MediaBrowserCompat queue find item

Question

As per Uamp sample when onPlayFromMediaId is called its mediaId is matched with list of queueitems already stored using iterator as below

public static int getMusicIndexOnQueue(Iterable<MediaSessionCompat.QueueItem> queue,
         String mediaId) {
    int index = 0;
    for (MediaSessionCompat.QueueItem item : queue) {
        if (mediaId.equals(item.getDescription().getMediaId())) {
            return index;
        }
        index++;
    }
    return -1;
} 

this works great unless you have some thousand items in your list, its lags badly, is there any way I can get the index on queue in this scenario?

P.S.- This code is from v1 branch although v2 kotlin based branch has the same concept.

Answer 1

There is no API available that gets you this directly. So, you have to build your own data structure.

I created a HashMap of MediaId's as key and Index as its value. This will help you fetch the QueueItem faster. The question then becomes, when to create this HashMap. I created this in the callback when you are fetching the media List (QueueItem) from the device. The idea is to create this Map in background.

HashMap<String, Integer> mediaIndexMap = new HashMap<String, Integer>();
int index = 0;
for (MediaSessionCompat.QueueItem item : queue) {
    mediaIndexMap.put(item.getDescription().getMediaId(), index++);
}

Hopefully this preprocessing QueuItem should work for constant time lookup/fetch.