From 7c33d978c49be945ec22c46c5f670c329cf2d307 Mon Sep 17 00:00:00 2001 From: Levi Date: Thu, 17 Sep 2026 23:35:40 +0800 Subject: [PATCH] fix(bt): clean partial files and empty parent directories --- internal/protocol/bt/fetcher.go | 34 ++++++++++++-- internal/protocol/bt/selection_test.go | 62 ++++++++++++++++++++++++-- 2 files changed, 88 insertions(+), 8 deletions(-) diff --git a/internal/protocol/bt/fetcher.go b/internal/protocol/bt/fetcher.go index 759b8fc1..bc32f741 100644 --- a/internal/protocol/bt/fetcher.go +++ b/internal/protocol/bt/fetcher.go @@ -399,10 +399,8 @@ func (f *Fetcher) Wait() (err error) { } } if !selected { - // Path already includes the torrent's root directory. - name := filepath.Join(f.meta.Opts.Path, file.Path()) - if err := util.SafeRemove(name); err != nil { - return fmt.Errorf("remove unselected torrent file %q: %w", name, err) + if err := removeUnselectedFile(f.meta.Opts.Path, file.Path()); err != nil { + return err } } } @@ -413,6 +411,34 @@ func (f *Fetcher) Wait() (err error) { } } +// Path already includes the torrent's root directory. Never prune the download +// directory itself, and only remove parent directories that are empty. +func removeUnselectedFile(downloadDir, torrentPath string) error { + root := filepath.Clean(downloadDir) + name := filepath.Join(root, torrentPath) + for _, candidate := range []string{name, name + ".part"} { + if err := util.SafeRemove(candidate); err != nil { + return fmt.Errorf("remove unselected torrent file %q: %w", candidate, err) + } + } + for dir := filepath.Dir(name); dir != root && dir != filepath.Dir(dir); dir = filepath.Dir(dir) { + entries, err := os.ReadDir(dir) + if os.IsNotExist(err) { + continue + } + if err != nil { + return fmt.Errorf("read torrent directory %q: %w", dir, err) + } + if len(entries) != 0 { + break + } + if err := util.SafeRemove(dir); err != nil { + return fmt.Errorf("remove empty torrent directory %q: %w", dir, err) + } + } + return nil +} + func (f *Fetcher) isDone() bool { if f.meta.Opts == nil { return false diff --git a/internal/protocol/bt/selection_test.go b/internal/protocol/bt/selection_test.go index 6b99a2a2..f147cfc5 100644 --- a/internal/protocol/bt/selection_test.go +++ b/internal/protocol/bt/selection_test.go @@ -3,6 +3,7 @@ package bt import ( "context" "crypto/sha1" + "fmt" "os" "path/filepath" "testing" @@ -62,7 +63,7 @@ func TestStartUsesSelectionSubmittedAfterResolve(t *testing.T) { } func TestWaitCleansUnselectedFilesFromSharedPiece(t *testing.T) { - for _, mode := range []string{"partial", "all", "already removed", "remove error"} { + for _, mode := range []string{"partial", "part only", "both paths", "all", "already removed", "remove error"} { t.Run(mode, func(t *testing.T) { dir := t.TempDir() keepPath := filepath.Join(dir, "bundle", "keep.txt") @@ -118,7 +119,12 @@ func TestWaitCleansUnselectedFilesFromSharedPiece(t *testing.T) { if !f.isDone() { t.Fatal("selected file is not complete") } - if mode == "already removed" || mode == "remove error" { + if mode == "part only" || mode == "both paths" || mode == "all" { + if err := os.WriteFile(skipPath+".part", []byte("skip"), 0644); err != nil { + t.Fatal(err) + } + } + if mode == "part only" || mode == "already removed" || mode == "remove error" { if err := os.Remove(skipPath); err != nil { t.Fatal(err) } @@ -147,15 +153,63 @@ func TestWaitCleansUnselectedFilesFromSharedPiece(t *testing.T) { t.Fatalf("selected file changed: %q, %v", data, err) } if mode == "all" { + if _, err := os.Stat(skipPath + ".part"); err != nil { + t.Fatalf("selected part file was removed: %v", err) + } data, err := os.ReadFile(skipPath) if err != nil || string(data) != "skip" { t.Fatalf("selected file changed: %q, %v", data, err) } } else if mode != "remove error" { - if _, err := os.Stat(skipPath); !os.IsNotExist(err) { - t.Fatalf("unselected file remains: %v", err) + for _, removed := range []string{skipPath, skipPath + ".part", filepath.Dir(skipPath)} { + if _, err := os.Stat(removed); !os.IsNotExist(err) { + t.Fatalf("unselected file or empty directory remains: %s: %v", removed, err) + } } } }) } } + +func TestRemoveUnselectedFilePrunesOnlyEmptyParents(t *testing.T) { + for _, preserveSibling := range []bool{false, true} { + t.Run(fmt.Sprint(preserveSibling), func(t *testing.T) { + root := t.TempDir() + relative := filepath.Join("bundle", "nested", "deep", "skip.txt") + name := filepath.Join(root, relative) + if err := os.MkdirAll(filepath.Dir(name), 0755); err != nil { + t.Fatal(err) + } + if err := os.WriteFile(name+".part", []byte("partial"), 0644); err != nil { + t.Fatal(err) + } + sibling := filepath.Join(root, "bundle", "keep.txt") + if preserveSibling { + if err := os.WriteFile(sibling, []byte("keep"), 0644); err != nil { + t.Fatal(err) + } + } + if err := removeUnselectedFile(root, relative); err != nil { + t.Fatal(err) + } + if _, err := os.Stat(filepath.Join(root, "bundle", "nested")); !os.IsNotExist(err) { + t.Fatalf("empty ancestors remain: %v", err) + } + if preserveSibling { + data, err := os.ReadFile(sibling) + if err != nil || string(data) != "keep" { + t.Fatalf("sibling changed: %q, %v", data, err) + } + } else if _, err := os.Stat(filepath.Join(root, "bundle")); !os.IsNotExist(err) { + t.Fatalf("empty torrent directory remains: %v", err) + } + if _, err := os.Stat(root); err != nil { + t.Fatalf("download directory was removed: %v", err) + } + // Repeating cleanup after all files and directories are gone is harmless. + if err := removeUnselectedFile(root, relative); err != nil { + t.Fatal(err) + } + }) + } +}