content: /*
   * Copyright (C) 2007 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.taobao.android.dx.dex.file;
  
  import com.taobao.android.dx.rop.cst.Constant;
  import com.taobao.android.dx.rop.cst.CstType;
  import com.taobao.android.dx.rop.type.Type;
  import com.taobao.android.dx.rop.type.TypeList;
  import com.taobao.android.dx.util.AnnotatedOutput;
  import com.taobao.android.dx.util.Hex;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.TreeMap;
  
  /**
   * Class definitions list section of a {@code .dex} file.
   */
  public final class ClassDefsSection extends UniformItemSection {
      /**
       * {@code non-null;} map from type constants for classes to {@link
       * ClassDefItem} instances that define those classes
       */
      private final TreeMap<Type, ClassDefItem> classDefs;
  
      /** {@code null-ok;} ordered list of classes; set in {@link #orderItems} */
      private ArrayList<ClassDefItem> orderedDefs;
  
      /**
       * Constructs an instance. The file offset is initially unknown.
       *
       * @param file {@code non-null;} file that this instance is part of
       */
      public ClassDefsSection(DexFile file) {
          super("class_defs", file, 4);
  
          classDefs = new TreeMap<Type, ClassDefItem>();
          orderedDefs = null;
      }
  
      /** {@inheritDoc} */
      @Override
      public Collection<? extends Item> items() {
          if (orderedDefs != null) {
              return orderedDefs;
          }
  
          return classDefs.values();
      }
  
      /** {@inheritDoc} */
      @Override
      public IndexedItem get(Constant cst) {
          if (cst == null) {
              throw new NullPointerException("cst == null");
          }
  
          throwIfNotPrepared();
  
          Type type = ((CstType) cst).getClassType();
          IndexedItem result = classDefs.get(type);
  
          if (result == null) {
              throw new IllegalArgumentException("not found");
          }
  
          return result;
      }
  
      /**
       * Writes the portion of the file header that refers to this instance.
       *
       * @param out {@code non-null;} where to write
       */
      public void writeHeaderPart(AnnotatedOutput out) {
          throwIfNotPrepared();
  
          int sz = classDefs.size();
          int offset = (sz == 0) ? 0 : getFileOffset();
  
          if (out.annotates()) {
              out.annotate(4, "class_defs_size: " + Hex.u4(sz));
              out.annotate(4, "class_defs_off:  " + Hex.u4(offset));
          }
  
          out.writeInt(sz);
          out.writeInt(offset);
      }
  
      /**
       * Adds an element to this instance. It is illegal to attempt to add more
       * than one class with the same name.
       *
       * @param clazz {@code non-null;} the class def to add
       */
      public void add(ClassDefItem clazz) {
          Type type;
  
          try {
              type = clazz.getThisClass().getClassType();
          } catch (NullPointerException ex) {
              // Elucidate the exception.
              throw new NullPointerException("clazz == null");
          }
          if (classDefs.get(type)!= null){
              return;
          }
          throwIfPrepared();
  
          if (classDefs.get(type) != null) {
              throw new IllegalArgumentException("already added: " + type);
          }
  
          classDefs.put(type, clazz);
      }
  
      /** {@inheritDoc} */
      @Override
      protected void orderItems() {
          int sz = classDefs.size();
          int idx = 0;
  
          orderedDefs = new ArrayList<ClassDefItem>(sz);
  
          /*
           * Iterate over all the classes, recursively assigning an
           * index to each, implicitly skipping the ones that have
           * already been assigned by the time this (top-level)
           * iteration reaches them.
           */
          for (Type type : classDefs.keySet()) {
              idx = orderItems0(type, idx, sz - idx);
          }
      }
  
      /**
       * Helper for {@link #orderItems}, which recursively assigns indices
       * to classes.
       *
       * @param type {@code null-ok;} type ref to assign, if any
       * @param idx {@code >= 0;} the next index to assign
       * @param maxDepth maximum recursion depth; if negative, this will
       * throw an exception indicating class definition circularity
       * @return {@code >= 0;} the next index to assign
       */
      private int orderItems0(Type type, int idx, int maxDepth) {
          ClassDefItem c = classDefs.get(type);
  
          if ((c == null) || (c.hasIndex())) {
              return idx;
          }
  
          if (maxDepth < 0) {
              throw new RuntimeException("class circularity with " + type);
          }
  
          maxDepth--;
  
          CstType superclassCst = c.getSuperclass();
          if (superclassCst != null) {
              Type superclass = superclassCst.getClassType();
              idx = orderItems0(superclass, idx, maxDepth);
          }
  
          TypeList interfaces = c.getInterfaces();
          int sz = interfaces.size();
          for (int i = 0; i < sz; i++) {
              idx = orderItems0(interfaces.getType(i), idx, maxDepth);
          }
  
          c.setIndex(idx);
          orderedDefs.add(c);
          return idx + 1;
      }
  }
  