Prune operation result after each bucket

This is to avoid uncontrollable growth of task operation result,
resulting in OOMs, extra large repo objects, and/or long task execution.

Should resolve MID-7830 (at least partially).

repo/repo-common/src/main/java/com/evolveum/midpoint/repo/common/activity/run/IterativeActivityRun.java

@@ -246,6 +246,8 @@ private void doRun(OperationResult result)
                 }
 
                 complete = processOrAnalyzeOrSkipSingleBucket(result);
+                pruneResult(result);
+
                 if (!complete) {
                     break;
                 }
@@ -263,6 +265,29 @@ private void doRun(OperationResult result)
         }
     }
 
+    /**
+     * Keeps the result of reasonable size:
+     *
+     * 1. removes successful minor subresults
+     * 2. summarizes operations (if there is a lot of buckets - see MID-7830)
+     *
+     * We catch all exceptions here, because we don't want the task to fail on these checks.
+     * We also want to execute the summarization even if the cleanup fails.
+     */
+    private void pruneResult(OperationResult result) {
+        try {
+            result.cleanupResultDeeply();
+        } catch (Exception e) {
+            LoggingUtils.logUnexpectedException(LOGGER, "Couldn't clean up the operation result in {}", e, this);
+        }
+
+        try {
+            result.summarize();
+        } catch (Exception e) {
+            LoggingUtils.logUnexpectedException(LOGGER, "Couldn't summarize the operation result in {}", e, this);
+        }
+    }
+
     private boolean shouldProcessBucket(OperationResult result) {
         ExpressionType condition = getActivity().getControlFlowDefinition().getBucketProcessingCondition();
         if (condition == null) {

repo/task-quartz-impl/src/main/java/com/evolveum/midpoint/task/quartzimpl/run/TaskCycleExecutor.java

@@ -205,6 +205,7 @@ private void updateTaskResult(TaskRunResult runResult) {
         if (runResult.getMessage() != null) {
             taskResult.setMessage(runResult.getMessage());
         }
+        // TODO Clean up the result before updating (summarize, remove minor operations - maybe deeply?) - see e.g. MID-7830
         task.setResult(taskResult); // This updates the result in the task prism object.
     }
 

repo/task-quartz-impl/src/main/java/com/evolveum/midpoint/task/quartzimpl/tasks/CloseHelper.java

@@ -66,10 +66,12 @@ private void updateTaskResult(Task task) {
             }
         }
 
+        // TODO Clean up the result before updating (summarize, remove minor operations - maybe deeply?) - see e.g. MID-7830
         // Update result and result status in prism.
         task.setResult(taskResult);
     }
 
+    /** Executes close operation in the repository task object, i.e. with no regards of Quartz. */
     private void closeInTask(TaskQuartzImpl task, OperationResult result)
             throws ObjectNotFoundException, SchemaException {
         LOGGER.trace("Closing task in repository: {}", task);