ClickHouse/dbms/include/DB/AggregateFunctions/AggregateFunctionUniq.h
2016-05-28 13:35:44 +03:00

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#pragma once
#include <city.h>
#include <type_traits>
#include <DB/AggregateFunctions/UniquesHashSet.h>
#include <DB/IO/WriteHelpers.h>
#include <DB/IO/ReadHelpers.h>
#include <DB/IO/WriteBufferFromString.h>
#include <DB/DataTypes/DataTypesNumberFixed.h>
#include <DB/DataTypes/DataTypeString.h>
#include <DB/DataTypes/DataTypeTuple.h>
#include <DB/Interpreters/AggregationCommon.h>
#include <DB/Common/HashTable/HashSet.h>
#include <DB/Common/HyperLogLogWithSmallSetOptimization.h>
#include <DB/Common/CombinedCardinalityEstimator.h>
#include <DB/Columns/ColumnString.h>
#include <DB/Columns/ColumnTuple.h>
#include <DB/AggregateFunctions/IUnaryAggregateFunction.h>
#include <DB/AggregateFunctions/UniqCombinedBiasData.h>
#include <DB/AggregateFunctions/UniqVariadicHash.h>
namespace DB
{
/// uniq
struct AggregateFunctionUniqUniquesHashSetData
{
using Set = UniquesHashSet<DefaultHash<UInt64>>;
Set set;
static String getName() { return "uniq"; }
};
/// Для функции, принимающей несколько аргументов. Такая функция сама заранее их хэширует, поэтому здесь используется TrivialHash.
struct AggregateFunctionUniqUniquesHashSetDataForVariadic
{
using Set = UniquesHashSet<TrivialHash>;
Set set;
static String getName() { return "uniq"; }
};
/// uniqHLL12
template <typename T>
struct AggregateFunctionUniqHLL12Data
{
using Set = HyperLogLogWithSmallSetOptimization<T, 16, 12>;
Set set;
static String getName() { return "uniqHLL12"; }
};
template <>
struct AggregateFunctionUniqHLL12Data<String>
{
using Set = HyperLogLogWithSmallSetOptimization<UInt64, 16, 12>;
Set set;
static String getName() { return "uniqHLL12"; }
};
struct AggregateFunctionUniqHLL12DataForVariadic
{
using Set = HyperLogLogWithSmallSetOptimization<UInt64, 16, 12, TrivialHash>;
Set set;
static String getName() { return "uniqHLL12"; }
};
/// uniqExact
template <typename T>
struct AggregateFunctionUniqExactData
{
using Key = T;
/// При создании, хэш-таблица должна быть небольшой.
typedef HashSet<
Key,
HashCRC32<Key>,
HashTableGrower<4>,
HashTableAllocatorWithStackMemory<sizeof(Key) * (1 << 4)>
> Set;
Set set;
static String getName() { return "uniqExact"; }
};
/// Для строк будем класть в хэш-таблицу значения SipHash-а (128 бит).
template <>
struct AggregateFunctionUniqExactData<String>
{
using Key = UInt128;
/// При создании, хэш-таблица должна быть небольшой.
typedef HashSet<
Key,
UInt128TrivialHash,
HashTableGrower<3>,
HashTableAllocatorWithStackMemory<sizeof(Key) * (1 << 3)>
> Set;
Set set;
static String getName() { return "uniqExact"; }
};
template <typename T, HyperLogLogMode mode>
struct BaseUniqCombinedData
{
using Key = UInt32;
using Set = CombinedCardinalityEstimator<
Key,
HashSet<Key, TrivialHash, HashTableGrower<> >,
16,
14,
17,
TrivialHash,
UInt32,
HyperLogLogBiasEstimator<UniqCombinedBiasData>,
mode
>;
Set set;
};
template <HyperLogLogMode mode>
struct BaseUniqCombinedData<String, mode>
{
using Key = UInt64;
using Set = CombinedCardinalityEstimator<
Key,
HashSet<Key, TrivialHash, HashTableGrower<> >,
16,
14,
17,
TrivialHash,
UInt64,
HyperLogLogBiasEstimator<UniqCombinedBiasData>,
mode
>;
Set set;
};
/// Агрегатные функции uniqCombinedRaw, uniqCombinedLinearCounting, и uniqCombinedBiasCorrected
/// предназначены для разработки новых версий функции uniqCombined.
/// Пользователи должны использовать только uniqCombined.
template <typename T>
struct AggregateFunctionUniqCombinedRawData
: public BaseUniqCombinedData<T, HyperLogLogMode::Raw>
{
static String getName() { return "uniqCombinedRaw"; }
};
template <typename T>
struct AggregateFunctionUniqCombinedLinearCountingData
: public BaseUniqCombinedData<T, HyperLogLogMode::LinearCounting>
{
static String getName() { return "uniqCombinedLinearCounting"; }
};
template <typename T>
struct AggregateFunctionUniqCombinedBiasCorrectedData
: public BaseUniqCombinedData<T, HyperLogLogMode::BiasCorrected>
{
static String getName() { return "uniqCombinedBiasCorrected"; }
};
template <typename T>
struct AggregateFunctionUniqCombinedData
: public BaseUniqCombinedData<T, HyperLogLogMode::FullFeatured>
{
static String getName() { return "uniqCombined"; }
};
namespace detail
{
/** Хэш-функция для uniq.
*/
template <typename T> struct AggregateFunctionUniqTraits
{
static UInt64 hash(T x) { return x; }
};
template <> struct AggregateFunctionUniqTraits<Float32>
{
static UInt64 hash(Float32 x)
{
UInt64 res = 0;
memcpy(reinterpret_cast<char *>(&res), reinterpret_cast<char *>(&x), sizeof(x));
return res;
}
};
template <> struct AggregateFunctionUniqTraits<Float64>
{
static UInt64 hash(Float64 x)
{
UInt64 res = 0;
memcpy(reinterpret_cast<char *>(&res), reinterpret_cast<char *>(&x), sizeof(x));
return res;
}
};
/** Хэш-функция для uniqCombined.
*/
template <typename T> struct AggregateFunctionUniqCombinedTraits
{
static UInt32 hash(T x) { return static_cast<UInt32>(intHash64(x)); }
};
template <> struct AggregateFunctionUniqCombinedTraits<Float32>
{
static UInt32 hash(Float32 x)
{
UInt64 res = 0;
memcpy(reinterpret_cast<char *>(&res), reinterpret_cast<char *>(&x), sizeof(x));
return static_cast<UInt32>(intHash64(res));
}
};
template <> struct AggregateFunctionUniqCombinedTraits<Float64>
{
static UInt32 hash(Float64 x)
{
UInt64 res = 0;
memcpy(reinterpret_cast<char *>(&res), reinterpret_cast<char *>(&x), sizeof(x));
return static_cast<UInt32>(intHash64(res));
}
};
/** Структура для делегации работы по добавлению одного элемента в агрегатные функции uniq.
* Используется для частичной специализации для добавления строк.
*/
template <typename T, typename Data, typename Enable = void>
struct OneAdder;
template <typename T, typename Data>
struct OneAdder<T, Data, typename std::enable_if<
std::is_same<Data, AggregateFunctionUniqUniquesHashSetData>::value ||
std::is_same<Data, AggregateFunctionUniqHLL12Data<T> >::value>::type>
{
template <typename T2 = T>
static void addImpl(Data & data, const IColumn & column, size_t row_num,
typename std::enable_if<!std::is_same<T2, String>::value>::type * = nullptr)
{
const auto & value = static_cast<const ColumnVector<T2> &>(column).getData()[row_num];
data.set.insert(AggregateFunctionUniqTraits<T2>::hash(value));
}
template <typename T2 = T>
static void addImpl(Data & data, const IColumn & column, size_t row_num,
typename std::enable_if<std::is_same<T2, String>::value>::type * = nullptr)
{
StringRef value = column.getDataAt(row_num);
data.set.insert(CityHash64(value.data, value.size));
}
};
template <typename T, typename Data>
struct OneAdder<T, Data, typename std::enable_if<
std::is_same<Data, AggregateFunctionUniqCombinedRawData<T> >::value ||
std::is_same<Data, AggregateFunctionUniqCombinedLinearCountingData<T> >::value ||
std::is_same<Data, AggregateFunctionUniqCombinedBiasCorrectedData<T> >::value ||
std::is_same<Data, AggregateFunctionUniqCombinedData<T> >::value>::type>
{
template <typename T2 = T>
static void addImpl(Data & data, const IColumn & column, size_t row_num,
typename std::enable_if<!std::is_same<T2, String>::value>::type * = nullptr)
{
const auto & value = static_cast<const ColumnVector<T2> &>(column).getData()[row_num];
data.set.insert(AggregateFunctionUniqCombinedTraits<T2>::hash(value));
}
template <typename T2 = T>
static void addImpl(Data & data, const IColumn & column, size_t row_num,
typename std::enable_if<std::is_same<T2, String>::value>::type * = nullptr)
{
StringRef value = column.getDataAt(row_num);
data.set.insert(CityHash64(value.data, value.size));
}
};
template <typename T, typename Data>
struct OneAdder<T, Data, typename std::enable_if<
std::is_same<Data, AggregateFunctionUniqExactData<T> >::value>::type>
{
template <typename T2 = T>
static void addImpl(Data & data, const IColumn & column, size_t row_num,
typename std::enable_if<!std::is_same<T2, String>::value>::type * = nullptr)
{
data.set.insert(static_cast<const ColumnVector<T2> &>(column).getData()[row_num]);
}
template <typename T2 = T>
static void addImpl(Data & data, const IColumn & column, size_t row_num,
typename std::enable_if<std::is_same<T2, String>::value>::type * = nullptr)
{
StringRef value = column.getDataAt(row_num);
UInt128 key;
SipHash hash;
hash.update(value.data, value.size);
hash.get128(key.first, key.second);
data.set.insert(key);
}
};
}
/// Приближённо или точно вычисляет количество различных значений.
template <typename T, typename Data>
class AggregateFunctionUniq final : public IUnaryAggregateFunction<Data, AggregateFunctionUniq<T, Data> >
{
public:
String getName() const override { return Data::getName(); }
DataTypePtr getReturnType() const override
{
return std::make_shared<DataTypeUInt64>();
}
void setArgument(const DataTypePtr & argument)
{
}
void addImpl(AggregateDataPtr place, const IColumn & column, size_t row_num) const
{
detail::OneAdder<T, Data>::addImpl(this->data(place), column, row_num);
}
void merge(AggregateDataPtr place, ConstAggregateDataPtr rhs) const override
{
this->data(place).set.merge(this->data(rhs).set);
}
void serialize(ConstAggregateDataPtr place, WriteBuffer & buf) const override
{
this->data(place).set.write(buf);
}
void deserialize(AggregateDataPtr place, ReadBuffer & buf) const override
{
this->data(place).set.read(buf);
}
void insertResultInto(ConstAggregateDataPtr place, IColumn & to) const override
{
static_cast<ColumnUInt64 &>(to).getData().push_back(this->data(place).set.size());
}
};
/** Для нескольких аргументов. Для вычисления, хэширует их.
* Можно передать несколько аргументов как есть; также можно передать один аргумент - кортеж.
* Но (для возможности эффективной реализации), нельзя передать несколько аргументов, среди которых есть кортежи.
*/
template <typename Data, bool argument_is_tuple>
class AggregateFunctionUniqVariadic final : public IAggregateFunctionHelper<Data>
{
private:
static constexpr bool is_exact = std::is_same<Data, AggregateFunctionUniqExactData<String>>::value;
size_t num_args = 0;
public:
String getName() const override { return Data::getName(); }
DataTypePtr getReturnType() const override
{
return std::make_shared<DataTypeUInt64>();
}
void setArguments(const DataTypes & arguments) override
{
if (argument_is_tuple)
num_args = typeid_cast<const DataTypeTuple &>(*arguments[0]).getElements().size();
else
num_args = arguments.size();
}
void add(AggregateDataPtr place, const IColumn ** columns, size_t row_num) const override
{
this->data(place).set.insert(UniqVariadicHash<is_exact, argument_is_tuple>::apply(num_args, columns, row_num));
}
void merge(AggregateDataPtr place, ConstAggregateDataPtr rhs) const override
{
this->data(place).set.merge(this->data(rhs).set);
}
void serialize(ConstAggregateDataPtr place, WriteBuffer & buf) const override
{
this->data(place).set.write(buf);
}
void deserialize(AggregateDataPtr place, ReadBuffer & buf) const override
{
this->data(place).set.read(buf);
}
void insertResultInto(ConstAggregateDataPtr place, IColumn & to) const override
{
static_cast<ColumnUInt64 &>(to).getData().push_back(this->data(place).set.size());
}
static void addFree(const IAggregateFunction * that, AggregateDataPtr place, const IColumn ** columns, size_t row_num)
{
return static_cast<const AggregateFunctionUniqVariadic &>(*that).add(place, columns, row_num);
}
IAggregateFunction::AddFunc getAddressOfAddFunction() const override final { return &addFree; }
};
}