/*
 * 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
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 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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 * 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;

import java.io.IOException;

import org.hsqldb.error.Error;
import org.hsqldb.error.ErrorCode;
import org.hsqldb.index.NodeAVL;
import org.hsqldb.index.NodeAVLDisk;
import org.hsqldb.lib.LongLookup;
import org.hsqldb.persist.PersistentStore;
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
// campbell-burnet@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. 

 New class derived from Hypersonic SQL code and enhanced in HSQLDB. 

Author:
Fred Toussi (fredt@users dot sourceforge dot net), Thomas Mueller (Hypersonic SQL Group)
Version:
2.3.5
Since:
Hypersonic SQL/**
 *  In-memory representation of a disk-based database row object with  methods
 *  for serialization and de-serialization. <p>
 *
 *  New class derived from Hypersonic SQL code and enhanced in HSQLDB. <p>
 *
 * @author Fred Toussi (fredt@users dot sourceforge dot net)
 * @author Thomas Mueller (Hypersonic SQL Group)
 * @version 2.3.5
 * @since Hypersonic SQL
 */
public class RowAVLDisk extends RowAVL {

    public static final int NO_POS = -1;

    //
    int              storageSize;
    int              keepCount;
    volatile boolean isInMemory;
    int              accessCount;
    boolean          isNew;

    
 Flag indicating unwritten data.
/**
     *  Flag indicating unwritten data.
     */
    boolean hasDataChanged;

    
 Flag indicating Node data has changed.
/**
     *  Flag indicating Node data has changed.
     */
    private boolean hasNodesChanged;

    
 Constructor for new Rows.  Variable hasDataChanged is set to true in
 order to indicate the data needs saving.
Params:
t – table
o – row data/**
     *  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, PersistentStore store) {

        super(t, o);

        setNewNodes(store);

        hasDataChanged = hasNodesChanged = isNew = true;
    }

    
 Constructor when read from the disk into the Cache.
Params:
t – table
in – data source
Throws:
IOException – /**
     *  Constructor when read from the disk into the Cache.
     *
     * @param t table
     * @param in data source
     * @throws IOException
     */
    public RowAVLDisk(PersistentStore store,
                      RowInputInterface in) throws IOException {

        super(store.getTable(), (Object[]) null);

        position    = in.getFilePosition();
        storageSize = in.getSize();

        int indexcount = store.getAccessorKeys().length;

        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(table.getColumnTypes());
    }

    RowAVLDisk(TableBase t) {
        super(t, (Object[]) null);
    }

    public NodeAVL insertNode(int index) {
        return null;
    }

    private void readRowInfo(RowInputInterface in) {

        // for use when additional transaction info is attached to rows
    }

    
Sets flag for Node data change.
/**
     * Sets flag for Node data change.
     */
    public synchronized void setNodesChanged() {
        hasNodesChanged = true;
    }

    public void updateAccessCount(int count) {
        accessCount = count;
    }

    public int getAccessCount() {
        return accessCount;
    }

    public int getStorageSize() {
        return storageSize;
    }

    public boolean isMemory() {
        return false;
    }

    
Sets the file position for the row
Params:
pos – position in data file/**
     * Sets the file position for the row
     *
     * @param pos position in data file
     */
    public void setPos(long pos) {
        position = pos;
    }

    public boolean isNew() {
        return isNew;
    }

    
Returns true if Node data has changed.
Returns:
boolean/**
     * Returns true if Node data has changed.
     *
     * @return boolean
     */
    public synchronized boolean hasChanged() {
        return hasNodesChanged || hasDataChanged;
    }

    public synchronized void setChanged(boolean flag) {

        hasNodesChanged = flag;
        hasDataChanged  = flag;
        isNew           = flag;
    }

    
Returns the Table to which this Row belongs.
Returns:
Table/**
     * Returns the Table to which this Row belongs.
     *
     * @return Table
     */
    public TableBase getTable() {
        return table;
    }

    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.
Returns:
boolean/**
     * 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;
    }

    
No action as references don't need to be removed
/**
     * No action as references don't need to be removed
     */
    public void delete(PersistentStore store) {}

    public void destroy() {}

    public synchronized boolean keepInMemory(boolean keep) {

        if (!isInMemory) {
            return false;
        }

        if (keep) {
            keepCount++;
        } else {
            keepCount--;

            if (keepCount < 0) {
                throw Error.runtimeError(ErrorCode.U_S0500,
                                         "RowAVLDisk - keep count");
            }
        }

        return true;
    }

    public synchronized boolean isInMemory() {
        return isInMemory;
    }

    public synchronized void setInMemory(boolean in) {
        isInMemory = in;
    }

    public void setNewNodes(PersistentStore store) {

        int indexcount = store.getAccessorKeys().length;

        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) {
        return out.getSize(this);
    }

    
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.
/**
     * 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) {

        writeNodes(out);

        if (hasDataChanged) {
            out.writeData(this, table.colTypes);
            out.writeEnd();
        }
    }

    public void write(RowOutputInterface out, LongLookup lookup) {

        out.writeSize(storageSize);

        NodeAVL rownode = nPrimaryNode;

        while (rownode != null) {
            rownode.write(out, lookup);

            rownode = rownode.nNext;
        }

        out.writeData(this, table.colTypes);
        out.writeEnd();
    }

    
 Writes the Nodes, immediately after the row size.
Params:
out – 
Throws:
IOException – /**
     *  Writes the Nodes, immediately after the row size.
     *
     * @param out
     *
     * @throws IOException
     */
    void writeNodes(RowOutputInterface out) {

        out.writeSize(storageSize);

        NodeAVL n = nPrimaryNode;

        while (n != null) {
            n.write(out);

            n = n.nNext;
        }
    }
}