1 | #pragma once |
2 | |
3 | #include <Columns/IColumn.h> |
4 | |
5 | |
6 | /// Common helper methods for implementation of different columns. |
7 | |
8 | namespace DB |
9 | { |
10 | |
11 | namespace ErrorCodes |
12 | { |
13 | extern const int LOGICAL_ERROR; |
14 | } |
15 | |
16 | /// Counts how many bytes of `filt` are greater than zero. |
17 | size_t countBytesInFilter(const IColumn::Filter & filt); |
18 | |
19 | /// Returns vector with num_columns elements. vector[i] is the count of i values in selector. |
20 | /// Selector must contain values from 0 to num_columns - 1. NOTE: this is not checked. |
21 | std::vector<size_t> countColumnsSizeInSelector(IColumn::ColumnIndex num_columns, const IColumn::Selector & selector); |
22 | |
23 | /// Returns true, if the memory contains only zeros. |
24 | bool memoryIsZero(const void * data, size_t size); |
25 | bool memoryIsByte(const void * data, size_t size, uint8_t byte); |
26 | |
27 | /// The general implementation of `filter` function for ColumnArray and ColumnString. |
28 | template <typename T> |
29 | void filterArraysImpl( |
30 | const PaddedPODArray<T> & src_elems, const IColumn::Offsets & src_offsets, |
31 | PaddedPODArray<T> & res_elems, IColumn::Offsets & res_offsets, |
32 | const IColumn::Filter & filt, ssize_t result_size_hint); |
33 | |
34 | /// Same as above, but not fills res_offsets. |
35 | template <typename T> |
36 | void filterArraysImplOnlyData( |
37 | const PaddedPODArray<T> & src_elems, const IColumn::Offsets & src_offsets, |
38 | PaddedPODArray<T> & res_elems, |
39 | const IColumn::Filter & filt, ssize_t result_size_hint); |
40 | |
41 | namespace detail |
42 | { |
43 | template <typename T> |
44 | const PaddedPODArray<T> * getIndexesData(const IColumn & indexes); |
45 | } |
46 | |
47 | /// Check limit <= indexes->size() and call column.indexImpl(const PaddedPodArray<Type> & indexes, UInt64 limit). |
48 | template <typename Column> |
49 | ColumnPtr selectIndexImpl(const Column & column, const IColumn & indexes, size_t limit) |
50 | { |
51 | if (limit == 0) |
52 | limit = indexes.size(); |
53 | |
54 | if (indexes.size() < limit) |
55 | throw Exception("Size of indexes is less than required." , ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH); |
56 | |
57 | if (auto * data_uint8 = detail::getIndexesData<UInt8>(indexes)) |
58 | return column.template indexImpl<UInt8>(*data_uint8, limit); |
59 | else if (auto * data_uint16 = detail::getIndexesData<UInt16>(indexes)) |
60 | return column.template indexImpl<UInt16>(*data_uint16, limit); |
61 | else if (auto * data_uint32 = detail::getIndexesData<UInt32>(indexes)) |
62 | return column.template indexImpl<UInt32>(*data_uint32, limit); |
63 | else if (auto * data_uint64 = detail::getIndexesData<UInt64>(indexes)) |
64 | return column.template indexImpl<UInt64>(*data_uint64, limit); |
65 | else |
66 | throw Exception("Indexes column for IColumn::select must be ColumnUInt, got" + indexes.getName(), |
67 | ErrorCodes::LOGICAL_ERROR); |
68 | } |
69 | |
70 | #define INSTANTIATE_INDEX_IMPL(Column) \ |
71 | template ColumnPtr Column::indexImpl<UInt8>(const PaddedPODArray<UInt8> & indexes, size_t limit) const; \ |
72 | template ColumnPtr Column::indexImpl<UInt16>(const PaddedPODArray<UInt16> & indexes, size_t limit) const; \ |
73 | template ColumnPtr Column::indexImpl<UInt32>(const PaddedPODArray<UInt32> & indexes, size_t limit) const; \ |
74 | template ColumnPtr Column::indexImpl<UInt64>(const PaddedPODArray<UInt64> & indexes, size_t limit) const; |
75 | } |
76 | |