plan9front/sys/src/libventi/root.c

68 lines
1.2 KiB
C

#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");
return -1;
}
return 0;
}
void
vtrootpack(VtRoot *r, uchar *p)
{
uchar *op = p;
U16PUT(p, VtRootVersion);
p += 2;
memmove(p, r->name, sizeof(r->name));
p += sizeof(r->name);
memmove(p, r->type, sizeof(r->type));
p += sizeof(r->type);
memmove(p, r->score, VtScoreSize);
p += VtScoreSize;
U16PUT(p, r->blocksize);
p += 2;
memmove(p, r->prev, VtScoreSize);
p += VtScoreSize;
assert(p-op == VtRootSize);
}
int
vtrootunpack(VtRoot *r, uchar *p)
{
uchar *op = p;
uint vers;
memset(r, 0, sizeof(*r));
vers = U16GET(p);
if(vers != VtRootVersion) {
werrstr("unknown root version");
return -1;
}
p += 2;
memmove(r->name, p, sizeof(r->name));
r->name[sizeof(r->name)-1] = 0;
p += sizeof(r->name);
memmove(r->type, p, sizeof(r->type));
r->type[sizeof(r->type)-1] = 0;
p += sizeof(r->type);
memmove(r->score, p, VtScoreSize);
p += VtScoreSize;
r->blocksize = U16GET(p);
if(checksize(r->blocksize) < 0)
return -1;
p += 2;
memmove(r->prev, p, VtScoreSize);
p += VtScoreSize;
assert(p-op == VtRootSize);
return 0;
}