Retards the current chain iterator by the requested length. Will set the iterator to the start of the chain if the requested decrement is too great.

Declared in file: hzChain.h
Defined in file : hzChain.cpp

Function Logic:

Function body:

hzChain::Iter& hzChain::Iter::operator-= (uint32_t nDec)
{
   //  Retards the current chain iterator by the requested length. Will set the iterator to the start of the chain if the requested decrement is too great.
   //  
   //  Arguments: 1) nInc The number of bytes to decrement the chain iterator by
   //  
   //  Returns: Reference to this chain iterator
   _hzfunc("hzChain::Iter::operator-=") ;
   _zblk*  zp ;    //  Chain block pointer
   zp = (_zblk*) m_block ;
   for (; zp && nDec ;)
   {
       if (m_nOset >&eq; nDec)
       {
           //  If we can decrement N places and still be on the same block, then just decrement the offset
           m_nOset -= nDec ;
           break ;
       }
       nDec -= m_nOset ;
       if (!zp->Prev())
       {
           m_nOset = 0;
           break ;
       }
       m_block = zp = zp->Prev() ;
       if (zp)
           m_nOset = (zp->m_nUsage - 1);
       else
           m_nOset = 0;
   }
   return *this ;
}