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#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;
}
}
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