1 | #include <AggregateFunctions/AggregateFunctionState.h> |
2 | #include <AggregateFunctions/AggregateFunctionMerge.h> |
3 | #include <AggregateFunctions/AggregateFunctionCombinatorFactory.h> |
4 | #include <DataTypes/DataTypeAggregateFunction.h> |
5 | #include "registerAggregateFunctions.h" |
6 | |
7 | |
8 | namespace DB |
9 | { |
10 | |
11 | namespace ErrorCodes |
12 | { |
13 | extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH; |
14 | extern const int BAD_ARGUMENTS; |
15 | } |
16 | |
17 | class AggregateFunctionCombinatorState final : public IAggregateFunctionCombinator |
18 | { |
19 | public: |
20 | String getName() const override { return "State" ; } |
21 | |
22 | DataTypes transformArguments(const DataTypes & arguments) const override |
23 | { |
24 | return arguments; |
25 | } |
26 | |
27 | AggregateFunctionPtr transformAggregateFunction( |
28 | const AggregateFunctionPtr & nested_function, const DataTypes & arguments, const Array & params) const override |
29 | { |
30 | return std::make_shared<AggregateFunctionState>(nested_function, arguments, params); |
31 | } |
32 | }; |
33 | |
34 | void registerAggregateFunctionCombinatorState(AggregateFunctionCombinatorFactory & factory) |
35 | { |
36 | factory.registerCombinator(std::make_shared<AggregateFunctionCombinatorState>()); |
37 | } |
38 | |
39 | |
40 | DataTypePtr AggregateFunctionState::getReturnType() const |
41 | { |
42 | auto ptr = std::make_shared<DataTypeAggregateFunction>(nested_func, arguments, params); |
43 | |
44 | /// Special case: it is -MergeState combinator. |
45 | /// We must return AggregateFunction(agg, ...) instead of AggregateFunction(aggMerge, ...) |
46 | if (typeid_cast<const AggregateFunctionMerge *>(ptr->getFunction().get())) |
47 | { |
48 | if (arguments.size() != 1) |
49 | throw Exception("Combinator -MergeState expects only one argument" , ErrorCodes::BAD_ARGUMENTS); |
50 | |
51 | if (!typeid_cast<const DataTypeAggregateFunction *>(arguments[0].get())) |
52 | throw Exception("Combinator -MergeState expects argument with AggregateFunction type" , ErrorCodes::BAD_ARGUMENTS); |
53 | |
54 | return arguments[0]; |
55 | } |
56 | if (arguments.size() > 0) |
57 | { |
58 | DataTypePtr argument_type_ptr = arguments[0]; |
59 | WhichDataType which(*argument_type_ptr); |
60 | if (which.idx == TypeIndex::AggregateFunction) |
61 | { |
62 | if (arguments.size() != 1) |
63 | throw Exception("Nested aggregation expects only one argument" , ErrorCodes::BAD_ARGUMENTS); |
64 | return arguments[0]; |
65 | } |
66 | } |
67 | |
68 | return ptr; |
69 | } |
70 | |
71 | } |
72 | |