/**
* Subscribe to a given USK. Callback will be notified when it is updated. Note that this does not
* imply that the USK will be checked on a regular basis, unless runBackgroundFetch=true.
*/
public void subscribe(
USK origUSK,
USKCallback cb,
boolean runBackgroundFetch,
boolean ignoreUSKDatehints,
RequestClient client) {
if (logMINOR) Logger.minor(this, "Subscribing to " + origUSK + " for " + cb);
if (client.persistent())
throw new UnsupportedOperationException("USKManager subscriptions cannot be persistent");
USKFetcher sched = null;
long ed = origUSK.suggestedEdition;
if (ed < 0) {
Logger.error(this, "Subscribing to USK with negative edition number: " + ed);
ed = -ed;
}
long curEd;
curEd = lookupLatestSlot(origUSK);
long goodEd;
goodEd = lookupKnownGood(origUSK);
synchronized (this) {
USK clear = origUSK.clearCopy();
USKCallback[] callbacks = subscribersByClearUSK.get(clear);
if (callbacks == null) {
callbacks = new USKCallback[] {cb};
} else {
boolean mustAdd = true;
for (USKCallback callback : callbacks) {
if (callback == cb) {
// Already subscribed.
// But it may still be waiting for the callback.
if (!(curEd > ed || goodEd > ed)) return;
mustAdd = false;
}
}
if (mustAdd) {
callbacks = Arrays.copyOf(callbacks, callbacks.length + 1);
callbacks[callbacks.length - 1] = cb;
}
}
subscribersByClearUSK.put(clear, callbacks);
if (runBackgroundFetch) {
USKFetcher f = backgroundFetchersByClearUSK.get(clear);
if (f == null) {
f =
new USKFetcher(
origUSK,
this,
ignoreUSKDatehints ? backgroundFetchContextIgnoreDBR : backgroundFetchContext,
new USKFetcherWrapper(origUSK, RequestStarter.UPDATE_PRIORITY_CLASS, client),
3,
true,
false,
false);
sched = f;
backgroundFetchersByClearUSK.put(clear, f);
}
f.addSubscriber(cb, origUSK.suggestedEdition);
}
}
if (goodEd > ed)
cb.onFoundEdition(
goodEd, origUSK.copy(curEd), null, context, false, (short) -1, null, true, curEd > ed);
else if (curEd > ed)
cb.onFoundEdition(
curEd, origUSK.copy(curEd), null, context, false, (short) -1, null, false, false);
final USKFetcher fetcher = sched;
if (fetcher != null) {
executor.execute(
new Runnable() {
@Override
public void run() {
if (logMINOR) Logger.minor(this, "Starting " + fetcher);
fetcher.schedule(null, context);
}
},
"USKManager.schedule for " + fetcher);
}
}
