org.hsqldb.index.IndexAVLMemory Maven / Gradle / Ivy
Show all versions of hsqldb Show documentation
/*
* For work developed by the HSQL Development Group:
*
* Copyright (c) 2001-2019, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*
*
* For work originally developed by the Hypersonic SQL Group:
*
* Copyright (c) 1995-2000, The Hypersonic SQL Group.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the Hypersonic SQL Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE HYPERSONIC SQL GROUP,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This software consists of voluntary contributions made by many individuals
* on behalf of the Hypersonic SQL Group.
*/
package org.hsqldb.index;
import org.hsqldb.HsqlNameManager.HsqlName;
import org.hsqldb.TableBase;
import org.hsqldb.persist.PersistentStore;
import org.hsqldb.types.Type;
/**
* Implementation of an AVL for memory tables.
*
* New class derived from Hypersonic SQL code and enhanced in HSQLDB.
*
* @author Thomas Mueller (Hypersonic SQL Group)
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 2.5.0
* @since Hypersonic SQL
*/
public class IndexAVLMemory extends IndexAVL {
/**
* Constructor declaration
*
* @param name HsqlName of the index
* @param id persistnece id
* @param table table of the index
* @param columns array of column indexes
* @param descending boolean[] for result sets
* @param nullsLast boolean[] for result sets
* @param colTypes array of column types
* @param pk is index for a primary key
* @param unique is this a unique index
* @param constraint does this index belong to a constraint
* @param forward is this an auto-index for an FK that refers to a table
* defined after this table
*/
public IndexAVLMemory(HsqlName name, long id, TableBase table,
int[] columns, boolean[] descending,
boolean[] nullsLast, Type[] colTypes, boolean pk,
boolean unique, boolean constraint,
boolean forward) {
super(name, id, table, columns, descending, nullsLast, colTypes, pk,
unique, constraint, forward);
}
void delete(PersistentStore store, NodeAVL x) {
if (x == null) {
return;
}
NodeAVL n;
if (x.nLeft == null) {
n = x.nRight;
} else if (x.nRight == null) {
n = x.nLeft;
} else {
NodeAVL d = x;
x = x.nLeft;
while (true) {
NodeAVL temp = x.nRight;
if (temp == null) {
break;
}
x = temp;
}
// x will be replaced with n later
n = x.nLeft;
// swap d and x
int b = x.iBalance;
x.iBalance = d.iBalance;
d.iBalance = b;
// set x.parent
NodeAVL xp = x.nParent;
NodeAVL dp = d.nParent;
if (d.isRoot(store)) {
store.setAccessor(this, x);
}
x.nParent = dp;
if (dp != null) {
if (dp.nRight == d) {
dp.nRight = x;
} else {
dp.nLeft = x;
}
}
// relink d.parent, x.left, x.right
if (d == xp) {
d.nParent = x;
if (d.nLeft == x) {
x.nLeft = d;
NodeAVL dr = d.nRight;
x.nRight = dr;
} else {
x.nRight = d;
NodeAVL dl = d.nLeft;
x.nLeft = dl;
}
} else {
d.nParent = xp;
xp.nRight = d;
NodeAVL dl = d.nLeft;
NodeAVL dr = d.nRight;
x.nLeft = dl;
x.nRight = dr;
}
x.nRight.nParent = x;
x.nLeft.nParent = x;
// set d.left, d.right
d.nLeft = n;
if (n != null) {
n.nParent = d;
}
d.nRight = null;
x = d;
}
boolean isleft = x.isFromLeft(store);
x.replace(store, this, n);
n = x.nParent;
x.delete();
while (n != null) {
x = n;
int sign = isleft ? 1
: -1;
switch (x.iBalance * sign) {
case -1 :
x.iBalance = 0;
break;
case 0 :
x.iBalance = sign;
return;
case 1 :
NodeAVL r = x.child(store, !isleft);
int b = r.iBalance;
if (b * sign >= 0) {
x.replace(store, this, r);
NodeAVL child = r.child(store, isleft);
x.set(store, !isleft, child);
r.set(store, isleft, x);
if (b == 0) {
x.iBalance = sign;
r.iBalance = -sign;
return;
}
x.iBalance = 0;
r.iBalance = 0;
x = r;
} else {
NodeAVL l = r.child(store, isleft);
x.replace(store, this, l);
b = l.iBalance;
r.set(store, isleft, l.child(store, !isleft));
l.set(store, !isleft, r);
x.set(store, !isleft, l.child(store, isleft));
l.set(store, isleft, x);
x.iBalance = (b == sign) ? -sign
: 0;
r.iBalance = (b == -sign) ? sign
: 0;
l.iBalance = 0;
x = l;
}
}
isleft = x.isFromLeft(store);
n = x.nParent;
}
}
NodeAVL next(PersistentStore store, NodeAVL x) {
NodeAVL r = x.nRight;
if (r != null) {
x = r;
NodeAVL l = x.nLeft;
while (l != null) {
x = l;
l = x.nLeft;
}
return x;
}
NodeAVL ch = x;
x = x.nParent;
while (x != null && ch == x.nRight) {
ch = x;
x = x.nParent;
}
return x;
}
NodeAVL last(PersistentStore store, NodeAVL x) {
if (x == null) {
return null;
}
NodeAVL left = x.nLeft;
if (left != null) {
x = left;
NodeAVL right = x.nRight;
while (right != null) {
x = right;
right = x.nRight;
}
return x;
}
NodeAVL ch = x;
x = x.nParent;
while (x != null && ch.equals(x.nLeft)) {
ch = x;
x = x.nParent;
}
return x;
}
/**
* Balances part of the tree after an alteration to the index.
*/
void balance(PersistentStore store, NodeAVL x, boolean isleft) {
while (true) {
int sign = isleft ? 1
: -1;
switch (x.iBalance * sign) {
case 1 :
x.iBalance = 0;
return;
case 0 :
x.iBalance = -sign;
break;
case -1 :
NodeAVL l = isleft ? x.nLeft
: x.nRight;
if (l.iBalance == -sign) {
x.replace(store, this, l);
x.set(store, isleft, l.child(store, !isleft));
l.set(store, !isleft, x);
x.iBalance = 0;
l.iBalance = 0;
} else {
NodeAVL r = !isleft ? l.nLeft
: l.nRight;
x.replace(store, this, r);
l.set(store, !isleft, r.child(store, isleft));
r.set(store, isleft, l);
x.set(store, isleft, r.child(store, !isleft));
r.set(store, !isleft, x);
int rb = r.iBalance;
x.iBalance = (rb == -sign) ? sign
: 0;
l.iBalance = (rb == sign) ? -sign
: 0;
r.iBalance = 0;
}
return;
}
if (x.nParent == null) {
return;
}
isleft = x == x.nParent.nLeft;
x = x.nParent;
}
}
}