/**
* Load data via the proxy, and pump the records into the store
*
* @throws Exception
*/
public ObservableFuture<Void> load() throws Exception {
if (lastLoadingFuture != null) {
// cancel the old ones.
lastLoadingFuture.cancel();
lastProxyLoadingFuture.cancel();
}
// this might take a long time.
// unfortunately i can't sync during it.
// but this means that after a LOAD operation is requested,
// any adds that someone does will be overridden by the proxy.load() return value.
// note: unfortunately this is synchronous.
lastProxyLoadingFuture = proxy.load();
lastLoadingFuture = new DefaultObservableFuture<Void>(this);
// listen for completion of this future.
lastProxyLoadingFuture.addObserver(onLoadCompleteCallback);
// this whitespace might be all it takes to miss a callback, so we have to listen first, check
// second.
if (handleImmediatelyDone(lastProxyLoadingFuture, lastLoadingFuture)) {
lastProxyLoadingFuture.removeObserver(onLoadCompleteCallback);
}
return lastLoadingFuture;
}
/**
* This future is the future of the proxy
*
* @param internal
* @param external
* @throws Exception
* @return if it was done or not
*/
private synchronized boolean handleImmediatelyDone(
ObservableFuture<D> internal, MutableObservableFuture<Void> external) throws Exception {
// if it's already done, we need to do some work.
if (internal.isDone()) {
if (internal.isSuccess()) {
// already done! shit! we missed it!
parseAndLoad(internal.getResult());
external.setSuccess(null);
} else if (internal.isCancelled()) {
// cascade the cancellation
external.cancel();
} else {
// must be in error?
external.setFailure(internal.getCause());
}
return true;
}
return false;
}