code: /**
   * Copyright (c) 2005, Regents of the University of California
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * Redistributions of source code must retain the above copyright notice,
   * this list of conditions and the following disclaimer.
   *
   * Redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution.
   *
   * Neither the name of the University of California, Los Angeles nor the
   * names of its contributors may be used to endorse or promote products
   * derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * Created Sep 5, 2005
   */
  package cck.elf;
  
  import java.io.IOException;
  import java.io.RandomAccessFile;
  
  /**
   * @author Ben L. Titzer
   */
  public class ELFDataInputStream {
  
      final boolean bigEndian;
      final ELFHeader header;
      final RandomAccessFile file;
  
      public ELFDataInputStream(ELFHeader header, RandomAccessFile f) {
          this.header = header;
          bigEndian = header.isBigEndian();
          file = f;
      }
  
      public byte[] read_section(int off, int length) throws IOException {
          byte[] buffer = new byte[length];
          file.seek(off);
          for ( int cntr = 0; cntr < length; ) {
              cntr += file.read(buffer, cntr, length - cntr);
          }
          return buffer;
      }
  
      public byte read_Elf32_byte() throws IOException {
          return (byte)read_1();
      }
  
      public int read_Elf32_uchar() throws IOException {
          return read_1();
      }
  
      public int read_Elf32_Addr() throws IOException {
          return read_4();
      }
  
      public short read_Elf32_Half() throws IOException {
          return (short)read_2();
      }
  
      public int read_Elf32_Off() throws IOException {
          return read_4();
      }
  
      public int read_Elf32_SWord() throws IOException {
          return read_4();
      }
  
      public int read_Elf32_Word() throws IOException {
          return read_4();
      }
  
      private int read_1() throws IOException {
          return file.read() & 0xff;
      }
  
      private int read_2() throws IOException {
          int b1 = read_1();
          int b2 = read_1();
          if ( bigEndian ) return asShort(b2, b1);
          return asShort(b1, b2);
      }
  
      private int read_4() throws IOException {
          int b1 = read_1();
          int b2 = read_1();
          int b3 = read_1();
          int b4 = read_1();
          if ( bigEndian ) return asInt(b4, b3, b2, b1);
          return asInt(b1, b2, b3, b4);
      }
  
      private short asShort(int bl, int bh) {
          return (short)((bh << 8) | bl);
      }
  
      private int asInt(int b1, int b2, int b3, int b4) {
          return (b4 << 24) | (b3 << 16) | (b2 << 8) | b1;
      }
  
  }
  