Set Status.PRESENT after synchronous preload

Fixes #949

src/main/java/com/conveyal/r5/analyst/NetworkPreloader.java

@@ -97,7 +97,10 @@ public LoaderState<TransportNetwork> preloadData (AnalysisWorkerTask task) {
      * data is prepared. 
      */
     public TransportNetwork synchronousPreload (AnalysisWorkerTask task) {
-        return buildValue(Key.forTask(task));
+        Key key = Key.forTask(task);
+        TransportNetwork scenarioNetwork = buildValue(key);
+        setComplete(key, scenarioNetwork);
+        return scenarioNetwork;
     }
 
     @Override
@@ -140,7 +143,7 @@ protected TransportNetwork buildValue(Key key) {
                 linkedPointSet.getEgressCostTable(progressListener);
             }
         }
-        // Finished building all needed inputs for analysis, return the completed network to the AsyncLoader code.
+        // Finished building all needed inputs for analysis, return the completed network
         return scenarioNetwork;
     }
 

src/main/java/com/conveyal/r5/util/AsyncLoader.java

@@ -28,7 +28,7 @@
  * "value is present in map".
  *
  * Potential problem: if we try to return immediately saying whether the needed data are available,
- * there are some cases where preparing the reqeusted object might take only a few hundred milliseconds or less.
+ * there are some cases where preparing the requested object might take only a few hundred milliseconds or less.
  * In that case then we don't want the caller to have to re-poll. In this case a Future.get() with timeout is good.
  *
  * Created by abyrd on 2018-09-14
@@ -123,9 +123,7 @@ public LoaderState<V> get (K key) {
                 setProgress(key, 0, "Starting...");
                 try {
                     V value = buildValue(key);
-                    synchronized (map) {
-                        map.put(key, new LoaderState(Status.PRESENT, null, 100, value));
-                    }
+                    setComplete(key, value);
                 } catch (Throwable t) {
                     // It's essential to trap Throwable rather than just Exception. Otherwise the executor
                     // threads can be killed by any Error that happens, stalling the executor.
@@ -139,7 +137,8 @@ public LoaderState<V> get (K key) {
 
     /**
      * Override this method in concrete subclasses to specify the logic to build/calculate/fetch a value.
-     * Implementations may call setProgress to report progress on long operations.
+     * Implementations may call setProgress to report progress on long operations; if they do so, any callers of this
+     * method are responsible for also calling setComplete() to ensure loaded objects are marked as PRESENT.
      * Throw an exception to indicate an error has occurred and the building process cannot complete.
      * It's not entirely clear this should return a value - might be better to call setValue within the overridden
      * method, just as we call setProgress or setError.
@@ -155,6 +154,12 @@ public void setProgress(K key, int percentComplete, String message) {
         }
     }
 
+    public void setComplete(K key, V value) {
+        synchronized (map) {
+            map.put(key, new LoaderState(Status.PRESENT, "Loaded", 100, value));
+        }
+    }
+
     /**
      * Call this method inside the buildValue method to indicate that an unrecoverable error has happened.
      * FIXME this will permanently associate an error with the key. No further attempt will ever be made to create the value.