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 *
 * 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,
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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package org.hsqldb.persist;

import java.io.IOException;

import org.hsqldb.HsqlException;
import org.hsqldb.Row;
import org.hsqldb.RowAVL;
import org.hsqldb.RowAVLDisk;
import org.hsqldb.RowAction;
import org.hsqldb.Session;
import org.hsqldb.TableBase;
import org.hsqldb.error.Error;
import org.hsqldb.error.ErrorCode;
import org.hsqldb.index.Index;
import org.hsqldb.index.IndexAVL;
import org.hsqldb.index.NodeAVL;
import org.hsqldb.index.NodeAVLDisk;
import org.hsqldb.lib.ArrayUtil;
import org.hsqldb.navigator.RowIterator;
import org.hsqldb.rowio.RowInputInterface;

/*
 * Implementation of PersistentStore for result sets.
 *
 * @author Fred Toussi (fredt@users dot sourceforge.net)
 * @version 2.5.1
 * @since 1.9.0
 */
public class RowStoreAVLHybrid extends RowStoreAVL {

    DataFileCache     cache;
    private final int maxMemoryRowCount;
    private boolean   useDisk;
    boolean           isCached;
    long              rowIdSequence = 0;

    public RowStoreAVLHybrid(Session session, TableBase table,
                             boolean diskBased) {

        this.table             = table;
        this.maxMemoryRowCount = session.getResultMemoryRowCount();
        this.useDisk           = diskBased;

        if (maxMemoryRowCount == 0) {
            this.useDisk = false;
        }

        if (table.getTableType() == TableBase.RESULT_TABLE) {
            setTimestamp(session.getActionTimestamp());
        }

// test code to force use of cache
/*
        if (diskBased) {
            this.maxMemoryRowCount = 0;
            this.useDisk           = true;
        }
*/

//
        resetAccessorKeys(session, table.getIndexList());

        nullsList = new boolean[table.getColumnCount()];
    }

    public boolean isMemory() {
        return !isCached;
    }

    public void setMemory(boolean mode) {
        useDisk = !mode;
    }

    public CachedObject get(long i, boolean keep) {

        try {
            if (isCached) {
                return cache.get(i, this, keep);
            } else {
                throw Error.runtimeError(ErrorCode.U_S0500,
                                         "RowStoreAVLHybrid");
            }
        } catch (HsqlException e) {
            return null;
        }
    }

    public CachedObject get(CachedObject object, boolean keep) {

        try {
            if (object.isMemory()) {
                return object;
            }

            if (isCached) {
                return cache.get(object, this, keep);
            } else {
                return object;
            }
        } catch (HsqlException e) {
            return null;
        }
    }

    public void add(Session session, CachedObject object, boolean tx) {

        if (isCached) {
            int size = object.getRealSize(cache.rowOut);

            size += indexList.length * NodeAVLDisk.SIZE_IN_BYTE;
            size = cache.rowOut.getStorageSize(size);

            object.setStorageSize(size);

            long pos = tableSpace.getFilePosition(size);

            object.setPos(pos);
            cache.add(object, false);
        }

        Object[] data = ((Row) object).getData();

        for (int i = 0; i < nullsList.length; i++) {
            if (data[i] == null) {
                nullsList[i] = true;
            }
        }
    }

    public CachedObject get(RowInputInterface in) {

        try {
            if (isCached) {
                return new RowAVLDisk(this, in);
            }
        } catch (HsqlException e) {
            return null;
        } catch (IOException e1) {
            return null;
        }

        return null;
    }

    public CachedObject getNewCachedObject(Session session, Object object,
                                           boolean tx) {

        if (!isCached) {
            if (useDisk && elementCount.get() >= maxMemoryRowCount) {
                changeToDiskTable(session);
            }
        }

        Row row;

        if (isCached) {
            row = new RowAVLDisk(table, (Object[]) object, this);
        } else {
            long id = rowIdSequence++;

            row = new RowAVL(table, (Object[]) object, id, this);
        }

        add(session, row, tx);

        return row;
    }

    public void indexRow(Session session, Row row) {

        try {
            row = (Row) get(row, true);

            super.indexRow(session, row);
        } finally {
            row.keepInMemory(false);
        }
    }

    public void removeAll() {

        if (!isCached) {
            destroyIndexes();
        }

        elementCount.set(0);
        ArrayUtil.fillArray(accessorList, null);

        for (int i = 0; i < nullsList.length; i++) {
            nullsList[i] = false;
        }
    }

    public void remove(CachedObject object) {

        if (object.isMemory()) {
            return;
        }

        if (isCached) {
            cache.remove(object);
        }
    }

    public void commitPersistence(CachedObject row) {}

    public void postCommitAction(Session session, RowAction rowAction) {}

    public void commitRow(Session session, Row row, int changeAction,
                          int txModel) {

        switch (changeAction) {

            case RowAction.ACTION_DELETE :
                remove(row);
                break;

            case RowAction.ACTION_INSERT :
                break;

            case RowAction.ACTION_INSERT_DELETE :

                // INSERT + DELEETE
                remove(row);
                break;

            case RowAction.ACTION_DELETE_FINAL :
                throw Error.runtimeError(ErrorCode.U_S0500, "RowStore");
        }
    }

    public void rollbackRow(Session session, Row row, int changeAction,
                            int txModel) {

        switch (changeAction) {

            case RowAction.ACTION_DELETE :
                row = (Row) get(row, true);

                ((RowAVL) row).setNewNodes(this);
                row.keepInMemory(false);
                indexRow(session, row);
                break;

            case RowAction.ACTION_INSERT :
                delete(session, row);
                remove(row);
                break;

            case RowAction.ACTION_INSERT_DELETE :

                // INSERT + DELEETE
                remove(row);
                break;
        }
    }

    //
    public DataFileCache getCache() {
        return cache;
    }

    public void setCache(DataFileCache cache) {
        throw Error.runtimeError(ErrorCode.U_S0500, "RowStoreAVLHybrid");
    }

    public void release() {

        if (isCached) {
            cache.adjustStoreCount(-1);

            cache    = null;
            isCached = false;
        } else {
            destroyIndexes();
        }

        elementCount.set(0);
        ArrayUtil.fillArray(accessorList, null);
    }

    public CachedObject getAccessor(Index key) {

        int     position = key.getPosition();
        NodeAVL node     = (NodeAVL) accessorList[position];

        if (node == null) {
            return null;
        }

        RowAVL oldRow = node.getRow(this);
        RowAVL row    = (RowAVL) get(oldRow, false);

        node                            = row.getNode(key.getPosition());
        accessorList[key.getPosition()] = node;

        return node;
    }

    public synchronized void resetAccessorKeys(Session session, Index[] keys) {

        if (indexList.length == 0 || accessorList[0] == null) {
            indexList    = keys;
            accessorList = new CachedObject[indexList.length];

            return;
        }

        if (isCached) {
            throw Error.runtimeError(ErrorCode.U_S0500, "RowStoreAVLHybrid");
        }

        super.resetAccessorKeys(session, keys);
    }

    public boolean hasNull(int pos) {
        return nullsList[pos];
    }

    public final void changeToDiskTable(Session session) {

        cache =
            session.sessionData.persistentStoreCollection
                .getSessionDataCache();

        if (cache == null) {
            useDisk = false;

            return;
        }

        tableSpace =
            cache.spaceManager.getTableSpace(DataSpaceManager.tableIdDefault);
        isCached = true;

        cache.adjustStoreCount(1);

        if (elementCount.get() == 0) {
            return;
        }

        IndexAVL    idx      = (IndexAVL) indexList[0];
        NodeAVL     root     = (NodeAVL) accessorList[0];
        RowIterator iterator = table.rowIterator(this);

        ArrayUtil.fillArray(accessorList, null);
        ArrayUtil.fillArray(nullsList, false);
        elementCount.set(0);

        while (iterator.next()) {
            Row row = iterator.getCurrentRow();
            Row newRow = (Row) getNewCachedObject(session, row.getData(),
                                                  false);

            indexRow(session, newRow);
        }

        idx.unlinkNodes(this, root);
    }
}
