#include <u.h>#include <libc.h>#include <venti.h>#include "cvt.h" static intchecksize(int n){	if(n < 256 || n > VtMaxLumpSize) {		werrstr("bad block size %#ux", n);		return -1;	}	return 0;} voidvtentrypack(VtEntry *e, uchar *p, int index){	ulong t32;	int flags;	uchar *op;	int depth; 	p += index * VtEntrySize;	op = p; 	U32PUT(p, e->gen);	p += 4;	U16PUT(p, e->psize);	p += 2;	U16PUT(p, e->dsize);	p += 2;	depth = e->type&VtTypeDepthMask;	flags = (e->flags&~(_VtEntryDir|_VtEntryDepthMask));	flags |= depth << _VtEntryDepthShift;	if(e->type - depth == VtDirType)		flags |= _VtEntryDir;	U8PUT(p, flags);	p++;	memset(p, 0, 5);	p += 5;	U48PUT(p, e->size, t32);	p += 6;	memmove(p, e->score, VtScoreSize);	p += VtScoreSize; 	assert(p-op == VtEntrySize);} intvtentryunpack(VtEntry *e, uchar *p, int index){	uchar *op; 	p += index * VtEntrySize;	op = p; 	e->gen = U32GET(p);	p += 4;	e->psize = U16GET(p);	p += 2;	e->dsize = U16GET(p);	p += 2;	e->flags = U8GET(p);	e->type = (e->flags&_VtEntryDir) ? VtDirType : VtDataType;	e->type += (e->flags & _VtEntryDepthMask) >> _VtEntryDepthShift;	e->flags &= ~(_VtEntryDir|_VtEntryDepthMask);	p++;	p += 5;	e->size = U48GET(p);	p += 6;	memmove(e->score, p, VtScoreSize);	p += VtScoreSize; 	assert(p-op == VtEntrySize);		if(!(e->flags & VtEntryActive))		return 0; 	/* 	 * Some old vac files use psize==0 and dsize==0 when the	 * file itself has size 0 or is zeros.  Just to make programs not	 * have to figure out what block sizes of 0 means, rewrite them.	 */	if(e->psize == 0 && e->dsize == 0	&& memcmp(e->score, vtzeroscore, VtScoreSize) == 0){		e->psize = 4096;		e->dsize = 4096;	}	if(checksize(e->psize) < 0 || checksize(e->dsize) < 0)		return -1; 	return 0;}