android.util.SparseIntArray#keyAt ( )源码实例Demo

/**
 * Notifies the tracker that the app transition is starting.
 *
 * @param windowingModeToReason A map from windowing mode to a reason integer, which must be on
 *                              of ActivityTaskManagerInternal.APP_TRANSITION_* reasons.
 */
void notifyTransitionStarting(SparseIntArray windowingModeToReason, long timestamp) {
    if (!isAnyTransitionActive() || mLoggedTransitionStarting) {
        return;
    }
    if (DEBUG_METRICS) Slog.i(TAG, "notifyTransitionStarting");
    mCurrentTransitionDelayMs = calculateDelay(timestamp);
    mLoggedTransitionStarting = true;
    for (int index = windowingModeToReason.size() - 1; index >= 0; index--) {
        final int windowingMode = windowingModeToReason.keyAt(index);
        final WindowingModeTransitionInfo info = mWindowingModeTransitionInfo.get(
                windowingMode);
        if (info == null) {
            continue;
        }
        info.reason = windowingModeToReason.valueAt(index);
    }
    if (allWindowsDrawn()) {
        reset(false /* abort */, null /* WindowingModeTransitionInfo */);
    }
}
 

/** Get the list of publically visible output formats; does not include IMPL_DEFINED */
private int[] getPublicFormats(boolean output) {
    int[] formats = new int[getPublicFormatCount(output)];

    int i = 0;

    SparseIntArray map = getFormatsMap(output);
    for (int j = 0; j < map.size(); j++) {
        int format = map.keyAt(j);
        formats[i++] = imageFormatToPublic(format);
    }
    if (output) {
        for (int j = 0; j < mDepthOutputFormats.size(); j++) {
            formats[i++] = depthFormatToPublic(mDepthOutputFormats.keyAt(j));
        }
    }
    if (formats.length != i) {
        throw new AssertionError("Too few formats " + i + ", expected " + formats.length);
    }

    return formats;
}
 

@Override
public void onBindViewHolder(@NonNull final ViewHolder holder, final int position) {
    if (mGroupedKeyModels.size() > 0) {
        final int keyIndex = mGroupedKeyModels.keyAt(position);
        holder.groupItemContainer.setTag(keyIndex);
        final ApplicationKey key = mMeshNetwork.getAppKey(keyIndex);
        holder.mGroupAppKeyTitle.setText(key.getName());
        final SparseIntArray groupedModels = mGroupedKeyModels.valueAt(position);
        holder.mGroupGrid.setRowCount(1);
        //Remove all child views to avoid duplicating
        holder.mGroupGrid.removeAllViews();
        for (int i = 0; i < groupedModels.size(); i++) {
            final int modelId = groupedModels.keyAt(i);
            final int count = groupedModels.valueAt(i);
            inflateView(holder, keyIndex, modelId, count, i);
        }
    }
}
 

/**
 * Based off {@link java.util.AbstractMap#equals} -- with simplifications because we're guaranteed
 * sparse int arrays with no nullable values or casts.
 *
 * <p>TODO Make this a utility method, along with hashcode.
 */
public static boolean sparseIntArrayEquals(SparseIntArray a, SparseIntArray b) {
  if (a == b) {
    return true;
  }

  int aSize = a.size();
  if (aSize != b.size()) {
    return false;
  }

  // Sparse int arrays keep a sorted list of values: which means equality can just walk through
  // both arrays to check.
  for (int i = 0; i < aSize; i++) {
    if (a.keyAt(i) != b.keyAt(i) || a.valueAt(i) != b.valueAt(i)) {
      return false;
    }
  }

  return true;
}
 

static int findFirstKeyLessThan(SparseIntArray cache, int position) {
    int lo = 0;
    int hi = cache.size() - 1;

    while (lo <= hi) {
        // Using unsigned shift here to divide by two because it is guaranteed to not
        // overflow.
        final int mid = (lo + hi) >>> 1;
        final int midVal = cache.keyAt(mid);
        if (midVal < position) {
            lo = mid + 1;
        } else {
            hi = mid - 1;
        }
    }
    int index = lo - 1;
    if (index >= 0 && index < cache.size()) {
        return cache.keyAt(index);
    }
    return -1;
}
 

static int findFirstKeyLessThan(SparseIntArray cache, int position) {
    int lo = 0;
    int hi = cache.size() - 1;

    while (lo <= hi) {
        // Using unsigned shift here to divide by two because it is guaranteed to not
        // overflow.
        final int mid = (lo + hi) >>> 1;
        final int midVal = cache.keyAt(mid);
        if (midVal < position) {
            lo = mid + 1;
        } else {
            hi = mid - 1;
        }
    }
    int index = lo - 1;
    if (index >= 0 && index < cache.size()) {
        return cache.keyAt(index);
    }
    return -1;
}
 

private static Pair[] toPairArray(SparseIntArray counts) {
    final int s = counts.size();
    Pair[] pairs = new Pair[s];
    for (int i = 0; i < s; i++) {
        Pair p = new Pair();
        p.key = counts.keyAt(i);
        p.value = counts.valueAt(i);
        pairs[i] = p;
    }
    return pairs;
}
 

/**
 * Dump per uid binder proxy counts to the logcat.
 */
private void dumpPerUidProxyCounts() {
    SparseIntArray counts = BinderInternal.nGetBinderProxyPerUidCounts();
    if (counts.size() == 0) return;
    Log.d(Binder.TAG, "Per Uid Binder Proxy Counts:");
    for (int i = 0; i < counts.size(); i++) {
        final int uid = counts.keyAt(i);
        final int binderCount = counts.valueAt(i);
        Log.d(Binder.TAG, "UID : " + uid + "  count = " + binderCount);
    }
}
 

/**
 * Creates a new instance of the GenericByteArrayPool class
 *
 * @param memoryTrimmableRegistry the memory manager to register with
 * @param poolParams provider for pool parameters
 * @param poolStatsTracker
 */
public GenericByteArrayPool(
    MemoryTrimmableRegistry memoryTrimmableRegistry,
    PoolParams poolParams,
    PoolStatsTracker poolStatsTracker) {
  super(memoryTrimmableRegistry, poolParams, poolStatsTracker);
  final SparseIntArray bucketSizes = poolParams.bucketSizes;
  mBucketSizes = new int[bucketSizes.size()];
  for (int i = 0; i < bucketSizes.size(); ++i) {
    mBucketSizes[i] = bucketSizes.keyAt(i);
  }
  initialize();
}
 

/**
 * Subtracts b from the current value while being aware of core restarts.
 *
 * <p>Cpu clusters can be switched on and off as required by some devices: in those cases, the
 * measured frequency can go <em>down</em> across snapshots legally.
 *
 * <p>If the time in state for any core appears to have reduced, we can infer that the core was
 * switched off and restarted. In that case, a better approximation is the current value of the
 * snapshot instead of a meaningless subtraction.
 *
 * <p>Some tests make this behavior more explicit: {@see CpuFrequencyMetricsTest#testDiff} and
 * {@see CpuFrequencyMetricsTest#testDiffWithCoreReset} for expected behavior.
 */
@Override
public CpuFrequencyMetrics diff(
    @Nullable CpuFrequencyMetrics b, @Nullable CpuFrequencyMetrics output) {
  if (output == null) {
    output = new CpuFrequencyMetrics();
  }

  if (b == null) {
    output.set(this);
  } else {
    for (int i = 0; i < timeInStateS.length; i++) {
      SparseIntArray aCore = timeInStateS[i];
      SparseIntArray bCore = b.timeInStateS[i];
      SparseIntArray outputCore = output.timeInStateS[i];

      boolean hasCoreReset = false;
      for (int j = 0, size = aCore.size(); j < size && !hasCoreReset; j++) {
        int frequency = aCore.keyAt(j);
        int difference = aCore.valueAt(j) - bCore.get(frequency, 0);

        if (difference < 0) {
          hasCoreReset = true;
          break;
        }
        outputCore.put(frequency, difference);
      }

      if (hasCoreReset) {
        copyArrayInto(aCore, outputCore);
      }
    }
  }

  return output;
}
 

/** Based off {@link AbstractMap#hashCode()}: returns the sum of the hashcodes of the entries. */
@Override
public int hashCode() {
  int hash = 0;
  for (int i = 0; i < timeInStateS.length; i++) {
    SparseIntArray array = timeInStateS[i];
    for (int j = 0, size = timeInStateS[i].size(); j < size; j++) {
      // hash of an integer is the integer itself - see {@link Integers#hashCode}
      hash += array.keyAt(j) ^ array.valueAt(j);
    }
  }
  return hash;
}
 

private int findLeftLimit(SparseIntArray points, int end) {
    int index = findPointIndex(points, end);
    if (index >= 0) {
        int limit = points.keyAt(index);
        if (limit < end) {
            return limit;
        }
        if (index > 0) {
            return points.keyAt(index - 1);
        }
    }
    return 0;
}
 

/**
 * Initialize a new instance of the MemoryChunkPool
 *
 * @param memoryTrimmableRegistry the memory manager to register with
 * @param poolParams provider for pool parameters
 * @param memoryChunkPoolStatsTracker the pool stats tracker
 */
MemoryChunkPool(
    MemoryTrimmableRegistry memoryTrimmableRegistry,
    PoolParams poolParams,
    PoolStatsTracker memoryChunkPoolStatsTracker) {
  super(memoryTrimmableRegistry, poolParams, memoryChunkPoolStatsTracker);
  SparseIntArray bucketSizes = poolParams.bucketSizes;
  mBucketSizes = new int[bucketSizes.size()];
  for (int i = 0; i < mBucketSizes.length; ++i) {
    mBucketSizes[i] = bucketSizes.keyAt(i);
  }
  initialize();
}
 

/**
 * Creates a new instance of the GenericByteArrayPool class
 * @param memoryTrimmableRegistry the memory manager to register with
 * @param poolParams provider for pool parameters
 * @param poolStatsTracker
 */
public GenericByteArrayPool(
    MemoryTrimmableRegistry memoryTrimmableRegistry,
    PoolParams poolParams,
    PoolStatsTracker poolStatsTracker) {
  super(memoryTrimmableRegistry, poolParams, poolStatsTracker);
  final SparseIntArray bucketSizes = poolParams.bucketSizes;
  mBucketSizes = new int[bucketSizes.size()];
  for (int i = 0; i < bucketSizes.size(); ++i) {
    mBucketSizes[i] = bucketSizes.keyAt(i);
  }
  initialize();
}
 

/**
 * Creates a new instance of the NativeMemoryChunkPool class
 * @param memoryTrimmableRegistry the memory manager to register with
 * @param poolParams provider for pool parameters
 * @param nativeMemoryChunkPoolStatsTracker
 */
public NativeMemoryChunkPool(
    MemoryTrimmableRegistry memoryTrimmableRegistry,
    PoolParams poolParams,
    PoolStatsTracker nativeMemoryChunkPoolStatsTracker) {
  super(memoryTrimmableRegistry, poolParams, nativeMemoryChunkPoolStatsTracker);
  SparseIntArray bucketSizes = poolParams.bucketSizes;
  mBucketSizes = new int[bucketSizes.size()];
  for (int i = 0; i < mBucketSizes.length; ++i) {
    mBucketSizes[i] = bucketSizes.keyAt(i);
  }
  initialize();
}
 

/**
 * Initialize the list of buckets. Get the bucket sizes (and bucket lengths) from the bucket sizes
 * provider
 *
 * @param inUseCounts map of current buckets and their in use counts
 */
private synchronized void legacyInitBuckets(SparseIntArray inUseCounts) {
  Preconditions.checkNotNull(inUseCounts);

  // clear out all the buckets
  mBuckets.clear();

  // create the new buckets
  final SparseIntArray bucketSizes = mPoolParams.bucketSizes;
  if (bucketSizes != null) {
    for (int i = 0; i < bucketSizes.size(); ++i) {
      final int bucketSize = bucketSizes.keyAt(i);
      final int maxLength = bucketSizes.valueAt(i);
      int bucketInUseCount = inUseCounts.get(bucketSize, 0);
      mBuckets.put(
          bucketSize,
          new Bucket<V>(
              getSizeInBytes(bucketSize),
              maxLength,
              bucketInUseCount,
              mPoolParams.fixBucketsReinitialization));
    }
    mAllowNewBuckets = false;
  } else {
    mAllowNewBuckets = true;
  }
}
 

private static boolean sparseIntArrayEquals(SparseIntArray a, SparseIntArray b) {
    if (a == b) return true;
    if (a == null) return b == null;
    if (b == null) return false;
    int size = a.size();
    if (size != b.size()) return false;
    for (int i=0; i<size; ++i) {
        if (a.keyAt(i) != b.keyAt(i)) return false;
        if (a.valueAt(i) != b.valueAt(i)) return false; 
    }
    return true;
}
 

/**
 * Finds {@link ViewNode ViewNodes} that have the requested ids.
 *
 * @param ids The ids of the node to find.
 *
 * @return The nodes indexed in the same way as the ids.
 *
 * @hide
 */
@NonNull public ViewNode[] findViewNodesByAutofillIds(@NonNull AutofillId[] ids) {
    final LinkedList<ViewNode> nodesToProcess = new LinkedList<>();
    final ViewNode[] foundNodes = new AssistStructure.ViewNode[ids.length];

    // Indexes of foundNodes that are not found yet
    final SparseIntArray missingNodeIndexes = new SparseIntArray(ids.length);

    for (int i = 0; i < ids.length; i++) {
        if (mViewNodeLookupTable != null) {
            int lookupTableIndex = mViewNodeLookupTable.indexOfKey(ids[i]);

            if (lookupTableIndex >= 0) {
                foundNodes[i] = mViewNodeLookupTable.valueAt(lookupTableIndex);
            } else {
                missingNodeIndexes.put(i, /* ignored */ 0);
            }
        } else {
            missingNodeIndexes.put(i, /* ignored */ 0);
        }
    }

    final int numWindowNodes = mStructure.getWindowNodeCount();
    for (int i = 0; i < numWindowNodes; i++) {
        nodesToProcess.add(mStructure.getWindowNodeAt(i).getRootViewNode());
    }

    while (missingNodeIndexes.size() > 0 && !nodesToProcess.isEmpty()) {
        final ViewNode node = nodesToProcess.removeFirst();

        for (int i = 0; i < missingNodeIndexes.size(); i++) {
            final int index = missingNodeIndexes.keyAt(i);
            final AutofillId id = ids[index];

            if (id.equals(node.getAutofillId())) {
                foundNodes[index] = node;

                if (mViewNodeLookupTable == null) {
                    mViewNodeLookupTable = new ArrayMap<>(ids.length);
                }

                mViewNodeLookupTable.put(id, node);

                missingNodeIndexes.removeAt(i);
                break;
            }
        }

        for (int i = 0; i < node.getChildCount(); i++) {
            nodesToProcess.addLast(node.getChildAt(i));
        }
    }

    // Remember which ids could not be resolved to not search for them again the next time
    for (int i = 0; i < missingNodeIndexes.size(); i++) {
        if (mViewNodeLookupTable == null) {
            mViewNodeLookupTable = new ArrayMap<>(missingNodeIndexes.size());
        }

        mViewNodeLookupTable.put(ids[missingNodeIndexes.keyAt(i)], null);
    }

    return foundNodes;
}
 

private int getPoemImageId() {
    final SparseIntArray imgList = poemTheme.getImageList();

    // the line below seems weird, but relies on the fact that the index of SparseIntArray could be any integer
    return imgList.keyAt(imgList.indexOfValue(imgList.get(poemImagePager.getCurrentItem() + 1)));
}
 

/**
 * Handles restoring an individual tab.
 *
 * @param tabToRestore Meta data about the tab to be restored.
 * @param tabState     The previously serialized state of the tab to be restored.
 * @param setAsActive  Whether the tab should be set as the active tab as part of the
 *                     restoration process.
 */
@VisibleForTesting
protected void restoreTab(
        TabRestoreDetails tabToRestore, TabState tabState, boolean setAsActive) {
    // If we don't have enough information about the Tab, bail out.
    boolean isIncognito = isIncognitoTabBeingRestored(tabToRestore, tabState);
    if (tabState == null) {
        if (tabToRestore.isIncognito == null) {
            Log.w(TAG, "Failed to restore tab: not enough info about its type was available.");
            return;
        } else if (isIncognito) {
            Log.i(TAG, "Failed to restore Incognito tab: its TabState could not be restored.");
            return;
        }
    }

    TabModel model = mTabModelSelector.getModel(isIncognito);
    SparseIntArray restoredTabs = isIncognito ? mIncognitoTabsRestored : mNormalTabsRestored;
    int restoredIndex = 0;
    if (tabToRestore.fromMerge) {
        // Put any tabs being merged into this list at the end.
        restoredIndex = mTabModelSelector.getModel(isIncognito).getCount();
    } else if (restoredTabs.size() > 0
            && tabToRestore.originalIndex > restoredTabs.keyAt(restoredTabs.size() - 1)) {
        // If the tab's index is too large, restore it at the end of the list.
        restoredIndex = restoredTabs.size();
    } else {
         // Otherwise try to find the tab we should restore before, if any.
        for (int i = 0; i < restoredTabs.size(); i++) {
            if (restoredTabs.keyAt(i) > tabToRestore.originalIndex) {
                Tab nextTabByIndex = TabModelUtils.getTabById(model, restoredTabs.valueAt(i));
                restoredIndex = nextTabByIndex != null ? model.indexOf(nextTabByIndex) : -1;
                break;
            }
        }
    }

    int tabId = tabToRestore.id;
    if (tabState != null) {
        mTabCreatorManager.getTabCreator(isIncognito).createFrozenTab(
                tabState, tabToRestore.id, restoredIndex);
    } else {
        if (NewTabPage.isNTPUrl(tabToRestore.url) && !setAsActive && !tabToRestore.fromMerge) {
            Log.i(TAG, "Skipping restore of non-selected NTP.");
            return;
        }

        Log.w(TAG, "Failed to restore TabState; creating Tab with last known URL.");
        Tab fallbackTab = mTabCreatorManager.getTabCreator(isIncognito).createNewTab(
                new LoadUrlParams(tabToRestore.url), TabModel.TabLaunchType.FROM_RESTORE, null);
        tabId = fallbackTab.getId();
        model.moveTab(tabId, restoredIndex);
    }

    // If the tab is being restored from a merge and its index is 0, then the model being
    // merged into doesn't contain any tabs. Select the first tab to avoid having no tab
    // selected. TODO(twellington): The first tab will always be selected. Instead, the tab that
    // was selected in the other model before the merge should be selected after the merge.
    if (setAsActive || (tabToRestore.fromMerge && restoredIndex == 0)) {
        boolean wasIncognitoTabModelSelected = mTabModelSelector.isIncognitoSelected();
        int selectedModelTabCount = mTabModelSelector.getCurrentModel().getCount();

        TabModelUtils.setIndex(model, TabModelUtils.getTabIndexById(model, tabId));
        boolean isIncognitoTabModelSelected = mTabModelSelector.isIncognitoSelected();

        // Setting the index will cause the tab's model to be selected. Set it back to the model
        // that was selected before setting the index if the index is being set during a merge
        // unless the previously selected model is empty (e.g. showing the empty background
        // view on tablets).
        if (tabToRestore.fromMerge
                && wasIncognitoTabModelSelected != isIncognitoTabModelSelected
                && selectedModelTabCount != 0) {
            mTabModelSelector.selectModel(wasIncognitoTabModelSelected);
        }
    }
    restoredTabs.put(tabToRestore.originalIndex, tabId);
}