Get everything in from ExoPlayer Cache

问题

Using https://google.github.io/ExoPlayer/doc/reference/com/google/android/exoplayer2/upstream/cache/CacheDataSourceFactory.html is there a way to grab all the MediaSources that have been cached?

回答1:

The Cache offers no convenient API to get all completely cached URIs or similar.

If you create your own CacheEvictor (for instance by wrapping a LeastRecentlyUsedCacheEvictor) you can do your own book keeping when spans are added or removed and then delegate to the LRUCacheEvictor. This way you can maintain a list of cached URLs.

You can check what portions for a given uri is cached:

// create the data spec of a given media file
Uri uri = Uri.parse("http://cool.stuff.com/song-123.mp3")
DataSpec dataSpec = new DataSpec(uri);
// get information about what is cached for the given data spec
CacheUtil.CachingCounters counters = new CacheUtil.CachingCounters();
CacheUtil.getCached(dataSpec, cache, counters);
if (counters.contentLength == counters.totalCachedBytes()) {
  // all bytes cached
} else if (counters.totalCachedBytes() == 0){
  // not cached at all
} else {
  // partially cached
}

If the data for a given uri is only partially cached you can check what spans are available like this:

NavigableSet<CacheSpan> cachedSpans =
   cache.getCachedSpans(CacheUtil.generateKey(uri));

来源：https://stackoverflow.com/questions/48087752/get-everything-in-from-exoplayer-cache