wip

internal/store/store.go

@@ -0,0 +1,179 @@
+package store
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+)
+
+// ErrNotFound is returned when a resource does not exist.
+var ErrNotFound = errors.New("not found")
+
+// ErrConflict is returned when trying to create a resource that already exists.
+var ErrConflict = errors.New("conflict")
+
+// Store is a filesystem-backed key/value store for DAV objects.
+// Each "collection" maps to a directory; each "object" maps to a file.
+type Store struct {
+	rootDir string
+	mu      sync.RWMutex
+}
+
+// NewStore creates or opens a Store rooted at rootDir.
+func NewStore(rootDir string) (*Store, error) {
+	if err := os.MkdirAll(rootDir, 0o755); err != nil {
+		return nil, fmt.Errorf("creating store root %q: %w", rootDir, err)
+	}
+	return &Store{rootDir: rootDir}, nil
+}
+
+// collectionPath returns the filesystem path for a collection.
+func (s *Store) collectionPath(user, collection string) string {
+	return filepath.Join(s.rootDir, sanitize(user), sanitize(collection))
+}
+
+// objectPath returns the filesystem path for an object within a collection.
+func (s *Store) objectPath(user, collection, objectID string) string {
+	return filepath.Join(s.collectionPath(user, collection), sanitize(objectID))
+}
+
+// EnsureCollection creates the collection directory if it does not exist.
+func (s *Store) EnsureCollection(user, collection string) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	dir := s.collectionPath(user, collection)
+	return os.MkdirAll(dir, 0o755)
+}
+
+// ListCollections returns all collection names for a user.
+func (s *Store) ListCollections(user string) ([]string, error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	userDir := filepath.Join(s.rootDir, sanitize(user))
+	entries, err := os.ReadDir(userDir)
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	var names []string
+	for _, e := range entries {
+		if e.IsDir() {
+			names = append(names, e.Name())
+		}
+	}
+	return names, nil
+}
+
+// GetCollection returns metadata about a collection.
+func (s *Store) GetCollection(user, collection string) (os.FileInfo, error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	info, err := os.Stat(s.collectionPath(user, collection))
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, ErrNotFound
+	}
+	return info, err
+}
+
+// PutObject writes data to an object, creating or replacing it.
+func (s *Store) PutObject(user, collection, objectID string, data []byte) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	dir := s.collectionPath(user, collection)
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return err
+	}
+
+	path := s.objectPath(user, collection, objectID)
+	// Write to a temp file then rename for atomicity.
+	tmp := path + ".tmp"
+	if err := os.WriteFile(tmp, data, 0o644); err != nil {
+		return fmt.Errorf("writing object: %w", err)
+	}
+	return os.Rename(tmp, path)
+}
+
+// GetObject reads an object's raw bytes.
+func (s *Store) GetObject(user, collection, objectID string) ([]byte, error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	data, err := os.ReadFile(s.objectPath(user, collection, objectID))
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, ErrNotFound
+	}
+	return data, err
+}
+
+// DeleteObject removes an object.
+func (s *Store) DeleteObject(user, collection, objectID string) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	err := os.Remove(s.objectPath(user, collection, objectID))
+	if errors.Is(err, os.ErrNotExist) {
+		return ErrNotFound
+	}
+	return err
+}
+
+// ListObjects returns all object filenames in a collection.
+func (s *Store) ListObjects(user, collection string) ([]string, error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	dir := s.collectionPath(user, collection)
+	entries, err := os.ReadDir(dir)
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	var names []string
+	for _, e := range entries {
+		if !e.IsDir() && !strings.HasSuffix(e.Name(), ".tmp") {
+			names = append(names, e.Name())
+		}
+	}
+	return names, nil
+}
+
+// StatObject returns FileInfo for an object.
+func (s *Store) StatObject(user, collection, objectID string) (os.FileInfo, error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	info, err := os.Stat(s.objectPath(user, collection, objectID))
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, ErrNotFound
+	}
+	return info, err
+}
+
+// DeleteCollection removes an entire collection directory.
+func (s *Store) DeleteCollection(user, collection string) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	err := os.RemoveAll(s.collectionPath(user, collection))
+	return err
+}
+
+// sanitize removes path-traversal characters from a path segment.
+func sanitize(s string) string {
+	s = filepath.Base(s)
+	s = strings.ReplaceAll(s, "..", "")
+	if s == "." || s == "" {
+		return "_"
+	}
+	return s
+}