refactor: 0.1.0-beta

cursor-backend/server.go

@@ -0,0 +1,144 @@
+// server.go 负责固定上游服务、流量捕获和调试界面的生命周期。
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+// Server 运行 Cursor API 转发服务及其本机调试界面。
+type Server struct {
+	config        Config
+	upstream      *url.URL
+	store         *exchangeStore
+	counter       atomic.Uint64
+	serviceServer *http.Server
+	serviceLn     net.Listener
+	runMu         sync.Mutex
+	captureMu     sync.RWMutex
+}
+
+// New 创建固定转发到 Cursor API 的协议调试服务。
+func New(config Config) (*Server, error) {
+	config = config.normalized()
+	if err := validateLoopbackAddress(config.ServiceAddr); err != nil {
+		return nil, fmt.Errorf("服务监听地址无效：%w", err)
+	}
+	upstream, err := url.Parse(defaultUpstreamURL)
+	if err != nil {
+		return nil, fmt.Errorf("解析固定上游地址：%w", err)
+	}
+	store, err := newPersistentExchangeStore(config.DatabasePath, config.MaxExchanges)
+	if err != nil {
+		return nil, err
+	}
+	server := &Server{
+		config:   config,
+		upstream: upstream,
+		store:    store,
+	}
+	server.counter.Store(store.maxNumericID())
+	server.serviceServer = &http.Server{
+		Handler:  server.newServiceHandler(),
+		ErrorLog: log.New(io.Discard, "", 0),
+	}
+	return server, nil
+}
+
+// Start 启动同时承载 API 转发和调试界面的单端口服务。
+func (server *Server) Start() error {
+	server.runMu.Lock()
+	defer server.runMu.Unlock()
+	if server.serviceLn != nil {
+		return errors.New("Cursor API 调试服务已经启动")
+	}
+	serviceListener, err := net.Listen("tcp", server.config.ServiceAddr)
+	if err != nil {
+		return fmt.Errorf("启动 API 服务监听失败：%w", err)
+	}
+	server.serviceLn = serviceListener
+	go func() { _ = server.serviceServer.Serve(serviceListener) }()
+	return nil
+}
+
+// Close 立即关闭监听器、活跃连接并释放捕获存储。
+func (server *Server) Close() error {
+	server.runMu.Lock()
+	serviceServer := server.serviceServer
+	server.serviceLn = nil
+	server.runMu.Unlock()
+	var errorsList []error
+	if serviceServer != nil {
+		if err := serviceServer.Close(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+			errorsList = append(errorsList, err)
+		}
+	}
+	if server.store != nil {
+		if err := server.store.close(); err != nil {
+			errorsList = append(errorsList, err)
+		}
+	}
+	return errors.Join(errorsList...)
+}
+
+// ServiceAddr 返回 Cursor API 服务监听地址。
+func (server *Server) ServiceAddr() string { return server.config.ServiceAddr }
+
+// UIURL 返回可在浏览器中打开的调试界面地址。
+func (server *Server) UIURL() string {
+	return "http://" + browserAddress(server.config.ServiceAddr) + debugBasePath + "/"
+}
+
+// DatabasePath 返回捕获数据库路径。
+func (server *Server) DatabasePath() string {
+	return server.config.DatabasePath
+}
+
+// newServiceHandler 创建单端口调试路由和固定上游流式转发。
+func (server *Server) newServiceHandler() http.Handler {
+	reverseProxy := httputil.NewSingleHostReverseProxy(server.upstream)
+	reverseProxy.FlushInterval = -1
+	reverseProxy.ErrorLog = log.New(io.Discard, "", 0)
+	originalDirector := reverseProxy.Director
+	reverseProxy.Director = func(request *http.Request) {
+		originalDirector(request)
+		request.Host = server.upstream.Host
+		request.Header["X-Forwarded-For"] = nil
+	}
+	reverseProxy.Transport = &http.Transport{
+		Proxy:                 nil,
+		DialContext:           (&net.Dialer{Timeout: 10 * time.Second, KeepAlive: 30 * time.Second}).DialContext,
+		ForceAttemptHTTP2:     true,
+		DisableCompression:    true,
+		MaxIdleConns:          200,
+		MaxIdleConnsPerHost:   32,
+		IdleConnTimeout:       90 * time.Second,
+		TLSHandshakeTimeout:   10 * time.Second,
+		ExpectContinueTimeout: 1 * time.Second,
+	}
+	reverseProxy.ModifyResponse = server.captureResponse
+	reverseProxy.ErrorHandler = func(writer http.ResponseWriter, request *http.Request, upstreamErr error) {
+		server.failExchange(request, upstreamErr)
+		http.Error(writer, "Cursor API upstream unavailable", http.StatusBadGateway)
+	}
+	forwardHandler := http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
+		reverseProxy.ServeHTTP(writer, server.captureRequest(request))
+	})
+	debugHandler := http.StripPrefix(debugBasePath, server.newUIHandler())
+	mux := http.NewServeMux()
+	mux.Handle(debugBasePath+"/", debugHandler)
+	mux.HandleFunc(debugBasePath, func(writer http.ResponseWriter, request *http.Request) {
+		http.Redirect(writer, request, debugBasePath+"/", http.StatusTemporaryRedirect)
+	})
+	mux.Handle("/", forwardHandler)
+	return mux
+}