/// <summary>
/// Creates a new updatable R-Tree instance.
/// </summary>
/// <param name="geoFactory">
/// An <see cref="IGeometryFactory"/> for creating extent instances.
/// </param>
/// <param name="insertStrategy">
/// Strategy used to insert new entries into the index.
/// </param>
/// <param name="nodeSplitStrategy">
/// Strategy used to split nodes when they are full.
/// </param>
/// <param name="heuristic">
/// Heuristics used to build the index and keep it balanced.
/// </param>
public DynamicRTree(
IGeometryFactory geoFactory,
IItemInsertStrategy <IExtents, TItem> insertStrategy,
INodeSplitStrategy <IExtents, TItem> nodeSplitStrategy,
DynamicRTreeBalanceHeuristic heuristic)
: base(geoFactory)
{
if (insertStrategy == null)
{
throw new ArgumentNullException("insertStrategy");
}
if (nodeSplitStrategy == null)
{
throw new ArgumentNullException("nodeSplitStrategy");
}
if (heuristic == null)
{
throw new ArgumentNullException("heuristic");
}
_insertStrategy = insertStrategy;
_nodeSplitStrategy = nodeSplitStrategy;
_heuristic = heuristic;
}
public ISpatialIndexNode <IExtents, TItem> SplitNode(
ISpatialIndexNode <IExtents, TItem> node, IndexBalanceHeuristic heuristic)
{
if (node == null)
{
throw new ArgumentNullException("node");
}
RTreeNode <TItem> rTreeNode = node as RTreeNode <TItem>;
Debug.Assert(rTreeNode != null);
DynamicRTreeBalanceHeuristic rTreeHueristic
= heuristic as DynamicRTreeBalanceHeuristic;
return(doSplit(rTreeNode, rTreeHueristic));
}
/// <summary>
/// Creates a new SelfOptimizingDynamicSpatialIndex.
/// </summary>
/// <param name="geoFactory">An <see cref="IGeometryFactory"/> instance.</param>
/// <param name="restructureStrategy">The strategy used to restructure the index.</param>
/// <param name="restructureHeuristic">The heuristic to control when the index is restructured.</param>
/// <param name="insertStrategy">The strategy used to insert entries into the index.</param>
/// <param name="nodeSplitStrategy">The strategy used to split index nodes.</param>
/// <param name="indexHeuristic">A heuristic used to balance the index for optimum efficiency.</param>
/// <param name="idleMonitor">A monitor to determine idle conditions on the executing machine.</param>
public SelfOptimizingDynamicSpatialIndex(IGeometryFactory geoFactory,
IIndexRestructureStrategy <IExtents, TItem> restructureStrategy,
RestructuringHuristic restructureHeuristic,
IItemInsertStrategy <IExtents, TItem> insertStrategy,
INodeSplitStrategy <IExtents, TItem> nodeSplitStrategy,
DynamicRTreeBalanceHeuristic indexHeuristic,
IdleMonitor idleMonitor)
: base(geoFactory, insertStrategy, nodeSplitStrategy, indexHeuristic)
{
_periodMilliseconds = restructureHeuristic.WhenToRestructure == RestructureOpportunity.Periodic
? (Int32)(restructureHeuristic.Period / 1000.0)
: -1;
_restructureStrategy = restructureStrategy;
_restructuringHeuristic = restructureHeuristic;
_idleMonitor = idleMonitor;
_userIdleEvent = new AutoResetEvent(false);
_machineIdleEvent = new AutoResetEvent(false);
_terminateEvent = new ManualResetEvent(false);
if (restructureHeuristic.WhenToRestructure != RestructureOpportunity.None)
{
_restructureThread = new Thread(doRestructure);
_restructureThread.Start();
}
RestructureOpportunity idle = RestructureOpportunity.OnMachineIdle | RestructureOpportunity.OnUserIdle;
if (((Int32)(restructureHeuristic.WhenToRestructure & idle)) > 0)
{
if (_idleMonitor == null)
{
throw new ArgumentNullException("idleMonitor",
"If the restructuring heuristic has a value of anything but " +
"None for WhenToRestructure, the idleMonitor cannot be null.");
}
_idleMonitor.UserIdle += _idleMonitor_UserIdle;
_idleMonitor.UserBusy += _idleMonitor_UserBusy;
_idleMonitor.MachineIdle += _idleMonitor_MachineIdle;
_idleMonitor.MachineBusy += _idleMonitor_MachineBusy;
}
}
private RTreeNode <TItem> doSplit(RTreeNode <TItem> node, DynamicRTreeBalanceHeuristic heuristic)
{
Boolean isLeaf = node.IsLeaf;
IEnumerable <IBoundable <IExtents> > boundables;
Int32 boundablesCount;
if (isLeaf)
{
boundables = Caster.Upcast <IBoundable <IExtents>, TItem>(node.Items);
boundablesCount = node.ItemCount;
}
else
{
boundables = Caster.Upcast <IBoundable <IExtents>, ISpatialIndexNode <IExtents, TItem> >(node.SubNodes);
boundablesCount = node.SubNodeCount;
}
List <IBoundable <IExtents> > entries = new List <IBoundable <IExtents> >(boundablesCount);
entries.AddRange(boundables);
IBoundable <IExtents>[] group1 = new IBoundable <IExtents> [heuristic.NodeItemMaximumCount];
IBoundable <IExtents>[] group2 = new IBoundable <IExtents> [heuristic.NodeItemMaximumCount];
pickSeeds(entries, group1, group2);
Int32 group1Count = 1, group2Count = 1;
distribute(entries, group1, group2, heuristic, ref group1Count, ref group2Count);
if (entries.Count > 0)
{
if (group1Count < group2Count)
{
fillShortGroup(entries, group1, ref group1Count);
}
else // group2Count < heuristic.NodeItemMinimumCount
{
fillShortGroup(entries, group2, ref group2Count);
}
}
node.Clear();
RTreeNode <TItem> sibling = (node.Index as RTree <TItem>).CreateNode(node.Level);
IEnumerable <IBoundable <IExtents> > g1Sized = Enumerable.Take(group1, group1Count);
IEnumerable <IBoundable <IExtents> > g2Sized = Enumerable.Take(group2, group2Count);
if (isLeaf)
{
IEnumerable <TItem> g1Cast = Caster.Downcast <TItem, IBoundable <IExtents> >(g1Sized);
node.InsertRange(g1Cast);
//IEnumerable<TItem> g2Cast = Caster.Downcast<TItem, IBoundable<IExtents>>(g2Sized);
sibling.AddRange(g2Sized);
}
else
{
//IEnumerable<ISpatialIndexNode<IExtents, TItem>> g1Cast
// = Caster.Downcast<ISpatialIndexNode<IExtents, TItem>, IBoundable<IExtents>>(g1Sized);
node.AddRange(g1Sized);
//IEnumerable<ISpatialIndexNode<IExtents, TItem>> g2Cast
// = Caster.Downcast<ISpatialIndexNode<IExtents, TItem>, IBoundable<IExtents>>(g2Sized);
sibling.AddRange(g2Sized);
}
return(sibling);
}
