While thinking about the intersection of RxJava and Android, I realized there was no default scheduler in the library that allowed for prioritizing actions before others, similar to how Volley's Request.Priority. I decided to try and work something together and this is what I initially came up with. Some of the threading seems a bit strange and the Worker works (no pun intended) a bit differently than others, but it seems to do the trick. Gladly accepting comments/pull requests!
final int PRIORITY_HIGH = 10;
final int PRIORITY_LOW = 1;
PriorityScheduler scheduler = new PriorityScheduler();
Observable.just(1, 2, 3, 4, 5)
.subscribeOn(scheduler.priority(PRIORITY_LOW))
.subscribe(System.out::println);
Observable.just(6, 7, 8, 9, 10)
.subscribeOn(scheduler.priority(PRIORITY_HIGH))
.subscribe(System.out::println);
Priorties are simply ints ordered in increasing order. An action with a priority higher than another will be scheduled before (note that actions with the same priority may run in any order). Priorities may be any valid integer; you may want to define:
private static final int PRIORITY_WHENEVER = Integer.MIN_VALUE;
and/or
private static final int PRIORITY_NEXT = Integer.MAX_VALUE;
Gradle:
compile 'me.ronshapiro.rx.priority:priority:0.2'
Since this is still a nascent idea, if you're using this library, please let me know (@rdshapiro) how it's going!