protected override List<Sector> GenerateSectors(List<IndexUnit> indexUnits)
{
SortedList<Address, List<IndexUnit>> groupings = new SortedList<Address, List<IndexUnit>>();
foreach (IndexUnit indexUnit in indexUnits)
{
if (!groupings.ContainsKey(indexUnit.Node))
groupings.Add(indexUnit.Node, new List<IndexUnit>());
groupings[indexUnit.Node].Add(indexUnit);
}
List<Sector> sectors = new List<Sector>();
List<List<IndexUnit>> newGroupings = new List<List<IndexUnit>>(groupings.Values);
while (newGroupings.Count > 0)
{
Sector newSector = new Sector();
List<IndexUnit> initialGrouping = newGroupings[0], addedUnits = new List<IndexUnit>();
newGroupings.Remove(initialGrouping);
while (initialGrouping.Count > 0 && newSector.IndexUnits.Count < Constants.INDEX_UNIT_ENTRIES_PER_SECTOR)
{
newSector.AddIndexUnit(initialGrouping[0]);
addedUnits.Add(initialGrouping[0]);
initialGrouping.RemoveAt(0);
}
if (initialGrouping.Count > 0)
newGroupings.Add(initialGrouping);
else
initialGrouping = addedUnits;
while (newSector.IndexUnits.Count < Constants.INDEX_UNIT_ENTRIES_PER_SECTOR &&
newGroupings.Count > 0)
{
List<List<IndexUnit>> eligibleGroupings = new List<List<IndexUnit>>();
foreach (List<IndexUnit> grouping in newGroupings)
if (grouping.Count + newSector.IndexUnits.Count <= Constants.INDEX_UNIT_ENTRIES_PER_SECTOR)
eligibleGroupings.Add(grouping);
if (eligibleGroupings.Count == 0)
break;
List<IndexUnit> closestGrouping = PickClosestGrouping(initialGrouping, eligibleGroupings);
foreach (IndexUnit i in closestGrouping)
newSector.AddIndexUnit(i);
initialGrouping.AddRange(closestGrouping);
newGroupings.Remove(closestGrouping);
}
sectors.Add(newSector);
}
return sectors;
}
protected virtual PageData LookupPageData(Address address)
{
PageData data;
Page page = LookupPage(address);
Byte type = page.Data[0], childType = page.Data[1];
if (type == (Byte)PageDataType.Node || type == (Byte)PageDataType.Leaf)
if (childType == (Byte)NodeChildType.Leaf)
data = new Node(address, typeof(Leaf), page.Data);
else if (childType == (Byte)NodeChildType.Node)
data = new Node(address, typeof(Node), page.Data);
else if (childType == (Byte)NodeChildType.Record)
data = new Leaf(address, page.Data);
else
throw new Exception("Not a node");
else if (type == (Byte)PageDataType.Record)
data = new Record(address, page.Data);
else if (type == (Byte)PageDataType.IndexUnitSector)
data = new Sector(address, page.Data);
else
throw new Exception("Not valid Page Data");
CacheOverflowCheck();
return data;
}
