/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hp.hpl.jena.sdb.layout2.expr;
import org.slf4j.LoggerFactory;
import com.hp.hpl.jena.sparql.core.Var;
import com.hp.hpl.jena.sparql.engine.binding.Binding;
import com.hp.hpl.jena.sparql.expr.Expr;
import com.hp.hpl.jena.sdb.SDBException;
import com.hp.hpl.jena.sdb.compiler.ConditionCompiler;
import com.hp.hpl.jena.sdb.compiler.SDBConstraint;
import com.hp.hpl.jena.sdb.core.ExprPattern;
import com.hp.hpl.jena.sdb.core.Scope;
import com.hp.hpl.jena.sdb.core.sqlexpr.*;
import com.hp.hpl.jena.sdb.exprmatch.ActionMatch;
import com.hp.hpl.jena.sdb.exprmatch.ActionMatchString;
import com.hp.hpl.jena.sdb.exprmatch.ActionMatchVar;
import com.hp.hpl.jena.sdb.exprmatch.MapResult;
import com.hp.hpl.jena.sdb.layout2.ValueType;
public class RegexCompiler implements ConditionCompiler
{
// --- regex : testing a term (in a variable)
// Change to SSE? ?? for meta variables (regex ??a1 ??a2 ["i"])
// Map of meta variable to action?
private static ExprPattern regex1 = new ExprPattern("regex(?a1, ?a2)",
new Var[]{ Var.alloc("a1") , Var.alloc("a2") },
new ActionMatch[]{ new ActionMatchVar() ,
new ActionMatchString()}) ;
private static ExprPattern regex1_i = new ExprPattern("regex(?a1, ?a2, 'i')",
new Var[]{ Var.alloc("a1") , Var.alloc("a2") },
new ActionMatch[]{ new ActionMatchVar() ,
new ActionMatchString()}) ;
@Override
public SDBConstraint recognize(Expr expr)
{
MapResult rMap = null ;
if ( ( rMap = regex1.match(expr) ) != null )
{
Var var = rMap.get("a1").getExprVar().asVar() ;
String pattern = rMap.get("a2").getConstant().getString() ;
return new RegexSqlGen(expr, regex1, pattern, null, true) ;
}
if ( ( rMap = regex1_i.match(expr) ) != null )
{
Var var = rMap.get(Var.alloc("a1")).getExprVar().asVar() ;
String pattern = rMap.get(Var.alloc("a2")).getConstant().getString() ;
return new RegexSqlGen(expr, regex1_i, pattern, "i", true) ;
}
return null ;
}
}
class RegexSqlGen extends SDBConstraint
{
ExprPattern exprPattern ;
String patternStr ;
String flags ;
boolean completeConstraint ;
public RegexSqlGen(Expr expr, ExprPattern exprPattern, String patternStr, String flags, boolean completeConstraint)
{
super(expr, completeConstraint) ;
this.exprPattern = exprPattern ;
this.patternStr = patternStr ;
this.flags = flags ;
}
@Override
public SDBConstraint substitute(Binding binding)
{
return new RegexSqlGen(getExpr().copySubstitute(binding),
exprPattern,
patternStr,
flags, completeConstraint) ;
}
@Override
public SqlExpr compile(Scope scope)
{
// TODO Convert regex to using a string value table?
MapResult rMap = exprPattern.match(getExpr()) ;
if ( rMap == null )
throw new SDBException("Couldn't compile after all: "+getExpr()) ;
Var var = rMap.get(Var.alloc("a1")).getExprVar().asVar() ;
String pattern = rMap.get(Var.alloc("a2")).getConstant().getString() ;
if ( ! scope.hasColumnForVar(var) )
{
LoggerFactory.getLogger(this.getClass()).error("Variable '"+var+"' not in scope") ;
return null ;
}
SqlColumn vCol = scope.findScopeForVar(var).getColumn() ;
// Ensure it's the lex column
SqlColumn lexCol = new SqlColumn(vCol.getTable(), "lex") ;
SqlColumn vTypeCol = new SqlColumn(vCol.getTable(), "type") ;
// "is a string"
SqlExpr isStr = new S_Equal(vTypeCol, new SqlConstant(ValueType.STRING.getTypeId())) ;
isStr.addNote("is a string" ) ;
// regex.
SqlExpr sCond = new S_Regex(vCol, pattern, flags) ;
sCond.addNote(getExpr().toString()) ;
SqlExpr sqlExpr = new S_And(isStr, sCond) ;
return sqlExpr ;
}
}