1/* 2 * Copyright 2012, Google Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: 8 * 9 * * Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * * Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following disclaimer 13 * in the documentation and/or other materials provided with the 14 * distribution. 15 * * Neither the name of Google Inc. nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32package org.jf.dexlib2.dexbacked; 33 34import org.jf.util.ExceptionWithContext; 35 36import javax.annotation.Nonnull; 37 38public class BaseDexBuffer { 39 @Nonnull /* package private */ final byte[] buf; 40 41 public BaseDexBuffer(@Nonnull byte[] buf) { 42 this.buf = buf; 43 } 44 45 public int readSmallUint(int offset) { 46 byte[] buf = this.buf; 47 int result = (buf[offset] & 0xff) | 48 ((buf[offset+1] & 0xff) << 8) | 49 ((buf[offset+2] & 0xff) << 16) | 50 ((buf[offset+3]) << 24); 51 if (result < 0) { 52 throw new ExceptionWithContext("Encountered small uint that is out of range at offset 0x%x", offset); 53 } 54 return result; 55 } 56 57 public int readOptionalUint(int offset) { 58 byte[] buf = this.buf; 59 int result = (buf[offset] & 0xff) | 60 ((buf[offset+1] & 0xff) << 8) | 61 ((buf[offset+2] & 0xff) << 16) | 62 ((buf[offset+3]) << 24); 63 if (result < -1) { 64 throw new ExceptionWithContext("Encountered optional uint that is out of range at offset 0x%x", offset); 65 } 66 return result; 67 } 68 69 public int readUshort(int offset) { 70 byte[] buf = this.buf; 71 return (buf[offset] & 0xff) | 72 ((buf[offset+1] & 0xff) << 8); 73 } 74 75 public int readUbyte(int offset) { 76 return buf[offset] & 0xff; 77 } 78 79 public long readLong(int offset) { 80 byte[] buf = this.buf; 81 return (buf[offset] & 0xff) | 82 ((buf[offset+1] & 0xff) << 8) | 83 ((buf[offset+2] & 0xff) << 16) | 84 ((buf[offset+3] & 0xffL) << 24) | 85 ((buf[offset+4] & 0xffL) << 32) | 86 ((buf[offset+5] & 0xffL) << 40) | 87 ((buf[offset+6] & 0xffL) << 48) | 88 (((long)buf[offset+7]) << 56); 89 } 90 91 public int readInt(int offset) { 92 byte[] buf = this.buf; 93 return (buf[offset] & 0xff) | 94 ((buf[offset+1] & 0xff) << 8) | 95 ((buf[offset+2] & 0xff) << 16) | 96 (buf[offset+3] << 24); 97 } 98 99 public int readShort(int offset) { 100 byte[] buf = this.buf; 101 return (buf[offset] & 0xff) | 102 (buf[offset+1] << 8); 103 } 104 105 public int readByte(int offset) { 106 return buf[offset]; 107 } 108 109 @Nonnull 110 public BaseDexReader readerAt(int offset) { 111 return new BaseDexReader<BaseDexBuffer>(this, offset); 112 } 113 114 @Nonnull 115 protected byte[] getBuf() { 116 return buf; 117 } 118} 119