    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one
    003 * or more contributor license agreements.  See the NOTICE file
    004 * distributed with this work for additional information
    005 * regarding copyright ownership.  The ASF licenses this file
    006 * to you under the Apache License, Version 2.0 (the
    007 * "License"); you may not use this file except in compliance
    008 * with the License.  You may obtain a copy of the License at
    009 *
    010 *   https://www.apache.org/licenses/LICENSE-2.0
    011 *
    012 * Unless required by applicable law or agreed to in writing,
    013 * software distributed under the License is distributed on an
    014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    015 * KIND, either express or implied.  See the License for the
    016 * specific language governing permissions and limitations
    017 * under the License.
    018 */
    019package org.apache.bcel.generic;
    020
    021import java.io.DataOutputStream;
    022import java.io.IOException;
    023
    024import org.apache.bcel.util.ByteSequence;
    025
    026/**
    027 * LOOKUPSWITCH - Switch with unordered set of values
    028 *
    029 * @see SWITCH
    030 */
    031public class LOOKUPSWITCH extends Select {
    032
    033    /**
    034     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
    035     */
    036    LOOKUPSWITCH() {
    037    }
    038
    039    public LOOKUPSWITCH(final int[] match, final InstructionHandle[] targets, final InstructionHandle defaultTarget) {
    040        super(org.apache.bcel.Const.LOOKUPSWITCH, match, targets, defaultTarget);
    041        /* alignment remainder assumed 0 here, until dump time. */
    042        final short length = (short) (9 + getMatchLength() * 8);
    043        super.setLength(length);
    044        setFixedLength(length);
    045    }
    046
    047    /**
    048     * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
    049     * methods according to the class hierarchy in descending order, that is, the most specific visitXXX() call comes last.
    050     *
    051     * @param v Visitor object.
    052     */
    053    @Override
    054    public void accept(final Visitor v) {
    055        v.visitVariableLengthInstruction(this);
    056        v.visitStackConsumer(this);
    057        v.visitBranchInstruction(this);
    058        v.visitSelect(this);
    059        v.visitLOOKUPSWITCH(this);
    060    }
    061
    062    /**
    063     * Dumps instruction as byte code to stream out.
    064     *
    065     * @param out Output stream.
    066     */
    067    @Override
    068    public void dump(final DataOutputStream out) throws IOException {
    069        super.dump(out);
    070        final int matchLength = getMatchLength();
    071        out.writeInt(matchLength); // npairs
    072        for (int i = 0; i < matchLength; i++) {
    073            out.writeInt(super.getMatch(i)); // match-offset pairs
    074            out.writeInt(setIndices(i, getTargetOffset(super.getTarget(i))));
    075        }
    076    }
    077
    078    /**
    079     * Reads needed data (for example index) from file.
    080     */
    081    @Override
    082    protected void initFromFile(final ByteSequence bytes, final boolean wide) throws IOException {
    083        super.initFromFile(bytes, wide); // reads padding
    084        final int matchLength = bytes.readInt();
    085        setMatchLength(matchLength);
    086        final short fixedLength = (short) (9 + matchLength * 8);
    087        setFixedLength(fixedLength);
    088        final short length = (short) (matchLength + super.getPadding());
    089        super.setLength(length);
    090        super.setMatches(new int[matchLength]);
    091        super.setIndices(new int[matchLength]);
    092        super.setTargets(new InstructionHandle[matchLength]);
    093        for (int i = 0; i < matchLength; i++) {
    094            super.setMatch(i, bytes.readInt());
    095            super.setIndices(i, bytes.readInt());
    096        }
    097    }
    098}