Revert "Add ChangeDetector interface and ResourceChangeDetector imple…

…mentation (apache#388)"

This reverts commit e0c1c66.

helix-core/src/main/java/org/apache/helix/controller/dataproviders/ResourceControllerDataProvider.java

@@ -26,7 +26,6 @@
 import java.util.Map;
 import java.util.Set;
 
-import java.util.concurrent.ConcurrentHashMap;
 import org.apache.helix.HelixConstants;
 import org.apache.helix.HelixDataAccessor;
 import org.apache.helix.PropertyKey;
@@ -66,9 +65,6 @@ public class ResourceControllerDataProvider extends BaseControllerDataProvider {
   private Map<String, Map<String, MissingTopStateRecord>> _missingTopStateMap;
   private Map<String, Map<String, String>> _lastTopStateLocationMap;
 
-  // Maintain a set of all ChangeTypes for change detection
-  private Set<HelixConstants.ChangeType> _refreshedChangeTypes;
-
   public ResourceControllerDataProvider() {
     this(AbstractDataCache.UNKNOWN_CLUSTER);
   }
@@ -111,21 +107,19 @@ public String getObjName(ExternalView obj) {
     _idealMappingCache = new HashMap<>();
     _missingTopStateMap = new HashMap<>();
     _lastTopStateLocationMap = new HashMap<>();
-    _refreshedChangeTypes = ConcurrentHashMap.newKeySet();
   }
 
   public synchronized void refresh(HelixDataAccessor accessor) {
     long startTime = System.currentTimeMillis();
 
     // Refresh base
-    Set<HelixConstants.ChangeType> changedTypes = super.doRefresh(accessor);
-    _refreshedChangeTypes.addAll(changedTypes);
+    Set<HelixConstants.ChangeType> propertyRefreshed = super.doRefresh(accessor);
 
     // Invalidate cached information if any of the important data has been refreshed
-    if (changedTypes.contains(HelixConstants.ChangeType.IDEAL_STATE)
-        || changedTypes.contains(HelixConstants.ChangeType.LIVE_INSTANCE)
-        || changedTypes.contains(HelixConstants.ChangeType.INSTANCE_CONFIG)
-        || changedTypes.contains(HelixConstants.ChangeType.RESOURCE_CONFIG)) {
+    if (propertyRefreshed.contains(HelixConstants.ChangeType.IDEAL_STATE)
+        || propertyRefreshed.contains(HelixConstants.ChangeType.LIVE_INSTANCE)
+        || propertyRefreshed.contains(HelixConstants.ChangeType.INSTANCE_CONFIG)
+        || propertyRefreshed.contains(HelixConstants.ChangeType.RESOURCE_CONFIG)) {
       clearCachedResourceAssignments();
     }
 
@@ -268,23 +262,6 @@ public void setCachedIdealMapping(String resource, ZNRecord mapping) {
     _idealMappingCache.put(resource, mapping);
   }
 
-  /**
-   * Return the set of all PropertyTypes that changed prior to this round of rebalance. The caller
-   * should clear this set by calling {@link #clearRefreshedChangeTypes()}.
-   * @return
-   */
-  public Set<HelixConstants.ChangeType> getRefreshedChangeTypes() {
-    return _refreshedChangeTypes;
-  }
-
-  /**
-   * Clears the set of all PropertyTypes that changed. The caller will have consumed all change
-   * types by calling {@link #getRefreshedChangeTypes()}.
-   */
-  public void clearRefreshedChangeTypes() {
-    _refreshedChangeTypes.clear();
-  }
-
   public void clearCachedResourceAssignments() {
     _resourceAssignmentCache.clear();
     _idealMappingCache.clear();