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95 lines
2.7 KiB
C++
95 lines
2.7 KiB
C++
#include <Functions/IFunction.h>
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#include <Functions/FunctionFactory.h>
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#include <Functions/FunctionHelpers.h>
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#include <DataTypes/DataTypeAggregateFunction.h>
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#include <Columns/ColumnAggregateFunction.h>
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#include <Common/typeid_cast.h>
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#include <iostream>
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#include <Common/PODArray.h>
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namespace DB
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{
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namespace ErrorCodes
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{
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extern const int BAD_ARGUMENTS;
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extern const int ILLEGAL_COLUMN;
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extern const int ILLEGAL_TYPE_OF_ARGUMENT;
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}
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namespace
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{
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/** finalizeAggregation(agg_state) - get the result from the aggregation state.
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* Takes state of aggregate function. Returns result of aggregation (finalized state).
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*/
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class FunctionEvalMLMethod : public IFunction
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{
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public:
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static constexpr auto name = "evalMLMethod";
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static FunctionPtr create(ContextPtr context)
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{
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return std::make_shared<FunctionEvalMLMethod>(context);
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}
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explicit FunctionEvalMLMethod(ContextPtr context_) : context(context_)
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{}
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String getName() const override
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{
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return name;
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}
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bool isVariadic() const override
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{
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return true;
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}
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size_t getNumberOfArguments() const override
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{
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return 0;
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}
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DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
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{
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if (arguments.empty())
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throw Exception("Function " + getName() + " requires at least one argument", ErrorCodes::BAD_ARGUMENTS);
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const auto * type = checkAndGetDataType<DataTypeAggregateFunction>(arguments[0].get());
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if (!type)
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throw Exception("Argument for function " + getName() + " must have type AggregateFunction - state of aggregate function.",
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ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
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return type->getReturnTypeToPredict();
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}
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ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t /*input_rows_count*/) const override
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{
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if (arguments.empty())
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throw Exception("Function " + getName() + " requires at least one argument", ErrorCodes::BAD_ARGUMENTS);
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const auto * model = arguments[0].column.get();
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if (const auto * column_with_states = typeid_cast<const ColumnConst *>(model))
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model = column_with_states->getDataColumnPtr().get();
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const auto * agg_function = typeid_cast<const ColumnAggregateFunction *>(model);
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if (!agg_function)
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throw Exception("Illegal column " + arguments[0].column->getName()
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+ " of first argument of function " + getName(), ErrorCodes::ILLEGAL_COLUMN);
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return agg_function->predictValues(arguments, context);
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}
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ContextPtr context;
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};
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}
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void registerFunctionEvalMLMethod(FunctionFactory & factory)
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{
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factory.registerFunction<FunctionEvalMLMethod>();
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}
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}
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