/*
* For work developed by the HSQL Development Group:
*
* Copyright (c) 2001-2010, 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.Row;
import org.hsqldb.RowAVLDisk;
import org.hsqldb.lib.IntLookup;
import org.hsqldb.persist.CachedObject;
import org.hsqldb.persist.PersistentStore;
import org.hsqldb.rowio.RowOutputInterface;
// fredt@users 20020221 - patch 513005 by sqlbob@users (RMP)
// fredt@users 20020920 - path 1.7.1 - refactoring to cut mamory footprint
// fredt@users 20021205 - path 1.7.2 - enhancements
// fredt@users 20021215 - doc 1.7.2 - javadoc comments
/**
* The parent for all AVL node implementations. Subclasses of Node vary
* in the way they hold
* references to other Nodes in the AVL tree, or to their Row data.<br>
*
* nNext links the Node objects belonging to different indexes for each
* table row. It is used solely by Row to locate the node belonging to a
* particular index.<br>
*
* New class derived from Hypersonic SQL code and enhanced in HSQLDB. <p>
*
* @author Thomas Mueller (Hypersonic SQL Group)
* @version 1.9.0
* @since Hypersonic SQL
*/
public class NodeAVL implements CachedObject {
static final int NO_POS = RowAVLDisk.NO_POS;
public int iBalance;
public NodeAVL nNext; // node of next index (nNext==null || nNext.iId=iId+1)
//
protected NodeAVL nLeft;
protected NodeAVL nRight;
protected NodeAVL nParent;
protected final Row row;
NodeAVL() {
row = null;
}
public NodeAVL(Row r) {
row = r;
}
public void delete() {
iBalance = 0;
nLeft = nRight = nParent = null;
}
NodeAVL getLeft(PersistentStore store) {
return nLeft;
}
NodeAVL setLeft(PersistentStore persistentStore, NodeAVL n) {
nLeft = n;
return this;
}
public int getBalance(PersistentStore store) {
return iBalance;
}
boolean isLeft(NodeAVL node) {
return nLeft == node;
}
boolean isRight(NodeAVL node) {
return nRight == node;
}
NodeAVL getRight(PersistentStore persistentStore) {
return nRight;
}
NodeAVL setRight(PersistentStore persistentStore, NodeAVL n) {
nRight = n;
return this;
}
NodeAVL getParent(PersistentStore store) {
return nParent;
}
boolean isRoot(PersistentStore store) {
return nParent == null;
}
NodeAVL setParent(PersistentStore persistentStore, NodeAVL n) {
nParent = n;
return this;
}
public NodeAVL setBalance(PersistentStore store, int b) {
iBalance = b;
return this;
}
boolean isFromLeft(PersistentStore store) {
if (nParent == null) {
return true;
}
return this == nParent.nLeft;
}
public NodeAVL child(PersistentStore store, boolean isleft) {
return isleft ? getLeft(store)
: getRight(store);
}
public NodeAVL set(PersistentStore store, boolean isLeft, NodeAVL n) {
if (isLeft) {
nLeft = n;
} else {
nRight = n;
}
if (n != null) {
n.nParent = this;
}
return this;
}
public void replace(PersistentStore store, Index index, NodeAVL n) {
if (nParent == null) {
if (n != null) {
n = n.setParent(store, null);
}
store.setAccessor(index, n);
} else {
nParent.set(store, isFromLeft(store), n);
}
}
boolean equals(NodeAVL n) {
return n == this;
}
public void setInMemory(boolean in) {}
public void write(RowOutputInterface out) {}
public void write(RowOutputInterface out, IntLookup lookup) {}
public int getPos() {
return 0;
}
protected Row getRow(PersistentStore store) {
return row;
}
protected Object[] getData(PersistentStore store) {
return row.getData();
}
public void updateAccessCount(int count) {}
public int getAccessCount() {
return 0;
}
public void setStorageSize(int size) {}
public int getStorageSize() {
return 0;
}
public void setPos(int pos) {}
public boolean hasChanged() {
return false;
}
public boolean isKeepInMemory() {
return false;
}
;
public boolean keepInMemory(boolean keep) {
return true;
}
public boolean isInMemory() {
return false;
}
public void restore() {}
public void destroy() {}
public int getRealSize(RowOutputInterface out) {
return 0;
}
public boolean isMemory() {
return true;
}
}