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    1   /*
    2    * Copyright  2000-2004 The Apache Software Foundation
    3    *
    4    *  Licensed under the Apache License, Version 2.0 (the "License");
    5    *  you may not use this file except in compliance with the License.
    6    *  You may obtain a copy of the License at
    7    *
    8    *      http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   *  Unless required by applicable law or agreed to in writing, software
    11   *  distributed under the License is distributed on an "AS IS" BASIS,
    12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   *  See the License for the specific language governing permissions and
    14   *  limitations under the License.
    15   *
    16   */
    17  package org.apache.bcel.generic;
    18
    19  import java.io.DataOutputStream;
    20  import java.io.IOException;
    21  import org.apache.bcel.util.ByteSequence;
    22
    23  /***
    24   * LOOKUPSWITCH - Switch with unordered set of values
    25   *
    26   * @version $Id: LOOKUPSWITCH.java 386056 2006-03-15 11:31:56Z tcurdt $
    27   * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
    28   * @see SWITCH
    29   */
    30  public class LOOKUPSWITCH extends Select {
    31
    32      /***
    33       * Empty constructor needed for the Class.newInstance() statement in
    34       * Instruction.readInstruction(). Not to be used otherwise.
    35       */
    36      LOOKUPSWITCH() {
    37      }
    38
    39
    40      public LOOKUPSWITCH(int[] match, InstructionHandle[] targets, InstructionHandle defaultTarget) {
    41          super(org.apache.bcel.Constants.LOOKUPSWITCH, match, targets, defaultTarget);
    42          length = (short) (9 + match_length * 8); /* alignment remainder assumed
    43           * 0 here, until dump time. */
    44          fixed_length = length;
    45      }
    46
    47
    48      /***
    49       * Dump instruction as byte code to stream out.
    50       * @param out Output stream
    51       */
    52      public void dump( DataOutputStream out ) throws IOException {
    53          super.dump(out);
    54          out.writeInt(match_length); // npairs
    55          for (int i = 0; i < match_length; i++) {
    56              out.writeInt(match[i]); // match-offset pairs
    57              out.writeInt(indices[i] = getTargetOffset(targets[i]));
    58          }
    59      }
    60
    61
    62      /***
    63       * Read needed data (e.g. index) from file.
    64       */
    65      protected void initFromFile( ByteSequence bytes, boolean wide ) throws IOException {
    66          super.initFromFile(bytes, wide); // reads padding
    67          match_length = bytes.readInt();
    68          fixed_length = (short) (9 + match_length * 8);
    69          length = (short) (fixed_length + padding);
    70          match = new int[match_length];
    71          indices = new int[match_length];
    72          targets = new InstructionHandle[match_length];
    73          for (int i = 0; i < match_length; i++) {
    74              match[i] = bytes.readInt();
    75              indices[i] = bytes.readInt();
    76          }
    77      }
    78
    79
    80      /***
    81       * Call corresponding visitor method(s). The order is:
    82       * Call visitor methods of implemented interfaces first, then
    83       * call methods according to the class hierarchy in descending order,
    84       * i.e., the most specific visitXXX() call comes last.
    85       *
    86       * @param v Visitor object
    87       */
    88      public void accept( Visitor v ) {
    89          v.visitVariableLengthInstruction(this);
    90          v.visitStackProducer(this);
    91          v.visitBranchInstruction(this);
    92          v.visitSelect(this);
    93          v.visitLOOKUPSWITCH(this);
    94      }
    95  }