[skip ci] Fix golint in index_coord.go (#8785)

Signed-off-by: Cai.Zhang <cai.zhang@zilliz.com>

internal/indexcoord/index_coord.go

@@ -44,6 +44,10 @@ import (
 	"github.com/milvus-io/milvus/internal/util/typeutil"
 )
 
+// IndexCoord is a component responsible for scheduling index construction tasks and maintaining index status.
+// IndexCoord accepts requests from rootcoord to build indexes, delete indexes, and query index information.
+// IndexCoord is responsible for assigning IndexBuildID to the request to build the index, and forwarding the
+// request to build the index to IndexNode. IndexCoord records the status of the index, and the index file.
 type IndexCoord struct {
 	stateCode atomic.Value
 
@@ -86,6 +90,7 @@ type IndexCoord struct {
 type UniqueID = typeutil.UniqueID
 type Timestamp = typeutil.Timestamp
 
+// NewIndexCoord creates a new IndexCoord component.
 func NewIndexCoord(ctx context.Context) (*IndexCoord, error) {
 	rand.Seed(time.Now().UnixNano())
 	ctx1, cancel := context.WithCancel(ctx)
@@ -101,7 +106,7 @@ func NewIndexCoord(ctx context.Context) (*IndexCoord, error) {
 	return i, nil
 }
 
-// Register register index service at etcd
+// Register register IndexCoord role at etcd.
 func (i *IndexCoord) Register() error {
 	i.session = sessionutil.NewSession(i.loopCtx, Params.MetaRootPath, Params.EtcdEndpoints)
 	if i.session == nil {
@@ -111,6 +116,7 @@ func (i *IndexCoord) Register() error {
 	return nil
 }
 
+// Init initializes the IndexCoord component.
 func (i *IndexCoord) Init() error {
 	var initErr error = nil
 	Params.InitOnce()
@@ -219,6 +225,7 @@ func (i *IndexCoord) Init() error {
 	return initErr
 }
 
+// Start starts the IndexCoord component.
 func (i *IndexCoord) Start() error {
 	var startErr error = nil
 	i.startOnce.Do(func() {
@@ -259,6 +266,7 @@ func (i *IndexCoord) Start() error {
 	return startErr
 }
 
+// Stop stops the IndexCoord component.
 func (i *IndexCoord) Stop() error {
 	i.loopCancel()
 	i.sched.Close()
@@ -269,6 +277,7 @@ func (i *IndexCoord) Stop() error {
 	return nil
 }
 
+// UpdateStateCode updates the component state of IndexCoord.
 func (i *IndexCoord) UpdateStateCode(code internalpb.StateCode) {
 	i.stateCode.Store(code)
 }
@@ -278,6 +287,7 @@ func (i *IndexCoord) isHealthy() bool {
 	return code == internalpb.StateCode_Healthy
 }
 
+// GetComponentStates gets the component states of IndexCoord.
 func (i *IndexCoord) GetComponentStates(ctx context.Context) (*internalpb.ComponentStates, error) {
 	log.Debug("get IndexCoord component states ...")
 	stateInfo := &internalpb.ComponentInfo{
@@ -297,6 +307,7 @@ func (i *IndexCoord) GetComponentStates(ctx context.Context) (*internalpb.Compon
 	return ret, nil
 }
 
+// GetTimeTickChannel gets the time tick channel of IndexCoord.
 func (i *IndexCoord) GetTimeTickChannel(ctx context.Context) (*milvuspb.StringResponse, error) {
 	log.Debug("get IndexCoord time tick channel ...")
 	return &milvuspb.StringResponse{
@@ -308,6 +319,7 @@ func (i *IndexCoord) GetTimeTickChannel(ctx context.Context) (*milvuspb.StringRe
 	}, nil
 }
 
+// GetStatisticsChannel gets the statistics channel of IndexCoord.
 func (i *IndexCoord) GetStatisticsChannel(ctx context.Context) (*milvuspb.StringResponse, error) {
 	log.Debug("get IndexCoord statistics channel ...")
 	return &milvuspb.StringResponse{
@@ -391,6 +403,7 @@ func (i *IndexCoord) BuildIndex(ctx context.Context, req *indexpb.BuildIndexRequ
 	return ret, nil
 }
 
+// GetIndexStates gets the index states from IndexCoord.
 func (i *IndexCoord) GetIndexStates(ctx context.Context, req *indexpb.GetIndexStatesRequest) (*indexpb.GetIndexStatesResponse, error) {
 	sp, _ := trace.StartSpanFromContextWithOperationName(ctx, "IndexCoord-BuildIndex")
 	defer sp.Finish()
@@ -429,6 +442,9 @@ func (i *IndexCoord) GetIndexStates(ctx context.Context, req *indexpb.GetIndexSt
 	return ret, nil
 }
 
+// DropIndex deletes indexes based on IndexID. One IndexID corresponds to the index of an entire column. A column is
+// divided into many segments, and each segment corresponds to an IndexBuildID. IndexCoord uses IndexBuildID to record
+// index tasks. Therefore, when DropIndex, delete all tasks corresponding to IndexBuildID corresponding to IndexID.
 func (i *IndexCoord) DropIndex(ctx context.Context, req *indexpb.DropIndexRequest) (*commonpb.Status, error) {
 	log.Debug("IndexCoord DropIndex", zap.Int64("IndexID", req.IndexID))
 	sp, _ := trace.StartSpanFromContextWithOperationName(ctx, "IndexCoord-BuildIndex")
@@ -457,6 +473,7 @@ func (i *IndexCoord) DropIndex(ctx context.Context, req *indexpb.DropIndexReques
 	return ret, nil
 }
 
+// GetIndexFilePaths gets the index file paths from IndexCoord.
 func (i *IndexCoord) GetIndexFilePaths(ctx context.Context, req *indexpb.GetIndexFilePathsRequest) (*indexpb.GetIndexFilePathsResponse, error) {
 	log.Debug("IndexCoord GetIndexFilePaths", zap.Int64s("IndexBuildIds", req.IndexBuildIDs))
 	sp, _ := trace.StartSpanFromContextWithOperationName(ctx, "IndexCoord-BuildIndex")
@@ -483,6 +500,7 @@ func (i *IndexCoord) GetIndexFilePaths(ctx context.Context, req *indexpb.GetInde
 	return ret, nil
 }
 
+// GetMetrics gets the metrics info of IndexCoord.
 func (i *IndexCoord) GetMetrics(ctx context.Context, req *milvuspb.GetMetricsRequest) (*milvuspb.GetMetricsResponse, error) {
 	log.Debug("IndexCoord.GetMetrics",
 		zap.Int64("node_id", i.ID),
@@ -708,7 +726,6 @@ func (i *IndexCoord) watchMetaLoop() {
 	}
 }
 
-// assignTaskLoop is used to assign index construction tasks.
 func (i *IndexCoord) assignTask(builderClient types.IndexNode, req *indexpb.CreateIndexRequest) bool {
 	ctx, cancel := context.WithTimeout(i.loopCtx, i.reqTimeoutInterval)
 	defer cancel()
@@ -725,6 +742,7 @@ func (i *IndexCoord) assignTask(builderClient types.IndexNode, req *indexpb.Crea
 	return true
 }
 
+// assignTaskLoop is used to assign index construction tasks.
 func (i *IndexCoord) assignTaskLoop() {
 	ctx, cancel := context.WithCancel(i.loopCtx)