[dubbo-go] branch 3.0 updated: feat: RandomLoadBalance code optimization, update that how to judge the same weight

[laurence]

This is an automated email from the ASF dual-hosted git repository.

laurence pushed a commit to branch 3.0
in repository https://gitbox.apache.org/repos/asf/dubbo-go.git


The following commit(s) were added to refs/heads/3.0 by this push:
     new 01de5d587 feat: RandomLoadBalance code optimization, update that how 
to judge the same weight
     new f6405fa79 Merge pull request #1899 from 
Codeprh/feture/loadBalancingAlgorithmUpdate
01de5d587 is described below

commit 01de5d587a17f1781de597b06e9edb97a20c8d48
Author: codingprh <coding...@gmail.com>
AuthorDate: Mon May 16 10:08:39 2022 +0800

    feat: RandomLoadBalance code optimization, update that how to judge the 
same weight
---
 cluster/loadbalance/random/loadbalance.go | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/cluster/loadbalance/random/loadbalance.go 
b/cluster/loadbalance/random/loadbalance.go
index ae05b2d19..ea9ee981a 100644
--- a/cluster/loadbalance/random/loadbalance.go
+++ b/cluster/loadbalance/random/loadbalance.go
@@ -42,23 +42,27 @@ func NewRandomLoadBalance() loadbalance.LoadBalance {
 }
 
 func (lb *randomLoadBalance) Select(invokers []protocol.Invoker, invocation 
protocol.Invocation) protocol.Invoker {
+
+       // Number of invokers
        var length int
        if length = len(invokers); length == 1 {
                return invokers[0]
        }
+
+       // Every invoker has the same weight?
        sameWeight := true
+       // the maxWeight of every invokers, the minWeight = 0 or the maxWeight 
of the last invoker
        weights := make([]int64, length)
+       // The sum of weights
+       var totalWeight int64 = 0
 
-       firstWeight := loadbalance.GetWeight(invokers[0], invocation)
-       totalWeight := firstWeight
-       weights[0] = firstWeight
-
-       for i := 1; i < length; i++ {
+       for i := 0; i < length; i++ {
                weight := loadbalance.GetWeight(invokers[i], invocation)
-               weights[i] = weight
-
+               //Sum
                totalWeight += weight
-               if sameWeight && weight != firstWeight {
+               // save for later use
+               weights[i] = totalWeight
+               if sameWeight && totalWeight != weight*(int64(i+1)) {
                        sameWeight = false
                }
        }
@@ -68,8 +72,7 @@ func (lb *randomLoadBalance) Select(invokers 
[]protocol.Invoker, invocation prot
                offset := rand.Int63n(totalWeight)
 
                for i := 0; i < length; i++ {
-                       offset -= weights[i]
-                       if offset < 0 {
+                       if offset < weights[i] {
                                return invokers[i]
                        }
                }