[skip ci] Add comment for exported items (#12126)

Signed-off-by: Nshaoyue.chen <shaoyue.chen@zilliz.com>

internal/datacoord/handler.go

@@ -11,6 +11,7 @@ import (
 	"go.uber.org/zap"
 )
 
+// Handler handles some channel method for ChannelManager
 type Handler interface {
 	GetVChanPositions(channel string, collectionID UniqueID, partitionID UniqueID) *datapb.VchannelInfo
 	CheckShouldDropChannel(channel string) bool

internal/datacoord/policy.go

@@ -429,10 +429,12 @@ func AverageReassignPolicy(store ROChannelStore, reassigns []*NodeChannelInfo) C
 // ChannelBGChecker check nodes' channels and return the channels needed to be reallocated.
 type ChannelBGChecker func(channels []*NodeChannelInfo, ts time.Time) ([]*NodeChannelInfo, error)
 
+// EmptyBgChecker does nothing
 func EmptyBgChecker(channels []*NodeChannelInfo, ts time.Time) ([]*NodeChannelInfo, error) {
 	return nil, nil
 }
 
+// BgCheckWithMaxWatchDuration returns a ChannelBGChecker with the maxWatchDuration
 func BgCheckWithMaxWatchDuration(kv kv.TxnKV) ChannelBGChecker {
 	return func(channels []*NodeChannelInfo, ts time.Time) ([]*NodeChannelInfo, error) {
 		reallocations := make([]*NodeChannelInfo, 0, len(channels))

internal/datacoord/services.go

@@ -747,6 +747,7 @@ func (s *Server) GetCompactionState(ctx context.Context, req *milvuspb.GetCompac
 	return resp, nil
 }
 
+// GetCompactionStateWithPlans returns the compaction state of given plan
 func (s *Server) GetCompactionStateWithPlans(ctx context.Context, req *milvuspb.GetCompactionPlansRequest) (*milvuspb.GetCompactionPlansResponse, error) {
 	log.Debug("received GetCompactionStateWithPlans request", zap.Int64("compactionID", req.GetCompactionID()))
 
@@ -815,6 +816,7 @@ func getCompactionState(tasks []*compactionTask) (state commonpb.CompactionState
 	return
 }
 
+// WatchChannels starts watch channels by give request
 func (s *Server) WatchChannels(ctx context.Context, req *datapb.WatchChannelsRequest) (*datapb.WatchChannelsResponse, error) {
 	log.Debug("receive watch channels request", zap.Any("channels", req.GetChannelNames()))
 	resp := &datapb.WatchChannelsResponse{