internal Core(Func <TItem, TItem, TDistance> distance, SmallWorld <TItem, TDistance> .Parameters parameters)
{
Distance = distance;
Parameters = parameters;
var initialSize = Math.Max(1024, parameters.InitialItemsSize);
Nodes = new List <Node>(initialSize);
Items = new List <TItem>(initialSize);
switch (Parameters.NeighbourHeuristic)
{
case NeighbourSelectionHeuristic.SelectSimple:
{
Algorithm = new Algorithms.Algorithm3 <TItem, TDistance>(this);
break;
}
case NeighbourSelectionHeuristic.SelectHeuristic:
{
Algorithm = new Algorithms.Algorithm4 <TItem, TDistance>(this);
break;
}
}
if (Parameters.EnableDistanceCacheForConstruction)
{
DistanceCache = new DistanceCache <TDistance>();
DistanceCache.Resize(parameters.InitialDistanceCacheSize, false);
}
DistanceCalculationsCount = 0;
}
/// <summary>
/// Initializes a new instance of the <see cref="Core"/> class.
/// </summary>
/// <param name="distance">The distance function in the items space.</param>
/// <param name="parameters">The parameters of the world.</param>
/// <param name="items">The original items.</param>
internal Core(Func <TItem, TItem, TDistance> distance, SmallWorld <TItem, TDistance> .Parameters parameters, IReadOnlyList <TItem> items)
{
this.distance = distance;
this.Parameters = parameters;
this.Items = items;
switch (this.Parameters.NeighbourHeuristic)
{
case SmallWorld <TItem, TDistance> .NeighbourSelectionHeuristic.SelectSimple:
this.Algorithm = new Node.Algorithm3 <TItem, TDistance>(this);
break;
case SmallWorld <TItem, TDistance> .NeighbourSelectionHeuristic.SelectHeuristic:
this.Algorithm = new Node.Algorithm4 <TItem, TDistance>(this);
break;
}
if (this.Parameters.EnableDistanceCacheForConstruction)
{
this.distanceCache = new DistanceCache <TDistance>(this.Items.Count);
}
this.distanceCacheHitCount = 0;
this.distanceCalculationsCount = 0;
}