Caching also the calculated anonymous bitmap as proposed by maniac103. This...

     */

    private static final int PICTURE_SIZE = 40;

    /**

     * Maximum number of email addresses to store in {@link #mUnknownContactsCache}.

     */

    private static final int MAX_UNKNOWN_CONTACTS = 1000;

    /**

     * Used as lightweight dummy value for entries in {@link #mUnknownContactsCache}.

     */

    private static final int[] DUMMY_INT_ARRAY = new int[0];

    private ContentResolver mContentResolver;

    private Resources mResources;

    private Contacts mContactsHelper;

     */

    private final LruCache<String, Bitmap> mBitmapCache;

    /**

     * LRU cache of email addresses that don't belong to a contact we have a picture for.

     *

     * <p>

     * We don't store the default picture for unknown contacts or contacts without a picture in

     * {@link #mBitmapCache}, because that would lead to an unnecessarily complex implementation of

     * the {@code LruCache.sizeOf()} method. Instead, we save the email addresses we know don't

     * belong to one of our contacts with a picture. Knowing this, we can avoid querying the

     * contacts database for those addresses and immediately return the default picture.

     * </p>

     */

    private final LruCache<String, int[]> mUnknownContactsCache;

    private final static int CONTACT_DUMMY_COLORS_ARGB[] = {

        0xffff0000, // 0 R, G, B

        0xff00ff00,

                return bitmap.getRowBytes() * bitmap.getHeight();

            }

        };

        mUnknownContactsCache = new LruCache<String, int[]>(MAX_UNKNOWN_CONTACTS);

    }

    /**

        if (bitmap != null) {

            // The picture was found in the bitmap cache

            badge.setImageBitmap(bitmap);

        } else if (isEmailInUnknownContactsCache(email)) {

            // This email address doesn't belong to a contact we have a picture for. Use the

            // default picture.

            badge.setImageBitmap(calculateFallbackBitmap(address));

        } else if (cancelPotentialWork(email, badge)) {

            // Query the contacts database in a background thread and try to load the contact

            // picture, if there is one.

        return mBitmapCache.get(key);

    }

    private void addEmailToUnknownContactsCache(String key) {

        if (!isEmailInUnknownContactsCache(key)) {

            mUnknownContactsCache.put(key, DUMMY_INT_ARRAY);

        }

    }

    private boolean isEmailInUnknownContactsCache(String key) {

        return mUnknownContactsCache.get(key) != null;

    }

    /**

     * Checks if a {@code ContactPictureRetrievalTask} was already created to load the contact

     * picture for the supplied email address.

            	bitmap = calculateFallbackBitmap(mAddress);

                // Remember that we don't have a contact picture for this email address

                addEmailToUnknownContactsCache(email);

                addBitmapToCache(email, bitmap);

            } else {

                // Save the picture of the contact with that email address in the memory cache

                addBitmapToCache(email, bitmap);