Inheritance: Volante.Persistent
Exemplo n.º 1
0
 public override void Clear()
 {
     if (root != null)
     {
         root.purge(height);
         root = null;
     }
     height         = 0;
     n              = 0;
     updateCounter += 1;
     Modify();
 }
Exemplo n.º 2
0
 internal RtreePage(IDatabase db, RtreePage root, RtreePage p)
 {
     branch        = db.CreateLink <IPersistent>(card);
     branch.Length = card;
     b             = new Rectangle[card];
     n             = 2;
     setBranch(0, root.cover(), root);
     setBranch(1, p.cover(), p);
     for (int i = 2; i < card; i++)
     {
         b[i] = new Rectangle();
     }
 }
Exemplo n.º 3
0
 internal RtreePage(IDatabase db, RtreePage root, RtreePage p)
 {
     branch = db.CreateLink<IPersistent>(card);
     branch.Length = card;
     b = new Rectangle[card];
     n = 2;
     setBranch(0, root.cover(), root);
     setBranch(1, p.cover(), p);
     for (int i = 2; i < card; i++)
     {
         b[i] = new Rectangle();
     }
 }
Exemplo n.º 4
0
            internal RtreeIterator(Rtree <T> tree, Rectangle r)
            {
                counter   = tree.updateCounter;
                height    = tree.height;
                this.tree = tree;
                if (height == 0)
                {
                    return;
                }

                this.r    = r;
                pageStack = new RtreePage[height];
                posStack  = new int[height];
                Reset();
            }
Exemplo n.º 5
0
 private bool gotoFirstItem(int sp, RtreePage pg)
 {
     for (int i = 0, n = pg.n; i < n; i++)
     {
         if (r.Intersects(pg.b[i]))
         {
             if (sp + 1 == height || gotoFirstItem(sp + 1, (RtreePage)pg.branch[i]))
             {
                 pageStack[sp] = pg;
                 posStack[sp]  = i;
                 return(true);
             }
         }
     }
     return(false);
 }
Exemplo n.º 6
0
 internal RtreePage insert(IDatabase db, Rectangle r, IPersistent obj, int level)
 {
     Modify();
     if (--level != 0)
     {
         // not leaf page
         int  i, mini = 0;
         long minIncr = long.MaxValue;
         long minArea = long.MaxValue;
         for (i = 0; i < n; i++)
         {
             long area = b[i].Area();
             long incr = Rectangle.JoinArea(b[i], r) - area;
             if (incr < minIncr)
             {
                 minIncr = incr;
                 minArea = area;
                 mini    = i;
             }
             else if (incr == minIncr && area < minArea)
             {
                 minArea = area;
                 mini    = i;
             }
         }
         RtreePage p = (RtreePage)branch[mini];
         RtreePage q = p.insert(db, r, obj, level);
         if (q == null)
         {
             // child was not split
             b[mini].Join(r);
             return(null);
         }
         else
         {
             // child was split
             setBranch(mini, p.cover(), p);
             return(addBranch(db, q.cover(), q));
         }
     }
     else
     {
         return(addBranch(db, new Rectangle(r), obj));
     }
 }
Exemplo n.º 7
0
            private bool gotoNextItem(int sp)
            {
                RtreePage pg = pageStack[sp];

                for (int i = posStack[sp], n = pg.n; ++i < n;)
                {
                    if (r.Intersects(pg.b[i]))
                    {
                        if (sp + 1 == height || gotoFirstItem(sp + 1, (RtreePage)pg.branch[i]))
                        {
                            pageStack[sp] = pg;
                            posStack[sp]  = i;
                            return(true);
                        }
                    }
                }
                pageStack[sp] = null;
                return((sp > 0) ? gotoNextItem(sp - 1) : false);
            }
Exemplo n.º 8
0
 internal int remove(Rectangle r, IPersistent obj, int level, ArrayList reinsertList)
 {
     if (--level != 0)
     {
         for (int i = 0; i < n; i++)
         {
             if (r.Intersects(b[i]))
             {
                 RtreePage pg            = (RtreePage)branch[i];
                 int       reinsertLevel = pg.remove(r, obj, level, reinsertList);
                 if (reinsertLevel >= 0)
                 {
                     if (pg.n >= minFill)
                     {
                         setBranch(i, pg.cover(), pg);
                         Modify();
                     }
                     else
                     {
                         // not enough entries in child
                         reinsertList.Add(pg);
                         reinsertLevel = level - 1;
                         removeBranch(i);
                     }
                     return(reinsertLevel);
                 }
             }
         }
     }
     else
     {
         for (int i = 0; i < n; i++)
         {
             if (branch.ContainsElement(i, obj))
             {
                 removeBranch(i);
                 return(0);
             }
         }
     }
     return(-1);
 }
Exemplo n.º 9
0
        public void Remove(Rectangle r, T obj)
        {
            if (root == null)
            {
                throw new DatabaseException(DatabaseException.ErrorCode.KEY_NOT_FOUND);
            }

            ArrayList reinsertList  = new ArrayList();
            int       reinsertLevel = root.remove(r, obj, height, reinsertList);

            if (reinsertLevel < 0)
            {
                throw new DatabaseException(DatabaseException.ErrorCode.KEY_NOT_FOUND);
            }

            for (int i = reinsertList.Count; --i >= 0;)
            {
                RtreePage p = (RtreePage)reinsertList[i];
                for (int j = 0, pn = p.n; j < pn; j++)
                {
                    RtreePage q = root.insert(Database, p.b[j], p.branch[j], height - reinsertLevel);
                    if (q != null)
                    {
                        // root splitted
                        root    = new RtreePage(Database, root, q);
                        height += 1;
                    }
                }
                reinsertLevel -= 1;
                p.Deallocate();
            }
            if (root.n == 1 && height > 1)
            {
                RtreePage newRoot = (RtreePage)root.branch[0];
                root.Deallocate();
                root    = newRoot;
                height -= 1;
            }
            n             -= 1;
            updateCounter += 1;
            Modify();
        }
Exemplo n.º 10
0
 public void Put(Rectangle r, T obj)
 {
     if (root == null)
     {
         root   = new RtreePage(Database, obj, r);
         height = 1;
     }
     else
     {
         RtreePage p = root.insert(Database, r, obj, height);
         if (p != null)
         {
             root    = new RtreePage(Database, root, p);
             height += 1;
         }
     }
     n             += 1;
     updateCounter += 1;
     Modify();
 }
Exemplo n.º 11
0
        RtreePage splitPage(IDatabase db, Rectangle r, IPersistent obj)
        {
            int i, j, seed0 = 0, seed1 = 0;

            long[] rectArea = new long[card + 1];
            long   waste;
            long   worstWaste = long.MinValue;

            //
            // As the seeds for the two groups, find two rectangles which waste
            // the most area if covered by a single rectangle.
            //
            rectArea[0] = r.Area();
            for (i = 0; i < card; i++)
            {
                rectArea[i + 1] = b[i].Area();
            }
            Rectangle bp = r;

            for (i = 0; i < card; i++)
            {
                for (j = i + 1; j <= card; j++)
                {
                    waste = Rectangle.JoinArea(bp, b[j - 1]) - rectArea[i] - rectArea[j];
                    if (waste > worstWaste)
                    {
                        worstWaste = waste;
                        seed0      = i;
                        seed1      = j;
                    }
                }
                bp = b[i];
            }
            byte[]    taken = new byte[card];
            Rectangle group0, group1;
            long      groupArea0, groupArea1;
            int       groupCard0, groupCard1;
            RtreePage pg;

            taken[seed1 - 1] = 2;
            group1           = new Rectangle(b[seed1 - 1]);

            if (seed0 == 0)
            {
                group0 = new Rectangle(r);
                pg     = new RtreePage(db, obj, r);
            }
            else
            {
                group0 = new Rectangle(b[seed0 - 1]);
                pg     = new RtreePage(db, branch.GetRaw(seed0 - 1), group0);
                setBranch(seed0 - 1, r, obj);
            }
            groupCard0 = groupCard1 = 1;
            groupArea0 = rectArea[seed0];
            groupArea1 = rectArea[seed1];
            //
            // Split remaining rectangles between two groups.
            // The one chosen is the one with the greatest difference in area
            // expansion depending on which group - the rect most strongly
            // attracted to one group and repelled from the other.
            //
            while (groupCard0 + groupCard1 < card + 1 &&
                   groupCard0 < card + 1 - minFill &&
                   groupCard1 < card + 1 - minFill)
            {
                int  betterGroup = -1, chosen = -1;
                long biggestDiff = -1;
                for (i = 0; i < card; i++)
                {
                    if (taken[i] == 0)
                    {
                        long diff = (Rectangle.JoinArea(group0, b[i]) - groupArea0)
                                    - (Rectangle.JoinArea(group1, b[i]) - groupArea1);
                        if (diff > biggestDiff || -diff > biggestDiff)
                        {
                            chosen = i;
                            if (diff < 0)
                            {
                                betterGroup = 0;
                                biggestDiff = -diff;
                            }
                            else
                            {
                                betterGroup = 1;
                                biggestDiff = diff;
                            }
                        }
                    }
                }
                Debug.Assert(chosen >= 0);
                if (betterGroup == 0)
                {
                    group0.Join(b[chosen]);
                    groupArea0    = group0.Area();
                    taken[chosen] = 1;
                    pg.setBranch(groupCard0++, b[chosen], branch.GetRaw(chosen));
                }
                else
                {
                    groupCard1 += 1;
                    group1.Join(b[chosen]);
                    groupArea1    = group1.Area();
                    taken[chosen] = 2;
                }
            }
            //
            // If one group gets too full, then remaining rectangle are
            // split between two groups in such way to balance cards of two groups.
            //
            if (groupCard0 + groupCard1 < card + 1)
            {
                for (i = 0; i < card; i++)
                {
                    if (taken[i] == 0)
                    {
                        if (groupCard0 >= groupCard1)
                        {
                            taken[i]    = 2;
                            groupCard1 += 1;
                        }
                        else
                        {
                            taken[i] = 1;
                            pg.setBranch(groupCard0++, b[i], branch.GetRaw(i));
                        }
                    }
                }
            }
            pg.n = groupCard0;
            n    = groupCard1;
            for (i = 0, j = 0; i < groupCard1; j++)
            {
                if (taken[j] == 2)
                {
                    setBranch(i++, b[j], branch.GetRaw(j));
                }
            }
            return(pg);
        }
Exemplo n.º 12
0
        RtreePage splitPage(IDatabase db, Rectangle r, IPersistent obj)
        {
            int i, j, seed0 = 0, seed1 = 0;
            long[] rectArea = new long[card + 1];
            long waste;
            long worstWaste = long.MinValue;
            //
            // As the seeds for the two groups, find two rectangles which waste
            // the most area if covered by a single rectangle.
            //
            rectArea[0] = r.Area();
            for (i = 0; i < card; i++)
            {
                rectArea[i + 1] = b[i].Area();
            }
            Rectangle bp = r;
            for (i = 0; i < card; i++)
            {
                for (j = i + 1; j <= card; j++)
                {
                    waste = Rectangle.JoinArea(bp, b[j - 1]) - rectArea[i] - rectArea[j];
                    if (waste > worstWaste)
                    {
                        worstWaste = waste;
                        seed0 = i;
                        seed1 = j;
                    }
                }
                bp = b[i];
            }
            byte[] taken = new byte[card];
            Rectangle group0, group1;
            long groupArea0, groupArea1;
            int groupCard0, groupCard1;
            RtreePage pg;

            taken[seed1 - 1] = 2;
            group1 = new Rectangle(b[seed1 - 1]);

            if (seed0 == 0)
            {
                group0 = new Rectangle(r);
                pg = new RtreePage(db, obj, r);
            }
            else
            {
                group0 = new Rectangle(b[seed0 - 1]);
                pg = new RtreePage(db, branch.GetRaw(seed0 - 1), group0);
                setBranch(seed0 - 1, r, obj);
            }
            groupCard0 = groupCard1 = 1;
            groupArea0 = rectArea[seed0];
            groupArea1 = rectArea[seed1];
            //
            // Split remaining rectangles between two groups.
            // The one chosen is the one with the greatest difference in area
            // expansion depending on which group - the rect most strongly
            // attracted to one group and repelled from the other.
            //
            while (groupCard0 + groupCard1 < card + 1
                && groupCard0 < card + 1 - minFill
                && groupCard1 < card + 1 - minFill)
            {
                int betterGroup = -1, chosen = -1;
                long biggestDiff = -1;
                for (i = 0; i < card; i++)
                {
                    if (taken[i] == 0)
                    {
                        long diff = (Rectangle.JoinArea(group0, b[i]) - groupArea0)
                            - (Rectangle.JoinArea(group1, b[i]) - groupArea1);
                        if (diff > biggestDiff || -diff > biggestDiff)
                        {
                            chosen = i;
                            if (diff < 0)
                            {
                                betterGroup = 0;
                                biggestDiff = -diff;
                            }
                            else
                            {
                                betterGroup = 1;
                                biggestDiff = diff;
                            }
                        }
                    }
                }
                Debug.Assert(chosen >= 0);
                if (betterGroup == 0)
                {
                    group0.Join(b[chosen]);
                    groupArea0 = group0.Area();
                    taken[chosen] = 1;
                    pg.setBranch(groupCard0++, b[chosen], branch.GetRaw(chosen));
                }
                else
                {
                    groupCard1 += 1;
                    group1.Join(b[chosen]);
                    groupArea1 = group1.Area();
                    taken[chosen] = 2;
                }
            }
            //
            // If one group gets too full, then remaining rectangle are
            // split between two groups in such way to balance cards of two groups.
            //
            if (groupCard0 + groupCard1 < card + 1)
            {
                for (i = 0; i < card; i++)
                {
                    if (taken[i] == 0)
                    {
                        if (groupCard0 >= groupCard1)
                        {
                            taken[i] = 2;
                            groupCard1 += 1;
                        }
                        else
                        {
                            taken[i] = 1;
                            pg.setBranch(groupCard0++, b[i], branch.GetRaw(i));
                        }
                    }
                }
            }
            pg.n = groupCard0;
            n = groupCard1;
            for (i = 0, j = 0; i < groupCard1; j++)
            {
                if (taken[j] == 2)
                {
                    setBranch(i++, b[j], branch.GetRaw(j));
                }
            }
            return pg;
        }