Golang Topic.ResetBackendEndNoLock方法代碼示例

func (self *NsqdCoordinator) PutMessagesToCluster(topic *nsqd.Topic,
	msgs []*nsqd.Message) (nsqd.MessageID, nsqd.BackendOffset, int32, error) {

	var commitLog CommitLogData
	topicName := topic.GetTopicName()
	partition := topic.GetTopicPart()
	coord, checkErr := self.getTopicCoord(topicName, partition)
	if checkErr != nil {
		return nsqd.MessageID(commitLog.LogID), nsqd.BackendOffset(commitLog.MsgOffset), commitLog.MsgSize, checkErr.ToErrorType()
	}

	var queueEnd nsqd.BackendQueueEnd
	var logMgr *TopicCommitLogMgr

	doLocalWrite := func(d *coordData) *CoordErr {
		topic.Lock()
		logMgr = d.logMgr
		id, offset, writeBytes, totalCnt, qe, localErr := topic.PutMessagesNoLock(msgs)
		queueEnd = qe
		topic.Unlock()
		if localErr != nil {
			coordLog.Warningf("put batch messages to local failed: %v", localErr)
			return &CoordErr{localErr.Error(), RpcNoErr, CoordLocalErr}
		}
		commitLog.LogID = int64(id)
		// epoch should not be changed.
		// leader epoch change means leadership change, leadership change
		// need disable write which should hold the write lock.
		// However, we are holding write lock while doing the cluster write replication.
		commitLog.Epoch = d.GetTopicEpochForWrite()
		commitLog.LastMsgLogID = int64(msgs[len(msgs)-1].ID)
		commitLog.MsgOffset = int64(offset)
		commitLog.MsgSize = writeBytes
		// This MsgCnt is the total count until now (include the current written batch message count)
		commitLog.MsgCnt = totalCnt
		commitLog.MsgNum = int32(len(msgs))
		return nil
	}
	doLocalExit := func(err *CoordErr) {
		if err != nil {
			coordLog.Infof("topic %v PutMessagesToCluster error: %v", topic.GetFullName(), err)
			if coord.IsWriteDisabled() {
				topic.DisableForSlave()
			}
		}
	}
	doLocalCommit := func() error {
		localErr := logMgr.AppendCommitLog(&commitLog, false)
		if localErr != nil {
			coordLog.Errorf("topic : %v, Generator %v failed write commit log : %v, logMgr: %v, %v",
				topic.GetFullName(), topic.GetMsgGenerator(), localErr, logMgr.pLogID, logMgr.nLogID)
		}
		topic.Lock()
		topic.UpdateCommittedOffset(queueEnd)
		topic.Unlock()
		return localErr
	}
	doLocalRollback := func() {
		coordLog.Warningf("failed write begin rollback : %v, %v", topic.GetFullName(), commitLog)
		topic.Lock()
		topic.ResetBackendEndNoLock(nsqd.BackendOffset(commitLog.MsgOffset), commitLog.MsgCnt-1)
		topic.Unlock()
	}
	doRefresh := func(d *coordData) *CoordErr {
		logMgr = d.logMgr
		if d.GetTopicEpochForWrite() != commitLog.Epoch {
			coordLog.Warningf("write epoch changed during write: %v, %v", d.GetTopicEpochForWrite(), commitLog)
			return ErrEpochMismatch
		}
		self.requestNotifyNewTopicInfo(d.topicInfo.Name, d.topicInfo.Partition)
		return nil
	}
	doSlaveSync := func(c *NsqdRpcClient, nodeID string, tcData *coordData) *CoordErr {
		// should retry if failed, and the slave should keep the last success write to avoid the duplicated
		putErr := c.PutMessages(&tcData.topicLeaderSession, &tcData.topicInfo, commitLog, msgs)
		if putErr != nil {
			coordLog.Infof("sync write to replica %v failed: %v, put offset: %v, logmgr: %v, %v",
				nodeID, putErr, commitLog, logMgr.pLogID, logMgr.nLogID)
		}
		return putErr
	}
	handleSyncResult := func(successNum int, tcData *coordData) bool {
		if successNum == len(tcData.topicInfo.ISR) {
			return true
		}
		return false
	}
	clusterErr := self.doSyncOpToCluster(true, coord, doLocalWrite, doLocalExit, doLocalCommit, doLocalRollback,
		doRefresh, doSlaveSync, handleSyncResult)

	var err error
	if clusterErr != nil {
		err = clusterErr.ToErrorType()
	}

	return nsqd.MessageID(commitLog.LogID), nsqd.BackendOffset(commitLog.MsgOffset), commitLog.MsgSize, err
}