Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <venti.h>

void
vtzeroextend(int type, uchar *buf, uint n, uint nn)
{
        uchar *p, *ep;

        switch(type&7) {
        case 0:
                memset(buf+n, 0, nn-n);
                break;
        default:
                p = buf + (n/VtScoreSize)*VtScoreSize;
                ep = buf + (nn/VtScoreSize)*VtScoreSize;
                while(p < ep) {
                        memmove(p, vtzeroscore, VtScoreSize);
                        p += VtScoreSize;
                }
                memset(p, 0, buf+nn-p);
                break;
        }
}

uint 
vtzerotruncate(int type, uchar *buf, uint n)
{
        uchar *p;

        if(type == VtRootType){
                if(n < VtRootSize)
                        return n;
                return VtRootSize;
        }

        switch(type&7){
        case 0:
                for(p = buf + n; p > buf; p--) {
                        if(p[-1] != 0)
                                break;
                }
                return p - buf;
        default:
                /* ignore slop at end of block */
                p = buf + (n/VtScoreSize)*VtScoreSize;

                while(p > buf) {
                        if(memcmp(p - VtScoreSize, vtzeroscore, VtScoreSize) != 0)
                                break;
                        p -= VtScoreSize;
                }
                return p - buf;
        }
}