dbms: add function IPv4NumToStringClassC [#METR-14266]

dbms/include/DB/Functions/FunctionsCoding.h

@@ -463,8 +463,6 @@ public:
 							ErrorCodes::ILLEGAL_COLUMN);
 	}
 };
-
-
 class FunctionIPv4NumToString : public IFunction
 {
 public:
@@ -661,6 +659,115 @@ public:
 };
 
 
+class FunctionIPv4NumToStringClassC : public IFunction
+{
+public:
+	static constexpr auto name = "IPv4NumToStringClassC";
+	static IFunction * create(const Context & context) { return new FunctionIPv4NumToStringClassC; }
+
+	/// Получить имя функции.
+	String getName() const
+	{
+		return name;
+	}
+
+	/// Получить тип результата по типам аргументов. Если функция неприменима для данных аргументов - кинуть исключение.
+	DataTypePtr getReturnType(const DataTypes & arguments) const
+	{
+		if (arguments.size() != 1)
+			throw Exception("Number of arguments for function " + getName() + " doesn't match: passed "
+			+ toString(arguments.size()) + ", should be 1.",
+			ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
+
+		if (!typeid_cast<const DataTypeUInt32 *>(&*arguments[0]))
+			throw Exception("Illegal type " + arguments[0]->getName() + " of argument of function " + getName() + ", expected UInt32",
+			ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
+
+		return new DataTypeString;
+	}
+
+	static void formatIP(UInt32 ip, char *& out)
+	{
+		char * begin = out;
+
+		for (auto i = 0; i < 3; ++i)
+			*(out++) = 'x';
+
+		/// Запишем все задом наперед.
+		for (size_t offset = 8; offset <= 24; offset += 8)
+		{
+			if (offset > 0)
+				*(out++) = '.';
+
+			/// Достаем очередной байт.
+			UInt32 value = (ip >> offset) & static_cast<UInt32>(255);
+
+			/// Быстрее, чем sprintf.
+			if (value == 0)
+			{
+				*(out++) = '0';
+			}
+			else
+			{
+				while (value > 0)
+				{
+					*(out++) = '0' + value % 10;
+					value /= 10;
+				}
+			}
+		}
+
+		/// И развернем.
+		std::reverse(begin, out);
+
+		*(out++) = '\0';
+	}
+
+	/// Выполнить функцию над блоком.
+	void execute(Block & block, const ColumnNumbers & arguments, size_t result)
+	{
+		const ColumnPtr column = block.getByPosition(arguments[0]).column;
+
+		if (const ColumnVector<UInt32> * col = typeid_cast<const ColumnVector<UInt32> *>(&*column))
+		{
+			const ColumnVector<UInt32>::Container_t & vec_in = col->getData();
+
+			ColumnString * col_res = new ColumnString;
+			block.getByPosition(result).column = col_res;
+
+			ColumnString::Chars_t & vec_res = col_res->getChars();
+			ColumnString::Offsets_t & offsets_res = col_res->getOffsets();
+
+			vec_res.resize(vec_in.size() * INET_ADDRSTRLEN); /// самое длинное значение: 255.255.255.255\0
+			offsets_res.resize(vec_in.size());
+			char * begin = reinterpret_cast<char *>(&vec_res[0]);
+			char * pos = begin;
+
+			for (size_t i = 0; i < vec_in.size(); ++i)
+			{
+				formatIP(vec_in[i], pos);
+				offsets_res[i] = pos - begin;
+			}
+
+			vec_res.resize(pos - begin);
+		}
+		else if (const ColumnConst<UInt32> * col = typeid_cast<const ColumnConst<UInt32> *>(&*column))
+		{
+			char buf[16];
+			char * pos = buf;
+			formatIP(col->getData(), pos);
+
+			ColumnConstString * col_res = new ColumnConstString(col->size(), buf);
+			block.getByPosition(result).column = col_res;
+		}
+		else
+			throw Exception("Illegal column " + block.getByPosition(arguments[0]).column->getName()
+			+ " of argument of function " + getName(),
+			ErrorCodes::ILLEGAL_COLUMN);
+	}
+};
+
+
 class FunctionHex : public IFunction
 {
 public:

dbms/src/Functions/FunctionsCoding.cpp

@@ -11,6 +11,7 @@ void registerFunctionsCoding(FunctionFactory & factory)
 	factory.registerFunction<FunctionIPv6StringToNum>();
 	factory.registerFunction<FunctionIPv4NumToString>();
 	factory.registerFunction<FunctionIPv4StringToNum>();
+	factory.registerFunction<FunctionIPv4NumToStringClassC>();
 	factory.registerFunction<FunctionHex>();
 	factory.registerFunction<FunctionUnhex>();
 	factory.registerFunction<FunctionBitmaskToArray>();

dbms/tests/queries/0_stateless/00103_ipv4_num_to_string_class_c.reference

@@ -0,0 +1,4 @@
+1
+1
+1
+1

dbms/tests/queries/0_stateless/00103_ipv4_num_to_string_class_c.sql

@@ -0,0 +1,4 @@
+select IPv4NumToStringClassC(toUInt32(0)) = '0.0.0.xxx';
+select IPv4NumToStringClassC(0x7f000001) = '127.0.0.xxx';
+select sum(IPv4NumToStringClassC(materialize(toUInt32(0))) = '0.0.0.xxx') = count() array join range(1024) as n;
+select sum(IPv4NumToStringClassC(materialize(0x7f000001)) = '127.0.0.xxx') = count() array join range(1024) as n;