Introduced edge session state object

@@ -100,10 +100,7 @@ public final class EdgeGrpcSession implements Closeable {
     private final Consumer<EdgeId> sessionCloseListener;
     private final ObjectMapper mapper;
 
-    private final Map<Integer, DownlinkMsg> pendingMsgsMap = new LinkedHashMap<>();
-    // TODO: voba - global future - possible refactoring
-    private SettableFuture<Void> sendDownlinkMsgsFuture;
-    private ScheduledFuture<?> scheduledSendDownlinkTask;
+    private final EdgeSessionState sessionState = new EdgeSessionState();
 
     private EdgeContextComponent ctx;
     private Edge edge;
@@ -256,17 +253,17 @@ public final class EdgeGrpcSession implements Closeable {
     private void onDownlinkResponse(DownlinkResponseMsg msg) {
         try {
             if (msg.getSuccess()) {
-                pendingMsgsMap.remove(msg.getDownlinkMsgId());
+                sessionState.getPendingMsgsMap().remove(msg.getDownlinkMsgId());
                 log.debug("[{}] Msg has been processed successfully! {}", edge.getRoutingKey(), msg);
             } else {
                 log.error("[{}] Msg processing failed! Error msg: {}", edge.getRoutingKey(), msg.getErrorMsg());
             }
-            if (pendingMsgsMap.size() == 0) {
+            if (sessionState.getPendingMsgsMap().isEmpty()) {
                 log.debug("[{}] Pending msgs map is empty. Stopping current iteration {}", edge.getRoutingKey(), msg);
-                if (scheduledSendDownlinkTask != null) {
-                    scheduledSendDownlinkTask.cancel(false);
+                if (sessionState.getScheduledSendDownlinkTask() != null) {
+                    sessionState.getScheduledSendDownlinkTask().cancel(false);
                 }
-                sendDownlinkMsgsFuture.set(null);
+                sessionState.getSendDownlinkMsgsFuture().set(null);
             }
         } catch (Exception e) {
             log.error("[{}] Can't process downlink response message [{}]", this.sessionId, msg, e);
@@ -389,27 +386,27 @@ public final class EdgeGrpcSession implements Closeable {
     }
 
     private ListenableFuture<Void> sendDownlinkMsgsPack(List<DownlinkMsg> downlinkMsgsPack) {
-        if (sendDownlinkMsgsFuture != null && !sendDownlinkMsgsFuture.isDone()) {
+        if (sessionState.getSendDownlinkMsgsFuture() != null && !sessionState.getSendDownlinkMsgsFuture().isDone()) {
             String erroMsg = "[" + this.sessionId + "] Previous send downdlink future was not properly completed, stopping it now";
             log.error(erroMsg);
-            sendDownlinkMsgsFuture.setException(new RuntimeException(erroMsg));
+            sessionState.getSendDownlinkMsgsFuture().setException(new RuntimeException(erroMsg));
         }
-        sendDownlinkMsgsFuture = SettableFuture.create();
-        pendingMsgsMap.clear();
-        downlinkMsgsPack.forEach(msg -> pendingMsgsMap.put(msg.getDownlinkMsgId(), msg));
+        sessionState.setSendDownlinkMsgsFuture(SettableFuture.create());
+        sessionState.getPendingMsgsMap().clear();
+        downlinkMsgsPack.forEach(msg -> sessionState.getPendingMsgsMap().put(msg.getDownlinkMsgId(), msg));
         scheduleDownlinkMsgsPackSend(true);
-        return sendDownlinkMsgsFuture;
+        return sessionState.getSendDownlinkMsgsFuture();
     }
 
     private void scheduleDownlinkMsgsPackSend(boolean firstRun) {
         Runnable sendDownlinkMsgsTask = () -> {
             try {
-                if (isConnected() && pendingMsgsMap.values().size() > 0) {
+                if (isConnected() && sessionState.getPendingMsgsMap().values().size() > 0) {
                     if (!firstRun) {
-                        log.warn("[{}] Failed to deliver the batch: {}", this.sessionId, pendingMsgsMap.values());
+                        log.warn("[{}] Failed to deliver the batch: {}", this.sessionId, sessionState.getPendingMsgsMap().values());
                     }
-                    log.trace("[{}] [{}] downlink msg(s) are going to be send.", this.sessionId, pendingMsgsMap.values().size());
-                    List<DownlinkMsg> copy = new ArrayList<>(pendingMsgsMap.values());
+                    log.trace("[{}] [{}] downlink msg(s) are going to be send.", this.sessionId, sessionState.getPendingMsgsMap().values().size());
+                    List<DownlinkMsg> copy = new ArrayList<>(sessionState.getPendingMsgsMap().values());
                     for (DownlinkMsg downlinkMsg : copy) {
                         sendDownlinkMsg(ResponseMsg.newBuilder()
                                 .setDownlinkMsg(downlinkMsg)
@@ -417,17 +414,22 @@ public final class EdgeGrpcSession implements Closeable {
                     }
                     scheduleDownlinkMsgsPackSend(false);
                 } else {
-                    sendDownlinkMsgsFuture.set(null);
+                    sessionState.getSendDownlinkMsgsFuture().set(null);
                 }
             } catch (Exception e) {
-                sendDownlinkMsgsFuture.setException(e);
+                sessionState.getSendDownlinkMsgsFuture().setException(e);
             }
         };
 
         if (firstRun) {
             sendDownlinkExecutorService.submit(sendDownlinkMsgsTask);
         } else {
-            scheduledSendDownlinkTask = sendDownlinkExecutorService.schedule(sendDownlinkMsgsTask, ctx.getEdgeEventStorageSettings().getSleepIntervalBetweenBatches(), TimeUnit.MILLISECONDS);
+            sessionState.setScheduledSendDownlinkTask(
+                    sendDownlinkExecutorService.schedule(
+                            sendDownlinkMsgsTask,
+                            ctx.getEdgeEventStorageSettings().getSleepIntervalBetweenBatches(),
+                            TimeUnit.MILLISECONDS)
+            );
         }
 
     }

+/**
+ * Copyright © 2016-2021 The Thingsboard Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.thingsboard.server.service.edge.rpc;
+
+import com.google.common.util.concurrent.SettableFuture;
+import lombok.Data;
+import org.thingsboard.server.gen.edge.v1.DownlinkMsg;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.concurrent.ScheduledFuture;
+
+@Data
+public class EdgeSessionState {
+
+    private final Map<Integer, DownlinkMsg> pendingMsgsMap = new LinkedHashMap<>();
+    private SettableFuture<Void> sendDownlinkMsgsFuture;
+    private ScheduledFuture<?> scheduledSendDownlinkTask;
+}