content: /*
   * Copyright (C) 2006 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.
   */
  
  /*
   * As per the Apache license requirements, this file has been modified
   * from its original state.
   *
   * Such modifications are Copyright (C) 2010 Ben Gruver, and are released
   * under the original license
   */
  
  package org.jf.dexlib.Util;
  
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  
  /**
   * SparseArrays map integers to Objects.  Unlike a normal array of Objects,
   * there can be gaps in the indices.  It is intended to be more efficient
   * than using a HashMap to map Integers to Objects.
   */
  public class SparseArray<E> {
      private static final Object DELETED = new Object();
      private boolean mGarbage = false;
  
      /**
       * Creates a new SparseArray containing no mappings.
       */
      public SparseArray() {
          this(10);
      }
  
      /**
       * Creates a new SparseArray containing no mappings that will not
       * require any additional memory allocation to store the specified
       * number of mappings.
       */
      public SparseArray(int initialCapacity) {
          mKeys = new int[initialCapacity];
          mValues = new Object[initialCapacity];
          mSize = 0;
      }
  
      /**
       * Gets the Object mapped from the specified key, or <code>null</code>
       * if no such mapping has been made.
       */
      public E get(int key) {
          return get(key, null);
      }
  
      /**
       * Gets the Object mapped from the specified key, or the specified Object
       * if no such mapping has been made.
       */
      public E get(int key, E valueIfKeyNotFound) {
          int i = binarySearch(mKeys, 0, mSize, key);
  
          if (i < 0 || mValues[i] == DELETED) {
              return valueIfKeyNotFound;
          } else {
              return (E) mValues[i];
          }
      }
  
      /**
       * Removes the mapping from the specified key, if there was any.
       */
      public void delete(int key) {
          int i = binarySearch(mKeys, 0, mSize, key);
  
          if (i >= 0) {
              if (mValues[i] != DELETED) {
                  mValues[i] = DELETED;
                  mGarbage = true;
              }
          }
      }
  
      /**
       * Alias for {@link #delete(int)}.
       */
      public void remove(int key) {
          delete(key);
      }
  
      private void gc() {
          // Log.e("SparseArray", "gc start with " + mSize);
  
          int n = mSize;
          int o = 0;
          int[] keys = mKeys;
          Object[] values = mValues;
  
          for (int i = 0; i < n; i++) {
              Object val = values[i];
  
              if (val != DELETED) {
                  if (i != o) {
                      keys[o] = keys[i];
                      values[o] = val;
                  }
  
                  o++;
              }
          }
  
          mGarbage = false;
          mSize = o;
  
          // Log.e("SparseArray", "gc end with " + mSize);
      }
  
      /**
       * Adds a mapping from the specified key to the specified value,
       * replacing the previous mapping from the specified key if there
       * was one.
       */
      public void put(int key, E value) {
          int i = binarySearch(mKeys, 0, mSize, key);
  
          if (i >= 0) {
              mValues[i] = value;
          } else {
              i = ~i;
  
              if (i < mSize && mValues[i] == DELETED) {
                  mKeys[i] = key;
                  mValues[i] = value;
                  return;
              }
  
              if (mGarbage && mSize >= mKeys.length) {
                  gc();
  
                  // Search again because indices may have changed.
                  i = ~binarySearch(mKeys, 0, mSize, key);
              }
  
              if (mSize >= mKeys.length) {
                  int n = Math.max(mSize + 1, mKeys.length * 2);
  
                  int[] nkeys = new int[n];
                  Object[] nvalues = new Object[n];
  
                  // Log.e("SparseArray", "grow " + mKeys.length + " to " + n);
                  System.arraycopy(mKeys, 0, nkeys, 0, mKeys.length);
                  System.arraycopy(mValues, 0, nvalues, 0, mValues.length);
  
                  mKeys = nkeys;
                  mValues = nvalues;
              }
  
              if (mSize - i != 0) {
                  // Log.e("SparseArray", "move " + (mSize - i));
                  System.arraycopy(mKeys, i, mKeys, i + 1, mSize - i);
                  System.arraycopy(mValues, i, mValues, i + 1, mSize - i);
              }
  
              mKeys[i] = key;
              mValues[i] = value;
              mSize++;
          }
      }
  
      /**
       * Returns the number of key-value mappings that this SparseArray
       * currently stores.
       */
      public int size() {
          if (mGarbage) {
              gc();
          }
  
          return mSize;
      }
  
      /**
       * Given an index in the range <code>0...size()-1</code>, returns
       * the key from the <code>index</code>th key-value mapping that this
       * SparseArray stores.
       */
      public int keyAt(int index) {
          if (mGarbage) {
              gc();
          }
  
          return mKeys[index];
      }
  
      /**
       * Given an index in the range <code>0...size()-1</code>, returns
       * the value from the <code>index</code>th key-value mapping that this
       * SparseArray stores.
       */
      public E valueAt(int index) {
          if (mGarbage) {
              gc();
          }
  
          return (E) mValues[index];
      }
  
      /**
       * Given an index in the range <code>0...size()-1</code>, sets a new
       * value for the <code>index</code>th key-value mapping that this
       * SparseArray stores.
       */
      public void setValueAt(int index, E value) {
          if (mGarbage) {
              gc();
          }
  
          mValues[index] = value;
      }
  
      /**
       * Returns the index for which {@link #keyAt} would return the
       * specified key, or a negative number if the specified
       * key is not mapped.
       */
      public int indexOfKey(int key) {
          if (mGarbage) {
              gc();
          }
  
          return binarySearch(mKeys, 0, mSize, key);
      }
  
      /**
       * Returns an index for which {@link #valueAt} would return the
       * specified key, or a negative number if no keys map to the
       * specified value.
       * Beware that this is a linear search, unlike lookups by key,
       * and that multiple keys can map to the same value and this will
       * find only one of them.
       */
      public int indexOfValue(E value) {
          if (mGarbage) {
              gc();
          }
  
          Object[] mValues=this.mValues;
  
          for (int i = 0; i < mSize; i++)
              if (mValues[i] == value)
                  return i;
  
          return -1;
      }
  
      /**
       * Removes all key-value mappings from this SparseArray.
       */
      public void clear() {
          int n = mSize;
          Object[] values = mValues;
  
          for (int i = 0; i < n; i++) {
              values[i] = null;
          }
  
          mSize = 0;
          mGarbage = false;
      }
  
      /**
       * Puts a key/value pair into the array, optimizing for the case where
       * the key is greater than all existing keys in the array.
       */
      public void append(int key, E value) {
          if (mSize != 0 && key <= mKeys[mSize - 1]) {
              put(key, value);
              return;
          }
  
          if (mGarbage && mSize >= mKeys.length) {
              gc();
          }
  
          int pos = mSize;
          if (pos >= mKeys.length) {
              int n = Math.max(pos + 1, mKeys.length * 2);
  
              int[] nkeys = new int[n];
              Object[] nvalues = new Object[n];
  
              // Log.e("SparseArray", "grow " + mKeys.length + " to " + n);
              System.arraycopy(mKeys, 0, nkeys, 0, mKeys.length);
              System.arraycopy(mValues, 0, nvalues, 0, mValues.length);
  
              mKeys = nkeys;
              mValues = nvalues;
          }
  
          mKeys[pos] = key;
          mValues[pos] = value;
          mSize = pos + 1;
      }
  
      /**
       * Increases the size of the underlying storage if needed, to ensure that it can
       * hold the specified number of items without having to allocate additional memory
       * @param capacity the number of items
       */
      public void ensureCapacity(int capacity) {
          if (mGarbage && mSize >= mKeys.length) {
              gc();
          }
  
          if (mKeys.length < capacity) {
              int[] nkeys = new int[capacity];
              Object[] nvalues = new Object[capacity];
  
              System.arraycopy(mKeys, 0, nkeys, 0, mKeys.length);
              System.arraycopy(mValues, 0, nvalues, 0, mValues.length);
  
              mKeys = nkeys;
              mValues = nvalues;
          }
      }
  
      private static int binarySearch(int[] a, int start, int len, int key) {
          int high = start + len, low = start - 1, guess;
  
          while (high - low > 1) {
              guess = (high + low) / 2;
  
              if (a[guess] < key)
                  low = guess;
              else
                  high = guess;
          }
  
          if (high == start + len)
              return ~(start + len);
          else if (a[high] == key)
              return high;
          else
              return ~high;
      }
  
      /**
       * @return a read-only list of the values in this SparseArray which are in ascending order, based on their
       * associated key
       */
      public List<E> getValues() {
          return Arrays.asList((E[])mValues);
      }
  
      private int[] mKeys;
      private Object[] mValues;
      private int mSize;
  }
  