Merge pull request #506 from aliiohs/featue/addCommentForConsistentHash

add the comment of ConsistentHash

.asf.yaml

+notifications:
+    commits:      commits@dubbo.apache.org
+    issues:       notifications@dubbo.apache.org
+    pullrequests: notifications@dubbo.apache.org
+    jira_options: link label link label

cluster/loadbalance/consistent_hash.go

@@ -27,7 +27,9 @@ import (
 	"strconv"
 	"strings"
 )
-
+import (
+	gxsort "github.com/dubbogo/gost/sort"
+)
 import (
 	"github.com/apache/dubbo-go/cluster"
 	"github.com/apache/dubbo-go/common/constant"
@@ -40,7 +42,7 @@ const (
 	ConsistentHash = "consistenthash"
 	// HashNodes ...
 	HashNodes = "hash.nodes"
-	// HashArguments ...
+	// HashArguments  key of hash arguments  in url
 	HashArguments = "hash.arguments"
 )
 
@@ -53,16 +55,16 @@ func init() {
 	extension.SetLoadbalance(ConsistentHash, NewConsistentHashLoadBalance)
 }
 
-// ConsistentHashLoadBalance ...
+// ConsistentHashLoadBalance implementation of load balancing: using consistent hashing
 type ConsistentHashLoadBalance struct {
 }
 
-// NewConsistentHashLoadBalance ...
+// NewConsistentHashLoadBalance creates NewConsistentHashLoadBalance
 func NewConsistentHashLoadBalance() cluster.LoadBalance {
 	return &ConsistentHashLoadBalance{}
 }
 
-// Select ...
+// Select gets invoker based on load balancing strategy
 func (lb *ConsistentHashLoadBalance) Select(invokers []protocol.Invoker, invocation protocol.Invocation) protocol.Invoker {
 	methodName := invocation.MethodName()
 	key := invokers[0].GetUrl().ServiceKey() + "." + methodName
@@ -85,27 +87,12 @@ func (lb *ConsistentHashLoadBalance) Select(invokers []protocol.Invoker, invocat
 	return selector.Select(invocation)
 }
 
-// Uint32Slice ...
-type Uint32Slice []uint32
-
-func (s Uint32Slice) Len() int {
-	return len(s)
-}
-
-func (s Uint32Slice) Less(i, j int) bool {
-	return s[i] < s[j]
-}
-
-func (s Uint32Slice) Swap(i, j int) {
-	s[i], s[j] = s[j], s[i]
-}
-
-// ConsistentHashSelector ...
+// ConsistentHashSelector implementation of Selector:get invoker based on load balancing strategy
 type ConsistentHashSelector struct {
 	hashCode        uint32
 	replicaNum      int
 	virtualInvokers map[uint32]protocol.Invoker
-	keys            Uint32Slice
+	keys            gxsort.Uint32Slice
 	argumentIndex   []int
 }
 
@@ -141,7 +128,7 @@ func newConsistentHashSelector(invokers []protocol.Invoker, methodName string,
 	return selector
 }
 
-// Select ...
+// Select gets invoker based on load balancing strategy
 func (c *ConsistentHashSelector) Select(invocation protocol.Invocation) protocol.Invoker {
 	key := c.toKey(invocation.Arguments())
 	digest := md5.Sum([]byte(key))