/*
* 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.sql.SQLException;
import java.util.ArrayList;
import com.caucho.util.CharBuffer;
final class AndExpr extends Expr {
private ArrayList<Expr> _exprList = new ArrayList<Expr>();
private Expr []_exprs;
AndExpr()
{
}
void add(Expr expr)
{
_exprList.add(expr);
}
Expr getSingleExpr()
{
if (_exprList.size() == 0)
return null;
else if (_exprList.size() == 1)
return _exprList.get(0);
else
return this;
}
public Expr bind(Query query)
throws SQLException
{
_exprs = new Expr[_exprList.size()];
for (int i = 0; i < _exprs.length; i++) {
Expr expr = _exprList.get(i);
expr = expr.bind(query);
if (! expr.getType().equals(boolean.class))
throw new SQLException(L.l("AND requires boolean operands at {0}",
expr));
_exprList.set(i, expr);
_exprs[i] = expr;
}
Expr tailExpr = _exprs[_exprs.length - 1];
for (int i = _exprs.length - 2; i >= 0; i--) {
tailExpr = new BinaryAndExpr(_exprs[i], tailExpr);
}
return tailExpr;
}
/**
* Returns the type of the expression.
*/
@Override
public Class<?> getType()
{
return boolean.class;
}
/**
* Returns the cost based on the given FromList.
*/
public long subCost(ArrayList<FromItem> fromList)
{
long cost = 0;
for (int i = 0; i < _exprList.size(); i++) {
cost += _exprList.get(i).subCost(fromList);
}
return cost;
}
/**
* Splits the expr into and blocks.
*/
public void splitAnd(ArrayList<Expr> andProduct)
{
for (int i = 0; i < _exprList.size(); i++) {
_exprList.get(i).splitAnd(andProduct);
}
}
/**
* Returns true for a null expression
*/
public boolean isNull(QueryContext context)
throws SQLException
{
Expr []exprs = _exprs;
int length = exprs.length;
boolean isNull = false;
for (int i = 0; i < length; i++) {
int value = exprs[i].evalBoolean(context);
if (value == FALSE)
return false;
else if (value != TRUE)
isNull = true;
}
return isNull;
}
/**
* Evaluates the expression as a boolean.
*/
public int evalBoolean(QueryContext context)
throws SQLException
{
Expr []exprs = _exprs;
int length = exprs.length;
int value = TRUE;
for (int i = 0; i < length; i++) {
int subValue = exprs[i].evalBoolean(context);
if (subValue == FALSE)
return FALSE;
else if (subValue == UNKNOWN)
value = UNKNOWN;
}
return value;
}
/**
* Evaluates the expression as a boolean.
*/
@Override
public final boolean isSelect(final QueryContext context)
throws SQLException
{
final Expr []exprs = _exprs;
final int length = exprs.length;
for (int i = 0; i < length; i++) {
if (! exprs[i].isSelect(context))
return false;
}
return true;
}
public String evalString(QueryContext context)
throws SQLException
{
switch (evalBoolean(context)) {
case TRUE:
return "1";
case FALSE:
return "0";
default:
return null;
}
}
public String toString()
{
CharBuffer cb = CharBuffer.allocate();
cb.append("(");
for (int i = 0; i < _exprList.size(); i++) {
if (i != 0)
cb.append(" AND ");
cb.append(_exprList.get(i));
}
cb.append(")");
return cb.close();
}
}