fix: check cycle when save process task relation in interface ProcessTaskRelationController#createProcessTaskRelation (#12294)

Co-authored-by: 熠然 <yangjianhua@cai-inc.com>

dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/service/impl/ProcessDefinitionServiceImpl.java

@@ -314,7 +314,7 @@ public class ProcessDefinitionServiceImpl extends BaseServiceImpl implements Pro
                     return result;
                 }
             }
-            if (graphHasCycle(taskNodeList)) {
+            if (processService.graphHasCycle(taskNodeList)) {
                 logger.error("process DAG has cycle");
                 putMsg(result, Status.PROCESS_NODE_HAS_CYCLE);
                 return result;
@@ -1096,7 +1096,7 @@ public class ProcessDefinitionServiceImpl extends BaseServiceImpl implements Pro
             }
 
             // check has cycle
-            if (graphHasCycle(taskNodes)) {
+            if (processService.graphHasCycle(taskNodes)) {
                 logger.error("process DAG has cycle");
                 putMsg(result, Status.PROCESS_NODE_HAS_CYCLE);
                 return result;
@@ -1348,32 +1348,6 @@ public class ProcessDefinitionServiceImpl extends BaseServiceImpl implements Pro
         return result;
     }
 
-    /**
-     * whether the graph has a ring
-     *
-     * @param taskNodeResponseList task node response list
-     * @return if graph has cycle flag
-     */
-    private boolean graphHasCycle(List<TaskNode> taskNodeResponseList) {
-        DAG<String, TaskNode, String> graph = new DAG<>();
-        // Fill the vertices
-        for (TaskNode taskNodeResponse : taskNodeResponseList) {
-            graph.addNode(Long.toString(taskNodeResponse.getCode()), taskNodeResponse);
-        }
-        // Fill edge relations
-        for (TaskNode taskNodeResponse : taskNodeResponseList) {
-            List<String> preTasks = JSONUtils.toList(taskNodeResponse.getPreTasks(), String.class);
-            if (CollectionUtils.isNotEmpty(preTasks)) {
-                for (String preTask : preTasks) {
-                    if (!graph.addEdge(preTask, Long.toString(taskNodeResponse.getCode()))) {
-                        return true;
-                    }
-                }
-            }
-        }
-        return graph.hasCycle();
-    }
-
     /**
      * batch copy process definition
      *

dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/service/impl/ProcessTaskRelationServiceImpl.java

@@ -24,6 +24,7 @@ import org.apache.dolphinscheduler.api.service.ProjectService;
 import org.apache.dolphinscheduler.common.Constants;
 import org.apache.dolphinscheduler.common.enums.ConditionType;
 import org.apache.dolphinscheduler.common.enums.TaskType;
+import org.apache.dolphinscheduler.common.model.TaskNode;
 import org.apache.dolphinscheduler.dao.entity.ProcessDefinition;
 import org.apache.dolphinscheduler.dao.entity.ProcessTaskRelation;
 import org.apache.dolphinscheduler.dao.entity.ProcessTaskRelationLog;
@@ -147,6 +148,13 @@ public class ProcessTaskRelationServiceImpl extends BaseServiceImpl implements P
             processTaskRelation.setPreTaskVersion(0);
         }
         processTaskRelations.add(processTaskRelation);
+
+        List<TaskNode> taskNodeList = processService.transformTask(processTaskRelations, null);
+        if (processService.graphHasCycle(taskNodeList)) {
+            putMsg(result, Status.PROCESS_NODE_HAS_CYCLE);
+            return result;
+        }
+
         updateRelation(loginUser, result, processDefinition, processTaskRelations);
         return result;
     }

dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/process/ProcessService.java

@@ -2587,6 +2587,32 @@ public class ProcessService {
         return processTaskMap;
     }
 
+    /**
+     * whether the graph has a ring
+     *
+     * @param taskNodeResponseList task node response list
+     * @return if graph has cycle flag
+     */
+    public boolean graphHasCycle(List<TaskNode> taskNodeResponseList) {
+        DAG<String, TaskNode, String> graph = new DAG<>();
+        // Fill the vertices
+        for (TaskNode taskNodeResponse : taskNodeResponseList) {
+            graph.addNode(Long.toString(taskNodeResponse.getCode()), taskNodeResponse);
+        }
+        // Fill edge relations
+        for (TaskNode taskNodeResponse : taskNodeResponseList) {
+            List<String> preTasks = JSONUtils.toList(taskNodeResponse.getPreTasks(), String.class);
+            if (org.apache.commons.collections4.CollectionUtils.isNotEmpty(preTasks)) {
+                for (String preTask : preTasks) {
+                    if (!graph.addEdge(preTask, Long.toString(taskNodeResponse.getCode()))) {
+                        return true;
+                    }
+                }
+            }
+        }
+        return graph.hasCycle();
+    }
+
     private void deleteCommandWithCheck(int commandId) {
         int delete = this.commandMapper.deleteById(commandId);
         if (delete != 1) {