address first round of review comments

backend/s3/config_test.go

@@ -11,6 +11,11 @@ var configTests = []struct {
 		Bucket:   "bucketname",
 		Prefix:   "restic",
 	}},
+	{"s3://eu-central-1/bucketname/", Config{
+		Endpoint: "eu-central-1",
+		Bucket:   "bucketname",
+		Prefix:   "",
+	}},
 	{"s3://eu-central-1/bucketname/prefix/directory", Config{
 		Endpoint: "eu-central-1",
 		Bucket:   "bucketname",
@@ -21,6 +26,11 @@ var configTests = []struct {
 		Bucket:   "foobar",
 		Prefix:   "restic",
 	}},
+	{"s3:eu-central-1/foobar/", Config{
+		Endpoint: "eu-central-1",
+		Bucket:   "foobar",
+		Prefix:   "",
+	}},
 	{"s3:eu-central-1/foobar/prefix/directory", Config{
 		Endpoint: "eu-central-1",
 		Bucket:   "foobar",
@@ -31,6 +41,11 @@ var configTests = []struct {
 		Bucket:   "foobar",
 		Prefix:   "restic",
 	}},
+	{"s3:https://hostname:9999/foobar/", Config{
+		Endpoint: "hostname:9999",
+		Bucket:   "foobar",
+		Prefix:   "",
+	}},
 	{"s3:http://hostname:9999/foobar", Config{
 		Endpoint: "hostname:9999",
 		Bucket:   "foobar",

backend/s3/s3.go

@@ -14,13 +14,6 @@ import (
 
 const connLimit = 10
 
-func s3path(prefix string, t backend.Type, name string) string {
-	if t == backend.Config {
-		return prefix + "/" + string(t)
-	}
-	return prefix + "/" + string(t) + "/" + name
-}
-
 // s3 is a backend which stores the data on an S3 endpoint.
 type s3 struct {
 	client     minio.CloudStorageClient
@@ -56,6 +49,20 @@ func Open(cfg Config) (backend.Backend, error) {
 	return be, nil
 }
 
+func (be *s3) s3path(t backend.Type, name string) string {
+	var path string
+
+	if be.prefix != "" {
+		path = be.prefix + "/"
+	}
+	path += string(t)
+
+	if t == backend.Config {
+		return path
+	}
+	return path + "/" + name
+}
+
 func (be *s3) createConnections() {
 	be.connChan = make(chan struct{}, connLimit)
 	for i := 0; i < connLimit; i++ {
@@ -72,7 +79,7 @@ func (be *s3) Location() string {
 // and saves it in p. Load has the same semantics as io.ReaderAt.
 func (be s3) Load(h backend.Handle, p []byte, off int64) (int, error) {
 	debug.Log("s3.Load", "%v, offset %v, len %v", h, off, len(p))
-	path := s3path(be.prefix, h.Type, h.Name)
+	path := be.s3path(h.Type, h.Name)
 	obj, err := be.client.GetObject(be.bucketname, path)
 	if err != nil {
 		debug.Log("s3.GetReader", "  err %v", err)
@@ -101,7 +108,7 @@ func (be s3) Save(h backend.Handle, p []byte) (err error) {
 
 	debug.Log("s3.Save", "%v bytes at %d", len(p), h)
 
-	path := s3path(be.prefix, h.Type, h.Name)
+	path := be.s3path(h.Type, h.Name)
 
 	// Check key does not already exist
 	_, err = be.client.StatObject(be.bucketname, path)
@@ -126,7 +133,7 @@ func (be s3) Save(h backend.Handle, p []byte) (err error) {
 // Stat returns information about a blob.
 func (be s3) Stat(h backend.Handle) (backend.BlobInfo, error) {
 	debug.Log("s3.Stat", "%v")
-	path := s3path(be.prefix, h.Type, h.Name)
+	path := be.s3path(h.Type, h.Name)
 	obj, err := be.client.GetObject(be.bucketname, path)
 	if err != nil {
 		debug.Log("s3.Stat", "GetObject() err %v", err)
@@ -145,7 +152,7 @@ func (be s3) Stat(h backend.Handle) (backend.BlobInfo, error) {
 // Test returns true if a blob of the given type and name exists in the backend.
 func (be *s3) Test(t backend.Type, name string) (bool, error) {
 	found := false
-	path := s3path(be.prefix, t, name)
+	path := be.s3path(t, name)
 	_, err := be.client.StatObject(be.bucketname, path)
 	if err == nil {
 		found = true
@@ -157,7 +164,7 @@ func (be *s3) Test(t backend.Type, name string) (bool, error) {
 
 // Remove removes the blob with the given name and type.
 func (be *s3) Remove(t backend.Type, name string) error {
-	path := s3path(be.prefix, t, name)
+	path := be.s3path(t, name)
 	err := be.client.RemoveObject(be.bucketname, path)
 	debug.Log("s3.Remove", "%v %v -> err %v", t, name, err)
 	return err
@@ -170,7 +177,7 @@ func (be *s3) List(t backend.Type, done <-chan struct{}) <-chan string {
 	debug.Log("s3.List", "listing %v", t)
 	ch := make(chan string)
 
-	prefix := s3path(be.prefix, t, "")
+	prefix := be.s3path(t, "")
 
 	listresp := be.client.ListObjects(be.bucketname, prefix, true, done)