internal int BalanceLeftBranch(PageReference ref_Renamed)
{
if (balance < 0)
{
balance = 0;
return UNDERFLOW;
}
else if (balance == 0)
{
balance = 1;
return OK;
}
else
{
TtreePage right = this.right;
right.Load();
right.Modify();
if (right.balance >= 0)
{
// single RR turn
this.right = right.left;
right.left = this;
if (right.balance == 0)
{
this.balance = 1;
right.balance = -1;
ref_Renamed.pg = right;
return OK;
}
else
{
balance = 0;
right.balance = 0;
ref_Renamed.pg = right;
return UNDERFLOW;
}
}
else
{
// double RL turn
TtreePage left = right.left;
left.Load();
left.Modify();
right.left = left.right;
left.right = right;
this.right = left.left;
left.left = this;
balance = left.balance > 0 ? -1 : 0;
right.balance = left.balance < 0 ? 1 : 0;
left.balance = 0;
ref_Renamed.pg = left;
return UNDERFLOW;
}
}
}
/// <summary> Add new member to collection</summary>
/// <param name="obj">new member
/// </param>
/// <returns> <code>true</code> if object is successfully added in the index,
/// <code>false</code> if collection was declared as unique and there is already member with such value
/// of the key in the collection.
/// </returns>
public virtual bool Add(IPersistent obj)
{
TtreePage newRoot;
if (root == null)
{
newRoot = new TtreePage(obj);
}
else
{
TtreePage.PageReference ref_Renamed = new TtreePage.PageReference(root);
if (root.Insert(comparator, obj, unique, ref_Renamed) == TtreePage.NOT_UNIQUE)
{
return false;
}
newRoot = ref_Renamed.pg;
}
root = newRoot;
nMembers += 1;
Modify();
return true;
}
internal PageReference(TtreePage p)
{
pg = p;
}
internal int Remove(PersistentComparator comparator, IPersistent mbr, PageReference ref_Renamed)
{
Load();
TtreePage pg;
int n = nItems;
int diff = comparator.CompareMembers(mbr, LoadItem(0));
if (diff <= 0)
{
if (left != null)
{
Modify();
pg = ref_Renamed.pg;
ref_Renamed.pg = left;
int h = left.Remove(comparator, mbr, ref_Renamed);
left = ref_Renamed.pg;
ref_Renamed.pg = pg;
if (h == UNDERFLOW)
{
return BalanceLeftBranch(ref_Renamed);
}
else if (h == OK)
{
return OK;
}
}
}
diff = comparator.CompareMembers(mbr, LoadItem(n - 1));
if (diff <= 0)
{
for (int i = 0; i < n; i++)
{
if (item[i] == mbr)
{
if (n == 1)
{
if (right == null)
{
Deallocate();
ref_Renamed.pg = left;
return UNDERFLOW;
}
else if (left == null)
{
Deallocate();
ref_Renamed.pg = right;
return UNDERFLOW;
}
}
Modify();
if (n <= minItems)
{
if (left != null && balance <= 0)
{
TtreePage prev = left;
prev.Load();
while (prev.right != null)
{
prev = prev.right;
prev.Load();
}
Array.Copy(item, 0, item, 1, i);
//while (--i >= 0) {
// item[i+1] = item[i];
//}
item[0] = prev.item[prev.nItems - 1];
pg = ref_Renamed.pg;
ref_Renamed.pg = left;
int h = left.Remove(comparator, LoadItem(0), ref_Renamed);
left = ref_Renamed.pg;
ref_Renamed.pg = pg;
if (h == UNDERFLOW)
{
h = BalanceLeftBranch(ref_Renamed);
}
return h;
}
else if (right != null)
{
TtreePage next = right;
next.Load();
while (next.left != null)
{
next = next.left;
next.Load();
}
Array.Copy(item, i + 1, item, i, n - i - 1);
//while (++i < n) {
// item[i-1] = item[i];
//}
item[n - 1] = next.item[0];
pg = ref_Renamed.pg;
ref_Renamed.pg = right;
int h = right.Remove(comparator, LoadItem(n - 1), ref_Renamed);
right = ref_Renamed.pg;
ref_Renamed.pg = pg;
if (h == UNDERFLOW)
{
h = BalanceRightBranch(ref_Renamed);
}
return h;
}
}
Array.Copy(item, i + 1, item, i, n - i - 1);
//while (++i < n) {
// item[i-1] = item[i];
//}
item[n - 1] = null;
nItems -= 1;
return OK;
}
}
}
if (right != null)
{
Modify();
pg = ref_Renamed.pg;
ref_Renamed.pg = right;
int h = right.Remove(comparator, mbr, ref_Renamed);
right = ref_Renamed.pg;
ref_Renamed.pg = pg;
if (h == UNDERFLOW)
{
return BalanceRightBranch(ref_Renamed);
}
else
{
return h;
}
}
return NOT_FOUND;
}
internal int Insert(PersistentComparator comparator, IPersistent mbr, bool unique, PageReference ref_Renamed)
{
Load();
int n = nItems;
TtreePage pg;
int diff = comparator.CompareMembers(mbr, LoadItem(0));
if (diff <= 0)
{
if (unique && diff == 0)
{
return NOT_UNIQUE;
}
if ((this.left == null || diff == 0) && n != maxItems)
{
Modify();
//for (int i = n; i > 0; i--) item[i] = item[i-1];
Array.Copy(item, 0, item, 1, n);
item[0] = mbr;
nItems += 1;
return OK;
}
if (this.left == null)
{
Modify();
this.left = new TtreePage(mbr);
}
else
{
pg = ref_Renamed.pg;
ref_Renamed.pg = this.left;
int result = this.left.Insert(comparator, mbr, unique, ref_Renamed);
if (result == NOT_UNIQUE)
{
return NOT_UNIQUE;
}
Modify();
this.left = ref_Renamed.pg;
ref_Renamed.pg = pg;
if (result == OK)
return OK;
}
if (balance > 0)
{
balance = 0;
return OK;
}
else if (balance == 0)
{
balance = -1;
return OVERFLOW;
}
else
{
TtreePage left = this.left;
left.Load();
left.Modify();
if (left.balance < 0)
{
// single LL turn
this.left = left.right;
left.right = this;
balance = 0;
left.balance = 0;
ref_Renamed.pg = left;
}
else
{
// double LR turn
TtreePage right = left.right;
right.Load();
right.Modify();
left.right = right.left;
right.left = left;
this.left = right.right;
right.right = this;
balance = (right.balance < 0) ? 1 : 0;
left.balance = (right.balance > 0) ? -1 : 0;
right.balance = 0;
ref_Renamed.pg = right;
}
return OK;
}
}
diff = comparator.CompareMembers(mbr, LoadItem(n - 1));
if (diff >= 0)
{
if (unique && diff == 0)
{
return NOT_UNIQUE;
}
if ((this.right == null || diff == 0) && n != maxItems)
{
Modify();
item[n] = mbr;
nItems += 1;
return OK;
}
if (this.right == null)
{
Modify();
this.right = new TtreePage(mbr);
}
else
{
pg = ref_Renamed.pg;
ref_Renamed.pg = this.right;
int result = this.right.Insert(comparator, mbr, unique, ref_Renamed);
if (result == NOT_UNIQUE)
{
return NOT_UNIQUE;
}
Modify();
this.right = ref_Renamed.pg;
ref_Renamed.pg = pg;
if (result == OK)
return OK;
}
if (balance < 0)
{
balance = 0;
return OK;
}
else if (balance == 0)
{
balance = 1;
return OVERFLOW;
}
else
{
TtreePage right = this.right;
right.Load();
right.Modify();
if (right.balance > 0)
{
// single RR turn
this.right = right.left;
right.left = this;
balance = 0;
right.balance = 0;
ref_Renamed.pg = right;
}
else
{
// double RL turn
TtreePage left = right.left;
left.Load();
left.Modify();
right.left = left.right;
left.right = right;
this.right = left.left;
left.left = this;
balance = (left.balance > 0) ? -1 : 0;
right.balance = (left.balance < 0) ? 1 : 0;
left.balance = 0;
ref_Renamed.pg = left;
}
return OK;
}
}
int l = 1, r = n - 1;
while (l < r)
{
int i = (l + r) >> 1;
diff = comparator.CompareMembers(mbr, LoadItem(i));
if (diff > 0)
{
l = i + 1;
}
else
{
r = i;
if (diff == 0)
{
if (unique)
{
return NOT_UNIQUE;
}
break;
}
}
}
// Insert before item[r]
Modify();
if (n != maxItems)
{
Array.Copy(item, r, item, r + 1, n - r);
//for (int i = n; i > r; i--) item[i] = item[i-1];
item[r] = mbr;
nItems += 1;
return OK;
}
else
{
IPersistent reinsertItem;
if (balance >= 0)
{
reinsertItem = LoadItem(0);
Array.Copy(item, 1, item, 0, r - 1);
//for (int i = 1; i < r; i++) item[i-1] = item[i];
item[r - 1] = mbr;
}
else
{
reinsertItem = LoadItem(n - 1);
Array.Copy(item, r, item, r + 1, n - r - 1);
//for (int i = n-1; i > r; i--) item[i] = item[i-1];
item[r] = mbr;
}
return Insert(comparator, reinsertItem, unique, ref_Renamed);
}
}
/// <summary> Remove member from collection</summary>
/// <param name="obj">member to be removed
/// </param>
/// <exception cref="StorageError(StorageError.KEY_NOT_FOUND)">exception if there is no such key in the collection
/// </exception>
public virtual void Remove(IPersistent obj)
{
if (root == null)
{
throw new StorageError(StorageError.KEY_NOT_FOUND);
}
TtreePage.PageReference ref_Renamed = new TtreePage.PageReference(root);
if (root.Remove(comparator, obj, ref_Renamed) == TtreePage.NOT_FOUND)
{
throw new StorageError(StorageError.KEY_NOT_FOUND);
}
root = ref_Renamed.pg;
nMembers -= 1;
Modify();
}
/// <summary> Remove all objects from the collection</summary>
public virtual void Clear()
{
if (root != null)
{
root.Prune();
root = null;
nMembers = 0;
Modify();
}
}
