/* 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
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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package org.hsqldb_voltpatches;
import java.io.IOException;
import org.hsqldb_voltpatches.index.NodeAVL;
import org.hsqldb_voltpatches.index.NodeAVLMemoryPointer;
import org.hsqldb_voltpatches.rowio.RowInputInterface;
import org.hsqldb_voltpatches.rowio.RowOutputInterface;
// fredt@users 20021205 - path 1.7.2 - enhancements
// fredt@users 20021215 - doc 1.7.2 - javadoc comments
/**
* Implementation of rows for tables with memory resident indexes and
* disk-based data, such as TEXT tables.
*
* @author Bob Preston (sqlbob@users dot sourceforge.net)
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 1.8.0
* @version 1.7.0
*/
public class RowAVLDiskData extends RowAVLDisk {
/**
* Constructor for new rows.
*/
public RowAVLDiskData(TableBase t, Object[] o) {
super(t, o);
hasDataChanged = true;
}
/**
* Constructor when read from the disk into the Cache. The link with
* the Nodes is made separetly.
*/
public RowAVLDiskData(TableBase t,
RowInputInterface in)
throws IOException {
tTable = t;
tableId = t.getId();
position = in.getPos();
storageSize = in.getSize();
rowData = in.readData(tTable.getColumnTypes());
hasDataChanged = false;
}
/**
* Used when data is read from the disk into the Cache the first time.
* New Nodes are created which are then indexed.
*/
void setNewNodes() {
int index = tTable.getIndexCount();
nPrimaryNode = new NodeAVLMemoryPointer(this);
NodeAVL n = nPrimaryNode;
for (int i = 1; i < index; i++) {
n.nNext = new NodeAVLMemoryPointer(this);
n = n.nNext;
}
}
public NodeAVL insertNode(int index) {
NodeAVL backnode = getNode(index - 1);
NodeAVL newnode = new NodeAVLMemoryPointer(this);
newnode.nNext = backnode.nNext;
backnode.nNext = newnode;
return newnode;
}
/**
* Used when data is re-read from the disk into the Cache. The Row is
* already indexed so it is linked with the Node in the primary index.
* the Nodes is made separetly.
*/
void setPrimaryNode(NodeAVL primary) {
nPrimaryNode = primary;
}
public int getRealSize(RowOutputInterface out) {
return out.getSize((RowAVLDisk) this);
}
/**
* Writes the data to disk. Unlike CachedRow, hasChanged is never set
* to true when changes are made to the Nodes. (Nodes are in-memory).
* The only time this is used is when a new Row is added to the Caches.
*/
public void write(RowOutputInterface out) {
out.writeSize(storageSize);
out.writeData(rowData, tTable.colTypes);
out.writeEnd();
hasDataChanged = false;
}
public boolean hasChanged() {
return hasDataChanged;
}
/**
* Sets the file position for the row and registers the row with
* the table.
*
* @param pos position in data file
*/
public void setPos(int pos) {
position = pos;
NodeAVL n = nPrimaryNode;
while (n != null) {
((NodeAVLMemoryPointer) n).iData = position;
n = n.nNext;
}
}
/**
* With the current implementation of TEXT table updates and inserts,
* the lifetime scope of this method extends until redefinition of table
* data source or shutdown.
*
* @param obj the reference object with which to compare.
* @return <code>true</code> if this object is the same as the obj argument;
* <code>false</code> otherwise.
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof RowAVLDiskData) {
return ((RowAVLDiskData) obj).position == position
&& ((RowAVLDiskData) obj).tTable == tTable;
}
return false;
}
}