Method loadFuture

output/java_guava/1.4.13/LocalCache.java:3585–3613

(K key, CacheLoader<? super K, V> loader)

    public ListenableFuture<V> loadFuture(K key, CacheLoader<? super K, V> loader) {
            try {
        stopwatch.start();
        V previousValue = oldValue.get();
        if (previousValue == null) {
                V newValue = loader.load(key);
                return set(newValue) ? futureValue : Futures.immediateFuture(newValue);
        }
        ListenableFuture<V> newValue = loader.reload(key, previousValue);
        if (newValue == null) {
                return Futures.immediateFuture(null);
        }
        // To avoid a race, make sure the refreshed value is set into loadingValueReference
        // *before* returning newValue from the cache query.
        return Futures.transform(newValue, new Function<V, V>() {
            @Override
            public V apply(V newValue) {
                                               LoadingValueReference.this.set(newValue);
                                               return newValue;
            }
                                           });
            } catch (Throwable t) {
              ListenableFuture<V> result = setException(t) ? futureValue : fullyFailedFuture(t);
              if (t instanceof InterruptedException) {
                Thread.currentThread().interrupt();
              }
              return result;
            }
           }


    public long elapsedNanos() {