/*
 * 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 org.apache.jena.sparql.algebra.op;

import org.apache.jena.sparql.algebra.Op;
import org.apache.jena.sparql.algebra.OpVisitor;
import org.apache.jena.sparql.algebra.Transform;
import org.apache.jena.sparql.sse.Tags;
import org.apache.jena.sparql.util.NodeIsomorphismMap;

public class OpSlice extends OpModifier
{
    private long start;
    private long length;

    public OpSlice(Op subOp, long start, long length) {
        super(subOp);
        this.start = start;
        this.length = length;
    }

    public long getLength()         { return length; }
    public long getStart()          { return start; }

    public Op copy() {
        return null;
    }

    @Override
    public String getName()                 { return Tags.tagSlice; }
    @Override
    public void visit(OpVisitor opVisitor)  { opVisitor.visit(this); }
    @Override
    public Op1 copy(Op subOp)                { return new OpSlice(subOp, start, length); }

    @Override
    public Op apply(Transform transform, Op subOp)
    { return transform.transform(this, subOp); }

    @Override
    public int hashCode() {
        return getSubOp().hashCode() ^ (int)(start & 0xFFFFFFFF) ^ (int)(length & 0xFFFFFFFF);
    }

    @Override
    public boolean equalTo(Op other, NodeIsomorphismMap labelMap) {
        if ( !(other instanceof OpSlice) )
            return false;
        OpSlice opSlice = (OpSlice)other;
        if ( opSlice.start != start || opSlice.length != length )
            return false;
        return getSubOp().equalTo(opSlice.getSubOp(), labelMap);
    }
}
