#include #include #include #include #include namespace DB { namespace { /** Incremental columns number among calls of this function. */ class FunctionBlockNumber : public IFunction { private: mutable std::atomic columns_number{0}; public: static constexpr auto name = "blockNumber"; static FunctionPtr create(ContextPtr) { return std::make_shared(); } /// Get the function name. String getName() const override { return name; } bool isStateful() const override { return true; } bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return false; } size_t getNumberOfArguments() const override { return 0; } bool isDeterministic() const override { return false; } bool isDeterministicInScopeOfQuery() const override { return false; } DataTypePtr getReturnTypeImpl(const DataTypes & /*arguments*/) const override { return std::make_shared(); } ColumnPtr executeImpl(const ColumnsWithTypeAndName &, const DataTypePtr &, size_t input_rows_count) const override { size_t current_columns_number = columns_number++; return ColumnUInt64::create(input_rows_count, current_columns_number); } }; } REGISTER_FUNCTION(BlockNumber) { factory.registerFunction(); } }