reduce the number of force() calls on storages

jps/jps-builders/src/org/jetbrains/jps/incremental/CompileContext.java

@@ -210,6 +210,10 @@ public class CompileContext extends UserDataHolderBase implements MessageHandler
     return myDataManager;
   }
 
+  public TimestampStorage getTimestampStorage() {
+    return myTsStorage;
+  }
+
   public void processMessage(BuildMessage msg) {
     if (msg.getKind() == BuildMessage.Kind.ERROR) {
       myErrorsFound = true;

jps/jps-builders/src/org/jetbrains/jps/incremental/IncProjectBuilder.java

@@ -102,6 +102,10 @@ public class IncProjectBuilder {
   }
 
   private static void flushContext(CompileContext context) {
+    if (context != null) {
+      context.getTimestampStorage().force();
+      context.getDataManager().flush(false);
+    }
     final ExternalJavacDescriptor descriptor = ExternalJavacDescriptor.KEY.get(context);
     if (descriptor != null) {
       try {

jps/jps-builders/src/org/jetbrains/jps/server/ProjectDescriptor.java

@@ -53,9 +53,5 @@ public final class ProjectDescriptor {
         }
       }
     }
-    else {
-      timestamps.getStorage().force();
-      dataManager.flush(false);
-    }
   }
 }