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;
}