init

Ocelot.Provider.Nacos/NacosClient/LoadBalance/WeightRandomLBStrategy.cs

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+using Nacos;
+using Nacos.V2.Naming.Dtos;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Ocelot.Provider.Nacos.NacosClient
+{
+    public class WeightRandomLBStrategy : ILBStrategy
+    {
+        public LBStrategyName Name => LBStrategyName.WeightRandom;
+
+        public Instance GetHost(List<Instance> list)
+        {
+            var dict = BuildScore(list);
+
+            Instance instance = null;
+
+            var rd = new Random().NextDouble();
+
+            foreach (var item in dict)
+            {
+                if (item.Value >= rd)
+                {
+                    instance = list.FirstOrDefault(x => x.InstanceId.Equals(item.Key));
+
+                    if (instance == null)
+                    {
+                        var arr = item.Key.Split("#");
+                        var ip = arr[0];
+                        int.TryParse(arr[1], out var port);
+                        var cluster = arr[2];
+
+                        instance = list.First(x => x.Ip.Equals(ip) && x.Port == port && x.ClusterName.Equals(cluster));
+                    }
+
+                    break;
+                }
+            }
+
+            return instance;
+        }
+
+        private Dictionary<string, double> BuildScore(List<Instance> list)
+        {
+            var dict = new Dictionary<string, double>();
+
+            // aliyun sae, the instanceid returns empty string
+            // when the instanceid is empty, create a new one, but the group was missed.
+            list.ForEach(x => { x.InstanceId = string.IsNullOrWhiteSpace(x.InstanceId) ? $"{x.Ip}#{x.Port}#{x.ClusterName}#{x.ServiceName}" : x.InstanceId; });
+
+            var tmp = list.Select(x => new LbKv
+            {
+                InstanceId = x.InstanceId,
+                Weight = x.Weight
+            }).GroupBy(x => x.InstanceId).Select(x => new LbKv
+            {
+                InstanceId = x.Key,
+                Weight = x.Max(y => y.Weight)
+            }).ToList();
+
+            var total = tmp.Sum(x => x.Weight);
+            var cur = 0d;
+
+            foreach (var item in tmp)
+            {
+                cur += item.Weight;
+                dict.TryAdd(item.InstanceId, cur / total);
+            }
+
+            return dict;
+        }
+    }
+}