there is the function : decodeURLComponent ,why not encodeURLComponent?

#include <Common/hex.h>
#include <Functions/FunctionFactory.h>
#include <Functions/FunctionStringToString.h>
#include <base/find_symbols.h>
namespace DB
{
namespace ErrorCodes
{
    extern const int ILLEGAL_COLUMN;
}
static size_t decodeURL(const char * src, size_t src_size, char * dst, bool plus_as_space)