/**
* Subscribe to a USK. When it is updated, the content will be fetched (subject to the limits in
* fctx), and returned to the callback. If we are asked to do a background fetch, we will only
* fetch editions when we are fairly confident there are no more to fetch.
*
* @param origUSK The USK to poll.
* @param cb Callback, called when we have downloaded a new key.
* @param runBackgroundFetch If true, start a background fetcher for the key, which will run
* forever until we unsubscribe. Note that internally we use subscribeSparse() in this case,
* i.e. we will only download editions which we are confident about.
* @param fctx Fetcher context for actually fetching the keys. Not used by the USK polling.
* @param prio Priority for fetching the content (see constants in RequestScheduler).
* @param sparse If true, only fetch once we're sure it's the latest edition.
* @return
*/
public USKRetriever subscribeContent(
USK origUSK,
USKRetrieverCallback cb,
boolean runBackgroundFetch,
FetchContext fctx,
short prio,
RequestClient client) {
USKRetriever ret = new USKRetriever(fctx, prio, client, cb, origUSK);
USKCallback toSub = ret;
if (logMINOR) Logger.minor(this, "Subscribing to " + origUSK + " for " + cb);
if (runBackgroundFetch) {
USKSparseProxyCallback proxy = new USKSparseProxyCallback(ret, origUSK);
ret.setProxy(proxy);
toSub = proxy;
}
subscribe(origUSK, toSub, runBackgroundFetch, fctx.ignoreUSKDatehints, client);
return ret;
}
/**
* Subscribe to a USK with a custom FetchContext. This is "off the books", i.e. the background
* fetcher isn't started by subscribe().
*/
public USKRetriever subscribeContentCustom(
USK origUSK, USKRetrieverCallback cb, FetchContext fctx, short prio, RequestClient client) {
USKRetriever ret = new USKRetriever(fctx, prio, client, cb, origUSK);
USKCallback toSub = ret;
if (logMINOR) Logger.minor(this, "Subscribing to " + origUSK + " for " + cb);
USKSparseProxyCallback proxy = new USKSparseProxyCallback(ret, origUSK);
ret.setProxy(proxy);
toSub = proxy;
/* runBackgroundFetch=false -> ignoreUSKDatehints unused */
subscribe(origUSK, toSub, false, client);
USKFetcher f =
new USKFetcher(
origUSK,
this,
fctx,
new USKFetcherWrapper(origUSK, prio, client),
3,
true,
false,
false);
ret.setFetcher(f);
return ret;
}
public void unsubscribeContent(USK origUSK, USKRetriever ret, boolean runBackgroundFetch) {
ret.unsubscribe(this);
}
