121 lines
3.4 KiB
Go
121 lines
3.4 KiB
Go
package middleware
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import (
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"net/http"
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"time"
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"github.com/gogf/gf/v2/frame/g"
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"github.com/gogf/gf/v2/net/ghttp"
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"github.com/gogf/gf/v2/os/gtime"
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"github.com/qianfree/team-api/internal/dao"
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do "github.com/qianfree/team-api/internal/model/do"
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"github.com/qianfree/team-api/internal/response"
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)
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const (
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IdempotencyHeader = "Idempotency-Key"
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// maxCachedBodyLen limits the response body size stored for idempotent replay.
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// Responses larger than this will still be deduplicated but won't cache the body.
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maxCachedBodyLen = 64 * 1024 // 64 KB
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// idempotencyTTL is how long an idempotency record is retained before it can be cleaned up.
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idempotencyTTL = 24 * time.Hour
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)
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// Idempotency ensures that requests with the same Idempotency-Key
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// are processed only once. Subsequent requests with the same key
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// return the cached response.
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func Idempotency(r *ghttp.Request) {
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idempotencyKey := r.GetHeader(IdempotencyHeader)
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if idempotencyKey == "" {
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r.Middleware.Next()
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return
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}
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ctx := r.Context()
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// Check if this key has been processed before
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var record struct {
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Id int64 `json:"id"`
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Status string `json:"status"`
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ResponseBody string `json:"response_body"`
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}
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err := dao.SysIdempotencyRecords.Ctx(ctx).
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Where("idempotency_key", idempotencyKey).
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Where("expires_at > NOW()").
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Scan(&record)
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if err != nil {
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// DB error: fail-closed to prevent duplicate processing
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response.ErrorMsg(r, 500, "系统繁忙，请稍后重试")
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return
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}
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if record.Id > 0 {
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if record.Status == "completed" && record.ResponseBody != "" {
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// 重放缓存响应。本中间件只挂载在 /api/* 统一响应端点上：成功响应恒为
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// HTTP 200 + JSON（response.Success 使用 WriteJson），业务错误为 HTTP 422
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// 且会被标记为 failed 而不进入此重放分支。因此固定回写 200 + JSON Content-Type，
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// 避免复用未初始化的 r.Response.Status（默认 0）以及丢失 Content-Type。
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r.Response.Header().Set("Content-Type", "application/json; charset=utf-8")
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r.Response.WriteStatus(http.StatusOK)
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r.Response.Write([]byte(record.ResponseBody))
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r.Exit()
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return
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}
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if record.Status == "processing" {
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writeConflictResponse(r)
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return
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}
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}
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// Insert processing record
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_, err = dao.SysIdempotencyRecords.Ctx(ctx).Data(do.SysIdempotencyRecords{
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IdempotencyKey: idempotencyKey,
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Status: "processing",
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ExpiresAt: gtime.Now().Add(idempotencyTTL),
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}).Insert()
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if err != nil {
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// If insert fails (duplicate key), another request is already processing
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writeConflictResponse(r)
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return
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}
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// Capture the response
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r.Middleware.Next()
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// After processing, update the record with cached body
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status := "completed"
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statusCode := r.Response.Status
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if statusCode >= 400 {
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status = "failed"
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}
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var responseBody string
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if buf := r.Response.Buffer(); len(buf) > 0 && len(buf) <= maxCachedBodyLen {
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responseBody = string(buf)
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}
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// Update the record
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dao.SysIdempotencyRecords.Ctx(ctx).
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Where("idempotency_key", idempotencyKey).
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Data(do.SysIdempotencyRecords{
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Status: status,
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ResponseBody: responseBody,
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}).Update()
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}
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// writeConflictResponse writes a 409 Conflict response for duplicate idempotency keys.
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func writeConflictResponse(r *ghttp.Request) {
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r.Response.WriteStatus(409)
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r.Response.WriteJson(g.Map{
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"error": g.Map{
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"type": "conflict",
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"message": "请求正在处理中，请勿重复提交",
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"code": "409",
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},
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})
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r.Exit()
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}
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