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 android.sax;
  
  /**
   * Contains element children. Using this class instead of HashMap results in
   * measurably better performance.
   */
  class Children {
  
      Child[] children = new Child[16];
  
      /**
       * Looks up a child by name and creates a new one if necessary.
       */
      Element getOrCreate(Element parent, String uri, String localName) {
          int hash = uri.hashCode() * 31 + localName.hashCode();
          int index = hash & 15;
  
          Child current = children[index];
          if (current == null) {
              // We have no children in this bucket yet.
              current = new Child(parent, uri, localName, parent.depth + 1, hash);
              children[index] = current;
              return current;
          } else {
              // Search this bucket.
              Child previous;
              do {
                  if (current.hash == hash
                          && current.uri.compareTo(uri) == 0
                          && current.localName.compareTo(localName) == 0) {
                      // We already have a child with that name.
                      return current;
                  }
  
                  previous = current;
                  current = current.next;
              } while (current != null);
  
              // Add a new child to the bucket.
              current = new Child(parent, uri, localName, parent.depth + 1, hash);
              previous.next = current;
              return current;         
          }
      }
  
      /**
       * Looks up a child by name.
       */
      Element get(String uri, String localName) {
          int hash = uri.hashCode() * 31 + localName.hashCode();
          int index = hash & 15;
  
          Child current = children[index];
          if (current == null) {
              return null;
          } else {
              do {
                  if (current.hash == hash
                          && current.uri.compareTo(uri) == 0
                          && current.localName.compareTo(localName) == 0) {
                      return current;
                  }
                  current = current.next;
              } while (current != null);
  
              return null;
          }
      }
  
      static class Child extends Element {
  
          final int hash;
          Child next;
  
          Child(Element parent, String uri, String localName, int depth,
                  int hash) {
              super(parent, uri, localName, depth);
              this.hash = hash;
          }
      }
  }
  