public override void Clear()
{
if (root != null)
{
root.purge(height);
root = null;
}
height = 0;
n = 0;
updateCounter += 1;
Modify();
}
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();
}
}
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();
}
}
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();
}
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);
}
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));
}
}
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);
}
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);
}
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();
}
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();
}
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);
}
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;
}