public MetaSlabs(ObjectSet mos, long metaSlabArray, int metaSlabShift, int aShift)
{
mMos = mos;
mSlabSize = 1L << metaSlabShift;
var slabDnode = mos.ReadEntry(metaSlabArray);
var someBytes = Program.RentBytes(checked ((int)slabDnode.AvailableDataSize));
slabDnode.Read(someBytes, 0);
int numberOfSlabs = someBytes.Count / 8;
mRangeMap = new RangeMap[numberOfSlabs];
long[] ids = new long[numberOfSlabs];
Buffer.BlockCopy(someBytes.Array, someBytes.Offset, ids, 0, someBytes.Count);
Program.ReturnBytes(someBytes);
someBytes = default(ArraySegment <byte>);
for (int i = 0; i < numberOfSlabs; i++)
{
var id = ids[i];
RangeMap map;
if (id == 0)
{
map = new RangeMap();
}
else
{
map = LoadEntrysForMetaSlab(id, aShift);
}
mRangeMap[i] = map;
}
}
unsafe RangeMap LoadEntrysForMetaSlab(long dnEntry, int sm_shift)
{
RangeMap ret = new RangeMap();
var dn = mMos.ReadEntry(dnEntry);
if (dn.Type != dmu_object_type_t.SPACE_MAP || dn.BonusType != dmu_object_type_t.SPACE_MAP_HEADER)
{
throw new Exception("Not a space map.");
}
var head = dn.GetBonus <space_map_obj>();
if (head.smo_object != dnEntry)
{
throw new Exception();
}
if (head.smo_objsize > int.MaxValue)
{
throw new Exception("Holy cow, this space map is greater than 2GB, what is wrong with your VDev!?!?");
}
var someBytes = Program.RentBytes((int)head.smo_objsize);
dn.Read(someBytes, 0);
for (int i = 0; i < someBytes.Count; i += 8)
{
var ent = Program.ToStruct <spaceMapEntry>(someBytes.SubSegment(i, sizeof(spaceMapEntry)));
if (ent.IsDebug)
{
continue;
}
ulong offset = (ent.Offset << sm_shift);
ulong range = ent.Run << sm_shift;
//Console.WriteLine("\t [{4,6}] {0} range: {1:x10}-{2:x10} size: {3:x6}", ent.Type, offset, offset + range, range, i / 8);
if (ent.Type == SpaceMapEntryType.A)
{
ret.AddRange(offset, range);
}
else if (ent.Type == SpaceMapEntryType.F)
{
ret.RemoveRange(offset, range);
}
}
Program.ReturnBytes(someBytes);
return(ret);
}