refactor: flatten repository structure to root and archive research notes

2026-09-22 03:41:27 +08:00
parent ae0becffec
commit 1a7658b1f7
40 changed files with 0 additions and 3 deletions
@@ -0,0 +1,332 @@
+package storage
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/Bios-Marcel/wastebasket"
+)
+
+type Trashable interface {
+	Trash(path string) error
+	MoveToTrash(path, trashRoot string) error
+}
+
+type Storage interface {
+	Stat(path string) (os.FileInfo, error)
+	Open(path string) (*os.File, error)
+	Create(path string) (*os.File, error)
+	Remove(path string) error
+	Rename(oldPath, newPath string) error
+	Copy(oldPath, newPath string) error
+	MkdirAll(path string) error
+	List(path string) ([]os.FileInfo, error)
+}
+
+type ExclusiveCreator interface {
+	CreateExclusive(path string) (*os.File, error)
+}
+
+type Local struct{ Root string }
+
+func (s Local) real(path string) (string, error) {
+	root, err := filepath.Abs(s.Root)
+	if err != nil {
+		return "", err
+	}
+	root, err = filepath.EvalSymlinks(root)
+	if err != nil {
+		return "", err
+	}
+	p := strings.TrimPrefix(filepath.Clean("/"+path), string(filepath.Separator))
+	full := filepath.Join(root, p)
+	rel, err := filepath.Rel(root, full)
+	if err != nil {
+		return "", err
+	}
+	if rel == ".." || strings.HasPrefix(rel, ".."+string(filepath.Separator)) {
+		return "", errors.New("path escapes storage root")
+	}
+	check := full
+	for {
+		if _, err = os.Lstat(check); !os.IsNotExist(err) {
+			break
+		}
+		next := filepath.Dir(check)
+		if next == check {
+			break
+		}
+		check = next
+	}
+	resolved, err := filepath.EvalSymlinks(check)
+	if err != nil {
+		return "", err
+	}
+	resolvedRel, err := filepath.Rel(root, resolved)
+	if err != nil || resolvedRel == ".." || strings.HasPrefix(resolvedRel, ".."+string(filepath.Separator)) {
+		return "", errors.New("path escapes storage root")
+	}
+	return full, nil
+}
+func (s Local) Stat(path string) (os.FileInfo, error) {
+	p, e := s.real(path)
+	if e != nil {
+		return nil, e
+	}
+	return os.Stat(p)
+}
+func (s Local) Open(path string) (*os.File, error) {
+	p, e := s.real(path)
+	if e != nil {
+		return nil, e
+	}
+	return os.Open(p)
+}
+func (s Local) Create(path string) (*os.File, error) {
+	p, e := s.real(path)
+	if e != nil {
+		return nil, e
+	}
+	if e = os.MkdirAll(filepath.Dir(p), 0755); e != nil {
+		return nil, e
+	}
+	return os.Create(p)
+}
+
+func (s Local) CreateExclusive(path string) (*os.File, error) {
+	p, e := s.real(path)
+	if e != nil {
+		return nil, e
+	}
+	if e = os.MkdirAll(filepath.Dir(p), 0755); e != nil {
+		return nil, e
+	}
+	return os.OpenFile(p, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0644)
+}
+func (s Local) Remove(path string) error {
+	p, e := s.real(path)
+	if e == nil {
+		return os.RemoveAll(p)
+	}
+	// A final symlink that points outside the root is still safe to delete:
+	// remove the link itself, but never follow it to its target. Validate its
+	// parent through real() so nested symlink escapes remain rejected.
+	clean := strings.TrimPrefix(filepath.Clean("/"+path), string(filepath.Separator))
+	if clean == "" {
+		return e
+	}
+	parent := filepath.ToSlash(filepath.Dir(clean))
+	if parent == "." {
+		parent = ""
+	}
+	if _, parentErr := s.real(parent); parentErr != nil {
+		return e
+	}
+	root, rootErr := filepath.Abs(s.Root)
+	if rootErr != nil {
+		return e
+	}
+	root, rootErr = filepath.EvalSymlinks(root)
+	if rootErr != nil {
+		return e
+	}
+	candidate := filepath.Join(root, filepath.FromSlash(clean))
+	if info, lstatErr := os.Lstat(candidate); lstatErr == nil && info.Mode()&os.ModeSymlink != 0 {
+		return os.Remove(candidate)
+	}
+	return e
+}
+
+func (s Local) Trash(path string) error {
+	p, e := s.real(path)
+	if e != nil {
+		return e
+	}
+	return wastebasket.Trash(p)
+}
+
+func (s Local) MoveToTrash(path, trashRoot string) error {
+	p, e := s.real(path)
+	if e != nil {
+		return e
+	}
+	root, e := filepath.Abs(s.Root)
+	if e != nil {
+		return e
+	}
+	rel, e := filepath.Rel(root, p)
+	if e != nil || rel == ".." || strings.HasPrefix(rel, ".."+string(filepath.Separator)) {
+		return errors.New("path escapes storage root")
+	}
+	if e = os.MkdirAll(trashRoot, 0755); e != nil {
+		return e
+	}
+	// Preserve the original relative path under the CHFS trash root so
+	// identically named files from different directories cannot collide.
+	target := filepath.Join(trashRoot, rel)
+	if e = os.MkdirAll(filepath.Dir(target), 0755); e != nil {
+		return e
+	}
+	for i := 1; ; i++ {
+		if _, e = os.Lstat(target); os.IsNotExist(e) {
+			break
+		}
+		target = filepath.Join(filepath.Dir(target), fmt.Sprintf("%s.%d", filepath.Base(p), i))
+	}
+	if e = movePath(p, target); e != nil {
+		return e
+	}
+	// Cleanup is maintenance work; a successful move must not be reported as
+	// a failed delete merely because an unrelated stale trash entry is busy.
+	_ = cleanupTrash(trashRoot, 30*24*time.Hour)
+	return nil
+}
+
+func cleanupTrash(root string, maxAge time.Duration) error {
+	now := time.Now()
+	return filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if path == root || d.IsDir() {
+			return nil
+		}
+		info, err := d.Info()
+		if err != nil {
+			return err
+		}
+		if now.Sub(info.ModTime()) > maxAge {
+			return os.Remove(path)
+		}
+		return nil
+	})
+}
+
+func movePath(src, dst string) error {
+	if err := os.Rename(src, dst); err == nil {
+		return nil
+	} else if !errors.Is(err, syscall.EXDEV) {
+		return err
+	}
+	if _, err := os.Lstat(dst); err == nil {
+		return fmt.Errorf("destination already exists: %s", dst)
+	} else if !os.IsNotExist(err) {
+		return err
+	}
+	if err := copyPath(src, dst); err != nil {
+		return err
+	}
+	return os.RemoveAll(src)
+}
+
+func copyPath(src, dst string) error {
+	info, err := os.Lstat(src)
+	if err != nil {
+		return err
+	}
+	if info.Mode()&os.ModeSymlink != 0 {
+		target, err := os.Readlink(src)
+		if err != nil {
+			return err
+		}
+		return os.Symlink(target, dst)
+	}
+	if info.IsDir() {
+		if err := os.MkdirAll(dst, info.Mode().Perm()); err != nil {
+			return err
+		}
+		entries, err := os.ReadDir(src)
+		if err != nil {
+			return err
+		}
+		for _, entry := range entries {
+			if err := copyPath(filepath.Join(src, entry.Name()), filepath.Join(dst, entry.Name())); err != nil {
+				return err
+			}
+		}
+		return os.Chtimes(dst, info.ModTime(), info.ModTime())
+	}
+	in, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer in.Close()
+	out, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_EXCL, info.Mode().Perm())
+	if err != nil {
+		return err
+	}
+	_, copyErr := io.Copy(out, in)
+	closeErr := out.Close()
+	if copyErr != nil {
+		_ = os.Remove(dst)
+		return copyErr
+	}
+	if closeErr != nil {
+		_ = os.Remove(dst)
+		return closeErr
+	}
+	return os.Chtimes(dst, info.ModTime(), info.ModTime())
+}
+
+func (s Local) Copy(a, b string) error {
+	pa, e := s.real(a)
+	if e != nil {
+		return e
+	}
+	pb, e := s.real(b)
+	if e != nil {
+		return e
+	}
+	if _, e := os.Lstat(pb); e == nil {
+		return os.ErrExist
+	} else if !os.IsNotExist(e) {
+		return e
+	}
+	return copyPath(pa, pb)
+}
+
+func (s Local) Rename(a, b string) error {
+	pa, e := s.real(a)
+	if e != nil {
+		return e
+	}
+	pb, e := s.real(b)
+	if e != nil {
+		return e
+	}
+	return movePath(pa, pb)
+}
+func (s Local) MkdirAll(path string) error {
+	p, e := s.real(path)
+	if e != nil {
+		return e
+	}
+	return os.MkdirAll(p, 0755)
+}
+func (s Local) List(path string) ([]os.FileInfo, error) {
+	p, e := s.real(path)
+	if e != nil {
+		return nil, e
+	}
+	f, e := os.Open(p)
+	if e != nil {
+		return nil, e
+	}
+	defer f.Close()
+	items, err := f.Readdir(-1)
+	if err != nil {
+		return nil, err
+	}
+	sort.Slice(items, func(i, j int) bool { return items[i].Name() < items[j].Name() })
+	return items, nil
+}
+
+var _ fs.FS