ClickHouse/dbms/src/IO/tests/var_uint.cpp

#include <string>

#include <iostream>
#include <DB/IO/VarInt.h>
#include <DB/IO/WriteBufferFromString.h>
#include <DB/IO/ReadBufferFromString.h>
#include <DB/IO/ReadHelpers.h>
#include <Poco/HexBinaryEncoder.h>


int main(int argc, char ** argv)
{
	if (argc != 2)
	{
		std::cerr << "Usage: " << std::endl
			<< argv[0] << " unsigned_number" << std::endl;
		return 1;
	}

	DB::UInt64 x = DB::parse<UInt64>(argv[1]);
	Poco::HexBinaryEncoder hex(std::cout);
	DB::writeVarUInt(x, hex);
	std::cout << std::endl;

	std::string s;

	{
		DB::WriteBufferFromString wb(s);
		DB::writeVarUInt(x, wb);
		wb.next();
	}

	hex << s;
	std::cout << std::endl;

	s.clear();
	s.resize(9);

	s.resize(DB::writeVarUInt(x, &s[0]) - s.data());

	hex << s;
	std::cout << std::endl;

	DB::UInt64 y = 0;

	DB::ReadBufferFromString rb(s);
	DB::readVarUInt(y, rb);

	std::cerr << "x: " << x << ", y: " << y << std::endl;

	return 0;
}