ClickHouse/src/AggregateFunctions/AggregateFunctionIf.cpp
2021-08-30 19:37:54 +02:00

416 lines
17 KiB
C++

#include <AggregateFunctions/AggregateFunctionCombinatorFactory.h>
#include <AggregateFunctions/AggregateFunctionIf.h>
#include "AggregateFunctionNull.h"
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
extern const int ILLEGAL_AGGREGATION;
}
class AggregateFunctionCombinatorIf final : public IAggregateFunctionCombinator
{
public:
String getName() const override { return "If"; }
DataTypes transformArguments(const DataTypes & arguments) const override
{
if (arguments.empty())
throw Exception("Incorrect number of arguments for aggregate function with " + getName() + " suffix",
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
if (!isUInt8(arguments.back()))
throw Exception("Illegal type " + arguments.back()->getName() + " of last argument for aggregate function with " + getName() + " suffix",
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
return DataTypes(arguments.begin(), std::prev(arguments.end()));
}
AggregateFunctionPtr transformAggregateFunction(
const AggregateFunctionPtr & nested_function,
const AggregateFunctionProperties &,
const DataTypes & arguments,
const Array & params) const override
{
if (nested_function->getName().find(getName()) != String::npos)
{
throw Exception(ErrorCodes::ILLEGAL_AGGREGATION, "nested function for {0}-combinator must not have {0}-combinator", getName());
}
return std::make_shared<AggregateFunctionIf>(nested_function, arguments, params);
}
};
/** Given an array of flags, checks if it's all zeros
* When the buffer is all zeros, this is slightly faster than doing a memcmp since doesn't require allocating memory
* When the buffer has values, this is much faster since it avoids visiting all memory (and the allocation and function calls)
*/
static bool ALWAYS_INLINE inline is_all_zeros(const UInt8 * flags, size_t size)
{
size_t unroll_size = size - size % 8;
size_t i = 0;
while (i < unroll_size)
{
UInt64 v = *reinterpret_cast<const UInt64 *>(&flags[i]);
if (v)
return false;
i += 8;
}
for (; i < size; i++)
if (flags[i])
return false;
return true;
}
/** There are two cases: for single argument and variadic.
* Code for single argument is much more efficient.
*/
template <bool result_is_nullable, bool serialize_flag>
class AggregateFunctionIfNullUnary final
: public AggregateFunctionNullBase<result_is_nullable, serialize_flag,
AggregateFunctionIfNullUnary<result_is_nullable, serialize_flag>>
{
private:
size_t num_arguments;
/// The name of the nested function, including combinators (i.e. *If)
///
/// getName() from the nested_function cannot be used because in case of *If combinator
/// with Nullable argument nested_function will point to the function w/o combinator.
/// (I.e. sumIf(Nullable, 1) -> sum()), and distributed query processing will fail.
///
/// And nested_function cannot point to the function with *If since
/// due to optimization in the add() which pass only one column with the result,
/// and so AggregateFunctionIf::add() cannot be called this way
/// (it write to the last argument -- num_arguments-1).
///
/// And to avoid extra level of indirection, the name of function is cached:
///
/// AggregateFunctionIfNullUnary::add -> [ AggregateFunctionIf::add -> ] AggregateFunctionSum::add
String name;
using Base = AggregateFunctionNullBase<result_is_nullable, serialize_flag,
AggregateFunctionIfNullUnary<result_is_nullable, serialize_flag>>;
public:
String getName() const override
{
return name;
}
AggregateFunctionIfNullUnary(const String & name_, AggregateFunctionPtr nested_function_, const DataTypes & arguments, const Array & params)
: Base(std::move(nested_function_), arguments, params)
, num_arguments(arguments.size())
, name(name_)
{
if (num_arguments == 0)
throw Exception("Aggregate function " + getName() + " require at least one argument",
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
}
static inline bool singleFilter(const IColumn ** columns, size_t row_num, size_t num_arguments)
{
const IColumn * filter_column = columns[num_arguments - 1];
if (const ColumnNullable * nullable_column = typeid_cast<const ColumnNullable *>(filter_column))
filter_column = nullable_column->getNestedColumnPtr().get();
return assert_cast<const ColumnUInt8 &>(*filter_column).getData()[row_num];
}
void add(AggregateDataPtr __restrict place, const IColumn ** columns, size_t row_num, Arena * arena) const override
{
const ColumnNullable * column = assert_cast<const ColumnNullable *>(columns[0]);
const IColumn * nested_column = &column->getNestedColumn();
if (!column->isNullAt(row_num) && singleFilter(columns, row_num, num_arguments))
{
this->setFlag(place);
this->nested_function->add(this->nestedPlace(place), &nested_column, row_num, arena);
}
}
void addBatchSinglePlace(size_t batch_size, AggregateDataPtr place, const IColumn ** columns, Arena * arena, ssize_t) const override
{
const ColumnNullable * column = assert_cast<const ColumnNullable *>(columns[0]);
const UInt8 * null_map = column->getNullMapData().data();
const IColumn * columns_param[] = {&column->getNestedColumn()};
const IColumn * filter_column = columns[num_arguments - 1];
if (const ColumnNullable * nullable_column = typeid_cast<const ColumnNullable *>(filter_column))
filter_column = nullable_column->getNestedColumnPtr().get();
if constexpr (result_is_nullable)
{
/// We need to check if there is work to do as otherwise setting the flag would be a mistake,
/// it would mean that the return value would be the default value of the nested type instead of NULL
if (is_all_zeros(assert_cast<const ColumnUInt8 *>(filter_column)->getData().data(), batch_size))
return;
}
/// Combine the 2 flag arrays so we can call a simplified version (one check vs 2)
/// Note that now the null map will contain 0 if not null and not filtered, or 1 for null or filtered (or both)
const auto * filter_flags = assert_cast<const ColumnUInt8 *>(filter_column)->getData().data();
auto final_nulls = std::make_unique<UInt8[]>(batch_size);
for (size_t i = 0; i < batch_size; ++i)
final_nulls[i] = (!!null_map[i]) | (!filter_flags[i]);
this->nested_function->addBatchSinglePlaceNotNull(
batch_size, this->nestedPlace(place), columns_param, final_nulls.get(), arena, -1);
if constexpr (result_is_nullable)
if (!memoryIsByte(null_map, batch_size, 1))
this->setFlag(place);
}
#if USE_EMBEDDED_COMPILER
void compileAdd(llvm::IRBuilderBase & builder, llvm::Value * aggregate_data_ptr, const DataTypes & arguments_types, const std::vector<llvm::Value *> & argument_values) const override
{
llvm::IRBuilder<> & b = static_cast<llvm::IRBuilder<> &>(builder);
const auto & nullable_type = arguments_types[0];
const auto & nullable_value = argument_values[0];
auto * wrapped_value = b.CreateExtractValue(nullable_value, {0});
auto * is_null_value = b.CreateExtractValue(nullable_value, {1});
const auto & predicate_type = arguments_types[argument_values.size() - 1];
auto * predicate_value = argument_values[argument_values.size() - 1];
auto * is_predicate_true = nativeBoolCast(b, predicate_type, predicate_value);
auto * head = b.GetInsertBlock();
auto * join_block = llvm::BasicBlock::Create(head->getContext(), "join_block", head->getParent());
auto * if_null = llvm::BasicBlock::Create(head->getContext(), "if_null", head->getParent());
auto * if_not_null = llvm::BasicBlock::Create(head->getContext(), "if_not_null", head->getParent());
b.CreateCondBr(b.CreateAnd(b.CreateNot(is_null_value), is_predicate_true), if_not_null, if_null);
b.SetInsertPoint(if_null);
b.CreateBr(join_block);
b.SetInsertPoint(if_not_null);
if constexpr (result_is_nullable)
b.CreateStore(llvm::ConstantInt::get(b.getInt8Ty(), 1), aggregate_data_ptr);
auto * aggregate_data_ptr_with_prefix_size_offset = b.CreateConstInBoundsGEP1_64(nullptr, aggregate_data_ptr, this->prefix_size);
this->nested_function->compileAdd(b, aggregate_data_ptr_with_prefix_size_offset, { removeNullable(nullable_type) }, { wrapped_value });
b.CreateBr(join_block);
b.SetInsertPoint(join_block);
}
#endif
};
template <bool result_is_nullable, bool serialize_flag, bool null_is_skipped>
class AggregateFunctionIfNullVariadic final
: public AggregateFunctionNullBase<result_is_nullable, serialize_flag,
AggregateFunctionIfNullVariadic<result_is_nullable, serialize_flag, null_is_skipped>>
{
public:
String getName() const override
{
return Base::getName();
}
AggregateFunctionIfNullVariadic(AggregateFunctionPtr nested_function_, const DataTypes & arguments, const Array & params)
: Base(std::move(nested_function_), arguments, params), number_of_arguments(arguments.size())
{
if (number_of_arguments == 1)
throw Exception("Logical error: single argument is passed to AggregateFunctionIfNullVariadic", ErrorCodes::LOGICAL_ERROR);
if (number_of_arguments > MAX_ARGS)
throw Exception("Maximum number of arguments for aggregate function with Nullable types is " + toString(size_t(MAX_ARGS)),
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
for (size_t i = 0; i < number_of_arguments; ++i)
is_nullable[i] = arguments[i]->isNullable();
}
static inline bool singleFilter(const IColumn ** columns, size_t row_num, size_t num_arguments)
{
return assert_cast<const ColumnUInt8 &>(*columns[num_arguments - 1]).getData()[row_num];
}
void add(AggregateDataPtr __restrict place, const IColumn ** columns, size_t row_num, Arena * arena) const override
{
/// This container stores the columns we really pass to the nested function.
const IColumn * nested_columns[number_of_arguments];
for (size_t i = 0; i < number_of_arguments; ++i)
{
if (is_nullable[i])
{
const ColumnNullable & nullable_col = assert_cast<const ColumnNullable &>(*columns[i]);
if (null_is_skipped && nullable_col.isNullAt(row_num))
{
/// If at least one column has a null value in the current row,
/// we don't process this row.
return;
}
nested_columns[i] = &nullable_col.getNestedColumn();
}
else
nested_columns[i] = columns[i];
}
if (singleFilter(nested_columns, row_num, number_of_arguments))
{
this->setFlag(place);
this->nested_function->add(this->nestedPlace(place), nested_columns, row_num, arena);
}
}
#if USE_EMBEDDED_COMPILER
void compileAdd(llvm::IRBuilderBase & builder, llvm::Value * aggregate_data_ptr, const DataTypes & arguments_types, const std::vector<llvm::Value *> & argument_values) const override
{
/// TODO: Check
llvm::IRBuilder<> & b = static_cast<llvm::IRBuilder<> &>(builder);
size_t arguments_size = arguments_types.size();
DataTypes non_nullable_types;
std::vector<llvm::Value * > wrapped_values;
std::vector<llvm::Value * > is_null_values;
non_nullable_types.resize(arguments_size);
wrapped_values.resize(arguments_size);
is_null_values.resize(arguments_size);
for (size_t i = 0; i < arguments_size; ++i)
{
const auto & argument_value = argument_values[i];
if (is_nullable[i])
{
auto * wrapped_value = b.CreateExtractValue(argument_value, {0});
if constexpr (null_is_skipped)
is_null_values[i] = b.CreateExtractValue(argument_value, {1});
wrapped_values[i] = wrapped_value;
non_nullable_types[i] = removeNullable(arguments_types[i]);
}
else
{
wrapped_values[i] = argument_value;
non_nullable_types[i] = arguments_types[i];
}
}
auto * head = b.GetInsertBlock();
auto * join_block = llvm::BasicBlock::Create(head->getContext(), "join_block", head->getParent());
auto * join_block_after_null_checks = llvm::BasicBlock::Create(head->getContext(), "join_block_after_null_checks", head->getParent());
if constexpr (null_is_skipped)
{
auto * values_have_null_ptr = b.CreateAlloca(b.getInt1Ty());
b.CreateStore(b.getInt1(false), values_have_null_ptr);
for (auto * is_null_value : is_null_values)
{
if (!is_null_value)
continue;
auto * values_have_null = b.CreateLoad(b.getInt1Ty(), values_have_null_ptr);
b.CreateStore(b.CreateOr(values_have_null, is_null_value), values_have_null_ptr);
}
b.CreateCondBr(b.CreateLoad(b.getInt1Ty(), values_have_null_ptr), join_block, join_block_after_null_checks);
}
b.SetInsertPoint(join_block_after_null_checks);
const auto & predicate_type = arguments_types[argument_values.size() - 1];
auto * predicate_value = argument_values[argument_values.size() - 1];
auto * is_predicate_true = nativeBoolCast(b, predicate_type, predicate_value);
auto * if_true = llvm::BasicBlock::Create(head->getContext(), "if_true", head->getParent());
auto * if_false = llvm::BasicBlock::Create(head->getContext(), "if_false", head->getParent());
b.CreateCondBr(is_predicate_true, if_true, if_false);
b.SetInsertPoint(if_false);
b.CreateBr(join_block);
b.SetInsertPoint(if_true);
if constexpr (result_is_nullable)
b.CreateStore(llvm::ConstantInt::get(b.getInt8Ty(), 1), aggregate_data_ptr);
auto * aggregate_data_ptr_with_prefix_size_offset = b.CreateConstInBoundsGEP1_64(nullptr, aggregate_data_ptr, this->prefix_size);
this->nested_function->compileAdd(b, aggregate_data_ptr_with_prefix_size_offset, non_nullable_types, wrapped_values);
b.CreateBr(join_block);
b.SetInsertPoint(join_block);
}
#endif
private:
using Base = AggregateFunctionNullBase<result_is_nullable, serialize_flag,
AggregateFunctionIfNullVariadic<result_is_nullable, serialize_flag, null_is_skipped>>;
enum { MAX_ARGS = 8 };
size_t number_of_arguments = 0;
std::array<char, MAX_ARGS> is_nullable; /// Plain array is better than std::vector due to one indirection less.
};
AggregateFunctionPtr AggregateFunctionIf::getOwnNullAdapter(
const AggregateFunctionPtr & nested_function, const DataTypes & arguments,
const Array & params, const AggregateFunctionProperties & properties) const
{
bool return_type_is_nullable = !properties.returns_default_when_only_null && getReturnType()->canBeInsideNullable();
size_t nullable_size = std::count_if(arguments.begin(), arguments.end(), [](const auto & element) { return element->isNullable(); });
return_type_is_nullable &= nullable_size != 1 || !arguments.back()->isNullable(); /// If only condition is nullable. we should non-nullable type.
bool serialize_flag = return_type_is_nullable || properties.returns_default_when_only_null;
if (arguments.size() <= 2 && arguments.front()->isNullable())
{
if (return_type_is_nullable)
{
return std::make_shared<AggregateFunctionIfNullUnary<true, true>>(nested_function->getName(), nested_func, arguments, params);
}
else
{
if (serialize_flag)
return std::make_shared<AggregateFunctionIfNullUnary<false, true>>(nested_function->getName(), nested_func, arguments, params);
else
return std::make_shared<AggregateFunctionIfNullUnary<false, false>>(nested_function->getName(), nested_func, arguments, params);
}
}
else
{
if (return_type_is_nullable)
{
return std::make_shared<AggregateFunctionIfNullVariadic<true, true, true>>(nested_function, arguments, params);
}
else
{
if (serialize_flag)
return std::make_shared<AggregateFunctionIfNullVariadic<false, true, true>>(nested_function, arguments, params);
else
return std::make_shared<AggregateFunctionIfNullVariadic<false, false, true>>(nested_function, arguments, params);
}
}
}
void registerAggregateFunctionCombinatorIf(AggregateFunctionCombinatorFactory & factory)
{
factory.registerCombinator(std::make_shared<AggregateFunctionCombinatorIf>());
}
}