1 /* 2 * [The "BSD licence"] 3 * Copyright (c) 2010 Ben Gruver (JesusFreke) 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 package org.jf.dexlib; 30 31 import org.jf.dexlib.Util.ExceptionWithContext; 32 import org.jf.dexlib.Util.SparseArray; 33 34 import java.util.List; 35 36 37 /** 38 * This class stores context information that is only needed when reading in a dex file 39 * Namely, it handles "pre-creating" items when an item needs to resolve some other item 40 * that it references, and keeps track of those pre-created items, so the corresponding section 41 * for the pre-created items uses them, instead of creating new items 42 */ 43 public class ReadContext { 44 private SparseArray<TypeListItem> typeListItems = new SparseArray<TypeListItem>(0); 45 private SparseArray<AnnotationSetRefList> annotationSetRefLists = new SparseArray<AnnotationSetRefList>(0); 46 private SparseArray<AnnotationSetItem> annotationSetItems = new SparseArray<AnnotationSetItem>(0); 47 private SparseArray<ClassDataItem> classDataItems = new SparseArray<ClassDataItem>(0); 48 private SparseArray<CodeItem> codeItems = new SparseArray<CodeItem>(0); 49 private SparseArray<StringDataItem> stringDataItems = new SparseArray<StringDataItem>(0); 50 private SparseArray<DebugInfoItem> debugInfoItems = new SparseArray<DebugInfoItem>(0); 51 private SparseArray<AnnotationItem> annotationItems = new SparseArray<AnnotationItem>(0); 52 private SparseArray<EncodedArrayItem> encodedArrayItems = new SparseArray<EncodedArrayItem>(0); 53 private SparseArray<AnnotationDirectoryItem> annotationDirectoryItems = new SparseArray<AnnotationDirectoryItem>(0); 54 55 private SparseArray[] itemsByType = new SparseArray[] { 56 null, //string_id_item 57 null, //type_id_item 58 null, //proto_id_item 59 null, //field_id_item 60 null, //method_id_item 61 null, //class_def_item 62 typeListItems, 63 annotationSetRefLists, 64 annotationSetItems, 65 classDataItems, 66 codeItems, 67 stringDataItems, 68 debugInfoItems, 69 annotationItems, 70 encodedArrayItems, 71 annotationDirectoryItems, 72 null, //map_list 73 null //header_item 74 }; 75 76 77 /** 78 * The section sizes that are passed in while reading HeaderItem/MapItem, via the 79 * addSection method. 80 */ 81 private int[] sectionSizes = new int[18]; 82 83 /** 84 * The section offsets that are passed in while reading MapItem/HeaderItem, via the 85 * addSection method. 86 */ 87 private int[] sectionOffsets = new int[18]; 88 89 /** 90 * Creates a new ReadContext instance. 91 */ 92 public ReadContext() { 93 for (int i=0; i<18; i++) { 94 sectionSizes[i] = -1; 95 sectionOffsets[i] = -1; 96 } 97 } 98 99 /** 100 * Gets the offsetted item of the specified type for the given offset. This method does not support retrieving an 101 * optional item where a value of 0 indicates "not present". Use getOptionalOffsettedItemByOffset instead. 102 * 103 * @param itemType The type of item to get 104 * @param offset The offset of the item 105 * @return the offsetted item of the specified type at the specified offset 106 */ 107 public Item getOffsettedItemByOffset(ItemType itemType, int offset) { 108 assert !itemType.isIndexedItem(); 109 110 SparseArray<Item> sa = itemsByType[itemType.SectionIndex]; 111 Item item = sa.get(offset); 112 if (item == null) { 113 throw new ExceptionWithContext(String.format("Could not find the %s item at offset %#x", 114 itemType.TypeName, offset)); 115 } 116 return item; 117 } 118 119 /** 120 * Gets the optional offsetted item of the specified type for the given offset 121 * 122 * @param itemType The type of item to get 123 * @param offset The offset of the item 124 * @return the offsetted item of the specified type at the specified offset, or null if the offset is 0 125 */ 126 public Item getOptionalOffsettedItemByOffset(ItemType itemType, int offset) { 127 assert !itemType.isIndexedItem(); 128 129 assert !itemType.isIndexedItem(); 130 131 SparseArray<Item> sa = itemsByType[itemType.SectionIndex]; 132 Item item = sa.get(offset); 133 if (item == null && offset != 0) { 134 throw new ExceptionWithContext(String.format("Could not find the %s item at offset %#x", 135 itemType.TypeName, offset)); 136 } 137 return item; 138 } 139 140 /** 141 * Adds the size and offset information for the given offset 142 * @param itemType the item type of the section 143 * @param sectionSize the size of the section 144 * @param sectionOffset the offset of the section 145 */ 146 public void addSection(final ItemType itemType, int sectionSize, int sectionOffset) { 147 int storedSectionSize = sectionSizes[itemType.SectionIndex]; 148 if (storedSectionSize == -1) { 149 sectionSizes[itemType.SectionIndex] = sectionSize; 150 } else { 151 if (storedSectionSize != sectionSize) { 152 throw new RuntimeException("The section size in the header and map for item type " 153 + itemType + " do not match"); 154 } 155 } 156 157 int storedSectionOffset = sectionOffsets[itemType.SectionIndex]; 158 if (storedSectionOffset == -1) { 159 sectionOffsets[itemType.SectionIndex] = sectionOffset; 160 } else { 161 if (storedSectionOffset != sectionOffset) { 162 throw new RuntimeException("The section offset in the header and map for item type " 163 + itemType + " do not match"); 164 } 165 } 166 } 167 168 /** 169 * Sets the items for the specified section. This should be called by an offsetted section 170 * after it is finished reading in all its items. 171 * @param itemType the item type of the section. This must be an offsetted item type 172 * @param items the full list of items in the section, ordered by offset 173 */ 174 public void setItemsForSection(ItemType itemType, List<? extends Item> items) { 175 assert !itemType.isIndexedItem(); 176 177 SparseArray<Item> sa = itemsByType[itemType.SectionIndex]; 178 179 sa.ensureCapacity(items.size()); 180 for (Item item: items) { 181 sa.append(item.getOffset(), item); 182 } 183 } 184 185 /** 186 * @param itemType the item type of the section 187 * @return the size of the given section as it was read in from the map item 188 */ 189 public int getSectionSize(ItemType itemType) { 190 return sectionSizes[itemType.SectionIndex]; 191 } 192 193 /** 194 * @param itemType the item type of the section 195 * @return the offset of the given section as it was read in from the map item 196 */ 197 public int getSectionOffset(ItemType itemType) { 198 return sectionOffsets[itemType.SectionIndex]; 199 } 200 } 201
