Subversion Repositories planix.SVN

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

static int
checksize(int n)
{
        if(n < 256 || n > VtMaxLumpSize) {
                werrstr("bad block size %#ux", n);
                return -1;
        }
        return 0;
}

void
vtentrypack(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);
}

int
vtentryunpack(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;
}