
Publicmirrored fromhttps://github.com/cloudflare/ClickHouse
src/Functions/GatherUtils/GatherUtils.h
64lines · modecode
5 years ago
| 1 | #pragma once |
| 2 | |
| 3 | #include <type_traits> |
| 4 | |
| 5 | #include <Columns/ColumnArray.h> |
| 6 | #include <Columns/ColumnsNumber.h> |
| 7 | |
| 8 | #include "IValueSource.h" |
| 9 | #include "IArraySource.h" |
| 10 | #include "IArraySink.h" |
| 11 | |
| 12 | /** These methods are intended for implementation of functions, that |
| 13 | * copy ranges from one or more columns to another column. |
| 14 | * |
| 15 | * Example: |
| 16 | * - concatenation of strings and arrays (concat); |
| 17 | * - extracting slices and elements of strings and arrays (substring, arraySlice, arrayElement); |
| 18 | * - creating arrays from several columns ([x, y]); |
| 19 | * - conditional selecting from several string or array columns (if, multiIf); |
| 20 | * - push and pop elements from array front or back (arrayPushBack, etc); |
| 21 | * - splitting strings into arrays and joining arrays back; |
| 22 | * - formatting strings (format). |
| 23 | * |
| 24 | * There are various Sources, Sinks and Slices. |
| 25 | * Source - allows to iterate over a column and obtain Slices. |
| 26 | * Slice - a reference to elements to copy. |
| 27 | * Sink - allows to build result column by copying Slices into it. |
| 28 | */ |
| 29 | |
| 30 | namespace DB::GatherUtils |
| 31 | { |
| 32 | |
| 33 | enum class ArraySearchType |
| 34 | { |
| 35 | Any, // Corresponds to the hasAny array function |
| 36 | All, // Corresponds to the hasAll array function |
| 37 | Substr // Corresponds to the hasSubstr array function |
| 38 | }; |
| 39 | |
| 40 | std::unique_ptr<IArraySource> createArraySource(const ColumnArray & col, bool is_const, size_t total_rows); |
| 41 | std::unique_ptr<IValueSource> createValueSource(const IColumn & col, bool is_const, size_t total_rows); |
| 42 | std::unique_ptr<IArraySink> createArraySink(ColumnArray & col, size_t column_size); |
| 43 | |
| 44 | void concat(const std::vector<std::unique_ptr<IArraySource>> & sources, IArraySink & sink); |
| 45 | |
| 46 | void sliceFromLeftConstantOffsetUnbounded(IArraySource & src, IArraySink & sink, size_t offset); |
| 47 | void sliceFromLeftConstantOffsetBounded(IArraySource & src, IArraySink & sink, size_t offset, ssize_t length); |
| 48 | |
| 49 | void sliceFromRightConstantOffsetUnbounded(IArraySource & src, IArraySink & sink, size_t offset); |
| 50 | void sliceFromRightConstantOffsetBounded(IArraySource & src, IArraySink & sink, size_t offset, ssize_t length); |
| 51 | |
| 52 | void sliceDynamicOffsetUnbounded(IArraySource & src, IArraySink & sink, const IColumn & offset_column); |
| 53 | void sliceDynamicOffsetBounded(IArraySource & src, IArraySink & sink, const IColumn & offset_column, const IColumn & length_column); |
| 54 | |
| 55 | void sliceHas(IArraySource & first, IArraySource & second, ArraySearchType & search_type, ColumnUInt8 & result); |
| 56 | |
| 57 | void push(IArraySource & array_source, IValueSource & value_source, IArraySink & sink, bool push_front); |
| 58 | |
| 59 | void resizeDynamicSize(IArraySource & array_source, IValueSource & value_source, IArraySink & sink, const IColumn & size_column); |
| 60 | |
| 61 | void resizeConstantSize(IArraySource & array_source, IValueSource & value_source, IArraySink & sink, ssize_t size); |
| 62 | |
| 63 | } |