override storage provider in config

#183

internal/storage/storage.go

@@ -17,3 +17,9 @@ type File interface {
 	io.WriterAt
 	io.Closer
 }
+
+// Provider is a torrent storage provider.
+type Provider interface {
+	// GetStorage returns a storage for a torrent.
+	GetStorage(torrentID string) (Storage, error)
+}

torrent/config.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/cenkalti/log"
 	"github.com/cenkalti/rain/internal/metainfo"
+	"github.com/cenkalti/rain/internal/storage"
 )
 
 var (
@@ -23,9 +24,11 @@ type Config struct {
 	// Database file to save resume data.
 	Database string `yaml:"database"`
 	// DataDir is where files are downloaded.
+	// Effective only when default storage provider is used.
 	DataDir string `yaml:"data-dir"`
 	// If true, torrent files are saved into <data_dir>/<torrent_id>/<torrent_name>.
 	// Useful if downloading the same torrent from multiple sources.
+	// Effective only when default storage provider is used.
 	DataDirIncludesTorrentID bool `yaml:"data-dir-includes-torrent-id"`
 	// Host to listen for TCP Acceptor. Port is computed automatically
 	Host string `yaml:"host"`
@@ -78,7 +81,8 @@ type Config struct {
 	HealthCheckInterval time.Duration `yaml:"health-check-interval"`
 	// If torrent loop is stuck for more than this duration. Program crashes with stacktrace.
 	HealthCheckTimeout time.Duration `yaml:"health-check-timeout"`
-	// The unix permission of created files, execute bit is removed for files
+	// The unix permission of created files, execute bit is removed for files.
+	// Effective only when default storage provider is used.
 	FilePermissions fs.FileMode `yaml:"file-permissions"`
 
 	// Enable RPC server
@@ -198,6 +202,9 @@ type Config struct {
 
 	// Replace default log handler
 	CustomLogHandler log.Handler `yaml:"-"`
+	// Replace default storage provider
+	CustomStorage storage.Provider `yaml:"-"`
+
 	// Enable debugging
 	Debug bool `yaml:"debug"`
 }

torrent/session.go

@@ -23,7 +23,6 @@ import (
 	"github.com/cenkalti/rain/internal/resumer/boltdbresumer"
 	"github.com/cenkalti/rain/internal/semaphore"
 	"github.com/cenkalti/rain/internal/storage"
-	"github.com/cenkalti/rain/internal/storage/filestorage"
 	"github.com/cenkalti/rain/internal/tracker"
 	"github.com/cenkalti/rain/internal/trackermanager"
 	"github.com/juju/ratelimit"
@@ -44,6 +43,7 @@ var (
 type Session struct {
 	config         Config
 	db             *bbolt.DB
+	storage        storage.Provider
 	resumer        *boltdbresumer.Resumer
 	log            logger.Logger
 	extensions     [8]byte
@@ -204,6 +204,11 @@ func NewSession(cfg Config) (*Session, error) {
 			},
 		},
 	}
+	if cfg.CustomStorage != nil {
+		c.storage = cfg.CustomStorage
+	} else {
+		c.storage = newFileStorageProvider(&cfg)
+	}
 	dlSpeed := cfg.SpeedLimitDownload * 1024
 	if cfg.SpeedLimitDownload > 0 {
 		c.bucketDownload = ratelimit.NewBucketWithRate(float64(dlSpeed), dlSpeed)
@@ -447,14 +452,3 @@ func (s *Session) StopAll() error {
 	}
 	return nil
 }
-
-func (s *Session) newStorage(id string) (storage.Storage, error) {
-	return filestorage.New(s.getDataDir(id), s.config.FilePermissions)
-}
-
-func (s *Session) getDataDir(torrentID string) string {
-	if s.config.DataDirIncludesTorrentID {
-		return filepath.Join(s.config.DataDir, torrentID)
-	}
-	return s.config.DataDir
-}

torrent/session_add.go

@@ -266,7 +266,7 @@ func (s *Session) add(opt *AddTorrentOptions) (id string, port int, sto storage.
 		}
 		id = base64.RawURLEncoding.EncodeToString(u1[:])
 	}
-	sto, err = s.newStorage(id)
+	sto, err = s.storage.GetStorage(id)
 	if err != nil {
 		return
 	}

torrent/session_load.go

@@ -83,7 +83,7 @@ func (s *Session) loadExistingTorrent(id string) (tt *Torrent, hasStarted bool,
 			bf = bf3
 		}
 	}
-	sto, err := s.newStorage(id)
+	sto, err := s.storage.GetStorage(id)
 	if err != nil {
 		return
 	}

torrent/session_rpc_handler.go

@@ -473,6 +473,15 @@ func (h *rpcHandler) MoveTorrent(args *rpctypes.MoveTorrentRequest, reply *rpcty
 }
 
 func (h *rpcHandler) handleMoveTorrent(w http.ResponseWriter, r *http.Request) {
+	var provider *fileStorageProvider
+	var ok bool
+	if provider, ok = h.session.storage.(*fileStorageProvider); !ok {
+		err := errors.New("session is not using file storage")
+		h.session.log.Error(err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
 	port, err := h.session.getPort()
 	if err != nil {
 		h.session.log.Error(err)
@@ -561,7 +570,7 @@ func (h *rpcHandler) handleMoveTorrent(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "data expected in multipart form", http.StatusBadRequest)
 		return
 	}
-	err = readData(p, h.session.getDataDir(id), h.session.config.FilePermissions)
+	err = readData(p, provider.getDataDir(id), h.session.config.FilePermissions)
 	if err != nil {
 		h.session.log.Error(err)
 		http.Error(w, err.Error(), http.StatusInternalServerError)

torrent/session_storage.go

@@ -0,0 +1,34 @@
+package torrent
+
+import (
+	"io/fs"
+	"path/filepath"
+
+	"github.com/cenkalti/rain/internal/storage"
+	"github.com/cenkalti/rain/internal/storage/filestorage"
+)
+
+type fileStorageProvider struct {
+	DataDir                  string
+	DataDirIncludesTorrentID bool
+	FilePermissions          fs.FileMode
+}
+
+func newFileStorageProvider(cfg *Config) *fileStorageProvider {
+	return &fileStorageProvider{
+		DataDir:                  cfg.DataDir,
+		DataDirIncludesTorrentID: cfg.DataDirIncludesTorrentID,
+		FilePermissions:          cfg.FilePermissions,
+	}
+}
+
+func (p *fileStorageProvider) GetStorage(torrentID string) (storage.Storage, error) {
+	return filestorage.New(p.getDataDir(torrentID), p.FilePermissions)
+}
+
+func (p *fileStorageProvider) getDataDir(torrentID string) string {
+	if p.DataDirIncludesTorrentID {
+		return filepath.Join(p.DataDir, torrentID)
+	}
+	return p.DataDir
+}

torrent/session_torrent.go

@@ -4,6 +4,7 @@ import (
 	"archive/tar"
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"mime/multipart"
@@ -290,8 +291,15 @@ func (t *Torrent) generateTar(pw *io.PipeWriter) {
 	var err error
 	defer func() { _ = pw.CloseWithError(err) }()
 
+	var root string
+	if provider, ok := t.torrent.session.storage.(*fileStorageProvider); !ok {
+		err = errors.New("session is not using file storage")
+		return
+	} else {
+		root = provider.getDataDir(t.torrent.id)
+	}
+
 	tw := tar.NewWriter(pw)
-	root := t.torrent.session.getDataDir(t.torrent.id)
 	walkFunc := func(path string, info os.FileInfo, err error) error {
 		if err != nil {
 			return err