Beispiel #1
0
        /// <summary>
        /// Initializes an empty node.
        /// </summary>
        /// <param name="comparer">The comparer used to compare two items.</param>
        public RangeTreeNode(IComparer <TKey> comparer)
        {
            this.comparer = comparer ?? Comparer <TKey> .Default;

            center    = default(TKey);
            leftNode  = null;
            rightNode = null;
            items     = null;
        }
Beispiel #2
0
        private void Rebuild()
        {
            if (isInSync)
            {
                return;
            }

            if (items.Count > 0)
            {
                root = new RangeTreeNode <TKey, TValue>(items, comparer);
            }
            else
            {
                root = new RangeTreeNode <TKey, TValue>(comparer);
            }
            isInSync = true;
        }
Beispiel #3
0
        /// <summary>
        /// Initializes a node with a list of items, builds the sub tree.
        /// </summary>
        /// <param name="items">The items that should be added to this node</param>
        /// <param name="comparer">The comparer used to compare two items.</param>
        public RangeTreeNode(IList <RangeValuePair <TKey, TValue> > items, IComparer <TKey> comparer)
        {
            this.comparer = comparer ?? Comparer <TKey> .Default;

            // first, find the median
            var endPoints = new List <TKey>(items.Count * 2);

            foreach (var item in items)
            {
                endPoints.Add(item.From);
                endPoints.Add(item.To);
            }
            endPoints.Sort(this.comparer);

            // the median is used as center value
            if (endPoints.Count > 0)
            {
                center = endPoints[endPoints.Count / 2];
            }

            var inner = new List <RangeValuePair <TKey, TValue> >();
            var left  = new List <RangeValuePair <TKey, TValue> >();
            var right = new List <RangeValuePair <TKey, TValue> >();

            // iterate over all items
            // if the range of an item is completely left of the center, add it to the left items
            // if it is on the right of the center, add it to the right items
            // otherwise (range overlaps the center), add the item to this node's items
            foreach (var o in items)
            {
                if (this.comparer.Compare(o.To, center) < 0)
                {
                    left.Add(o);
                }
                else if (this.comparer.Compare(o.From, center) > 0)
                {
                    right.Add(o);
                }
                else
                {
                    inner.Add(o);
                }
            }

            // sort the items, this way the query is faster later on
            if (inner.Count > 0)
            {
                if (inner.Count > 1)
                {
                    inner.Sort(this);
                }
                this.items = inner.ToArray();
            }
            else
            {
                this.items = null;
            }

            // create left and right nodes, if there are any items
            if (left.Count > 0)
            {
                leftNode = new RangeTreeNode <TKey, TValue>(left, this.comparer);
            }
            if (right.Count > 0)
            {
                rightNode = new RangeTreeNode <TKey, TValue>(right, this.comparer);
            }
        }
Beispiel #4
0
 public void Clear()
 {
     root     = new RangeTreeNode <TKey, TValue>(comparer);
     items    = new List <RangeValuePair <TKey, TValue> >();
     isInSync = true;
 }