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#include <u.h>
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#include <libc.h>
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#include <venti.h>
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void
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vtzeroextend(int type, uchar *buf, uint n, uint nn)
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{
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	uchar *p, *ep;
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	switch(type&7) {
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	case 0:
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		memset(buf+n, 0, nn-n);
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		break;
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	default:
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		p = buf + (n/VtScoreSize)*VtScoreSize;
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		ep = buf + (nn/VtScoreSize)*VtScoreSize;
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		while(p < ep) {
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			memmove(p, vtzeroscore, VtScoreSize);
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			p += VtScoreSize;
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		}
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		memset(p, 0, buf+nn-p);
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		break;
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	}
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}
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uint
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vtzerotruncate(int type, uchar *buf, uint n)
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{
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	uchar *p;
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	if(type == VtRootType){
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		if(n < VtRootSize)
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			return n;
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		return VtRootSize;
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	}
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	switch(type&7){
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	case 0:
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		for(p = buf + n; p > buf; p--) {
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			if(p[-1] != 0)
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				break;
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		}
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		return p - buf;
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	default:
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		/* ignore slop at end of block */
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		p = buf + (n/VtScoreSize)*VtScoreSize;
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		while(p > buf) {
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			if(memcmp(p - VtScoreSize, vtzeroscore, VtScoreSize) != 0)
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				break;
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			p -= VtScoreSize;
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		}
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		return p - buf;
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	}
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}