content: /*
   * [The "BSD licence"]
   * Copyright (c) 2010 Ben Gruver (JesusFreke)
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. 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.
   * 3. The name of the author may not be used to endorse or promote products
   *    derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
   */
  
  package org.jf.dexlib;
  
  import org.jf.dexlib.Util.ExceptionWithContext;
  import org.jf.dexlib.Util.SparseArray;
  
  import java.util.List;
  import java.util.ArrayList;
  
  
  /**
   * This class stores context information that is only needed when reading in a dex file
   * Namely, it handles "pre-creating" items when an item needs to resolve some other item
   * that it references, and keeps track of those pre-created items, so the corresponding section
   * for the pre-created items uses them, instead of creating new items
   */
  public class ReadContext {
      private SparseArray<TypeListItem> typeListItems = new SparseArray<TypeListItem>(0);
      private SparseArray<AnnotationSetRefList> annotationSetRefLists = new SparseArray<AnnotationSetRefList>(0);
      private SparseArray<AnnotationSetItem> annotationSetItems = new SparseArray<AnnotationSetItem>(0);
      private SparseArray<ClassDataItem> classDataItems = new SparseArray<ClassDataItem>(0);
      private SparseArray<CodeItem> codeItems = new SparseArray<CodeItem>(0);
      private SparseArray<StringDataItem> stringDataItems = new SparseArray<StringDataItem>(0);
      private SparseArray<DebugInfoItem> debugInfoItems = new SparseArray<DebugInfoItem>(0);
      private SparseArray<AnnotationItem> annotationItems = new SparseArray<AnnotationItem>(0);
      private SparseArray<EncodedArrayItem> encodedArrayItems = new SparseArray<EncodedArrayItem>(0);
      private SparseArray<AnnotationDirectoryItem> annotationDirectoryItems = new SparseArray<AnnotationDirectoryItem>(0);
  
      private SparseArray[] itemsByType = new SparseArray[] {
              null, //string_id_item
              null, //type_id_item
              null, //proto_id_item
              null, //field_id_item
              null, //method_id_item
              null, //class_def_item
              typeListItems,
              annotationSetRefLists,
              annotationSetItems,
              classDataItems,
              codeItems,
              stringDataItems,
              debugInfoItems,
              annotationItems,
              encodedArrayItems,
              annotationDirectoryItems,
              null, //map_list
              null //header_item
      };
  
  
      /**
       * The section sizes that are passed in while reading HeaderItem/MapItem, via the
       * addSection method.
       */
      private int[] sectionSizes = new int[18];
  
      /**
       * The section offsets that are passed in while reading MapItem/HeaderItem, via the
       * addSection method.
       */
      private int[] sectionOffsets = new int[18];
  
      /**
       * Creates a new ReadContext instance.
       */
      public ReadContext() {
          for (int i=0; i<18; i++) {
              sectionSizes[i] = -1;
              sectionOffsets[i] = -1;
          }
      }
  
      /**
       * Gets the offsetted item of the specified type for the given offset. This method does not support retrieving an
       * optional item where a value of 0 indicates "not present". Use getOptionalOffsettedItemByOffset instead.
       *
       * @param itemType The type of item to get
       * @param offset The offset of the item
       * @return the offsetted item of the specified type at the specified offset
       */
      public Item getOffsettedItemByOffset(ItemType itemType, int offset) {
          assert !itemType.isIndexedItem();
  
          SparseArray<Item> sa = itemsByType[itemType.SectionIndex];
          Item item = sa.get(offset);
          if (item == null) {
              throw new ExceptionWithContext(String.format("Could not find the %s item at offset %#x",
                      itemType.TypeName, offset));
          }
          return item;
      }
  
      /**
       * Gets the optional offsetted item of the specified type for the given offset
       *
       * @param itemType The type of item to get
       * @param offset The offset of the item
       * @return the offsetted item of the specified type at the specified offset, or null if the offset is 0
       */
      public Item getOptionalOffsettedItemByOffset(ItemType itemType, int offset) {
          assert !itemType.isIndexedItem();
  
          assert !itemType.isIndexedItem();
  
          SparseArray<Item> sa = itemsByType[itemType.SectionIndex];
          Item item = sa.get(offset);
          if (item == null && offset != 0) {
              throw new ExceptionWithContext(String.format("Could not find the %s item at offset %#x",
                      itemType.TypeName, offset));
          }
          return item;
      }
  
      /**
       * Adds the size and offset information for the given offset
       * @param itemType the item type of the section
       * @param sectionSize the size of the section
       * @param sectionOffset the offset of the section
       */
      public void addSection(final ItemType itemType, int sectionSize, int sectionOffset) {
          int storedSectionSize = sectionSizes[itemType.SectionIndex];
          if (storedSectionSize == -1) {
              sectionSizes[itemType.SectionIndex] = sectionSize;
          } else {
              if (storedSectionSize  != sectionSize) {
                  throw new RuntimeException("The section size in the header and map for item type "
                          + itemType + " do not match");
              }
          }
  
          int storedSectionOffset = sectionOffsets[itemType.SectionIndex];
          if (storedSectionOffset == -1) {
              sectionOffsets[itemType.SectionIndex] = sectionOffset;
          } else {
              if (storedSectionOffset != sectionOffset) {
                  throw new RuntimeException("The section offset in the header and map for item type "
                          + itemType + " do not match");
              }
          }
      }
  
      /**
       * Sets the items for the specified section. This should be called by an offsetted section
       * after it is finished reading in all its items.
       * @param itemType the item type of the section. This must be an offsetted item type
       * @param items the full list of items in the section, ordered by offset
       */
      public void setItemsForSection(ItemType itemType, ArrayList<? extends Item> items) {
          assert !itemType.isIndexedItem();
  
          SparseArray<Item> sa = itemsByType[itemType.SectionIndex];
  
          sa.ensureCapacity(items.size());
          for (Item item: items) {
              sa.append(item.getOffset(), item);
          }
      }
  
      /**
       * @param itemType the item type of the section
       * @return the size of the given section as it was read in from the map item
       */
      public int getSectionSize(ItemType itemType) {
          return sectionSizes[itemType.SectionIndex];
      }
  
      /**
       * @param itemType the item type of the section
       * @return the offset of the given section as it was read in from the map item
       */
      public int getSectionOffset(ItemType itemType) {
          return sectionOffsets[itemType.SectionIndex];
      }
  }
  