refactor: optimize stream, link, and resource management (#486)

* refactor: optimize stream, link, and resource management

* Link.MFile改为io.ReadSeeker类型

* fix (crypt): read on closed response body

* chore

* chore

* chore

server/common/proxy.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-	"os"
 	"strings"
 
 	"maps"
@@ -19,21 +18,15 @@ import (
 
 func Proxy(w http.ResponseWriter, r *http.Request, link *model.Link, file model.Obj) error {
 	if link.MFile != nil {
-		defer link.MFile.Close()
+		if clr, ok := link.MFile.(io.Closer); ok {
+			defer clr.Close()
+		}
 		attachHeader(w, file)
 		contentType := link.Header.Get("Content-Type")
 		if contentType != "" {
 			w.Header().Set("Content-Type", contentType)
 		}
-		mFile := link.MFile
-		if _, ok := mFile.(*os.File); !ok {
-			mFile = &stream.RateLimitFile{
-				File:    mFile,
-				Limiter: stream.ServerDownloadLimit,
-				Ctx:     r.Context(),
-			}
-		}
-		http.ServeContent(w, r, file.GetName(), file.ModTime(), mFile)
+		http.ServeContent(w, r, file.GetName(), file.ModTime(), link.MFile)
 		return nil
 	} else if link.RangeReadCloser != nil {
 		attachHeader(w, file)

server/ftp/fsread.go

@@ -2,6 +2,7 @@ package ftp
 
 import (
 	"context"
+	"io"
 	fs2 "io/fs"
 	"net/http"
 	"os"
@@ -13,13 +14,13 @@ import (
 	"github.com/OpenListTeam/OpenList/v4/internal/op"
 	"github.com/OpenListTeam/OpenList/v4/internal/stream"
 	"github.com/OpenListTeam/OpenList/v4/server/common"
-	ftpserver "github.com/fclairamb/ftpserverlib"
 	"github.com/pkg/errors"
 )
 
 type FileDownloadProxy struct {
-	ftpserver.FileTransfer
-	reader stream.SStreamReadAtSeeker
+	model.File
+	io.Closer
+	ctx context.Context
 }
 
 func OpenDownload(ctx context.Context, reqPath string, offset int64) (*FileDownloadProxy, error) {
@@ -57,15 +58,24 @@ func OpenDownload(ctx context.Context, reqPath string, offset int64) (*FileDownl
 		_ = ss.Close()
 		return nil, err
 	}
-	return &FileDownloadProxy{reader: reader}, nil
+	return &FileDownloadProxy{File: reader, Closer: ss, ctx: ctx}, nil
 }
 
 func (f *FileDownloadProxy) Read(p []byte) (n int, err error) {
-	n, err = f.reader.Read(p)
+	n, err = f.File.Read(p)
 	if err != nil {
 		return
 	}
-	err = stream.ClientDownloadLimit.WaitN(f.reader.GetRawStream().Ctx, n)
+	err = stream.ClientDownloadLimit.WaitN(f.ctx, n)
+	return
+}
+
+func (f *FileDownloadProxy) ReadAt(p []byte, off int64) (n int, err error) {
+	n, err = f.File.ReadAt(p, off)
+	if err != nil {
+		return
+	}
+	err = stream.ClientDownloadLimit.WaitN(f.ctx, n)
 	return
 }
 
@@ -73,14 +83,6 @@ func (f *FileDownloadProxy) Write(p []byte) (n int, err error) {
 	return 0, errs.NotSupport
 }
 
-func (f *FileDownloadProxy) Seek(offset int64, whence int) (int64, error) {
-	return f.reader.Seek(offset, whence)
-}
-
-func (f *FileDownloadProxy) Close() error {
-	return f.reader.Close()
-}
-
 type OsFileInfoAdapter struct {
 	obj model.Obj
 }

server/handles/down.go

@@ -85,15 +85,15 @@ func Proxy(c *gin.Context) {
 }
 
 func down(c *gin.Context, link *model.Link) {
-	var err error
-	if link.MFile != nil {
-		defer func(ReadSeekCloser io.ReadCloser) {
-			err := ReadSeekCloser.Close()
+	if clr, ok := link.MFile.(io.Closer); ok {
+		defer func(clr io.Closer) {
+			err := clr.Close()
 			if err != nil {
-				log.Errorf("close data error: %s", err)
+				log.Errorf("close link data error: %v", err)
 			}
-		}(link.MFile)
+		}(clr)
 	}
+	var err error
 	c.Header("Referrer-Policy", "no-referrer")
 	c.Header("Cache-Control", "max-age=0, no-cache, no-store, must-revalidate")
 	if setting.GetBool(conf.ForwardDirectLinkParams) {

server/handles/fsmanage.go

@@ -390,14 +390,13 @@ func Link(c *gin.Context) {
 		common.ErrorResp(c, err, 500)
 		return
 	}
-	if link.MFile != nil {
-		defer func(ReadSeekCloser io.ReadCloser) {
-			err := ReadSeekCloser.Close()
+	if clr, ok := link.MFile.(io.Closer); ok {
+		defer func(clr io.Closer) {
+			err := clr.Close()
 			if err != nil {
 				log.Errorf("close link data error: %v", err)
 			}
-		}(link.MFile)
+		}(clr)
 	}
 	common.SuccessResp(c, link)
-	return
 }

server/s3/backend.go

@@ -187,7 +187,11 @@ func (b *s3Backend) GetObject(ctx context.Context, bucketName, objectName string
 		if err != nil {
 			return nil, err
 		}
-		rdr = link.MFile
+		if rdr2, ok := link.MFile.(io.ReadCloser); ok {
+			rdr = rdr2
+		} else {
+			rdr = io.NopCloser(link.MFile)
+		}
 	} else {
 		remoteFileSize := file.GetSize()
 		if length >= 0 && start+length >= remoteFileSize {