Backend: Expose connections parameter

internal/backend/azure/azure.go

@@ -24,6 +24,7 @@ import (
 type Backend struct {
 	accountName  string
 	container    *storage.Container
+	connections  uint
 	sem          *backend.Semaphore
 	prefix       string
 	listMaxItems int
@@ -55,6 +56,7 @@ func open(cfg Config, rt http.RoundTripper) (*Backend, error) {
 	be := &Backend{
 		container:   service.GetContainerReference(cfg.Container),
 		accountName: cfg.AccountName,
+		connections: cfg.Connections,
 		sem:         sem,
 		prefix:      cfg.Prefix,
 		Layout: &backend.DefaultLayout{
@@ -109,6 +111,10 @@ func (be *Backend) Join(p ...string) string {
 	return path.Join(p...)
 }
 
+func (be *Backend) Connections() uint {
+	return be.connections
+}
+
 // Location returns this backend's location (the container name).
 func (be *Backend) Location() string {
 	return be.Join(be.container.Name, be.prefix)

internal/backend/b2/b2.go

@@ -133,6 +133,10 @@ func (be *b2Backend) SetListMaxItems(i int) {
 	be.listMaxItems = i
 }
 
+func (be *b2Backend) Connections() uint {
+	return be.cfg.Connections
+}
+
 // Location returns the location for the backend.
 func (be *b2Backend) Location() string {
 	return be.cfg.Bucket

internal/backend/dryrun/dry_backend.go

@@ -45,6 +45,10 @@ func (be *Backend) Remove(ctx context.Context, h restic.Handle) error {
 	return nil
 }
 
+func (be *Backend) Connections() uint {
+	return be.b.Connections()
+}
+
 // Location returns the location of the backend.
 func (be *Backend) Location() string {
 	return "DRY:" + be.b.Location()

internal/backend/gs/gs.go

@@ -34,6 +34,7 @@ import (
 type Backend struct {
 	gcsClient    *storage.Client
 	projectID    string
+	connections  uint
 	sem          *backend.Semaphore
 	bucketName   string
 	bucket       *storage.BucketHandle
@@ -102,12 +103,13 @@ func open(cfg Config, rt http.RoundTripper) (*Backend, error) {
 	}
 
 	be := &Backend{
-		gcsClient:  gcsClient,
-		projectID:  cfg.ProjectID,
-		sem:        sem,
-		bucketName: cfg.Bucket,
-		bucket:     gcsClient.Bucket(cfg.Bucket),
-		prefix:     cfg.Prefix,
+		gcsClient:   gcsClient,
+		projectID:   cfg.ProjectID,
+		connections: cfg.Connections,
+		sem:         sem,
+		bucketName:  cfg.Bucket,
+		bucket:      gcsClient.Bucket(cfg.Bucket),
+		prefix:      cfg.Prefix,
 		Layout: &backend.DefaultLayout{
 			Path: cfg.Prefix,
 			Join: path.Join,
@@ -185,6 +187,10 @@ func (be *Backend) Join(p ...string) string {
 	return path.Join(p...)
 }
 
+func (be *Backend) Connections() uint {
+	return be.connections
+}
+
 // Location returns this backend's location (the bucket name).
 func (be *Backend) Location() string {
 	return be.Join(be.bucketName, be.prefix)

internal/backend/mem/mem_backend.go

@@ -229,6 +229,10 @@ func (be *MemoryBackend) List(ctx context.Context, t restic.FileType, fn func(re
 	return ctx.Err()
 }
 
+func (be *MemoryBackend) Connections() uint {
+	return 2
+}
+
 // Location returns the location of the backend (RAM).
 func (be *MemoryBackend) Location() string {
 	return "RAM"

internal/backend/rest/rest.go

@@ -29,9 +29,10 @@ var _ restic.Backend = &Backend{}
 
 // Backend uses the REST protocol to access data stored on a server.
 type Backend struct {
-	url    *url.URL
-	sem    *backend.Semaphore
-	client *http.Client
+	url         *url.URL
+	connections uint
+	sem         *backend.Semaphore
+	client      *http.Client
 	backend.Layout
 }
 
@@ -57,10 +58,11 @@ func Open(cfg Config, rt http.RoundTripper) (*Backend, error) {
 	}
 
 	be := &Backend{
-		url:    cfg.URL,
-		client: client,
-		Layout: &backend.RESTLayout{URL: url, Join: path.Join},
-		sem:    sem,
+		url:         cfg.URL,
+		client:      client,
+		Layout:      &backend.RESTLayout{URL: url, Join: path.Join},
+		connections: cfg.Connections,
+		sem:         sem,
 	}
 
 	return be, nil
@@ -105,6 +107,10 @@ func Create(ctx context.Context, cfg Config, rt http.RoundTripper) (*Backend, er
 	return be, nil
 }
 
+func (b *Backend) Connections() uint {
+	return b.connections
+}
+
 // Location returns this backend's location (the server's URL).
 func (b *Backend) Location() string {
 	return b.url.String()

internal/backend/s3/s3.go

@@ -255,6 +255,10 @@ func (be *Backend) ReadDir(ctx context.Context, dir string) (list []os.FileInfo,
 	return list, nil
 }
 
+func (be *Backend) Connections() uint {
+	return be.cfg.Connections
+}
+
 // Location returns this backend's location (the bucket name).
 func (be *Backend) Location() string {
 	return be.Join(be.cfg.Bucket, be.cfg.Prefix)

internal/backend/swift/swift.go

@@ -24,10 +24,11 @@ import (
 
 // beSwift is a backend which stores the data on a swift endpoint.
 type beSwift struct {
-	conn      *swift.Connection
-	sem       *backend.Semaphore
-	container string // Container name
-	prefix    string // Prefix of object names in the container
+	conn        *swift.Connection
+	connections uint
+	sem         *backend.Semaphore
+	container   string // Container name
+	prefix      string // Prefix of object names in the container
 	backend.Layout
 }
 
@@ -68,9 +69,10 @@ func Open(ctx context.Context, cfg Config, rt http.RoundTripper) (restic.Backend
 
 			Transport: rt,
 		},
-		sem:       sem,
-		container: cfg.Container,
-		prefix:    cfg.Prefix,
+		connections: cfg.Connections,
+		sem:         sem,
+		container:   cfg.Container,
+		prefix:      cfg.Prefix,
 		Layout: &backend.DefaultLayout{
 			Path: cfg.Prefix,
 			Join: path.Join,
@@ -113,6 +115,10 @@ func (be *beSwift) createContainer(ctx context.Context, policy string) error {
 	return be.conn.ContainerCreate(ctx, be.container, h)
 }
 
+func (be *beSwift) Connections() uint {
+	return be.connections
+}
+
 // Location returns this backend's location (the container name).
 func (be *beSwift) Location() string {
 	return be.container

internal/mock/backend.go

@@ -11,17 +11,18 @@ import (
 
 // Backend implements a mock backend.
 type Backend struct {
-	CloseFn      func() error
-	IsNotExistFn func(err error) bool
-	SaveFn       func(ctx context.Context, h restic.Handle, rd restic.RewindReader) error
-	OpenReaderFn func(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error)
-	StatFn       func(ctx context.Context, h restic.Handle) (restic.FileInfo, error)
-	ListFn       func(ctx context.Context, t restic.FileType, fn func(restic.FileInfo) error) error
-	RemoveFn     func(ctx context.Context, h restic.Handle) error
-	TestFn       func(ctx context.Context, h restic.Handle) (bool, error)
-	DeleteFn     func(ctx context.Context) error
-	LocationFn   func() string
-	HasherFn     func() hash.Hash
+	CloseFn       func() error
+	IsNotExistFn  func(err error) bool
+	SaveFn        func(ctx context.Context, h restic.Handle, rd restic.RewindReader) error
+	OpenReaderFn  func(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error)
+	StatFn        func(ctx context.Context, h restic.Handle) (restic.FileInfo, error)
+	ListFn        func(ctx context.Context, t restic.FileType, fn func(restic.FileInfo) error) error
+	RemoveFn      func(ctx context.Context, h restic.Handle) error
+	TestFn        func(ctx context.Context, h restic.Handle) (bool, error)
+	DeleteFn      func(ctx context.Context) error
+	ConnectionsFn func() uint
+	LocationFn    func() string
+	HasherFn      func() hash.Hash
 }
 
 // NewBackend returns new mock Backend instance
@@ -39,6 +40,14 @@ func (m *Backend) Close() error {
 	return m.CloseFn()
 }
 
+func (m *Backend) Connections() uint {
+	if m.ConnectionsFn == nil {
+		return 2
+	}
+
+	return m.ConnectionsFn()
+}
+
 // Location returns a location string.
 func (m *Backend) Location() string {
 	if m.LocationFn == nil {

internal/restic/backend.go

@@ -18,6 +18,9 @@ type Backend interface {
 	// repository.
 	Location() string
 
+	// Connections returns the maxmimum number of concurrent backend operations.
+	Connections() uint
+
 	// Hasher may return a hash function for calculating a content hash for the backend
 	Hasher() hash.Hash