///////    FIle Cirbuf.C    ///////
#include        <iostream.h>
#include        "Cirbuf.h"

Cirbuf::Cirbuf(int s /* = D_SIZE */)
{    head = tail = length = 0;
     size = s;
     cb = new char[s];  // allocate buffer space
}

Cirbuf::~Cirbuf()
{    delete [] cb;      // free up space
}


int Cirbuf::produce(char c)
{    if ( is_full() ) 
     {    cerr << "produce: buffer full\n";
          return(-1);
     }
     cb[tail++] = c;
     length++;
     tail = mod(tail);
     return(0);
}

int Cirbuf::consume()
{    char c;
     if ( is_empty() )
     {    cerr << "consume: buffer empty\n";
          return(-1);
     }
     c = cb[head++];
     length--;
     head = mod(head);
     return(c);
}