Allows using less ch weightings than loaded, fixes graphhopper#1413. (graphhopper#1488)

* Allows using less ch weightings than loaded, fixes graphhopper#1413.

* Fixes test (do not allow loading CH graph without CH weightings).

Author: easbar

core/src/main/java/com/graphhopper/storage/GraphHopperStorage.java

@@ -25,10 +25,7 @@
 import com.graphhopper.util.EdgeIteratorState;
 import com.graphhopper.util.shapes.BBox;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
+import java.util.*;
 
 /**
  * This class manages all storage related methods and delegates the calls to the associated graphs.
@@ -248,10 +245,7 @@ public boolean loadExisting() {
             String dim = properties.get("graph.dimension");
             baseGraph.loadExisting(dim);
 
-            String loadedCHWeightings = properties.get("graph.ch.weightings");
-            String configuredCHWeightings = getCHWeightings().toString();
-            if (!loadedCHWeightings.equals(configuredCHWeightings))
-                throw new IllegalStateException("Configured graph.ch.weightings: " + configuredCHWeightings + " is not equal to loaded " + loadedCHWeightings);
+            checkIfConfiguredAndLoadedWeightingsCompatible();
 
             for (CHGraphImpl cg : chGraphs) {
                 if (!cg.loadExisting())
@@ -263,6 +257,37 @@ public boolean loadExisting() {
         return false;
     }
 
+    private void checkIfConfiguredAndLoadedWeightingsCompatible() {
+        String loadedStr = properties.get("graph.ch.weightings");
+        List<String> loaded = parseList(loadedStr);
+        List<Weighting> configured = getCHWeightings();
+        if (configured.isEmpty() && !loaded.isEmpty()) {
+            throw new IllegalStateException("You loaded a CH graph, but you did not specify graph.ch.weightings");
+        }
+        for (Weighting w : configured) {
+            if (!loaded.contains(w.toString())) {
+                throw new IllegalStateException("Configured weighting: " + w.toString() + " is not contained in loaded weightings " + loadedStr + ".\n" +
+                        "You configured graph.ch.weightings: " + configured);
+            }
+        }
+    }
+
+    /**
+     * parses a string like [a,b,c]
+     */
+    private List<String> parseList(String listStr) {
+        String trimmed = listStr.trim();
+        String[] items = trimmed.substring(1, trimmed.length() - 1).split(",");
+        List<String> result = new ArrayList<>();
+        for (String item : items) {
+            String s = item.trim();
+            if (!s.isEmpty()) {
+                result.add(s);
+            }
+        }
+        return result;
+    }
+
     @Override
     public void flush() {
         for (CHGraphImpl cg : chGraphs) {

core/src/test/java/com/graphhopper/storage/GraphHopperStorageCHTest.java

@@ -21,6 +21,7 @@
 import com.graphhopper.routing.ch.PrepareEncoder;
 import com.graphhopper.routing.util.*;
 import com.graphhopper.routing.weighting.FastestWeighting;
+import com.graphhopper.routing.weighting.ShortestWeighting;
 import com.graphhopper.routing.weighting.Weighting;
 import com.graphhopper.storage.index.QueryResult;
 import com.graphhopper.util.*;
@@ -252,7 +253,7 @@ public void testQueryGraph() {
         EdgeExplorer explorer = baseGraph.createEdgeExplorer();
 
         assertTrue(chGraph.getNodes() < qGraph.getNodes());
-        assertTrue(baseGraph.getNodes() == qGraph.getNodes());
+        assertEquals(baseGraph.getNodes(), qGraph.getNodes());
 
         // traverse virtual edges and normal edges but no shortcuts!
         assertEquals(GHUtility.asSet(fromRes.getClosestNode()), GHUtility.getNeighbors(explorer.setBaseNode(0)));
@@ -414,7 +415,7 @@ public void testShortcutCreationAndAccessForManyVehicles() {
         // throw exception for wrong encoder
         try {
             assertFalse(carCHGraph.getEdgeIteratorState(carSC02.getEdge(), 2).isForward(tmpBike));
-            assertTrue(false);
+            fail();
         } catch (AssertionError ex) {
         }
 
@@ -425,8 +426,60 @@ public void testShortcutCreationAndAccessForManyVehicles() {
         // throw exception for wrong encoder
         try {
             assertFalse(bikeCHGraph.getEdgeIteratorState(bikeSC02.getEdge(), 2).isBackward(tmpCar));
-            assertTrue(false);
+            fail();
         } catch (AssertionError ex) {
         }
     }
+
+    @Test(expected = IllegalStateException.class)
+    public void testLoadingWithWrongWeighting_throws() {
+        // we start with one weighting
+        GraphHopperStorage ghStorage = newGHStorage(new GHDirectory(defaultGraphLoc, DAType.RAM_STORE), false);
+        ghStorage.create(defaultSize);
+        ghStorage.flush();
+
+        // but then configure another weighting and try to load the graph from disk -> error
+        GraphHopperStorage newGHStorage = createStorageWithWeightings(new ShortestWeighting(carEncoder));
+        newGHStorage.loadExisting();
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void testLoadingWithExtraWeighting_throws() {
+        // we start with one weighting
+        GraphHopperStorage ghStorage = newGHStorage(new GHDirectory(defaultGraphLoc, DAType.RAM_STORE), false);
+        ghStorage.create(defaultSize);
+        ghStorage.flush();
+
+        // but then add an additional weighting and try to load the graph from disk -> error
+        GraphHopperStorage newGHStorage = createStorageWithWeightings(
+                new FastestWeighting(carEncoder), new ShortestWeighting(carEncoder));
+        newGHStorage.loadExisting();
+    }
+
+    @Test
+    public void testLoadingWithLessWeightings_works() {
+        // we start with a gh storage with two ch weightings and flush it to disk
+        FastestWeighting weighting1 = new FastestWeighting(carEncoder);
+        ShortestWeighting weighting2 = new ShortestWeighting(carEncoder);
+        GraphHopperStorage originalStorage = createStorageWithWeightings(weighting1, weighting2);
+        originalStorage.create(defaultSize);
+        originalStorage.flush();
+
+        // now we create a new storage but only use one of the weightings, which should be ok
+        GraphHopperStorage smallStorage = createStorageWithWeightings(weighting1);
+        smallStorage.loadExisting();
+        assertEquals(1, smallStorage.getCHWeightings().size());
+        smallStorage.flush();
+
+        // now we create yet another storage that uses both weightings again, which still works
+        GraphHopperStorage fullStorage = createStorageWithWeightings(weighting1, weighting2);
+        fullStorage.loadExisting();
+        assertEquals(2, fullStorage.getCHWeightings().size());
+        fullStorage.flush();
+    }
+
+    private GraphHopperStorage createStorageWithWeightings(Weighting... weightings) {
+        return new GraphHopperStorage(Arrays.asList(weightings), new GHDirectory(defaultGraphLoc, DAType.RAM_STORE),
+                encodingManager, false, new GraphExtension.NoOpExtension());
+    }
 }

reader-osm/src/test/java/com/graphhopper/reader/osm/GraphHopperOSMTest.java

@@ -168,7 +168,7 @@ public void testLoadingWithDifferentCHConfig_issue471() {
             gh.load(ghLoc);
             fail();
         } catch (Exception ex) {
-            assertTrue(ex.getMessage(), ex.getMessage().startsWith("Configured graph.ch.weightings:"));
+            assertTrue(ex.getMessage(), ex.getMessage().startsWith("You loaded a CH graph, but you did not specify graph.ch.weightings"));
         }
 
         Helper.removeDir(new File(ghLoc));
@@ -190,7 +190,7 @@ public void testLoadingWithDifferentCHConfig_issue471() {
             gh.load(ghLoc);
             fail();
         } catch (Exception ex) {
-            assertTrue(ex.getMessage(), ex.getMessage().startsWith("Configured graph.ch.weightings:"));
+            assertTrue(ex.getMessage(), ex.getMessage().contains("is not contained in loaded weightings"));
         }
     }