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dbms: Cleanup [#METR-19266]

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This commit is contained in:
Alexey Arno 2016-08-05 12:19:32 +03:00
parent a1218c3134
commit f6ab219176
2 changed files with 25 additions and 10 deletions
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2
dbms/src/Functions/FunctionsNull.cpp
View File

@ -172,7 +172,7 @@ void FunctionCoalesce::executeImpl(Block & block, const ColumnNumbers & argument
/// For the NULL value.
new_args.push_back(block.columns());
/// Append a NULL column to block.
/// Append a NULL column.
ColumnWithTypeAndName elem;
elem.column = std::make_shared<ColumnNull>(block.rowsInFirstColumn(), Null());
elem.type = std::make_shared<DataTypeNull>();

33
dbms/src/Functions/IFunction.cpp
View File

@ -8,6 +8,13 @@
namespace DB
{
/// Except for functions whose method hasSpecialSupportForNulls() returns true,
/// such as multiIf, most of them deal with nullable or null arguments according
/// to the following scheme:
/// - If at least one argument is null, we return null.
/// - If at least one argument is nullable, we run the function on non-nullable
/// columns, then we wrap the result we have obtained into a nullable column.
namespace
{
@ -29,6 +36,7 @@ void createNullValuesByteMap(Block & block, size_t result)
}
}
/// Check if a block contains at least one null column.
bool hasNullColumns(const Block & block, const ColumnNumbers & arguments)
{
for (const auto & arg : arguments)
@ -40,6 +48,7 @@ bool hasNullColumns(const Block & block, const ColumnNumbers & arguments)
return false;
}
/// Check if at least one column is null.
bool hasNullColumns(const ColumnsWithTypeAndName & args)
{
for (const auto & arg : args)
@ -51,7 +60,8 @@ bool hasNullColumns(const ColumnsWithTypeAndName & args)
return false;
}
bool hasNullColumns(const DataTypes & args)
/// Check if at least one argument is null.
bool hasNullArguments(const DataTypes & args)
{
for (const auto & arg : args)
{
@ -62,6 +72,7 @@ bool hasNullColumns(const DataTypes & args)
return false;
}
/// Check if a block contains at least one nullable column.
bool hasNullableColumns(const Block & block, const ColumnNumbers & arguments)
{
for (const auto & arg : arguments)
@ -73,6 +84,7 @@ bool hasNullableColumns(const Block & block, const ColumnNumbers & arguments)
return false;
}
/// Check if at least one column is nullable.
bool hasNullableColumns(const ColumnsWithTypeAndName & args)
{
for (const auto & arg : args)
@ -84,7 +96,8 @@ bool hasNullableColumns(const ColumnsWithTypeAndName & args)
return false;
}
bool hasNullableColumns(const DataTypes & args)
/// Check if at least one argument is nullable.
bool hasNullableArguments(const DataTypes & args)
{
for (const auto & arg : args)
{
@ -95,6 +108,7 @@ bool hasNullableColumns(const DataTypes & args)
return false;
}
/// Turn the specified set of columns into a set of non-nullable columns.
ColumnsWithTypeAndName toNonNullableColumns(const ColumnsWithTypeAndName & args)
{
ColumnsWithTypeAndName new_args;
@ -118,7 +132,8 @@ ColumnsWithTypeAndName toNonNullableColumns(const ColumnsWithTypeAndName & args)
return new_args;
}
DataTypes toNonNullableColumns(const DataTypes & args)
/// Turn the specified set of data types into a set of non-nullable data types.
DataTypes toNonNullableArguments(const DataTypes & args)
{
DataTypes new_args;
new_args.reserve(args.size());
@ -142,12 +157,12 @@ DataTypes toNonNullableColumns(const DataTypes & args)
DataTypePtr IFunction::getReturnType(const DataTypes & arguments) const
{
if (!hasSpecialSupportForNulls() && hasNullColumns(arguments))
if (!hasSpecialSupportForNulls() && hasNullArguments(arguments))
return std::make_shared<DataTypeNull>();
if (!hasSpecialSupportForNulls() && hasNullableColumns(arguments))
if (!hasSpecialSupportForNulls() && hasNullableArguments(arguments))
{
const DataTypes new_args = toNonNullableColumns(arguments);
const DataTypes new_args = toNonNullableArguments(arguments);
return getReturnTypeImpl(new_args);
}
else
@ -177,12 +192,12 @@ void IFunction::getReturnTypeAndPrerequisites(
void IFunction::getLambdaArgumentTypes(DataTypes & arguments) const
{
if (!hasSpecialSupportForNulls() && hasNullColumns(arguments))
if (!hasSpecialSupportForNulls() && hasNullArguments(arguments))
return;
if (!hasSpecialSupportForNulls() && hasNullableColumns(arguments))
if (!hasSpecialSupportForNulls() && hasNullableArguments(arguments))
{
DataTypes new_args = toNonNullableColumns(arguments);
DataTypes new_args = toNonNullableArguments(arguments);
getLambdaArgumentTypesImpl(new_args);
arguments = std::move(new_args);
}