feat: file down handle

server/common/proxy.go

@@ -0,0 +1,99 @@
+package common
+
+import (
+	"fmt"
+	"github.com/alist-org/alist/v3/internal/model"
+	"github.com/pkg/errors"
+	log "github.com/sirupsen/logrus"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var HttpClient = &http.Client{}
+
+func Proxy(w http.ResponseWriter, r *http.Request, link *model.Link, file model.Obj) error {
+	// read data with native
+	var err error
+	if link.Data != nil {
+		defer func() {
+			_ = link.Data.Close()
+		}()
+		w.Header().Set("Content-Type", "application/octet-stream")
+		w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"; filename*=UTF-8''%s`, file.GetName(), url.QueryEscape(file.GetName())))
+		w.Header().Set("Content-Length", strconv.FormatInt(file.GetSize(), 10))
+		if link.Header != nil {
+			for h, val := range link.Header {
+				w.Header()[h] = val
+			}
+		}
+		if link.Status == 0 {
+			w.WriteHeader(http.StatusOK)
+		} else {
+			w.WriteHeader(link.Status)
+		}
+		_, err = io.Copy(w, link.Data)
+		if err != nil {
+			return err
+		}
+		return nil
+	}
+	// local file
+	if link.FilePath != nil && *link.FilePath != "" {
+		f, err := os.Open(*link.FilePath)
+		if err != nil {
+			return err
+		}
+		defer func() {
+			_ = f.Close()
+		}()
+		fileStat, err := os.Stat(*link.FilePath)
+		if err != nil {
+			return err
+		}
+		w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"; filename*=UTF-8''%s`, file.GetName(), url.QueryEscape(file.GetName())))
+		http.ServeContent(w, r, file.GetName(), fileStat.ModTime(), f)
+		return nil
+	} else {
+		req, err := http.NewRequest(r.Method, link.URL, nil)
+		if err != nil {
+			return err
+		}
+		for h, val := range r.Header {
+			if strings.ToLower(h) == "authorization" {
+				continue
+			}
+			req.Header[h] = val
+		}
+		for h, val := range link.Header {
+			req.Header[h] = val
+		}
+		res, err := HttpClient.Do(req)
+		if err != nil {
+			return err
+		}
+		defer func() {
+			_ = res.Body.Close()
+		}()
+		log.Debugf("proxy status: %d", res.StatusCode)
+		for h, v := range res.Header {
+			w.Header()[h] = v
+		}
+		w.WriteHeader(res.StatusCode)
+		if res.StatusCode >= 400 {
+			all, _ := ioutil.ReadAll(res.Body)
+			msg := string(all)
+			log.Debugln(msg)
+			return errors.New(msg)
+		}
+		_, err = io.Copy(w, res.Body)
+		if err != nil {
+			return err
+		}
+		return nil
+	}
+}