ClickHouse/dbms/include/DB/Functions/FunctionsHigherOrder.h

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#pragma once
#include <DB/DataTypes/DataTypeArray.h>
#include <DB/DataTypes/DataTypeExpression.h>
#include <DB/DataTypes/DataTypesNumberFixed.h>
#include <DB/Columns/ColumnArray.h>
#include <DB/Columns/ColumnReplicated.h>
#include <DB/Columns/ColumnExpression.h>
#include <DB/Functions/IFunction.h>
#include "FunctionsMiscellaneous.h"
namespace DB
{
/** Функции высшего порядка для массивов:
*
* arrayMap(x1,...,xn -> expression, array1,...,arrayn) - применить выражение к каждому элементу массива (или набора параллельных массивов).
* arrayFilter(x -> predicate, array) - оставить в массиве только элементы, для которых выражение истинно.
* arrayCount(x1,...,xn -> expression, array1,...,arrayn) - для скольки элементов массива выражение истинно.
* arrayExists(x1,...,xn -> expression, array1,...,arrayn) - истинно ли выражение для хотя бы одного элемента массива.
* arrayAll(x1,...,xn -> expression, array1,...,arrayn) - истинно ли выражение для всех элементов массива.
*
* Для функций arrayCount, arrayExists, arrayAll доступна еще перегрузка вида f(array), которая работает так же, как f(x -> x, array).
*/
struct ArrayMapImpl
{
/// true, если выражение (для перегрузки f(expression, arrays)) или массив (для f(array)) должно быть булевым.
static bool needBoolean() { return false; }
/// true, если перегрузка f(array) недоступна.
static bool needExpression() { return true; }
/// true, если массив должен быть ровно один.
static bool needOneArray() { return false; }
static DataTypePtr getReturnType(const DataTypePtr & expression_return, const DataTypePtr & array_element)
{
return new DataTypeArray(expression_return);
}
static ColumnPtr execute(const ColumnArray * array, ColumnPtr mapped)
{
return new ColumnArray(mapped, array->getOffsetsColumn());
}
};
struct ArrayFilterImpl
{
static bool needBoolean() { return true; }
static bool needExpression() { return true; }
static bool needOneArray() { return false; }
static DataTypePtr getReturnType(const DataTypePtr & expression_return, const DataTypePtr & array_element)
{
return new DataTypeArray(array_element);
}
/// Если массивов несколько, сюда передается первый.
static ColumnPtr execute(const ColumnArray * array, ColumnPtr mapped)
{
ColumnVector<UInt8> * column_filter = dynamic_cast<ColumnVector<UInt8> *>(&*mapped);
if (!column_filter)
throw Exception("Unexpected type of filter column", ErrorCodes::ILLEGAL_COLUMN);
const IColumn::Filter & filter = column_filter->getData();
ColumnPtr filtered = array->getData().filter(filter);
const IColumn::Offsets_t & in_offsets = array->getOffsets();
ColumnArray::ColumnOffsets_t * column_offsets = new ColumnArray::ColumnOffsets_t(in_offsets.size());
ColumnPtr column_offsets_ptr = column_offsets;
IColumn::Offsets_t & out_offsets = column_offsets->getData();
size_t in_pos = 0;
size_t out_pos = 0;
for (size_t i = 0; i < in_offsets.size(); ++i)
{
for (; in_pos < in_offsets[i]; ++in_pos)
{
if (filter[in_pos])
++out_pos;
}
out_offsets[i] = out_pos;
}
return new ColumnArray(filtered, column_offsets_ptr);
}
};
struct ArrayCountImpl
{
static bool needBoolean() { return true; }
static bool needExpression() { return false; }
static bool needOneArray() { return false; }
static DataTypePtr getReturnType(const DataTypePtr & expression_return, const DataTypePtr & array_element)
{
return new DataTypeUInt32;
}
static ColumnPtr execute(const ColumnArray * array, ColumnPtr mapped)
{
ColumnVector<UInt8> * column_filter = dynamic_cast<ColumnVector<UInt8> *>(&*mapped);
if (!column_filter)
throw Exception("Unexpected type of filter column", ErrorCodes::ILLEGAL_COLUMN);
const IColumn::Filter & filter = column_filter->getData();
const IColumn::Offsets_t & offsets = array->getOffsets();
ColumnVector<UInt32> * out_column = new ColumnVector<UInt32>(offsets.size());
ColumnPtr out_column_ptr = out_column;
ColumnVector<UInt32>::Container_t & out_counts = out_column->getData();
size_t pos = 0;
for (size_t i = 0; i < offsets.size(); ++i)
{
size_t count = 0;
for (; pos < offsets[i]; ++pos)
{
if (filter[pos])
++count;
}
out_counts[i] = count;
}
return out_column_ptr;
}
};
struct ArrayExistsImpl
{
static bool needBoolean() { return true; }
static bool needExpression() { return false; }
static bool needOneArray() { return false; }
static DataTypePtr getReturnType(const DataTypePtr & expression_return, const DataTypePtr & array_element)
{
return new DataTypeUInt8;
}
static ColumnPtr execute(const ColumnArray * array, ColumnPtr mapped)
{
ColumnVector<UInt8> * column_filter = dynamic_cast<ColumnVector<UInt8> *>(&*mapped);
if (!column_filter)
throw Exception("Unexpected type of filter column", ErrorCodes::ILLEGAL_COLUMN);
const IColumn::Filter & filter = column_filter->getData();
const IColumn::Offsets_t & offsets = array->getOffsets();
ColumnVector<UInt8> * out_column = new ColumnVector<UInt8>(offsets.size());
ColumnPtr out_column_ptr = out_column;
ColumnVector<UInt8>::Container_t & out_exists = out_column->getData();
size_t pos = 0;
for (size_t i = 0; i < offsets.size(); ++i)
{
UInt8 exists = 0;
for (; pos < offsets[i]; ++pos)
{
if (filter[pos])
{
exists = 1;
pos = offsets[i];
break;
}
}
out_exists[i] = exists;
}
return out_column_ptr;
}
};
struct ArrayAllImpl
{
static bool needBoolean() { return true; }
static bool needExpression() { return false; }
static bool needOneArray() { return false; }
static DataTypePtr getReturnType(const DataTypePtr & expression_return, const DataTypePtr & array_element)
{
return new DataTypeUInt8;
}
static ColumnPtr execute(const ColumnArray * array, ColumnPtr mapped)
{
ColumnVector<UInt8> * column_filter = dynamic_cast<ColumnVector<UInt8> *>(&*mapped);
if (!column_filter)
throw Exception("Unexpected type of filter column", ErrorCodes::ILLEGAL_COLUMN);
const IColumn::Filter & filter = column_filter->getData();
const IColumn::Offsets_t & offsets = array->getOffsets();
ColumnVector<UInt8> * out_column = new ColumnVector<UInt8>(offsets.size());
ColumnPtr out_column_ptr = out_column;
ColumnVector<UInt8>::Container_t & out_all = out_column->getData();
size_t pos = 0;
for (size_t i = 0; i < offsets.size(); ++i)
{
UInt8 all = 1;
for (; pos < offsets[i]; ++pos)
{
if (!filter[pos])
{
all = 0;
pos = offsets[i];
break;
}
}
out_all[i] = all;
}
return out_column_ptr;
}
};
struct ArraySumImpl
{
static bool needBoolean() { return false; }
static bool needExpression() { return false; }
static bool needOneArray() { return false; }
static DataTypePtr getReturnType(const DataTypePtr & expression_return, const DataTypePtr & array_element)
{
if (dynamic_cast<const DataTypeUInt8 *>(&*expression_return) ||
dynamic_cast<const DataTypeUInt16 *>(&*expression_return) ||
dynamic_cast<const DataTypeUInt32 *>(&*expression_return) ||
dynamic_cast<const DataTypeUInt64 *>(&*expression_return))
return new DataTypeUInt64;
if (dynamic_cast<const DataTypeInt8 *>(&*expression_return) ||
dynamic_cast<const DataTypeInt16 *>(&*expression_return) ||
dynamic_cast<const DataTypeInt32 *>(&*expression_return) ||
dynamic_cast<const DataTypeInt64 *>(&*expression_return))
return new DataTypeInt64;
if (dynamic_cast<const DataTypeFloat32 *>(&*expression_return) ||
dynamic_cast<const DataTypeFloat64 *>(&*expression_return))
return new DataTypeFloat64;
throw Exception("arraySum cannot add values of type " + expression_return->getName(), ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
}
template <class Element, class Result>
static bool executeType(const ColumnPtr & mapped, const ColumnArray::Offsets_t & offsets, ColumnPtr & res_ptr)
{
const ColumnVector<Element> * column = dynamic_cast<const ColumnVector<Element> *>(&*mapped);
if (!column)
return false;
const typename ColumnVector<Element>::Container_t & data = column->getData();
ColumnVector<Result> * res_column = new ColumnVector<Result>(offsets.size());
res_ptr = res_column;
typename ColumnVector<Result>::Container_t & res = res_column->getData();
size_t pos = 0;
for (size_t i = 0; i < offsets.size(); ++i)
{
Result s = 0;
for (; pos < offsets[i]; ++pos)
{
s += data[pos];
}
res[i] = s;
}
return true;
}
static ColumnPtr execute(const ColumnArray * array, ColumnPtr mapped)
{
const IColumn::Offsets_t & offsets = array->getOffsets();
ColumnPtr res;
if (executeType< UInt8 , UInt64>(mapped, offsets, res) ||
executeType< UInt16, UInt64>(mapped, offsets, res) ||
executeType< UInt32, UInt64>(mapped, offsets, res) ||
executeType< UInt64, UInt64>(mapped, offsets, res) ||
executeType< Int8 , Int64>(mapped, offsets, res) ||
executeType< Int16, Int64>(mapped, offsets, res) ||
executeType< Int32, Int64>(mapped, offsets, res) ||
executeType< Int64, Int64>(mapped, offsets, res) ||
executeType<Float32,Float64>(mapped, offsets, res) ||
executeType<Float64,Float64>(mapped, offsets, res))
return res;
else
throw Exception("Unexpected column for arraySum: " + mapped->getName());
}
};
template <typename Impl, typename Name>
class FunctionArrayMapped : public IFunction
{
public:
/// Получить имя функции.
String getName() const
{
return Name::get();
}
/// Вызывается, если хоть один агрумент функции - лямбда-выражение.
/// Для аргументов-лямбда-выражений определяет типы аргументов этих выражений.
void getLambdaArgumentTypes(DataTypes & arguments) const
{
if (arguments.size() < 1)
throw Exception("Function " + getName() + " needs at least one argument; passed "
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+ toString(arguments.size()) + ".",
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
if (arguments.size() == 1)
throw Exception("Function " + getName() + " needs at least one array argument.",
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
DataTypes nested_types(arguments.size() - 1);
for (size_t i = 0; i < nested_types.size(); ++i)
{
const DataTypeArray * array_type = dynamic_cast<const DataTypeArray *>(&*arguments[i + 1]);
if (!array_type)
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throw Exception("Argument " + toString(i + 2) + " of function " + getName() + " must be array. Found "
+ arguments[i + 1]->getName() + " instead.", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
nested_types[i] = array_type->getNestedType();
}
const DataTypeExpression * expression_type = dynamic_cast<const DataTypeExpression *>(&*arguments[0]);
if (!expression_type || expression_type->getArgumentTypes().size() != nested_types.size())
throw Exception("First argument for this overload of " + getName() + " must be an expression with "
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+ toString(nested_types.size()) + " arguments. Found "
+ arguments[0]->getName() + " instead.", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
arguments[0] = new DataTypeExpression(nested_types);
}
void getReturnTypeAndPrerequisites(const ColumnsWithNameAndType & arguments,
DataTypePtr & out_return_type,
ExpressionActions::Actions & out_prerequisites)
{
size_t min_args = Impl::needExpression() ? 2 : 1;
if (arguments.size() < min_args)
throw Exception("Function " + getName() + " needs at least "
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+ toString(min_args) + " argument; passed "
+ toString(arguments.size()) + ".",
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
if (arguments.size() == 1)
{
const DataTypeArray * array_type = dynamic_cast<const DataTypeArray *>(&*arguments[0].type);
if (!array_type)
throw Exception("The only argument for function " + getName() + " must be array. Found "
+ arguments[0].type->getName() + " instead.", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
DataTypePtr nested_type = array_type->getNestedType();
if (Impl::needBoolean() && !dynamic_cast<const DataTypeUInt8 *>(&*nested_type))
throw Exception("The only argument for function " + getName() + " must be array of UInt8. Found "
+ arguments[0].type->getName() + " instead.", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
out_return_type = Impl::getReturnType(nested_type, nested_type);
}
else
{
if (arguments.size() > 2 && Impl::needOneArray())
throw Exception("Function " + getName() + " needs one array argument.",
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
const ColumnExpression * column_expression = dynamic_cast<const ColumnExpression *>(arguments[0].column.get());
if (!column_expression)
throw Exception("First argument for function " + getName() + " must be an expression.",
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
/// Типы остальных аргументов уже проверены в getLambdaArgumentTypes.
/// Попросим добавить в блок все столбцы, упоминаемые в выражении, размноженные в массив, параллельный обрабатываемому.
const ExpressionActions & expression = *column_expression->getExpression();
Names required_columns = expression.getRequiredColumns();
Names argument_name_vector = column_expression->getArgumentNames();
NameSet argument_names(argument_name_vector.begin(), argument_name_vector.end());
for (size_t i = 0; i < required_columns.size(); ++i)
{
if (argument_names.count(required_columns[i]))
continue;
Names replicate_arguments;
replicate_arguments.push_back(required_columns[i]);
replicate_arguments.push_back(arguments[1].name);
out_prerequisites.push_back(ExpressionActions::Action::applyFunction(new FunctionReplicate, replicate_arguments));
}
DataTypePtr return_type = column_expression->getReturnType();
if (Impl::needBoolean() && !dynamic_cast<const DataTypeUInt8 *>(&*return_type))
throw Exception("Expression for function " + getName() + " must return UInt8, found "
+ return_type->getName(), ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
const DataTypeArray * first_array_type = dynamic_cast<const DataTypeArray *>(&*arguments[1].type);
out_return_type = Impl::getReturnType(return_type, first_array_type->getNestedType());
}
}
/// Выполнить функцию над блоком.
void execute(Block & block, const ColumnNumbers & arguments, const ColumnNumbers & prerequisites, size_t result)
{
if (arguments.size() == 1)
{
ColumnPtr column_array_ptr = block.getByPosition(arguments[0]).column;
const ColumnArray * column_array = dynamic_cast<const ColumnArray *>(&*column_array_ptr);
if (!column_array)
{
const ColumnConstArray * column_const_array = dynamic_cast<const ColumnConstArray *>(&*column_array_ptr);
if (!column_const_array)
throw Exception("Expected array column, found " + column_array_ptr->getName(), ErrorCodes::ILLEGAL_COLUMN);
column_array_ptr = column_const_array->convertToFullColumn();
column_array = dynamic_cast<const ColumnArray *>(&*column_array_ptr);
}
block.getByPosition(result).column = Impl::execute(column_array, column_array->getDataPtr());
}
else
{
ColumnExpression * column_expression = dynamic_cast<ColumnExpression *>(&*block.getByPosition(arguments[0]).column);
ColumnPtr offsets_column;
Block temp_block;
const ExpressionActions & expression = *column_expression->getExpression();
NamesAndTypes expression_arguments = column_expression->getArguments();
NameSet argument_names;
ColumnPtr column_first_array_ptr;
const ColumnArray * column_first_array = NULL;
/// Положим в блок аргументы выражения.
for (size_t i = 0; i < expression_arguments.size(); ++i)
{
const std::string & argument_name = expression_arguments[i].first;
DataTypePtr argument_type = expression_arguments[i].second;
ColumnPtr column_array_ptr = block.getByPosition(arguments[i + 1]).column;
const ColumnArray * column_array = dynamic_cast<const ColumnArray *>(&*column_array_ptr);
if (!column_array)
{
const ColumnConstArray * column_const_array = dynamic_cast<const ColumnConstArray *>(&*column_array_ptr);
if (!column_const_array)
throw Exception("Expected array column, found " + column_array_ptr->getName(), ErrorCodes::ILLEGAL_COLUMN);
column_array_ptr = column_const_array->convertToFullColumn();
column_array = dynamic_cast<const ColumnArray *>(&*column_array_ptr);
}
if (!offsets_column)
{
offsets_column = column_array->getOffsetsColumn();
}
else
{
/// Первое условие - оптимизация: не сравнивать данные, если указатели равны.
if (column_array->getOffsetsColumn() != offsets_column
&& column_array->getOffsets() != dynamic_cast<const ColumnArray::ColumnOffsets_t &>(*offsets_column).getData())
throw Exception("Arrays passed to " + getName() + " must have equal size", ErrorCodes::SIZES_OF_ARRAYS_DOESNT_MATCH);
}
if (i == 0)
{
column_first_array_ptr = column_array_ptr;
column_first_array = column_array;
}
temp_block.insert(ColumnWithNameAndType(column_array->getDataPtr(), argument_type, argument_name));
argument_names.insert(argument_name);
}
/// Положим в блок все нужные столбцы, размноженные по размерам массивов.
Names required_columns = expression.getRequiredColumns();
size_t prerequisite_index = 0;
for (size_t i = 0; i < required_columns.size(); ++i)
{
const String & name = required_columns[i];
if (argument_names.count(name))
continue;
ColumnWithNameAndType replicated_column = block.getByPosition(prerequisites[prerequisite_index]);
replicated_column.name = name;
replicated_column.column = dynamic_cast<ColumnReplicated &>(*replicated_column.column).getData();
temp_block.insert(replicated_column);
++prerequisite_index;
}
expression.execute(temp_block);
block.getByPosition(result).column = Impl::execute(column_first_array, temp_block.getByName(column_expression->getReturnName()).column);
}
}
};
struct NameArrayMap { static const char * get() { return "arrayMap"; } };
struct NameArrayFilter { static const char * get() { return "arrayFilter"; } };
struct NameArrayCount { static const char * get() { return "arrayCount"; } };
struct NameArrayExists { static const char * get() { return "arrayExists"; } };
struct NameArrayAll { static const char * get() { return "arrayAll"; } };
struct NameArraySum { static const char * get() { return "arraySum"; } };
typedef FunctionArrayMapped<ArrayMapImpl, NameArrayMap> FunctionArrayMap;
typedef FunctionArrayMapped<ArrayFilterImpl, NameArrayFilter> FunctionArrayFilter;
typedef FunctionArrayMapped<ArrayCountImpl, NameArrayCount> FunctionArrayCount;
typedef FunctionArrayMapped<ArrayExistsImpl, NameArrayExists> FunctionArrayExists;
typedef FunctionArrayMapped<ArrayAllImpl, NameArrayAll> FunctionArrayAll;
typedef FunctionArrayMapped<ArraySumImpl, NameArraySum> FunctionArraySum;
}