refactor: fethcer interface & download flow (#1229)

internal/fetcher/fetcher.go

@@ -1,20 +1,18 @@
 package fetcher
 
 import (
-	"github.com/GopeedLab/gopeed/internal/controller"
-	"github.com/GopeedLab/gopeed/pkg/base"
 	"path"
 	"strings"
+
+	"github.com/GopeedLab/gopeed/internal/controller"
+	"github.com/GopeedLab/gopeed/pkg/base"
 )
 
 // Fetcher defines the interface for a download protocol.
 // Each download task will have a corresponding Fetcher instance for the management of the download task
 type Fetcher interface {
 	Setup(ctl *controller.Controller)
-	// Resolve resource info from request
-	Resolve(req *base.Request) error
-	// Create ready to download, but not started
-	Create(opts *base.Options) error
+	Resolve(req *base.Request, opts *base.Options) error
 	Start() error
 	Pause() error
 	Close() error

internal/protocol/bt/fetcher.go

@@ -20,15 +20,15 @@ import (
 	"github.com/GopeedLab/gopeed/pkg/util"
 	"github.com/anacrolix/torrent"
 	"github.com/anacrolix/torrent/metainfo"
+	"github.com/anacrolix/torrent/storage"
 )
 
 var (
-	client        *torrent.Client
-	lock          sync.Mutex
-	torrentDirMap = make(map[string]string)
-	ftMap         = make(map[string]*fileTorrentImpl)
-	closeCtx      context.Context
-	closeFunc     func()
+	cfg       *torrent.ClientConfig
+	client    *torrent.Client
+	lock      sync.Mutex
+	closeCtx  context.Context
+	closeFunc func()
 )
 
 type Fetcher struct {
@@ -71,21 +71,12 @@ func (f *Fetcher) initClient() (err error) {
 		closeCtx, closeFunc = context.WithCancel(context.Background())
 	}
 
-	cfg := torrent.NewDefaultClientConfig()
+	cfg = torrent.NewDefaultClientConfig()
 	cfg.Seed = true
 	cfg.Bep20 = fmt.Sprintf("-GP%s-", parseBep20())
 	cfg.ExtendedHandshakeClientVersion = fmt.Sprintf("Gopeed %s", base.Version)
 	cfg.ListenPort = f.config.ListenPort
 	cfg.HTTPProxy = f.ctl.GetProxy(f.meta.Req.Proxy)
-	cfg.DefaultStorage = newFileOpts(newFileClientOpts{
-		ClientBaseDir: cfg.DataDir,
-		HandleFileTorrent: func(infoHash metainfo.Hash, ft *fileTorrentImpl) {
-			if dir, ok := torrentDirMap[infoHash.String()]; ok {
-				ft.setTorrentDir(dir)
-			}
-			ftMap[infoHash.String()] = ft
-		},
-	})
 	dnsResolver := &DnsCacheResolver{RefreshTimeout: 5 * time.Minute}
 	cfg.TrackerDialContext = dnsResolver.DialContext
 	client, err = torrent.NewClient(cfg)
@@ -100,8 +91,12 @@ func (f *Fetcher) initClient() (err error) {
 	return
 }
 
-func (f *Fetcher) Resolve(req *base.Request) error {
+func (f *Fetcher) Resolve(req *base.Request, opts *base.Options) error {
 	f.meta.Req = req
+	f.meta.Opts = opts
+	if f.meta.Opts == nil {
+		f.meta.Opts = &base.Options{}
+	}
 	if err := f.addTorrent(req, false); err != nil {
 		return err
 	}
@@ -109,23 +104,12 @@ func (f *Fetcher) Resolve(req *base.Request) error {
 	return nil
 }
 
-func (f *Fetcher) Create(opts *base.Options) (err error) {
-	f.meta.Opts = opts
-	if f.meta.Res != nil {
-		torrentDirMap[f.meta.Res.Hash] = opts.Path
-	}
-	return nil
-}
-
 func (f *Fetcher) Start() (err error) {
 	if !f.torrentReady.Load() {
 		if err = f.addTorrent(f.meta.Req, false); err != nil {
 			return
 		}
 	}
-	if ft, ok := ftMap[f.meta.Res.Hash]; ok {
-		ft.setTorrentDir(f.meta.Opts.Path)
-	}
 	files := f.torrent.Files()
 	// If the user does not specify the file to download, all files will be downloaded by default
 	if f.data.Progress == nil {
@@ -361,8 +345,12 @@ func (f *Fetcher) addTorrent(req *base.Request, fromUpload bool) (err error) {
 	}
 	schema := util.ParseSchema(req.URL)
 	privateTorrent := false
+	var spec *torrent.TorrentSpec
 	if schema == "MAGNET" {
-		f.torrent, err = client.AddMagnet(req.URL)
+		spec, err = torrent.TorrentSpecFromMagnetUri(req.URL)
+		if err != nil {
+			return
+		}
 	} else {
 		var reader io.Reader
 		if schema == "FILE" {
@@ -399,8 +387,18 @@ func (f *Fetcher) addTorrent(req *base.Request, fromUpload bool) (err error) {
 		if info.Private != nil && *info.Private {
 			privateTorrent = true
 		}
-		f.torrent, err = client.AddTorrent(metaInfo)
+		spec, err = torrent.TorrentSpecFromMetaInfoErr(metaInfo)
+		if err != nil {
+			return
+		}
 	}
+	spec.Storage = storage.NewFileOpts(storage.NewFileClientOpts{
+		ClientBaseDir: cfg.DataDir,
+		TorrentDirMaker: func(baseDir string, info *metainfo.Info, infoHash metainfo.Hash) string {
+			return f.meta.Opts.Path
+		},
+	})
+	f.torrent, _, err = client.AddTorrentSpec(spec)
 	if err != nil {
 		return
 	}

internal/protocol/bt/fetcher_test.go

@@ -31,7 +31,7 @@ func TestFetcher_Resolve_DataUri_Torrent(t *testing.T) {
 	dataUri := "data:application/x-bittorrent;base64," + base64.StdEncoding.EncodeToString(buf)
 	err = fetcher.Resolve(&base.Request{
 		URL: dataUri,
-	})
+	}, nil)
 	if err != nil {
 		panic(err)
 	}
@@ -81,7 +81,7 @@ func doResolve(t *testing.T, fetcher fetcher.Fetcher) {
 					"udp://tracker.bitsearch.to:1337/announce",
 				},
 			},
-		})
+		}, nil)
 		if err != nil {
 			panic(err)
 		}
@@ -111,7 +111,7 @@ func doResolve(t *testing.T, fetcher fetcher.Fetcher) {
 					"udp://tracker.bitsearch.to:1337/announce",
 				},
 			},
-		})
+		}, nil)
 		if err != nil {
 			panic(err)
 		}
@@ -145,7 +145,7 @@ func doResolve(t *testing.T, fetcher fetcher.Fetcher) {
 	t.Run("Resolve Unclean Torrent", func(t *testing.T) {
 		err := fetcher.Resolve(&base.Request{
 			URL: "./testdata/test.unclean.torrent",
-		})
+		}, nil)
 		if err != nil {
 			t.Errorf("Resolve Unclean Torrent Resolve() got = %v, want nil", err)
 		}
@@ -156,7 +156,7 @@ func doResolve(t *testing.T, fetcher fetcher.Fetcher) {
 		uri := "file:///" + file
 		err := fetcher.Resolve(&base.Request{
 			URL: uri,
-		})
+		}, nil)
 		if err != nil {
 			t.Errorf("Resolve file scheme Torrent Resolve() got = %v, want nil", err)
 		}

internal/protocol/bt/file.go

@@ -1,216 +0,0 @@
-// modify from github.com/anacrolix/torrent/storage/file.go
-
-package bt
-
-import (
-	"context"
-	"fmt"
-	"io"
-	"os"
-	"path/filepath"
-
-	"github.com/anacrolix/torrent/storage"
-
-	"github.com/anacrolix/missinggo/v2"
-
-	"github.com/anacrolix/torrent/common"
-	"github.com/anacrolix/torrent/metainfo"
-	"github.com/anacrolix/torrent/segments"
-)
-
-// File-based storage for torrents, that isn't yet bound to a particular torrent.
-type fileClientImpl struct {
-	opts newFileClientOpts
-}
-
-type newFileClientOpts struct {
-	// The base directory for all downloads.
-	ClientBaseDir     string
-	HandleFileTorrent func(infoHash metainfo.Hash, ft *fileTorrentImpl)
-	FilePathMaker     storage.FilePathMaker
-	PieceCompletion   storage.PieceCompletion
-}
-
-func newFileOpts(opts newFileClientOpts) storage.ClientImplCloser {
-	if opts.FilePathMaker == nil {
-		opts.FilePathMaker = func(opts storage.FilePathMakerOpts) string {
-			var parts []string
-			if opts.Info.Length == 0 || opts.File.Path == nil {
-				parts = append(parts, opts.Info.Name)
-			}
-			return filepath.Join(append(parts, opts.File.Path...)...)
-		}
-	}
-	if opts.PieceCompletion == nil {
-		ret, err := storage.NewDefaultPieceCompletionForDir(opts.ClientBaseDir)
-		if err != nil {
-			ret = storage.NewMapPieceCompletion()
-		}
-		opts.PieceCompletion = ret
-	}
-	return fileClientImpl{opts}
-}
-
-func (fs fileClientImpl) Close() error {
-	return fs.opts.PieceCompletion.Close()
-}
-
-func (fs fileClientImpl) OpenTorrent(ctx context.Context, info *metainfo.Info, infoHash metainfo.Hash) (_ storage.TorrentImpl, err error) {
-	upvertedFiles := info.UpvertedFiles()
-	files := make([]file, 0, len(upvertedFiles))
-	for _, fileInfo := range upvertedFiles {
-		filePath := filepath.Join("", fs.opts.FilePathMaker(storage.FilePathMakerOpts{
-			Info: info,
-			File: &fileInfo,
-		}))
-		f := file{
-			rawPath: filePath,
-			path:    filePath,
-			length:  fileInfo.Length,
-		}
-		if f.length == 0 {
-			err = CreateNativeZeroLengthFile(f.path)
-			if err != nil {
-				err = fmt.Errorf("creating zero length file: %w", err)
-				return
-			}
-		}
-		files = append(files, f)
-	}
-	t := &fileTorrentImpl{
-		files,
-		segments.NewIndex(common.LengthIterFromUpvertedFiles(upvertedFiles)),
-		infoHash,
-		fs.opts.PieceCompletion,
-	}
-	fs.opts.HandleFileTorrent(infoHash, t)
-	return storage.TorrentImpl{
-		Piece: t.Piece,
-		Close: t.Close,
-	}, nil
-}
-
-type file struct {
-	// The safe, OS-local file path.
-	rawPath string
-	path    string
-	length  int64
-}
-
-type fileTorrentImpl struct {
-	files          []file
-	segmentLocater segments.Index
-	infoHash       metainfo.Hash
-	completion     storage.PieceCompletion
-}
-
-func (fts *fileTorrentImpl) Piece(p metainfo.Piece) storage.PieceImpl {
-	// Create a view onto the file-based torrent storage.
-	_io := fileTorrentImplIO{fts}
-	// Return the appropriate segments of this.
-	return &filePieceImpl{
-		fts,
-		p,
-		missinggo.NewSectionWriter(_io, p.Offset(), p.Length()),
-		io.NewSectionReader(_io, p.Offset(), p.Length()),
-	}
-}
-
-func (fts *fileTorrentImpl) Close() error {
-	return nil
-}
-
-func (fts *fileTorrentImpl) setTorrentDir(dir string) {
-	for i, f := range fts.files {
-		fts.files[i].path = filepath.Join(dir, f.rawPath)
-	}
-}
-
-// A helper to create zero-length files which won't appear for file-orientated storage since no
-// writes will ever occur to them (no torrent data is associated with a zero-length file). The
-// caller should make sure the file name provided is safe/sanitized.
-func CreateNativeZeroLengthFile(name string) error {
-	os.MkdirAll(filepath.Dir(name), 0o777)
-	var f io.Closer
-	f, err := os.Create(name)
-	if err != nil {
-		return err
-	}
-	return f.Close()
-}
-
-// Exposes file-based storage of a torrent, as one big ReadWriterAt.
-type fileTorrentImplIO struct {
-	fts *fileTorrentImpl
-}
-
-// Returns EOF on short or missing file.
-func (fst *fileTorrentImplIO) readFileAt(file file, b []byte, off int64) (n int, err error) {
-	f, err := os.Open(file.path)
-	if os.IsNotExist(err) {
-		// File missing is treated the same as a short file.
-		err = io.EOF
-		return
-	}
-	if err != nil {
-		return
-	}
-	defer f.Close()
-	// Limit the read to within the expected bounds of this file.
-	if int64(len(b)) > file.length-off {
-		b = b[:file.length-off]
-	}
-	for off < file.length && len(b) != 0 {
-		n1, err1 := f.ReadAt(b, off)
-		b = b[n1:]
-		n += n1
-		off += int64(n1)
-		if n1 == 0 {
-			err = err1
-			break
-		}
-	}
-	return
-}
-
-// Only returns EOF at the end of the torrent. Premature EOF is ErrUnexpectedEOF.
-func (fst fileTorrentImplIO) ReadAt(b []byte, off int64) (n int, err error) {
-	fst.fts.segmentLocater.Locate(segments.Extent{off, int64(len(b))}, func(i int, e segments.Extent) bool {
-		n1, err1 := fst.readFileAt(fst.fts.files[i], b[:e.Length], e.Start)
-		n += n1
-		b = b[n1:]
-		err = err1
-		return err == nil // && int64(n1) == e.Length
-	})
-	if len(b) != 0 && err == nil {
-		err = io.EOF
-	}
-	return
-}
-
-func (fst fileTorrentImplIO) WriteAt(p []byte, off int64) (n int, err error) {
-	// log.Printf("write at %v: %v bytes", off, len(p))
-	fst.fts.segmentLocater.Locate(segments.Extent{off, int64(len(p))}, func(i int, e segments.Extent) bool {
-		name := fst.fts.files[i].path
-		os.MkdirAll(filepath.Dir(name), 0o777)
-		var f *os.File
-		f, err = os.OpenFile(name, os.O_WRONLY|os.O_CREATE, 0o666)
-		if err != nil {
-			return false
-		}
-		var n1 int
-		n1, err = f.WriteAt(p[:e.Length], e.Start)
-		// log.Printf("%v %v wrote %v: %v", i, e, n1, err)
-		closeErr := f.Close()
-		n += n1
-		p = p[n1:]
-		if err == nil {
-			err = closeErr
-		}
-		if err == nil && int64(n1) != e.Length {
-			err = io.ErrShortWrite
-		}
-		return err == nil
-	})
-	return
-}

internal/protocol/bt/file_misc.go

@@ -1,36 +0,0 @@
-// modify from github.com/anacrolix/torrent/storage/file_misc.go
-
-package bt
-
-import "github.com/anacrolix/torrent/metainfo"
-
-type requiredLength struct {
-	fileIndex int
-	length    int64
-}
-
-func extentCompleteRequiredLengths(info *metainfo.Info, off, n int64) (ret []requiredLength) {
-	if n == 0 {
-		return
-	}
-	for i, fi := range info.UpvertedFiles() {
-		if off >= fi.Length {
-			off -= fi.Length
-			continue
-		}
-		n1 := n
-		if off+n1 > fi.Length {
-			n1 = fi.Length - off
-		}
-		ret = append(ret, requiredLength{
-			fileIndex: i,
-			length:    off + n1,
-		})
-		n -= n1
-		if n == 0 {
-			return
-		}
-		off = 0
-	}
-	return
-}

internal/protocol/bt/file_piece.go

@@ -1,61 +0,0 @@
-// modify from github.com/anacrolix/torrent/storage/file_piece.go
-
-package bt
-
-import (
-	"github.com/anacrolix/torrent/metainfo"
-	"github.com/anacrolix/torrent/storage"
-	"io"
-	"log"
-	"os"
-)
-
-type filePieceImpl struct {
-	*fileTorrentImpl
-	p metainfo.Piece
-	io.WriterAt
-	io.ReaderAt
-}
-
-var _ storage.PieceImpl = (*filePieceImpl)(nil)
-
-func (fs *filePieceImpl) pieceKey() metainfo.PieceKey {
-	return metainfo.PieceKey{InfoHash: fs.infoHash, Index: fs.p.Index()}
-}
-
-func (fs *filePieceImpl) Completion() storage.Completion {
-	c, err := fs.completion.Get(fs.pieceKey())
-	if err != nil {
-		log.Printf("error getting piece completion: %s", err)
-		c.Ok = false
-		return c
-	}
-
-	verified := true
-	if c.Complete {
-		// If it's allegedly complete, check that its constituent files have the necessary length.
-		for _, fi := range extentCompleteRequiredLengths(fs.p.Info, fs.p.Offset(), fs.p.Length()) {
-			s, err := os.Stat(fs.files[fi.fileIndex].path)
-			if err != nil || s.Size() < fi.length {
-				verified = false
-				break
-			}
-		}
-	}
-
-	if !verified {
-		// The completion was wrong, fix it.
-		c.Complete = false
-		fs.completion.Set(fs.pieceKey(), false)
-	}
-
-	return c
-}
-
-func (fs *filePieceImpl) MarkComplete() error {
-	return fs.completion.Set(fs.pieceKey(), true)
-}
-
-func (fs *filePieceImpl) MarkNotComplete() error {
-	return fs.completion.Set(fs.pieceKey(), false)
-}

internal/protocol/http/fetcher_manager.go

@@ -0,0 +1,96 @@
+package http
+
+import (
+	"net/url"
+	"path"
+
+	"github.com/GopeedLab/gopeed/internal/fetcher"
+	"github.com/GopeedLab/gopeed/pkg/base"
+	fhttp "github.com/GopeedLab/gopeed/pkg/protocol/http"
+)
+
+// ============================================================================
+// Fetcher Data (for Store/Restore)
+// ============================================================================
+
+type fetcherData struct {
+	Connections []*connection
+}
+
+// ============================================================================
+// Fetcher Manager
+// ============================================================================
+
+type FetcherManager struct {
+}
+
+func (fm *FetcherManager) Name() string {
+	return "http"
+}
+
+func (fm *FetcherManager) Filters() []*fetcher.SchemeFilter {
+	return []*fetcher.SchemeFilter{
+		{
+			Type:    fetcher.FilterTypeUrl,
+			Pattern: "HTTP",
+		},
+		{
+			Type:    fetcher.FilterTypeUrl,
+			Pattern: "HTTPS",
+		},
+	}
+}
+
+func (fm *FetcherManager) Build() fetcher.Fetcher {
+	return &Fetcher{}
+}
+
+func (fm *FetcherManager) ParseName(u string) string {
+	var name string
+	url, err := url.Parse(u)
+	if err != nil {
+		return ""
+	}
+	name = path.Base(url.Path)
+	if name == "" || name == "/" || name == "." {
+		name = url.Hostname()
+	}
+	return name
+}
+
+func (fm *FetcherManager) AutoRename() bool {
+	return true
+}
+
+func (fm *FetcherManager) DefaultConfig() any {
+	return &config{
+		UserAgent:   "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36",
+		Connections: 16,
+	}
+}
+
+func (fm *FetcherManager) Store(f fetcher.Fetcher) (data any, err error) {
+	_f := f.(*Fetcher)
+	return &fetcherData{
+		Connections: _f.connections,
+	}, nil
+}
+
+func (fm *FetcherManager) Restore() (v any, f func(meta *fetcher.FetcherMeta, v any) fetcher.Fetcher) {
+	return &fetcherData{}, func(meta *fetcher.FetcherMeta, v any) fetcher.Fetcher {
+		fd := v.(*fetcherData)
+		fb := &FetcherManager{}
+		fetcher := fb.Build().(*Fetcher)
+		fetcher.meta = meta
+		base.ParseReqExtra[fhttp.ReqExtra](fetcher.meta.Req)
+		base.ParseOptExtra[fhttp.OptsExtra](fetcher.meta.Opts)
+		if len(fd.Connections) > 0 {
+			fetcher.connections = fd.Connections
+		}
+		return fetcher
+	}
+}
+
+func (fm *FetcherManager) Close() error {
+	return nil
+}

internal/protocol/http/helper.go

@@ -0,0 +1,378 @@
+package http
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"io"
+	"mime"
+	"net"
+	"net/http"
+	"net/http/cookiejar"
+	"net/url"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/GopeedLab/gopeed/pkg/base"
+	fhttp "github.com/GopeedLab/gopeed/pkg/protocol/http"
+	"github.com/GopeedLab/gopeed/pkg/util"
+	"golang.org/x/text/encoding/simplifiedchinese"
+)
+
+type RequestError struct {
+	Code int
+}
+
+func NewRequestError(code int) *RequestError {
+	return &RequestError{Code: code}
+}
+
+func (re *RequestError) Error() string {
+	return fmt.Sprintf("http request fail, code:%d", re.Code)
+}
+
+func isFailureExemptHTTPCode(code int) bool {
+	if code >= 500 && code <= 599 {
+		return true
+	}
+
+	switch code {
+	case 429, 408, 440, 499:
+		return true
+	default:
+		return false
+	}
+}
+
+func shouldCountHTTPFailure(err error) bool {
+	var re *RequestError
+	if !errors.As(err, &re) {
+		return false
+	}
+
+	return !isFailureExemptHTTPCode(re.Code)
+}
+
+func extractRequestError(err error) *RequestError {
+	var re *RequestError
+	if errors.As(err, &re) {
+		return re
+	}
+
+	return nil
+}
+
+// ============================================================================
+// HTTP Request/Client Building
+// ============================================================================
+
+func (f *Fetcher) buildRequest(ctx context.Context, req *base.Request) (httpReq *http.Request, err error) {
+	var reqUrl string
+	f.redirectLock.Lock()
+	if f.redirectURL != "" {
+		reqUrl = f.redirectURL
+	} else {
+		reqUrl = req.URL
+	}
+	f.redirectLock.Unlock()
+
+	var (
+		method string
+		body   io.Reader
+	)
+	headers := http.Header{}
+	if req.Extra == nil {
+		method = http.MethodGet
+	} else {
+		extra := req.Extra.(*fhttp.ReqExtra)
+		if extra.Method != "" {
+			method = extra.Method
+		} else {
+			method = http.MethodGet
+		}
+		if len(extra.Header) > 0 {
+			for k, v := range extra.Header {
+				headers.Set(k, strings.TrimSpace(v))
+			}
+		}
+		if extra.Body != "" {
+			body = bytes.NewBufferString(extra.Body)
+		}
+	}
+	if _, ok := headers[base.HttpHeaderUserAgent]; !ok {
+		headers.Set(base.HttpHeaderUserAgent, strings.TrimSpace(f.config.UserAgent))
+	}
+
+	if ctx != nil {
+		httpReq, err = http.NewRequestWithContext(ctx, method, reqUrl, body)
+	} else {
+		httpReq, err = http.NewRequest(method, reqUrl, body)
+	}
+	if err != nil {
+		return
+	}
+	httpReq.Header = headers
+	if host := headers.Get(base.HttpHeaderHost); host != "" {
+		httpReq.Host = host
+	}
+	return httpReq, nil
+}
+
+func (f *Fetcher) buildClient() *http.Client {
+	transport := &http.Transport{
+		DialContext: (&net.Dialer{
+			Timeout: connectTimeout,
+		}).DialContext,
+		Proxy: f.ctl.GetProxy(f.meta.Req.Proxy),
+		TLSClientConfig: &tls.Config{
+			InsecureSkipVerify: f.meta.Req.SkipVerifyCert,
+		},
+	}
+	jar, _ := cookiejar.New(nil)
+	return &http.Client{
+		Transport: transport,
+		Jar:       jar,
+	}
+}
+
+// ============================================================================
+// Filename Parsing
+// ============================================================================
+
+// parseFilename extracts filename from Content-Disposition header
+func parseFilename(contentDisposition string) string {
+	// Try RFC 5987 extended notation first (filename*=)
+	if filename := parseFilenameExtended(contentDisposition); filename != "" {
+		return filename
+	}
+
+	// Try standard MIME parsing
+	_, params, err := mime.ParseMediaType(contentDisposition)
+	if err == nil {
+		if filename := params["filename"]; filename != "" {
+			return decodeFilenameParam(filename)
+		}
+	}
+
+	// Fallback to manual parsing
+	return parseFilenameFallback(contentDisposition)
+}
+
+// parseFilenameExtended handles RFC 5987 extended notation (filename*=)
+// Format: filename*=charset'language'value (e.g., UTF-8”%E6%B5%8B%E8%AF%95.zip)
+func parseFilenameExtended(cd string) string {
+	lower := strings.ToLower(cd)
+	idx := strings.Index(lower, "filename*=")
+	if idx == -1 {
+		return ""
+	}
+
+	value := cd[idx+len("filename*="):]
+
+	// Find the end of the value using proper quote handling
+	endIdx := findParamValueEnd(value)
+	if endIdx != -1 {
+		value = value[:endIdx]
+	}
+	value = strings.TrimSpace(value)
+
+	// Try charset''encoded format (e.g., UTF-8''%E4%B8%AD%E6%96%87.txt)
+	parts := strings.SplitN(value, "''", 2)
+	if len(parts) == 2 {
+		// Use PathUnescape to handle %2B correctly (should decode to +, not space)
+		decoded, err := url.PathUnescape(parts[1])
+		if err == nil {
+			return decoded
+		}
+	}
+
+	// Try charset'language'encoded format
+	parts = strings.SplitN(value, "'", 3)
+	if len(parts) >= 3 {
+		// Use PathUnescape to handle %2B correctly (should decode to +, not space)
+		decoded, err := url.PathUnescape(parts[2])
+		if err == nil {
+			return decoded
+		}
+	}
+
+	return ""
+}
+
+// decodeFilenameParam decodes filename parameter value
+// Handles HTML entities, MIME encoded-word, URL encoding, and GBK encoding fallback
+func decodeFilenameParam(filename string) string {
+	// First, unescape HTML entities (e.g., &amp; -> &, &lt; -> <, &gt; -> >)
+	// This must be done before other decoding to handle cases where servers
+	// HTML-encode special characters in filenames
+	filename = unescapeHTMLEntities(filename)
+
+	// Handle RFC 2047 encoded word (=?charset?encoding?text?=)
+	if strings.HasPrefix(filename, "=?") {
+		decoder := new(mime.WordDecoder)
+		normalizedFilename := strings.Replace(filename, "UTF8", "UTF-8", 1)
+		if decoded, err := decoder.Decode(normalizedFilename); err == nil {
+			return decoded
+		}
+	}
+
+	// Try URL decoding - use PathUnescape for filenames to handle %2B correctly
+	decoded := util.TryUrlPathUnescape(filename)
+
+	// If not valid UTF-8, try GBK decoding (common for Chinese websites)
+	if !utf8.ValidString(decoded) {
+		if gbkDecoded := tryDecodeGBK(decoded); gbkDecoded != "" {
+			return gbkDecoded
+		}
+	}
+
+	return decoded
+}
+
+// unescapeHTMLEntities unescapes common HTML entities in filenames
+// This handles cases where servers HTML-encode special characters like & to &amp;
+func unescapeHTMLEntities(s string) string {
+	// Common HTML entities that might appear in filenames
+	replacements := map[string]string{
+		"&amp;":  "&",
+		"&lt;":   "<",
+		"&gt;":   ">",
+		"&quot;": "\"",
+		"&#39;":  "'",
+		"&apos;": "'",
+	}
+
+	result := s
+	for entity, char := range replacements {
+		result = strings.ReplaceAll(result, entity, char)
+	}
+	return result
+}
+
+// tryDecodeGBK attempts to decode string as GBK encoding
+func tryDecodeGBK(s string) string {
+	if len(s) == 0 {
+		return ""
+	}
+
+	decoder := simplifiedchinese.GBK.NewDecoder()
+	decoded, err := decoder.Bytes([]byte(s))
+	if err != nil {
+		return ""
+	}
+	result := string(decoded)
+	if utf8.ValidString(result) {
+		return result
+	}
+	return ""
+}
+
+// parseFilenameFallback is a fallback parser for non-standard Content-Disposition
+func parseFilenameFallback(cd string) string {
+	lower := strings.ToLower(cd)
+	idx := strings.Index(lower, "filename=")
+	if idx == -1 {
+		return ""
+	}
+
+	value := cd[idx+len("filename="):]
+
+	// Find the end of the value using proper quote handling
+	endIdx := findParamValueEnd(value)
+	if endIdx != -1 {
+		value = value[:endIdx]
+	}
+	value = strings.TrimSpace(value)
+
+	// Remove surrounding quotes
+	if len(value) >= 2 {
+		if (value[0] == '"' && value[len(value)-1] == '"') ||
+			(value[0] == '\'' && value[len(value)-1] == '\'') {
+			value = value[1 : len(value)-1]
+		}
+	}
+
+	return decodeFilenameParam(value)
+}
+
+// findParamValueEnd finds the end position of a parameter value in a Content-Disposition header.
+// It correctly handles quoted values where semicolons inside quotes should not be treated as delimiters.
+// It also handles HTML entities in unquoted values (e.g., &amp; should not be split at the semicolon).
+// Returns the end index (exclusive) of the value, or -1 if it extends to the end of the string.
+func findParamValueEnd(value string) int {
+	value = strings.TrimSpace(value)
+	if len(value) == 0 {
+		return 0
+	}
+
+	// If the value starts with a quote, find the matching closing quote
+	if value[0] == '"' || value[0] == '\'' {
+		quote := value[0]
+		// Find the closing quote, handling escaped quotes
+		for i := 1; i < len(value); i++ {
+			if value[i] == quote {
+				// Check if it's escaped
+				if i > 0 && value[i-1] == '\\' {
+					continue
+				}
+				// Found closing quote, now look for ; after it
+				remaining := value[i+1:]
+				if semiIdx := strings.Index(remaining, ";"); semiIdx != -1 {
+					return i + 1 + semiIdx
+				}
+				return -1 // No semicolon after closing quote
+			}
+		}
+		// No closing quote found, treat rest of string as value
+		return -1
+	}
+
+	// Unquoted value - find the next semicolon that's not part of an HTML entity
+	// HTML entities have the pattern &...;  (e.g., &amp; &lt; &gt; &quot; &#39;)
+	for i := 0; i < len(value); i++ {
+		if value[i] == ';' {
+			// Check if this semicolon is part of an HTML entity
+			// Look backwards for an & character
+			isEntity := false
+			if i > 0 {
+				// Look for & before this semicolon (within reasonable distance, max 10 chars)
+				for j := i - 1; j >= 0 && j >= i-10; j-- {
+					if value[j] == '&' {
+						// Found &, this semicolon might be part of an HTML entity
+						// Check if there are only alphanumeric or # between & and ;
+						entityChars := value[j+1 : i]
+						if len(entityChars) > 0 && isValidHTMLEntityChars(entityChars) {
+							isEntity = true
+						}
+						break
+					}
+					// If we hit whitespace or another special char, stop looking
+					if value[j] == ' ' || value[j] == '"' || value[j] == '\'' {
+						break
+					}
+				}
+			}
+
+			if !isEntity {
+				return i
+			}
+		}
+	}
+	return -1 // No semicolon, extends to end
+}
+
+// isValidHTMLEntityChars checks if a string contains only valid HTML entity characters
+// (alphanumeric and #, typically for entities like &amp; &lt; &#39; etc.)
+func isValidHTMLEntityChars(s string) bool {
+	if len(s) == 0 {
+		return false
+	}
+	for _, c := range s {
+		if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '#') {
+			return false
+		}
+	}
+	return true
+}

internal/test/httptest.go

@@ -70,6 +70,9 @@ func StartTestSlowFileServer(delay time.Duration) net.Listener {
 func StartTestCustomServer() net.Listener {
 	return startTestServer(func(sl *shutdownListener) http.Handler {
 		mux := http.NewServeMux()
+		mux.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) {
+			writer.WriteHeader(200)
+		})
 		mux.HandleFunc("/"+BuildName, func(writer http.ResponseWriter, request *http.Request) {
 			file, err := os.Open(BuildFile)
 			if err != nil {
@@ -221,6 +224,10 @@ func StartTestCustomServer() net.Listener {
 			defer file.Close()
 			io.Copy(writer, file)
 		})
+		// Test 403 Forbidden endpoint
+		mux.HandleFunc("/forbidden", func(writer http.ResponseWriter, request *http.Request) {
+			writer.WriteHeader(403)
+		})
 		return mux
 	})
 }
@@ -244,20 +251,6 @@ func StartTestHostHeaderServer() net.Listener {
 	})
 }
 
-// StartTestRootServer starts a simple server at the root path
-// Used to test URL resolution when no filename is provided
-func StartTestRootServer() net.Listener {
-	return startTestServer(func(sl *shutdownListener) http.Handler {
-		mux := http.NewServeMux()
-		mux.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) {
-			writer.Header().Set("Content-Type", "text/html")
-			writer.WriteHeader(200)
-			writer.Write([]byte("<html><body>Test Page</body></html>"))
-		})
-		return mux
-	})
-}
-
 func StartTestRetryServer() net.Listener {
 	counter := 0
 	return startTestServer(func(sl *shutdownListener) http.Handler {
@@ -303,23 +296,100 @@ func StartTestPostServer() net.Listener {
 }
 
 func StartTestErrorServer() net.Listener {
-	counter := 0
 	return startTestServer(func(sl *shutdownListener) http.Handler {
 		mux := http.NewServeMux()
 		mux.HandleFunc("/"+BuildName, func(writer http.ResponseWriter, request *http.Request) {
-			counter++
-			if counter != 1 {
-				writer.WriteHeader(500)
-				return
-			}
+			// Always return 404 error to test error handling
+			writer.WriteHeader(404)
+			return
 		})
 		return mux
 	})
 }
 
+// StartTestOneTimeServer creates a server where the URL can only be downloaded once
+// The first non-probe request succeeds, all subsequent requests return 404
+// This simulates one-time download URLs (e.g., signed URLs that expire after first use)
+func StartTestOneTimeServer() net.Listener {
+	var accessed atomic.Bool
+
+	return startTestServer(func(sl *shutdownListener) http.Handler {
+		mux := http.NewServeMux()
+		mux.HandleFunc("/"+BuildName, func(writer http.ResponseWriter, request *http.Request) {
+			// First full download request succeeds, subsequent requests fail
+			if accessed.Swap(true) {
+				writer.WriteHeader(404)
+				return
+			}
+
+			// First request - return full file without Range support
+			writer.Header().Set("Content-Length", fmt.Sprintf("%d", BuildSize))
+			file, err := os.Open(BuildFile)
+			if err != nil {
+				return
+			}
+			defer file.Close()
+			io.Copy(writer, file)
+		})
+		return mux
+	})
+}
+
+// StartTestSlowStartServer creates a server with configurable delay per request
+// This allows testing slow-start connection expansion to reach max connections
+func StartTestSlowStartServer(delayPerByte time.Duration) net.Listener {
+	return startTestServer(func(sl *shutdownListener) http.Handler {
+		mux := http.NewServeMux()
+		mux.HandleFunc("/"+BuildName, func(writer http.ResponseWriter, request *http.Request) {
+			rangeFileHandle(
+				writer,
+				request,
+				nil,
+				func(file *os.File, n int64) {
+					slowCopyNWithDelay(sl, writer, file, n, delayPerByte)
+				},
+			)
+		})
+		return mux
+	})
+}
+
+// slowCopyNWithDelay copies n bytes from src to dst with a delay per byte
+func slowCopyNWithDelay(sl *shutdownListener, dst io.Writer, src io.Reader, n int64, delayPerByte time.Duration) {
+	buf := make([]byte, 32*1024)
+	remaining := n
+	for remaining > 0 {
+		if sl.isShutdown {
+			return
+		}
+		toRead := int64(len(buf))
+		if toRead > remaining {
+			toRead = remaining
+		}
+		nr, er := src.Read(buf[:toRead])
+		if nr > 0 {
+			nw, ew := dst.Write(buf[0:nr])
+			if nw > 0 {
+				remaining -= int64(nw)
+				// Add delay based on bytes written
+				if delayPerByte > 0 {
+					time.Sleep(delayPerByte * time.Duration(nw))
+				}
+			}
+			if ew != nil {
+				break
+			}
+		}
+		if er != nil {
+			break
+		}
+	}
+}
+
 // StartTestLimitServer connections limit server
 func StartTestLimitServer(maxConnections int32, delay int64) net.Listener {
 	var connections atomic.Int32
+	var slowOnce atomic.Bool
 
 	return startTestServer(func(sl *shutdownListener) http.Handler {
 		mux := http.NewServeMux()
@@ -332,12 +402,93 @@ func StartTestLimitServer(maxConnections int32, delay int64) net.Listener {
 				writer.WriteHeader(403)
 				return
 			}
+
+			// First request intentionally delays the first write to trigger a single read timeout,
+			// subsequent requests respond at normal speed.
+			useInitialDelay := delay > 0 && !slowOnce.Swap(true)
 			rangeFileHandle(
 				writer,
 				request,
 				nil,
 				func(file *os.File, n int64) {
-					slowCopyN(sl, writer, file, n, delay)
+					if useInitialDelay {
+						slowCopyAfterDelay(sl, writer, file, n, delay)
+						return
+					}
+					slowCopyN(sl, writer, file, n, 0)
+				},
+			)
+		})
+		return mux
+	})
+}
+
+// StartTestTimeoutOnceServer creates a server that times out on first request, then works normally
+func StartTestTimeoutOnceServer(delay int64) net.Listener {
+	var timeoutOnce atomic.Bool
+
+	return startTestServer(func(sl *shutdownListener) http.Handler {
+		mux := http.NewServeMux()
+		mux.HandleFunc("/"+BuildName, func(writer http.ResponseWriter, request *http.Request) {
+			// First request delays to trigger timeout, subsequent requests respond normally
+			useInitialDelay := delay > 0 && !timeoutOnce.Swap(true)
+			rangeFileHandle(
+				writer,
+				request,
+				nil,
+				func(file *os.File, n int64) {
+					if useInitialDelay {
+						slowCopyAfterDelay(sl, writer, file, n, delay)
+						return
+					}
+					slowCopyN(sl, writer, file, n, 0)
+				},
+			)
+		})
+		return mux
+	})
+}
+
+// StartTestTemporary500Server creates a server that returns 500 for a duration, then recovers
+// Uses slow transfer to ensure the file isn't fully downloaded during resolve phase
+func StartTestTemporary500Server(errorDuration time.Duration) net.Listener {
+	startTime := time.Now()
+	var requestCount atomic.Int32
+
+	return startTestServer(func(sl *shutdownListener) http.Handler {
+		mux := http.NewServeMux()
+		mux.HandleFunc("/"+BuildName, func(writer http.ResponseWriter, request *http.Request) {
+			reqNum := requestCount.Add(1)
+
+			// First request (Resolve) succeeds with slow transfer to prevent full download
+			// Subsequent requests return 500 for the specified duration, then recover
+			if reqNum == 1 {
+				// Slow transfer for resolve: 50 microsecond per byte (~20MB/s)
+				// This ensures resolve doesn't complete the full 200MB file
+				rangeFileHandle(
+					writer,
+					request,
+					nil,
+					func(file *os.File, n int64) {
+						slowCopyNWithDelay(sl, writer, file, n, 50*time.Microsecond)
+					},
+				)
+				return
+			}
+
+			// Subsequent requests: return 500 for errorDuration, then normal
+			if time.Since(startTime) < errorDuration {
+				writer.WriteHeader(500)
+				writer.Write([]byte("Internal Server Error"))
+				return
+			}
+
+			rangeFileHandle(
+				writer,
+				request,
+				nil,
+				func(file *os.File, n int64) {
+					slowCopyN(sl, writer, file, n, 0)
 				},
 			)
 		})
@@ -375,6 +526,26 @@ func StartTestRangeBugServer() net.Listener {
 
 func rangeFileHandle(writer http.ResponseWriter, request *http.Request, modifyEnd func(end int64) int64, iocpN func(file *os.File, n int64)) {
 	r := request.Header.Get("Range")
+
+	// If no Range header, return full file with Accept-Ranges header
+	if r == "" {
+		// Open file first to ensure it exists
+		file, err := os.Open(BuildFile)
+		if err != nil {
+			writer.WriteHeader(500)
+			return
+		}
+		defer file.Close()
+
+		writer.Header().Set("Content-Length", fmt.Sprintf("%d", BuildSize))
+		writer.Header().Set("Accept-Ranges", "bytes")
+		writer.WriteHeader(200)
+		(writer.(http.Flusher)).Flush()
+
+		iocpN(file, BuildSize)
+		return
+	}
+
 	// split range
 	s := strings.Split(r, "=")
 	if len(s) != 2 {
@@ -408,12 +579,7 @@ func rangeFileHandle(writer http.ResponseWriter, request *http.Request, modifyEn
 		end = modifyEnd(end)
 	}
 
-	writer.Header().Set("Content-Length", fmt.Sprintf("%d", end-start+1))
-	writer.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", start, end, BuildSize))
-	writer.Header().Set("Accept-Ranges", "bytes")
-	writer.WriteHeader(206)
-	(writer.(http.Flusher)).Flush()
-
+	// Open file before sending headers to ensure it exists
 	file, err := os.Open(BuildFile)
 	if err != nil {
 		writer.WriteHeader(500)
@@ -421,6 +587,13 @@ func rangeFileHandle(writer http.ResponseWriter, request *http.Request, modifyEn
 	}
 	defer file.Close()
 	file.Seek(start, 0)
+
+	writer.Header().Set("Content-Length", fmt.Sprintf("%d", end-start+1))
+	writer.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", start, end, BuildSize))
+	writer.Header().Set("Accept-Ranges", "bytes")
+	writer.WriteHeader(206)
+	(writer.(http.Flusher)).Flush()
+
 	iocpN(file, end-start+1)
 }
 
@@ -471,6 +644,14 @@ func slowCopyN(sl *shutdownListener, dst io.Writer, src io.Reader, n int64, dela
 	return
 }
 
+// slowCopyAfterDelay sleeps once before performing a normal copy to simulate a single timeout.
+func slowCopyAfterDelay(sl *shutdownListener, dst io.Writer, src io.Reader, n int64, delay int64) (written int64, err error) {
+	if delay > 0 {
+		time.Sleep(time.Millisecond * time.Duration(delay))
+	}
+	return slowCopyN(sl, dst, src, n, 0)
+}
+
 func startTestServer(serverHandle func(sl *shutdownListener) http.Handler) net.Listener {
 	listener, err := net.Listen("tcp", "127.0.0.1:0")
 	if err != nil {
@@ -515,8 +696,9 @@ type shutdownListener struct {
 }
 
 func (c *shutdownListener) Close() error {
-	c.isShutdown = true
+	// Shutdown server first (waits for in-flight requests), then set isShutdown
 	closeErr := c.server.Shutdown(context.Background())
+	c.isShutdown = true
 	if err := ifExistAndRemove(BuildFile); err != nil {
 		fmt.Println(err)
 	}