    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 *
    017 */
    018package org.apache.bcel.generic;
    019
    020import java.io.DataOutputStream;
    021import java.io.IOException;
    022
    023import org.apache.bcel.util.ByteSequence;
    024
    025/**
    026 * TABLESWITCH - Switch within given range of values, i.e., low..high
    027 *
    028 * @see SWITCH
    029 */
    030public class TABLESWITCH extends Select {
    031
    032    /**
    033     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
    034     */
    035    TABLESWITCH() {
    036    }
    037
    038    /**
    039     * @param match sorted array of match values, match[0] must be low value, match[match_length - 1] high value
    040     * @param targets where to branch for matched values
    041     * @param defaultTarget default branch
    042     */
    043    public TABLESWITCH(final int[] match, final InstructionHandle[] targets, final InstructionHandle defaultTarget) {
    044        super(org.apache.bcel.Const.TABLESWITCH, match, targets, defaultTarget);
    045        /* Alignment remainder assumed 0 here, until dump time */
    046        final short length = (short) (13 + getMatch_length() * 4);
    047        super.setLength(length);
    048        setFixed_length(length);
    049    }
    050
    051    /**
    052     * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
    053     * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last.
    054     *
    055     * @param v Visitor object
    056     */
    057    @Override
    058    public void accept(final Visitor v) {
    059        v.visitVariableLengthInstruction(this);
    060        v.visitStackConsumer(this);
    061        v.visitBranchInstruction(this);
    062        v.visitSelect(this);
    063        v.visitTABLESWITCH(this);
    064    }
    065
    066    /**
    067     * Dump instruction as byte code to stream out.
    068     *
    069     * @param out Output stream
    070     */
    071    @Override
    072    public void dump(final DataOutputStream out) throws IOException {
    073        super.dump(out);
    074        final int match_length = getMatch_length();
    075        final int low = match_length > 0 ? super.getMatch(0) : 0;
    076        out.writeInt(low);
    077        final int high = match_length > 0 ? super.getMatch(match_length - 1) : 0;
    078        out.writeInt(high);
    079        for (int i = 0; i < match_length; i++) {
    080            out.writeInt(setIndices(i, getTargetOffset(super.getTarget(i))));
    081        }
    082    }
    083
    084    /**
    085     * Read needed data (e.g. index) from file.
    086     */
    087    @Override
    088    protected void initFromFile(final ByteSequence bytes, final boolean wide) throws IOException {
    089        super.initFromFile(bytes, wide);
    090        final int low = bytes.readInt();
    091        final int high = bytes.readInt();
    092        final int matchLength = high - low + 1;
    093        setMatch_length(matchLength);
    094        final short fixedLength = (short) (13 + matchLength * 4);
    095        setFixed_length(fixedLength);
    096        super.setLength((short) (fixedLength + super.getPadding()));
    097        super.setMatches(new int[matchLength]);
    098        super.setIndices(new int[matchLength]);
    099        super.setTargets(new InstructionHandle[matchLength]);
    100        for (int i = 0; i < matchLength; i++) {
    101            super.setMatch(i, low + i);
    102            super.setIndices(i, bytes.readInt());
    103        }
    104    }
    105}