/*
* Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.db.sql;
import java.io.InputStream;
import java.sql.SQLException;
import java.sql.Types;
import java.util.ArrayList;
import com.caucho.db.table.Column;
import com.caucho.db.table.Table;
import com.caucho.db.table.Column.ColumnType;
import com.caucho.inject.Module;
import com.caucho.sql.SQLExceptionWrapper;
import com.caucho.util.L10N;
import com.caucho.util.QDate;
@Module
abstract public class Expr {
protected static final L10N L = new L10N(Expr.class);
public static final int UNKNOWN = -1;
public static final int FALSE = 0;
public static final int TRUE = 1;
final static long COST_INVALID = Long.MAX_VALUE / 1000;
final static long COST_NO_TABLE = Integer.MAX_VALUE;
final static long COST_SCAN = 1000000L;
final static long COST_UNIQUE = 10000L;
final static long COST_INDEX = 100L;
final static long COST_CONSTANT = 0L;
final static long INDEX_COST_INDEX = COST_SCAN * 100;
private static QDate _gmtDate = new QDate();
public Expr bind(Query query)
throws SQLException
{
return this;
}
/**
* Returns the expected result type of the expression.
*/
public Class<?> getType()
{
return Object.class;
}
/**
* Returns the java type code if known.
*/
public ColumnType getTypeCode()
{
return ColumnType.NONE;
}
/**
* Returns true if the expression returns a long.
*/
public boolean isLong()
{
Class<?> type = getType();
return (int.class.equals(type)
|| long.class.equals(type)
|| java.sql.Date.class.equals(type));
}
/**
* Returns true if the expression returns a double.
*/
public boolean isDouble()
{
Class<?> type = getType();
return isLong() || double.class.isAssignableFrom(type);
}
/**
* Returns true if the expression returns a boolean.
*/
public boolean isBoolean()
{
return boolean.class.equals(getType());
}
/**
* Returns true if the expression returns a binary stream.
*/
public boolean isBinaryStream(QueryContext context)
{
Class<?> type = getType();
return (InputStream.class.equals(type));
}
/**
* Returns true for a parameter expression.
*/
public boolean isParam()
{
return false;
}
/**
* Returns true if the expression can return a null value.
*/
public boolean isNullable()
{
return true;
}
/**
* Returns any column name.
*/
public String getName()
{
return "";
}
/**
* Returns the column type.
*/
public int getSQLType()
{
return Types.VARCHAR;
}
/**
* Returns the table.
*/
public Table getTable()
{
return null;
}
/**
* Splits the expr into and blocks.
*/
public void splitAnd(ArrayList<Expr> andProduct)
{
andProduct.add(this);
}
/**
* Returns the cost based on the given FromList.
*/
public long cost(ArrayList<FromItem> fromList)
{
return subCost(fromList);
}
/**
* Returns the cost based on the given FromList.
*/
public long subCost(ArrayList<FromItem> fromList)
{
return COST_INVALID;
}
/**
* Returns the cost bonus for an index.
*/
public long indexCost(ArrayList<FromItem> costItems)
{
return indexSubCost(costItems);
}
/**
* Returns the cost bonus for an index.
*/
public long indexSubCost(ArrayList<FromItem> costItems)
{
return COST_INVALID;
}
/**
* Returns an index expression if available.
*/
public RowIterateExpr getIndexExpr(FromItem fromItem)
{
return null;
}
/**
* Returns the order.
*/
public Order createOrder(int index)
{
if (int.class.equals(getType()))
return new IntOrder(index);
else if (isLong())
return new LongOrder(index);
else if (isDouble())
return new DoubleOrder(index);
else
return new StringOrder(index);
}
/**
* Returns true if result is null
*
* @param rows the current database tuple
*
* @return true if null
*/
public boolean isNull(QueryContext context)
throws SQLException
{
return false;
}
/**
* Returns true if the expression selects the row.
*
* @param rows the current database tuple
*
* @return the boolean value
*/
public boolean isSelect(QueryContext context)
throws SQLException
{
return evalBoolean(context) == TRUE;
}
/**
* Evaluates the expression as a boolean.
*
* @param rows the current database tuple
*
* @return the boolean value
*/
public int evalBoolean(QueryContext context)
throws SQLException
{
throw new UnsupportedOperationException(getClass().getName());
}
/**
* Evaluates the expression as a string.
*
* @param rows the current database tuple
*
* @return the string value
*/
public String evalString(QueryContext context)
throws SQLException
{
throw new UnsupportedOperationException(getClass().getName());
}
/**
* Updates the expression as a string
*/
public void updateString(QueryContext context, String value)
throws SQLException
{
throw new UnsupportedOperationException(getClass().getName());
}
/**
* Evaluates the expression as a long.
*
* @param rows the current database tuple
*
* @return the long value
*/
public long evalLong(QueryContext context)
throws SQLException
{
String strValue = evalString(context);
if (strValue == null)
return 0;
else
return Long.parseLong(strValue);
}
/**
* Updates the expression as a long
*/
public void updateLong(QueryContext context, long value)
throws SQLException
{
throw new UnsupportedOperationException(getClass().getName());
}
/**
* Evaluates the expression as a double.
*
* @param rows the current database tuple
*
* @return the double value
*/
public double evalDouble(QueryContext context)
throws SQLException
{
String strValue = evalString(context);
if (strValue == null)
return 0;
else
return Double.parseDouble(strValue);
}
/**
* Updates the expression as a double
*/
public void updateDouble(QueryContext context, double value)
throws SQLException
{
throw new UnsupportedOperationException(getClass().getName());
}
/**
* Evaluates the expression as a date.
*
* @param rows the current database tuple
*
* @return the double value
*/
public long evalDate(QueryContext context)
throws SQLException
{
String dateString = evalString(context);
try {
synchronized (_gmtDate) {
return _gmtDate.parseDate(dateString);
}
} catch (Exception e) {
throw new SQLExceptionWrapper(e);
}
}
/**
* Evaluates the expression, writing to the result stream.
*
* @param result the output result
*/
public void evalToResult(QueryContext context, SelectResult result)
throws SQLException
{
String s = evalString(context);
if (s == null) {
result.writeNull();
return;
}
result.writeString(s);
}
/**
* Evaluates the expression as a stream.
*
* @param rows the current database tuple
*
* @return the string value
*/
public InputStream evalStream(QueryContext context)
throws SQLException
{
throw new UnsupportedOperationException(getClass().getName());
}
/**
* Evaluates the expression as a stream.
*
* @param rows the current database tuple
*
* @return the string value
*/
public byte []evalBytes(QueryContext context)
throws SQLException
{
throw new UnsupportedOperationException(getClass().getName());
}
/**
* Evaluates the expression to a buffer
*
* @param result the result buffer
*
* @return the length of the result
*/
public int evalToBuffer(QueryContext context,
byte []buffer,
int offset)
throws SQLException
{
throw new UnsupportedOperationException(getClass().getName());
}
/**
* Evaluates the expression to a buffer
*
* @param result the result buffer
*
* @return the length of the result
*/
public int evalToBuffer(QueryContext context,
byte []buffer,
int off,
Column.ColumnType columnType)
throws SQLException
{
switch (columnType) {
case INT:
{
int v = (int) evalLong(context);
buffer[0] = (byte) (v >> 24);
buffer[1] = (byte) (v >> 16);
buffer[2] = (byte) (v >> 8);
buffer[3] = (byte) (v);
return 4;
}
case LONG:
case DATE:
{
long v = evalLong(context);
buffer[0] = (byte) (v >> 56);
buffer[1] = (byte) (v >> 48);
buffer[2] = (byte) (v >> 40);
buffer[3] = (byte) (v >> 32);
buffer[4] = (byte) (v >> 24);
buffer[5] = (byte) (v >> 16);
buffer[6] = (byte) (v >> 8);
buffer[7] = (byte) (v);
return 8;
}
case VARCHAR:
{
String v = evalString(context);
if (v == null)
return -1;
int length = v.length();
int offset = 0;
buffer[offset++] = (byte) length;
for (int i = 0; i < length; i++) {
int ch = v.charAt(i);
buffer[offset++] = (byte) (ch >> 8);
buffer[offset++] = (byte) (ch);
}
return offset;
}
case VARBINARY:
{
String v = evalString(context);
if (v == null)
return -1;
int length = v.length();
int offset = 1;
for (int i = 0; i < length; i++) {
int ch = v.charAt(i);
if (ch < 0x80)
buffer[offset++] = (byte) (ch & 0xff);
else if (ch < 0x800) {
buffer[offset++] = (byte) (0xc0 + ((ch >> 6) & 0x1f));
buffer[offset++] = (byte) (0x80 + (ch & 0x3f));
}
else {
buffer[offset++] = (byte) (0xe0 + ((ch >> 12) & 0x0f));
buffer[offset++] = (byte) (0x80 + ((ch >> 6) & 0x3f));
buffer[offset++] = (byte) (0x80 + (ch & 0x3f));
}
}
buffer[0] = (byte) (offset - 1);
return offset;
}
/*
case BINARY:
{
byte []bytes = evalBytes(context);
if (bytes != null) {
System.arraycopy(bytes, 0, buffer, off, bytes.length);
return bytes.length;
}
else
return 0;
}
*/
case BINARY:
{
return evalToBuffer(context, buffer, off);
}
default:
throw new UnsupportedOperationException(getClass().getName() + " unknown column: " + columnType);
}
}
/**
* Initializes aggregate functions during the group phase.
*
* @param context the current database tuple
*/
public void initGroup(QueryContext context)
throws SQLException
{
}
/**
* Evaluates aggregate functions during the group phase.
*
* @param context the current database tuple
*/
public void evalGroup(QueryContext context)
throws SQLException
{
}
public boolean evalEqual(QueryContext context, String evalString)
throws SQLException
{
throw new UnsupportedOperationException(getClass().getName());
}
public boolean evalEqual(QueryContext context, byte []data)
throws SQLException
{
throw new UnsupportedOperationException(getClass().getName());
}
}