@Override
    public synchronized long available() throws ProxyCacheException {
        try {
            return (int) dataFile.length();
        } catch (IOException e) {
            throw new ProxyCacheException("Error reading length of file " + file, e);
        }
    }
{@link Cache} that uses file for storing data.

@author Alexey Danilov (danikula@gmail.com).
dkplayer-videocache/src/main/java/com/danikula/videocache/file/FileCache.java