From f02711a9cb39e5b7cc6e94e2b728b216c0c82182 Mon Sep 17 00:00:00 2001
From: Kevin Wan <wanjunfeng@gmail.com>
Date: Sat, 27 Feb 2021 23:56:18 +0800
Subject: [PATCH] golint core/discov (#525)

---
 core/discov/internal/etcdclient.go     |  1 +
 core/discov/internal/listener.go       |  1 +
 core/discov/internal/registry.go       | 25 +++++++++++++++----------
 core/discov/internal/updatelistener.go |  2 ++
 core/discov/internal/vars.go           | 11 ++++++++---
 5 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/core/discov/internal/etcdclient.go b/core/discov/internal/etcdclient.go
index b3ade160..4ce82cf2 100644
--- a/core/discov/internal/etcdclient.go
+++ b/core/discov/internal/etcdclient.go
@@ -9,6 +9,7 @@ import (
 	"google.golang.org/grpc"
 )
 
+// EtcdClient interface represents an etcd client.
 type EtcdClient interface {
 	ActiveConnection() *grpc.ClientConn
 	Close() error
diff --git a/core/discov/internal/listener.go b/core/discov/internal/listener.go
index 6340b1cb..3087410f 100644
--- a/core/discov/internal/listener.go
+++ b/core/discov/internal/listener.go
@@ -1,5 +1,6 @@
 package internal
 
+// Listener interface wraps the OnUpdate method.
 type Listener interface {
 	OnUpdate(keys []string, values []string, newKey string)
 }
diff --git a/core/discov/internal/registry.go b/core/discov/internal/registry.go
index 679f998d..38e5765e 100644
--- a/core/discov/internal/registry.go
+++ b/core/discov/internal/registry.go
@@ -18,19 +18,31 @@ import (
 )
 
 var (
-	registryInstance = Registry{
+	registry = Registry{
 		clusters: make(map[string]*cluster),
 	}
 	connManager = syncx.NewResourceManager()
 )
 
+// A Registry is a registry that manages the etcd client connections.
 type Registry struct {
 	clusters map[string]*cluster
 	lock     sync.Mutex
 }
 
+// GetRegistry returns a global Registry.
 func GetRegistry() *Registry {
-	return &registryInstance
+	return &registry
+}
+
+// GetConn returns an etcd client connection associated with given endpoints.
+func (r *Registry) GetConn(endpoints []string) (EtcdClient, error) {
+	return r.getCluster(endpoints).getClient()
+}
+
+// Monitor monitors the key on given etcd endpoints, notify with the given UpdateListener.
+func (r *Registry) Monitor(endpoints []string, key string, l UpdateListener) error {
+	return r.getCluster(endpoints).monitor(key, l)
 }
 
 func (r *Registry) getCluster(endpoints []string) *cluster {
@@ -46,14 +58,6 @@ func (r *Registry) getCluster(endpoints []string) *cluster {
 	return c
 }
 
-func (r *Registry) GetConn(endpoints []string) (EtcdClient, error) {
-	return r.getCluster(endpoints).getClient()
-}
-
-func (r *Registry) Monitor(endpoints []string, key string, l UpdateListener) error {
-	return r.getCluster(endpoints).monitor(key, l)
-}
-
 type cluster struct {
 	endpoints  []string
 	key        string
@@ -288,6 +292,7 @@ func (c *cluster) watchConnState(cli EtcdClient) {
 	watcher.watch(cli.ActiveConnection())
 }
 
+// DialClient dials an etcd cluster with given endpoints.
 func DialClient(endpoints []string) (EtcdClient, error) {
 	return clientv3.New(clientv3.Config{
 		Endpoints:            endpoints,
diff --git a/core/discov/internal/updatelistener.go b/core/discov/internal/updatelistener.go
index 645469f3..535ceda1 100644
--- a/core/discov/internal/updatelistener.go
+++ b/core/discov/internal/updatelistener.go
@@ -3,11 +3,13 @@
 package internal
 
 type (
+	// A KV is used to store an etcd entry with key and value.
 	KV struct {
 		Key string
 		Val string
 	}
 
+	// UpdateListener wraps the OnAdd and OnDelete methods.
 	UpdateListener interface {
 		OnAdd(kv KV)
 		OnDelete(kv KV)
diff --git a/core/discov/internal/vars.go b/core/discov/internal/vars.go
index 719612e6..77360b49 100644
--- a/core/discov/internal/vars.go
+++ b/core/discov/internal/vars.go
@@ -3,17 +3,22 @@ package internal
 import "time"
 
 const (
+	// Delimiter is a separator that separates the etcd path.
+	Delimiter = '/'
+
 	autoSyncInterval   = time.Minute
 	coolDownInterval   = time.Second
 	dialTimeout        = 5 * time.Second
 	dialKeepAliveTime  = 5 * time.Second
 	requestTimeout     = 3 * time.Second
-	Delimiter          = '/'
 	endpointsSeparator = ","
 )
 
 var (
-	DialTimeout    = dialTimeout
+	// DialTimeout is the dial timeout.
+	DialTimeout = dialTimeout
+	// RequestTimeout is the request timeout.
 	RequestTimeout = requestTimeout
-	NewClient      = DialClient
+	// NewClient is used to create etcd clients.
+	NewClient = DialClient
 )