#include <db_cxx.h> int DbMpoolFile::get_clear_len(u_int32_t *lenp);
         The DbMpoolFile::get_clear_len() method returns the bytes to be
         cleared.
    
         The DbMpoolFile::get_clear_len() method may be called at any time
         during the life of the application.
    
         The DbMpoolFile::get_clear_len() 
            
            
                method either returns a non-zero error value or throws an
                exception that encapsulates a non-zero error value on
                failure, and returns 0 on success.