/* 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.
*
*
* For work added by the HSQL Development Group:
*
* Copyright (c) 2001-2009, 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.
*/
package org.hsqldb;
import java.io.IOException;
import org.hsqldb.index.NodeAVLDisk;
import org.hsqldb.index.NodeAVL;
import org.hsqldb.lib.IntLookup;
import org.hsqldb.rowio.RowInputInterface;
import org.hsqldb.rowio.RowOutputInterface;
// fredt@users 20020221 - patch 513005 by sqlbob@users (RMP)
// fredt@users 20020920 - patch 1.7.1 - refactoring to cut memory footprint
// fredt@users 20021205 - patch 1.7.2 - enhancements
// fredt@users 20021215 - doc 1.7.2 - javadoc comments
// boucherb@users - 20040411 - doc 1.7.2 - javadoc comments
/**
* In-memory representation of a disk-based database row object with methods
* for serialization and de-serialization. <p>
*
* A CachedRow is normally part of a circular double linked list which
* contains all of the Rows currently in the Cache for the database. It is
* unlinked from this list when it is freed from the Cache to make way for
* other rows.
*
* New class from the Hypersonic Original
*
* @author Thomas Mueller (Hypersonic SQL Group)
* @version 1.8.0
* @since Hypersonic SQL
*/
public class RowAVLDisk extends RowAVL {
public static final int NO_POS = -1;
//
protected TableBase tTable;
int storageSize;
int keepCount;
boolean isInMemory;
int usageCount;
/**
* Flag indicating unwritten data.
*/
protected boolean hasDataChanged;
/**
* Flag indicating Node data has changed.
*/
boolean hasNodesChanged;
/**
* Default constructor used only in subclasses.
*/
RowAVLDisk() {}
/**
* Constructor for new Rows. Variable hasDataChanged is set to true in
* order to indicate the data needs saving.
*
* @param t table
* @param o row data
*/
public RowAVLDisk(TableBase t, Object[] o) {
tTable = t;
tableId = tTable.getId();
setNewNodes();
rowData = o;
hasDataChanged = hasNodesChanged = true;
}
/**
* Constructor when read from the disk into the Cache.
*
* @param t table
* @param in data source
* @throws IOException
*/
public RowAVLDisk(TableBase t,
RowInputInterface in) throws IOException {
tTable = t;
position = in.getPos();
storageSize = in.getSize();
int indexcount = t.getIndexCount();
nPrimaryNode = new NodeAVLDisk(this, in, 0);
NodeAVL n = nPrimaryNode;
for (int i = 1; i < indexcount; i++) {
n.nNext = new NodeAVLDisk(this, in, i);
n = n.nNext;
}
rowData = in.readData(tTable.getColumnTypes());
}
public NodeAVL insertNode(int index) {
return null;
}
private void readRowInfo(RowInputInterface in)
throws IOException {
// for use when additional transaction info is attached to rows
}
/**
* Sets flag for Node data change.
*/
public synchronized void setNodesChanged() {
hasNodesChanged = true;
}
public void updateAccessCount(int count) {
usageCount = count;
}
public int getAccessCount() {
return usageCount;
}
public int getStorageSize() {
return storageSize;
}
public boolean isMemory() {
return false;
}
/**
* Sets the file position for the row
*
* @param pos position in data file
*/
public void setPos(int pos) {
position = pos;
NodeAVL n = nPrimaryNode;
while (n != null) {
((NodeAVLDisk) n).iData = position;
n = n.nNext;
}
}
/**
* Sets flag for row data change.
*/
public synchronized void setChanged() {
hasDataChanged = true;
}
/**
* Returns true if Node data has changed.
*
* @return boolean
*/
public synchronized boolean hasChanged() {
return hasNodesChanged || hasDataChanged;
}
/**
* Returns the Table to which this Row belongs.
*
* @return Table
*/
public TableBase getTable() {
return tTable;
}
public void setStorageSize(int size) {
storageSize = size;
}
/**
* Returns true if any of the Nodes for this row is a root node.
* Used only in Cache.java to avoid removing the row from the cache.
*
* @return boolean
*/
public synchronized boolean isKeepInMemory() {
return keepCount > 0;
}
public void destroy() {
super.destroy();
tTable = null;
}
public synchronized boolean keepInMemory(boolean keep) {
if (!isInMemory) {
return false;
}
if (keep) {
keepCount++;
} else {
keepCount--;
if (keepCount < 0) {
throw Error.runtimeError(ErrorCode.U_S0500,
"CachedRow keep count");
}
}
return true;
}
public synchronized boolean isInMemory() {
return isInMemory;
}
public synchronized void setInMemory(boolean in) {
isInMemory = in;
if (in) {
return;
}
NodeAVL n = nPrimaryNode;
while (n != null) {
n.setInMemory(in);
n = n.nNext;
}
RowAction action = rowAction;
if (action != null) {
action.memoryRow = null;
}
}
/**
* used in CachedDataRow
*/
void setNewNodes() {
int indexcount = tTable.getIndexCount();
nPrimaryNode = new NodeAVLDisk(this, 0);
NodeAVL n = nPrimaryNode;
for (int i = 1; i < indexcount; i++) {
n.nNext = new NodeAVLDisk(this, i);
n = n.nNext;
}
}
public int getRealSize(RowOutputInterface out) {
int size = out.getSize((RowAVLDisk) this)
+ tTable.getIndexCount() * NodeAVLDisk.SIZE_IN_BYTE;
return size;
}
/**
* Used exclusively by Cache to save the row to disk. New implementation in
* 1.7.2 writes out only the Node data if the table row data has not
* changed. This situation accounts for the majority of invocations as for
* each row deleted or inserted, the Nodes for several other rows will
* change.
*/
public void write(RowOutputInterface out) {
try {
writeNodes(out);
if (hasDataChanged) {
out.writeData(rowData, tTable.colTypes);
out.writeEnd();
hasDataChanged = false;
}
} catch (IOException e) {}
}
private void writeRowInfo(RowOutputInterface out) {
// for use when additional transaction info is attached to rows
}
public void write(RowOutputInterface out, IntLookup lookup) {
out.writeSize(storageSize);
NodeAVL rownode = nPrimaryNode;
while (rownode != null) {
((NodeAVLDisk) rownode).writeTranslate(out, lookup);
rownode = rownode.nNext;
}
out.writeData(getData(), tTable.colTypes);
out.writeEnd();
}
/**
* Writes the Nodes, immediately after the row size.
*
* @param out
*
* @throws IOException
*/
private void writeNodes(RowOutputInterface out) throws IOException {
out.writeSize(storageSize);
NodeAVL n = nPrimaryNode;
while (n != null) {
n.write(out);
n = n.nNext;
}
hasNodesChanged = false;
}
/**
* Lifetime scope of this method depends on the operations performed on
* any cached tables since this row or the parameter were constructed.
* If only deletes or only inserts have been performed, this method
* remains valid. Otherwise it can return invalid results.
*
* @param obj row to compare
* @return boolean
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof RowAVLDisk) {
return ((RowAVLDisk) obj).position == position;
}
return false;
}
/**
* Hash code is valid only until a modification to the cache
*
* @return file position of row
*/
public int hashCode() {
return position;
}
}