Quadcap Embeddable Database

com/quadcap/sql/InsertRow.java

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package com.quadcap.sql;

/* Copyright 1999 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
 * provided with the distribution.
 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

import java.io.BufferedOutputStream;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.OutputStream;

import java.sql.SQLException;

import com.quadcap.sql.io.ObjectInputStream;
import com.quadcap.sql.io.ObjectOutputStream;
import com.quadcap.sql.io.Extern;

import com.quadcap.sql.file.BlockAccess;
import com.quadcap.sql.file.BlockFile;
import com.quadcap.sql.file.ByteArrayRandomAccess;
import com.quadcap.sql.file.Datafile;
import com.quadcap.sql.file.Log;
import com.quadcap.sql.file.PageManager;
import com.quadcap.sql.file.SubPageManager;

import com.quadcap.sql.types.Value;
import com.quadcap.sql.types.ValueBlob;
 
import com.quadcap.util.Debug;
import com.quadcap.util.Util;

/**
 * Log step to insert a row into a table.
 *
 * @author Stan Bailes
 */
public class InsertRow extends LogStep implements Externalizable {

    transient Table                     table;
    transient Row                       row                     = null;

    byte[]                              rowBytes;
    String                              tableName               = null;
    long                                rowId                   = 0;

    public InsertRow() {}
    
    public InsertRow(Session session, Table table, Row row) {
        super(session);
        this.table = table;
        this.row = row;
        this.tableName = table.getName();
    }

    public long getRowId() { return rowId; }

    Table getTable(Database db) throws IOException {
        if (table == null) {
            table = (Table)db.getRelation(tableName);
            if (table == null) {
                throw new IOException("Table not found: " + tableName);
            }
        }
        return table;
    }

    /**
     * Instantiate the row from the serialized byte array (if necessary)
     */
    final void getRow(Datafile db) throws IOException, SQLException {
        if (row == null) {
            LazyRow lrow = new LazyRow(table.getColumnCount());
            lrow.reset(rowBytes, db);
            row = lrow;
        }
    }

    public void redo(Session session) throws IOException, SQLException {
        Database db = session.getDatabase();
        BlockFile file = db.getFile();
        if (session.getConnection().inRecovery()) {
            Log log = session.getLog();
            getTable(db);

            // The row may contain blobs which have been mapped.
            if (table.hasBlobs()) {
                boolean anyChanged = false;
                getRow(db);
                for (int i = 1; i <= row.size(); i++) {
                    Value v = row.item(i);
                    if (v instanceof ValueBlob) {
                        ValueBlob vb = (ValueBlob)v;
                        long blk = vb.getPermBlock();
                        long blk2 = log.getRowMap(blk);
                        if (blk != blk2) {
                            vb.setPermBlock(blk2);
                            anyChanged = true;
                        }
                    }
                }
                if (anyChanged) {
                    row.set(1, row.item(1));
                    this.rowBytes = LazyRow.writeRow(session, table, row);
                }
            }
            long oldRowId = rowId;
            rowId = file.putBytes(rowBytes);
            if (oldRowId != 0) log.putRowMap(oldRowId, rowId);
        }
        session.incrUpdateCount();
    }

    public void undo(Session session) throws IOException, SQLException {
        Database db = session.getDatabase();
        Log log = session.getLog();
        BlockFile file = db.getFile();
        getTable(db);

        long actualRowId = log.getRowMap(rowId);
        log.removeRowMap(rowId);
        if (actualRowId != 0) db.removeRow(actualRowId);
        
        session.decrUpdateCount();
    }

    /**
     * Serialize the row to a byte array and allocate a page for it.
     */
    public void prepare(Session session) throws IOException, SQLException {
        Database db = session.getDatabase();
        if (db.inMemory()) {
            this.rowId = db.putRow(session, db.getFile(), getTable(db), row);
        } else {
            BlockFile file = db.getFile();
            this.rowBytes = LazyRow.writeRow(session, table, row);
            this.rowId = file.putBytes(rowBytes);
        }
    }
    
    public void readExternal(ObjectInput in)
        throws IOException, ClassNotFoundException
    {
        super.readExternal(in);
        rowId = in.readLong();
        tableName = (String)in.readObject();
        int size = in.readInt();
        this.rowBytes = new byte[size];
        in.read(rowBytes);
    }
    
    public void writeExternal(ObjectOutput out) throws IOException {
        super.writeExternal(out);
        out.writeLong(rowId);
        out.writeObject(tableName);
        out.writeInt(rowBytes.length);
        out.write(rowBytes);
    }

    //#ifdef DEBUG
    public String toString() {
        StringBuffer sb = new StringBuffer(super.toString());
        sb.append(" InsertRow(");
        sb.append(tableName);
        sb.append(',');
        sb.append(SubPageManager.toString(rowId));
        if (!Trace.bit(3)) {
            sb.append(',');
            sb.append(Util.hexBytes(rowBytes));
        }
        sb.append(')');
        return sb.toString();
    }
    //#endif

    static Extern extern;
    public void setExtern(Extern extern) { InsertRow.extern = extern; }
    public Extern getExtern() { return extern; }
}