@@ -6,27 +6,32 @@ import (
66 "io"
77 "io/ioutil"
88 "net/http"
9+ "sort"
10+ "strconv"
11+ "syscall"
12+ "time"
913
1014 "github.com/easyops-cn/giraffe-micro"
1115)
1216
13- //Middleware 中间件定义
17+ // Middleware 中间件定义
1418type Middleware interface {
1519 NewRequest (rule giraffe.HttpRule , in interface {}) (* http.Request , error )
1620 ParseResponse (rule giraffe.HttpRule , resp * http.Response , out interface {}) error
1721}
1822
19- //Client REST Client对象
23+ // Client REST Client对象
2024type Client struct {
2125 * http.Client
2226 Middleware Middleware
2327 NameService giraffe.NameService
28+ retryConf RetryConfig
2429}
2530
26- //ClientOption Client 配置函数
31+ // ClientOption Client 配置函数
2732type ClientOption func (c * Client )
2833
29- //Invoke 单次请求方法
34+ // Invoke 单次请求方法
3035func (c * Client ) Invoke (ctx context.Context , md * giraffe.MethodDesc , in interface {}, out interface {}, opts ... giraffe.CallOption ) error {
3136 req , err := c .middleware ().NewRequest (md .HttpRule , in )
3237 if err != nil {
@@ -50,7 +55,7 @@ func (c *Client) Invoke(ctx context.Context, md *giraffe.MethodDesc, in interfac
5055 return c .middleware ().ParseResponse (md .HttpRule , resp , out )
5156}
5257
53- //NewStream 流式请求方法(未实现)
58+ // NewStream 流式请求方法(未实现)
5459func (c * Client ) NewStream (context.Context , * giraffe.StreamDesc , ... giraffe.CallOption ) (giraffe.ClientStream , error ) {
5560 return nil , errors .New ("not supported" )
5661}
@@ -69,7 +74,7 @@ func (c *Client) httpClient() *http.Client {
6974 return c .Client
7075}
7176
72- //Call 请求函数
77+ // Call 请求函数
7378func (c * Client ) Call (contract giraffe.Contract , req * http.Request , opts ... giraffe.CallOption ) (* http.Response , error ) {
7479 if req == nil {
7580 return nil , errors .New ("request was nil" )
@@ -90,35 +95,108 @@ func (c *Client) Call(contract giraffe.Contract, req *http.Request, opts ...gira
9095 if hostname := req .Header .Get ("host" ); hostname != "" {
9196 req .Host = hostname
9297 }
98+ if c .NameService == nil {
99+ // 原逻辑中NameService没有设置也会发送http请求，保留这个特征
100+ return c .httpClient ().Do (req )
101+ }
102+ return c .sendWithENS (req , contract )
103+ }
93104
94- if c .NameService != nil {
95- addr , err := c .NameService .GetAddress (req .Context (), contract )
96- if err != nil {
97- return nil , err
105+ func (c * Client ) sendWithENS (req * http.Request , contract giraffe.Contract ) (resp * http.Response , err error ) {
106+ // ENS服务发现
107+ addrList , err := c .getAllAddressesWithENS (req .Context (), contract )
108+ if err != nil {
109+ return
110+ }
111+
112+ // 备份 http body
113+ var originalBody []byte
114+ req .URL .Scheme = "http"
115+ if req != nil && req .Body != nil {
116+ originalBody , _ = copyBody (req )
117+ }
118+
119+ // 如果 retryConf.Enabled 为false, 获取 sendCount 的值为1，表示只执行一次，不会重试
120+ sendCount := c .retryConf .getSendCount ()
121+
122+ retryInterval := c .retryConf .RetryInterval
123+ addr := addrList [0 ]
124+ i := 0
125+ unavailableRetry := false
126+ for ; i < sendCount ; i ++ {
127+ // 当i为1时，表示已经是重试循环, 需要根据情况进行等待
128+ // 当 单节点连接被拒绝重试 或者 503重试, 需要等待一段时间后再发起请求
129+ // 多节点下，连接被拒绝，就不等待了，直接访问其他节点
130+ if i > 0 && (len (addrList ) <= 0 || unavailableRetry ) {
131+ time .Sleep (retryInterval )
132+ }
133+ // 服务重试，以轮询策略为节点选择策略
134+ if addr == "" {
135+ addr = addrList [i % len (addrList )]
98136 }
137+ // 根据执行次数, 轮询节点
99138 req .URL .Host = addr
100- req .URL .Scheme = "http"
139+
140+ resp , err = c .httpClient ().Do (req )
141+ if err != nil {
142+ // connection refuse 重试机制
143+ if errors .Is (err , syscall .ECONNREFUSED ) {
144+ resetBody (req , originalBody )
145+ addr = "" // 当前节点的访问被拒绝, addr置空, 获取其他节点
146+ unavailableRetry = false
147+ continue
148+ }
149+ return // 非 connection refuse 错误直接退出
150+ }
151+ if err == nil && resp .StatusCode != http .StatusServiceUnavailable {
152+ return // 非 503 异常, 直接退出不重试
153+ }
154+
155+ // 503异常的重试机制
156+ retryAfterStr := resp .Header .Get ("Retry-After" )
157+ retryAfter , _ := strconv .Atoi (retryAfterStr )
158+ if retryAfter <= 0 {
159+ // 没有设置 Retry-After , 重试机制失效, 直接退出
160+ return
161+ }
162+ // Retry-After单位为秒: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Retry-After
163+ // TODO 对获取的retryAfter进行校验，不要让它因为错误的设置而等待超长的时间
164+ retryInterval = time .Duration (retryAfter ) * time .Second
165+ unavailableRetry = true
166+ _ = resp .Body .Close () // 重试, 所以释放当前fd
167+ resetBody (req , originalBody )
101168 }
169+ return
170+ }
102171
103- return c .httpClient ().Do (req )
172+ func (c * Client ) getAllAddressesWithENS (ctx context.Context , contract giraffe.Contract ) (addresses []string , err error ) {
173+ if c .NameService == nil {
174+ return
175+ }
176+ addresses , err = c .NameService .GetAllAddresses (ctx , contract )
177+ if err != nil {
178+ return
179+ }
180+ // 排序
181+ sort .Strings (addresses )
182+ return
104183}
105184
106- //NewClient Client实例化函数
185+ // NewClient Client实例化函数
107186func NewClient (opts ... ClientOption ) * Client {
108187 c := & Client {
109188 Client : & http.Client {},
110189 Middleware : DefaultMiddleware ,
111190 NameService : nil ,
112191 }
113-
114192 for _ , o := range opts {
115193 o (c )
116194 }
117-
195+ c . retryConf . init ()
118196 return c
119197}
120198
121- //WithClient 注入 http.Client
199+ // WithClient 注入 http.Client
122200func WithClient (client * http.Client ) ClientOption {
123201 return func (c * Client ) {
124202 if client == nil {
@@ -128,9 +206,15 @@ func WithClient(client *http.Client) ClientOption {
128206 }
129207}
130208
131- //WithNameService 注入 NameService
209+ // WithNameService 注入 NameService
132210func WithNameService (n giraffe.NameService ) ClientOption {
133211 return func (c * Client ) {
134212 c .NameService = n
135213 }
136214}
215+
216+ func WithRetryConfig (conf RetryConfig ) ClientOption {
217+ return func (c * Client ) {
218+ c .retryConf = conf
219+ }
220+ }
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