java.util.ArrayList#hashCode ( )源码实例Demo

public void testOffHeapAutoFree()
{
    long sum = 0;
    long constructed = 0;
    while(true)
    {
        ArrayList list = new ArrayList();
        for(int i=0;i<1000;i++)
        {
            list.add(new OffHeapTest(100));
            constructed++;
        }
        sum += list.hashCode();
        if ((constructed & ((1 << 10) - 1)) == 0)
        {
            System.out.println("constructed: "+constructed+", freed: "+ OffHeapCleaner.getInstance().getFreedCount());
        }
        if (constructed < 0)
        {
            break;
        }
    }
    System.out.println("sum: "+sum);
}
 

public void testOffHeapAutoFreeAfterRealloc()
{
    long sum = 0;
    long constructed = 0;
    while(true)
    {
        ArrayList list = new ArrayList();
        for(int i=0;i<1000;i++)
        {
            OffHeapTest e = new OffHeapTest(100);
            list.add(e);
            e.reallocate(200);
            constructed++;
        }
        sum += list.hashCode();
        if ((constructed & ((1 << 10) - 1)) == 0)
        {
            System.out.println("constructed: "+constructed+", freed: "+ OffHeapCleaner.getInstance().getFreedCount());
        }
        if (constructed < 0)
        {
            break;
        }
    }
    System.out.println("sum: "+sum);
}
 

boolean haveContentsChanged() {
    if (!PermissionsUtil.checkAllPermissionsGranted(
            mContext, Manifest.permission.READ_CONTACTS)) {
        Log.i(TAG, "No permission to read contacts. Marking contacts as not changed.");
        return false;
    }

    final long startTime = SystemClock.uptimeMillis();
    final int contactCount = mManager.getContactCount();
    if (contactCount > ContactsDictionaryConstants.MAX_CONTACTS_PROVIDER_QUERY_LIMIT) {
        // If there are too many contacts then return false. In this rare case it is impossible
        // to include all of them anyways and the cost of rebuilding the dictionary is too high.
        // TODO: Sort and check only the most recent contacts?
        return false;
    }
    if (contactCount != mManager.getContactCountAtLastRebuild()) {
        if (DebugFlags.DEBUG_ENABLED) {
            Log.d(TAG, "haveContentsChanged() : Count changed from "
                    + mManager.getContactCountAtLastRebuild() + " to " + contactCount);
        }
        return true;
    }
    final ArrayList<String> names = mManager.getValidNames(Contacts.CONTENT_URI);
    if (names.hashCode() != mManager.getHashCodeAtLastRebuild()) {
        return true;
    }
    if (DebugFlags.DEBUG_ENABLED) {
        Log.d(TAG, "haveContentsChanged() : No change detected in "
                + (SystemClock.uptimeMillis() - startTime) + " ms)");
    }
    return false;
}
 

boolean haveContentsChanged() {
    if (!PermissionsUtil.checkAllPermissionsGranted(
            mContext, Manifest.permission.READ_CONTACTS)) {
        Log.i(TAG, "No permission to read contacts. Marking contacts as not changed.");
        return false;
    }

    final long startTime = SystemClock.uptimeMillis();
    final int contactCount = mManager.getContactCount();
    if (contactCount > ContactsDictionaryConstants.MAX_CONTACTS_PROVIDER_QUERY_LIMIT) {
        // If there are too many contacts then return false. In this rare case it is impossible
        // to include all of them anyways and the cost of rebuilding the dictionary is too high.
        // TODO: Sort and check only the most recent contacts?
        return false;
    }
    if (contactCount != mManager.getContactCountAtLastRebuild()) {
        if (DebugFlags.DEBUG_ENABLED) {
            Log.d(TAG, "haveContentsChanged() : Count changed from "
                    + mManager.getContactCountAtLastRebuild() + " to " + contactCount);
        }
        return true;
    }
    final ArrayList<String> names = mManager.getValidNames(Contacts.CONTENT_URI);
    if (names.hashCode() != mManager.getHashCodeAtLastRebuild()) {
        return true;
    }
    if (DebugFlags.DEBUG_ENABLED) {
        Log.d(TAG, "haveContentsChanged() : No change detected in "
                + (SystemClock.uptimeMillis() - startTime) + " ms)");
    }
    return false;
}
 

public void testOffHeapAutoFreeManual()
{
    long sum = 0;
    long constructed = 0;
    while(true)
    {
        ArrayList list = new ArrayList();
        for(int i=0;i<1000;i++)
        {
            list.add(new OffHeapTest(100));
            constructed++;
        }
        sum += list.hashCode();
        for(int i=0;i<1000;i++)
        {
            OffHeapTest t = (OffHeapTest) list.get(i);
            t.destroy();
        }

        if ((constructed & ((1 << 10) - 1)) == 0)
        {
            System.out.println("constructed: "+constructed+", freed: "+ OffHeapCleaner.getInstance().getFreedCount());
        }
        if (constructed < 0)
        {
            break;
        }
    }
    System.out.println("sum: "+sum);
}
 

public int hashCode() {
  ArrayList<Integer> hs = new ArrayList<Integer>(2 + f2e.length + e2f.length);
  hs.add(e().hashCode());
  hs.add(f().hashCode());
  for (Set<Integer> af2e : f2e)
    hs.add(Arrays.hashCode(af2e.toArray()));
  for (Set<Integer> ae2f : e2f)
    hs.add(Arrays.hashCode(ae2f.toArray()));
  return hs.hashCode();
}
 

boolean haveContentsChanged() {
    if (!PermissionsUtil.checkAllPermissionsGranted(
            mContext, Manifest.permission.READ_CONTACTS)) {
        Log.i(TAG, "No permission to read contacts. Marking contacts as not changed.");
        return false;
    }

    final long startTime = SystemClock.uptimeMillis();
    final int contactCount = mManager.getContactCount();
    if (contactCount > ContactsDictionaryConstants.MAX_CONTACTS_PROVIDER_QUERY_LIMIT) {
        // If there are too many contacts then return false. In this rare case it is impossible
        // to include all of them anyways and the cost of rebuilding the dictionary is too high.
        // TODO: Sort and check only the most recent contacts?
        return false;
    }
    if (contactCount != mManager.getContactCountAtLastRebuild()) {
        if (DebugFlags.DEBUG_ENABLED) {
            Log.d(TAG, "haveContentsChanged() : Count changed from "
                    + mManager.getContactCountAtLastRebuild() + " to " + contactCount);
        }
        return true;
    }
    final ArrayList<String> names = mManager.getValidNames(Contacts.CONTENT_URI);
    if (names.hashCode() != mManager.getHashCodeAtLastRebuild()) {
        return true;
    }
    if (DebugFlags.DEBUG_ENABLED) {
        Log.d(TAG, "haveContentsChanged() : No change detected in "
                + (SystemClock.uptimeMillis() - startTime) + " ms)");
    }
    return false;
}