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, i.e., 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     * Dump 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}