add query zone with backup hosts

Author: lihsai0

src/Qiniu/Storage/Config.cs

@@ -1,4 +1,6 @@
 
+using System.Collections.Generic;
+
 namespace Qiniu.Storage
 {
     /// <summary>
@@ -13,6 +15,15 @@ public class Config
         /// 默认空间管理域名
         /// </summary>
         public static string DefaultUcHost = "uc.qbox.me";
+        /// <summary>
+        /// 默认备用空间管理域名
+        /// </summary>
+        public static List<string> DefaultBackupUcHosts = new List<string>
+        {
+            "kodo-config.qiniuapi.com",
+            "api.qiniu.com"
+        };
+        
         /// <summary>
         /// 默认高级资源管理域名
         /// </summary>
@@ -57,9 +68,12 @@ public class Config
 
         private string _ucHost = DefaultUcHost;
 
+        private List<string> _backupUcHosts = DefaultBackupUcHosts;
+
         public void SetUcHost(string val)
         {
             _ucHost = val;
+            _backupUcHosts.Clear();
         }
 
         public string UcHost()
@@ -68,6 +82,16 @@ public string UcHost()
             return string.Format("{0}{1}", scheme, _ucHost);
         }
 
+        public void SetBackupUcHost(List<string> val)
+        {
+            _backupUcHosts = val;
+        }
+
+        public List<string> BackupUcHost()
+        {
+            return _backupUcHosts;
+        }
+
         /// <summary>
         /// 获取资源管理域名
         /// </summary>
@@ -80,7 +104,7 @@ public string RsHost(string ak, string bucket)
             Zone z = this.Zone;
             if (z == null)
             {
-                z = ZoneHelper.QueryZone(ak, bucket, UcHost());
+                z = ZoneHelper.QueryZone(ak, bucket, UcHost(), BackupUcHost());
             }
             return string.Format("{0}{1}", scheme, z.RsHost);
         }
@@ -97,7 +121,7 @@ public string RsfHost(string ak, string bucket)
             Zone z = this.Zone;
             if (z == null)
             {
-                z = ZoneHelper.QueryZone(ak, bucket, UcHost());
+                z = ZoneHelper.QueryZone(ak, bucket, UcHost(), BackupUcHost());
             }
             return string.Format("{0}{1}", scheme, z.RsfHost);
         }
@@ -114,7 +138,7 @@ public string ApiHost(string ak, string bucket)
             Zone z = this.Zone;
             if (z == null)
             {
-                z = ZoneHelper.QueryZone(ak, bucket, UcHost());
+                z = ZoneHelper.QueryZone(ak, bucket, UcHost(), BackupUcHost());
             }
             return string.Format("{0}{1}", scheme, z.ApiHost);
         }
@@ -131,7 +155,7 @@ public string IovipHost(string ak, string bucket)
             Zone z = this.Zone;
             if (z == null)
             {
-                z = ZoneHelper.QueryZone(ak, bucket, UcHost());
+                z = ZoneHelper.QueryZone(ak, bucket, UcHost(), BackupUcHost());
             }
             return string.Format("{0}{1}", scheme, z.IovipHost);
         }
@@ -148,7 +172,7 @@ public string UpHost(string ak, string bucket)
             Zone z = this.Zone;
             if (z == null)
             {
-                z = ZoneHelper.QueryZone(ak, bucket, UcHost());
+                z = ZoneHelper.QueryZone(ak, bucket, UcHost(), BackupUcHost());
             }
             string upHost = z.SrcUpHosts[0];
             if (this.UseCdnDomains)

src/Qiniu/Storage/ZoneHelper.cs

@@ -26,7 +26,12 @@ public class ZoneHelper
         /// <param name="accessKey">AccessKey</param>
         /// <param name="bucket">空间名称</param>
         /// <param name="ucHost">UC 域名</param>
-        public static Zone QueryZone(string accessKey, string bucket, string ucHost = null)
+        public static Zone QueryZone(
+            string accessKey,
+            string bucket,
+            string ucHost = null,
+            List<string> backupUcHosts = null
+        )
         {
             ZoneCacheValue zoneCacheValue = null;
             string cacheKey = string.Format("{0}:{1}", accessKey, bucket);
@@ -56,6 +61,12 @@ public static Zone QueryZone(string accessKey, string bucket, string ucHost = nu
             {
                 ucHost = "https://" + Config.DefaultUcHost;
             }
+
+            if (backupUcHosts == null)
+            {
+                backupUcHosts = Config.DefaultBackupUcHosts;
+            }
+            
             try
             {
                 string queryUrl = string.Format("{0}/v4/query?ak={1}&bucket={2}",
@@ -64,7 +75,13 @@ public static Zone QueryZone(string accessKey, string bucket, string ucHost = nu
                     bucket
                 );
                 HttpManager httpManager = new HttpManager();
-                hr = httpManager.Get(queryUrl, null);
+                List<IMiddleware> middlewares = new List<IMiddleware>
+                {
+                    new RetryDomainsMiddleware(
+                        backupUcHosts
+                    )
+                };
+                hr = httpManager.Get(queryUrl, null, null, middlewares);
                 if (hr.Code != (int) HttpCode.OK || string.IsNullOrEmpty(hr.Text))
                 {
                     throw new Exception("code: " + hr.Code + ", text: " + hr.Text + ", ref-text:" + hr.RefText);

src/QiniuTests/Storage/ZoneHelperTests.cs

@@ -1,3 +1,4 @@
+using System.Collections.Generic;
 using NUnit.Framework;
 using Qiniu.Tests;
 
@@ -10,7 +11,29 @@ public class ZoneHelperTests : TestEnv
         public void QueryZoneTest()
         {
             Zone zone = ZoneHelper.QueryZone(AccessKey, Bucket);
+
+            Assert.NotNull(zone);
+        }
+
+        [Test]
+        public void QueryZoneWithBackupHostsTest()
+        {
+            Config config = new Config();
+            config.SetUcHost("fake-uc.csharp.qiniu.com");
+            config.SetBackupUcHost(new List<string>
+                {
+                    "unavailable-uc.csharp.qiniu.com",
+                    "uc.qbox.me"
+                }
+            );
+            config.UseHttps = true;
 
+            Zone zone = ZoneHelper.QueryZone(
+                AccessKey,
+                Bucket,
+                config.UcHost(),
+                config.BackupUcHost()
+            );
             Assert.NotNull(zone);
         }
     }