Ability to have unknown parts of multi-part ProgressListener

where the unknown parts won't affect total count and instead be seen
as periods where no progress is happening.

community/consistency-check/src/main/java/org/neo4j/consistency/checking/full/RecordScanner.java

@@ -39,7 +39,10 @@ public RecordScanner( String name, Statistics statistics, int threads, BoundedIt
         super( name, statistics, threads );
         this.store = store;
         this.processor = processor;
-        this.progress = builder.progressForPart( name, store.maxCount() );
+        long maxCount = store.maxCount();
+        this.progress = maxCount == -1
+                ? builder.progressForUnknownPart( name )
+                : builder.progressForPart( name, maxCount );
         this.warmUpStores = warmUpStores;
     }
 

community/kernel/src/main/java/org/neo4j/helpers/progress/Aggregator.java

@@ -28,9 +28,9 @@
 
 final class Aggregator
 {
-    private final Map<ProgressListener.MultiPartProgressListener, ProgressListener.MultiPartProgressListener.State> states =
+    private final Map<ProgressListener, ProgressListener.MultiPartProgressListener.State> states =
             new ConcurrentHashMap<>();
-    private Indicator indicator;
+    private final Indicator indicator;
     @SuppressWarnings("unused"/*accessed through updater*/)
     private volatile long progress;
     @SuppressWarnings("unused"/*accessed through updater*/)
@@ -46,10 +46,10 @@ public Aggregator( Indicator indicator )
         this.indicator = indicator;
     }
 
-    synchronized void add( ProgressListener.MultiPartProgressListener progress )
+    synchronized void add( ProgressListener progress, long totalCount )
     {
         states.put( progress, ProgressListener.MultiPartProgressListener.State.INIT );
-        this.totalCount += progress.totalCount;
+        this.totalCount += totalCount;
     }
 
     synchronized Completion initialize()

community/kernel/src/main/java/org/neo4j/helpers/progress/ProgressMonitorFactory.java

@@ -94,7 +94,7 @@ public final ProgressListener openEnded( String process, int resolution )
     public static class MultiPartBuilder
     {
         private Aggregator aggregator;
-        private Set<String> parts = new HashSet<String>();
+        private Set<String> parts = new HashSet<>();
         private Completion completion = null;
 
         private MultiPartBuilder( ProgressMonitorFactory factory, String process )
@@ -104,17 +104,37 @@ private MultiPartBuilder( ProgressMonitorFactory factory, String process )
 
         public ProgressListener progressForPart( String part, long totalCount )
         {
-            if ( aggregator == null )
-            {
-                throw new IllegalStateException( "Builder has been completed." );
-            }
+            assertNotBuilt();
+            assertUniquePart( part );
+            ProgressListener.MultiPartProgressListener progress =
+                    new ProgressListener.MultiPartProgressListener( aggregator, part, totalCount );
+            aggregator.add( progress, totalCount );
+            return progress;
+        }
+
+        public ProgressListener progressForUnknownPart( String part )
+        {
+            assertNotBuilt();
+            assertUniquePart( part );
+            ProgressListener progress = ProgressListener.NONE;
+            aggregator.add( progress, 0 );
+            return progress;
+        }
+
+        private void assertUniquePart( String part )
+        {
             if ( !parts.add( part ) )
             {
                 throw new IllegalArgumentException( String.format( "Part '%s' has already been defined.", part ) );
             }
-            ProgressListener.MultiPartProgressListener progress = new ProgressListener.MultiPartProgressListener( aggregator, part, totalCount );
-            aggregator.add( progress );
-            return progress;
+        }
+
+        private void assertNotBuilt()
+        {
+            if ( aggregator == null )
+            {
+                throw new IllegalStateException( "Builder has been completed." );
+            }
         }
 
         public Completion build()