private synchronized void invalidateFutureCache() {
        // cancel and remove requests
        mSegmentDownloader.cancelDownloads(mAdaptationSet);

        // delete and remove files
        for(Integer segmentNumber : mFutureCache.keySet()) {
            mFutureCache.get(segmentNumber).file.delete();
        }
        mFutureCache.clear();
    }
Invalidates the cache by cancelling all pending requests and deleting all buffered segments.
MediaPlayer-DASH/src/main/java/net/protyposis/android/mediaplayer/dash/DashMediaExtractor.java