What is LeastRecentlyUsedCacheEvictor in ExoPlayer?

ExoPlayer video cache uses a CacheEvictor instance to tell the library when to delete cached files. LeastRecentlyUsedCacheEvictor as the name represents declares that policy in a least recently used order.

Assuming you have watched video A, B, C, A (again) and D (order matters) and you hit the maximum cache capacity passed in LeastRecentlyUsedCacheEvictor constructor. The evictor instance lists the cache usages and finds video B as the least recently used one and deletes it to free space.

Here is a simple usage example:

public class VideoCacheSingleton {
    private static final int MAX_VIDEO_CACHE_SIZE_IN_BYTES = 200 * 1024 * 1024;  // 200MB

    private static Cache sInstance;

    public static Cache getInstance(Context context) {
        if (sInstance != null) return sInstance;
        else return sInstance = new SimpleCache(new File(context.getCacheDir(), "video"), new LeastRecentlyUsedCacheEvictor(MAX_VIDEO_CACHE_SIZE_IN_BYTES), new ExoDatabaseProvider(context)));
    }
}