cloudflare/ClickHouse
Publicmirrored fromhttps://github.com/cloudflare/ClickHouse
src/Columns/ColumnConst.h
234lines · modecode
unknown
| 1 | #pragma once |
| 2 | |
| 3 | #include <Core/Field.h> |
| 4 | #include <Common/Exception.h> |
| 5 | #include <Columns/IColumn.h> |
| 6 | #include <Common/typeid_cast.h> |
| 7 | #include <Common/assert_cast.h> |
| 8 | |
| 9 | |
| 10 | namespace DB |
| 11 | { |
| 12 | |
| 13 | namespace ErrorCodes |
| 14 | { |
| 15 | extern const int NOT_IMPLEMENTED; |
| 16 | } |
| 17 | |
| 18 | |
| 19 | /** ColumnConst contains another column with single element, |
| 20 | * but looks like a column with arbitrary amount of same elements. |
| 21 | */ |
| 22 | class ColumnConst final : public COWHelper<IColumn, ColumnConst> |
| 23 | { |
| 24 | private: |
| 25 | friend class COWHelper<IColumn, ColumnConst>; |
| 26 | |
| 27 | WrappedPtr data; |
| 28 | size_t s; |
| 29 | |
| 30 | ColumnConst(const ColumnPtr & data, size_t s_); |
| 31 | ColumnConst(const ColumnConst & src) = default; |
| 32 | |
| 33 | public: |
| 34 | ColumnPtr convertToFullColumn() const; |
| 35 | |
| 36 | ColumnPtr convertToFullColumnIfConst() const override |
| 37 | { |
| 38 | return convertToFullColumn(); |
| 39 | } |
| 40 | |
| 41 | ColumnPtr removeLowCardinality() const; |
| 42 | |
| 43 | std::string getName() const override |
| 44 | { |
| 45 | return "Const(" + data->getName() + ")"; |
| 46 | } |
| 47 | |
| 48 | const char * getFamilyName() const override |
| 49 | { |
| 50 | return "Const"; |
| 51 | } |
| 52 | |
| 53 | MutableColumnPtr cloneResized(size_t new_size) const override |
| 54 | { |
| 55 | return ColumnConst::create(data, new_size); |
| 56 | } |
| 57 | |
| 58 | size_t size() const override |
| 59 | { |
| 60 | return s; |
| 61 | } |
| 62 | |
| 63 | Field operator[](size_t) const override |
| 64 | { |
| 65 | return (*data)[0]; |
| 66 | } |
| 67 | |
| 68 | void get(size_t, Field & res) const override |
| 69 | { |
| 70 | data->get(0, res); |
| 71 | } |
| 72 | |
| 73 | StringRef getDataAt(size_t) const override |
| 74 | { |
| 75 | return data->getDataAt(0); |
| 76 | } |
| 77 | |
| 78 | StringRef getDataAtWithTerminatingZero(size_t) const override |
| 79 | { |
| 80 | return data->getDataAtWithTerminatingZero(0); |
| 81 | } |
| 82 | |
| 83 | UInt64 get64(size_t) const override |
| 84 | { |
| 85 | return data->get64(0); |
| 86 | } |
| 87 | |
| 88 | UInt64 getUInt(size_t) const override |
| 89 | { |
| 90 | return data->getUInt(0); |
| 91 | } |
| 92 | |
| 93 | Int64 getInt(size_t) const override |
| 94 | { |
| 95 | return data->getInt(0); |
| 96 | } |
| 97 | |
| 98 | bool getBool(size_t) const override |
| 99 | { |
| 100 | return data->getBool(0); |
| 101 | } |
| 102 | |
| 103 | Float64 getFloat64(size_t) const override |
| 104 | { |
| 105 | return data->getFloat64(0); |
| 106 | } |
| 107 | |
| 108 | Float32 getFloat32(size_t) const override |
| 109 | { |
| 110 | return data->getFloat32(0); |
| 111 | } |
| 112 | |
| 113 | bool isNullAt(size_t) const override |
| 114 | { |
| 115 | return data->isNullAt(0); |
| 116 | } |
| 117 | |
| 118 | void insertRangeFrom(const IColumn &, size_t /*start*/, size_t length) override |
| 119 | { |
| 120 | s += length; |
| 121 | } |
| 122 | |
| 123 | void insert(const Field &) override |
| 124 | { |
| 125 | ++s; |
| 126 | } |
| 127 | |
| 128 | void insertData(const char *, size_t) override |
| 129 | { |
| 130 | ++s; |
| 131 | } |
| 132 | |
| 133 | void insertFrom(const IColumn &, size_t) override |
| 134 | { |
| 135 | ++s; |
| 136 | } |
| 137 | |
| 138 | void insertDefault() override |
| 139 | { |
| 140 | ++s; |
| 141 | } |
| 142 | |
| 143 | void popBack(size_t n) override |
| 144 | { |
| 145 | s -= n; |
| 146 | } |
| 147 | |
| 148 | StringRef serializeValueIntoArena(size_t, Arena & arena, char const *& begin) const override |
| 149 | { |
| 150 | return data->serializeValueIntoArena(0, arena, begin); |
| 151 | } |
| 152 | |
| 153 | const char * deserializeAndInsertFromArena(const char * pos) override |
| 154 | { |
| 155 | auto res = data->deserializeAndInsertFromArena(pos); |
| 156 | data->popBack(1); |
| 157 | ++s; |
| 158 | return res; |
| 159 | } |
| 160 | |
| 161 | void updateHashWithValue(size_t, SipHash & hash) const override |
| 162 | { |
| 163 | data->updateHashWithValue(0, hash); |
| 164 | } |
| 165 | |
| 166 | void updateWeakHash32(WeakHash32 & hash) const override; |
| 167 | |
| 168 | ColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override; |
| 169 | ColumnPtr replicate(const Offsets & offsets) const override; |
| 170 | ColumnPtr permute(const Permutation & perm, size_t limit) const override; |
| 171 | ColumnPtr index(const IColumn & indexes, size_t limit) const override; |
| 172 | void getPermutation(bool reverse, size_t limit, int nan_direction_hint, Permutation & res) const override; |
| 173 | |
| 174 | size_t byteSize() const override |
| 175 | { |
| 176 | return data->byteSize() + sizeof(s); |
| 177 | } |
| 178 | |
| 179 | size_t allocatedBytes() const override |
| 180 | { |
| 181 | return data->allocatedBytes() + sizeof(s); |
| 182 | } |
| 183 | |
| 184 | int compareAt(size_t, size_t, const IColumn & rhs, int nan_direction_hint) const override |
| 185 | { |
| 186 | return data->compareAt(0, 0, *assert_cast<const ColumnConst &>(rhs).data, nan_direction_hint); |
| 187 | } |
| 188 | |
| 189 | MutableColumns scatter(ColumnIndex num_columns, const Selector & selector) const override; |
| 190 | |
| 191 | void gather(ColumnGathererStream &) override |
| 192 | { |
| 193 | throw Exception("Cannot gather into constant column " + getName(), ErrorCodes::NOT_IMPLEMENTED); |
| 194 | } |
| 195 | |
| 196 | void getExtremes(Field & min, Field & max) const override |
| 197 | { |
| 198 | data->getExtremes(min, max); |
| 199 | } |
| 200 | |
| 201 | void forEachSubcolumn(ColumnCallback callback) override |
| 202 | { |
| 203 | callback(data); |
| 204 | } |
| 205 | |
| 206 | bool structureEquals(const IColumn & rhs) const override |
| 207 | { |
| 208 | if (auto rhs_concrete = typeid_cast<const ColumnConst *>(&rhs)) |
| 209 | return data->structureEquals(*rhs_concrete->data); |
| 210 | return false; |
| 211 | } |
| 212 | |
| 213 | bool isNullable() const override { return isColumnNullable(*data); } |
| 214 | bool onlyNull() const override { return data->isNullAt(0); } |
| 215 | bool isNumeric() const override { return data->isNumeric(); } |
| 216 | bool isFixedAndContiguous() const override { return data->isFixedAndContiguous(); } |
| 217 | bool valuesHaveFixedSize() const override { return data->valuesHaveFixedSize(); } |
| 218 | size_t sizeOfValueIfFixed() const override { return data->sizeOfValueIfFixed(); } |
| 219 | StringRef getRawData() const override { return data->getRawData(); } |
| 220 | |
| 221 | /// Not part of the common interface. |
| 222 | |
| 223 | IColumn & getDataColumn() { return *data; } |
| 224 | const IColumn & getDataColumn() const { return *data; } |
| 225 | const ColumnPtr & getDataColumnPtr() const { return data; } |
| 226 | |
| 227 | Field getField() const { return getDataColumn()[0]; } |
| 228 | |
| 229 | /// The constant value. It is valid even if the size of the column is 0. |
| 230 | template <typename T> |
| 231 | T getValue() const { return getField().safeGet<NearestFieldType<T>>(); } |
| 232 | }; |
| 233 | |
| 234 | } |