final ConsumerSendMsgBackRequestHeader requestHeader =
(ConsumerSendMsgBackRequestHeader) request
.decodeCommandCustomHeader(ConsumerSendMsgBackRequestHeader.class);
// 确保订阅组存在
SubscriptionGroupConfig subscriptionGroupConfig =
this.brokerController.getSubscriptionGroupManager().findSubscriptionGroupConfig(
requestHeader.getGroup());
if (null == subscriptionGroupConfig) {
response.setCode(ResponseCode.SUBSCRIPTION_GROUP_NOT_EXIST);
response.setRemark("subscription group not exist, " + requestHeader.getGroup() + " "
+ FAQUrl.suggestTodo(FAQUrl.SUBSCRIPTION_GROUP_NOT_EXIST));
return response;
}
// 如果重试队列数目为0，则直接丢弃消息
if (subscriptionGroupConfig.getRetryQueueNums() <= 0) {
response.setCode(ResponseCode.SUCCESS);
response.setRemark(null);
return response;
}
String newTopic = MixAll.getRetryTopic(requestHeader.getGroup());
int queueIdInt =
Math.abs(this.random.nextInt() % 99999999) % subscriptionGroupConfig.getRetryQueueNums();
// 检查topic是否存在
TopicConfig topicConfig =
this.brokerController.getTopicConfigManager().createTopicInSendMessageBackMethod(//
newTopic,//
subscriptionGroupConfig.getRetryQueueNums(), //
PermName.PERM_WRITE | PermName.PERM_READ);
if (null == topicConfig) {
response.setCode(ResponseCode.SYSTEM_ERROR);
response.setRemark("topic[" + newTopic + "] not exist");
return response;
}
// 检查topic权限
if (!PermName.isWriteable(topicConfig.getPerm())) {
response.setCode(ResponseCode.NO_PERMISSION);
response.setRemark("the topic[" + newTopic + "] sending message is forbidden");
return response;
}
// 查询消息，这里如果堆积消息过多，会访问磁盘
// 另外如果频繁调用，是否会引起gc问题，需要关注 TODO
MessageExt msgExt =
this.brokerController.getMessageStore().lookMessageByOffset(requestHeader.getOffset());
if (null == msgExt) {
response.setCode(ResponseCode.SYSTEM_ERROR);
response.setRemark("look message by offset failed, " + requestHeader.getOffset());
return response;
}
// 构造消息
final String retryTopic = msgExt.getProperty(MessageConst.PROPERTY_RETRY_TOPIC);
if (null == retryTopic) {
MessageAccessor.putProperty(msgExt, MessageConst.PROPERTY_RETRY_TOPIC, msgExt.getTopic());
}
msgExt.setWaitStoreMsgOK(false);
// 客户端自动决定定时级别
int delayLevel = requestHeader.getDelayLevel();
// 死信消息处理
if (msgExt.getReconsumeTimes() >= subscriptionGroupConfig.getRetryMaxTimes()//
|| delayLevel < 0) {
newTopic = MixAll.getDLQTopic(requestHeader.getGroup());
queueIdInt = Math.abs(this.random.nextInt() % 99999999) % DLQ_NUMS_PER_GROUP;
topicConfig =