[ADDED] Listing buckets and bucket names

object.go

@@ -44,6 +44,10 @@ type ObjectStoreManager interface {
 	CreateObjectStore(cfg *ObjectStoreConfig) (ObjectStore, error)
 	// DeleteObjectStore will delete the underlying stream for the named object.
 	DeleteObjectStore(bucket string) error
+	// BucketNames is used to retrieve a list of bucket names
+	BucketNames(opts ...ObjectOpt) <-chan string
+	// BucketsInfo is used to retrieve a list of buckets
+	BucketsInfo(opts ...ObjectOpt) <-chan ObjectStore
 }
 
 // ObjectStore is a blob store capable of storing large objects efficiently in
@@ -1136,3 +1140,83 @@ func (o *objResult) Error() error {
 	defer o.Unlock()
 	return o.err
 }
+
+// BucketNames is used to retrieve a list of bucket names
+func (js *js) BucketNames(opts ...ObjectOpt) <-chan string {
+	var o objOpts
+	for _, opt := range opts {
+		if opt != nil {
+			if err := opt.configureObject(&o); err != nil {
+				return nil
+			}
+		}
+	}
+	ch := make(chan string)
+	var cancel context.CancelFunc
+	if o.ctx == nil {
+		o.ctx, cancel = context.WithTimeout(context.Background(), defaultRequestWait)
+	}
+	l := &streamLister{js: js}
+	l.js.opts.streamListSubject = fmt.Sprintf(objAllChunksPreTmpl, "*")
+	l.js.opts.ctx = o.ctx
+	go func() {
+		if cancel != nil {
+			defer cancel()
+		}
+		defer close(ch)
+		for l.Next() {
+			for _, info := range l.Page() {
+				if !strings.HasPrefix(info.Config.Name, "OBJ_") {
+					continue
+				}
+				select {
+				case ch <- info.Config.Name:
+				case <-o.ctx.Done():
+					return
+				}
+			}
+		}
+	}()
+
+	return ch
+}
+
+// BucketsInfo is used to retrieve a list of buckets
+func (js *js) BucketsInfo(opts ...ObjectOpt) <-chan ObjectStore {
+	var o objOpts
+	for _, opt := range opts {
+		if opt != nil {
+			if err := opt.configureObject(&o); err != nil {
+				return nil
+			}
+		}
+	}
+	ch := make(chan ObjectStore)
+	var cancel context.CancelFunc
+	if o.ctx == nil {
+		o.ctx, cancel = context.WithTimeout(context.Background(), defaultRequestWait)
+	}
+	l := &streamLister{js: js}
+	l.js.opts.streamListSubject = fmt.Sprintf(objAllChunksPreTmpl, "*")
+	l.js.opts.ctx = o.ctx
+	go func() {
+		if cancel != nil {
+			defer cancel()
+		}
+		defer close(ch)
+		for l.Next() {
+			for _, info := range l.Page() {
+				if !strings.HasPrefix(info.Config.Name, "OBJ_") {
+					continue
+				}
+				select {
+				case ch <- &obs{name: strings.TrimPrefix(info.Config.Name, "OBJ_"), stream: info.Config.Name, js: js}:
+				case <-o.ctx.Done():
+					return
+				}
+			}
+		}
+	}()
+
+	return ch
+}

test/object_test.go

@@ -777,3 +777,53 @@ func TestObjectMaxBytes(t *testing.T) {
 		t.Fatalf("invalid object stream MaxSize %+v", info.Config.MaxBytes)
 	}
 }
+
+func TestBucketNames(t *testing.T) {
+	tests := []struct {
+		name       string
+		bucketsNum int
+	}{
+		{
+			name:       "single page",
+			bucketsNum: 5,
+		},
+		{
+			name:       "multi page",
+			bucketsNum: 1025,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			s := RunBasicJetStreamServer()
+			defer shutdownJSServerAndRemoveStorage(t, s)
+
+			nc, js := jsClient(t, s)
+			defer nc.Close()
+			// create stream without the chunk subject, but with OBJ_ prefix
+			_, err := js.AddStream(&nats.StreamConfig{Name: "OBJ_FOO", Subjects: []string{"FOO.*"}})
+			expectOk(t, err)
+			// create stream with chunk subject, but without "OBJ_" prefix
+			_, err = js.AddStream(&nats.StreamConfig{Name: "FOO", Subjects: []string{"$O.ABC.C.>"}})
+			expectOk(t, err)
+			for i := 0; i < test.bucketsNum; i++ {
+				_, err = js.CreateObjectStore(&nats.ObjectStoreConfig{Bucket: fmt.Sprintf("OBJS_%d", i), MaxBytes: 1024})
+				expectOk(t, err)
+			}
+			names := make([]string, 0)
+			for name := range js.BucketNames() {
+				names = append(names, name)
+			}
+			if len(names) != test.bucketsNum {
+				t.Fatalf("Invalid number of stream names; want: %d; got: %d", test.bucketsNum, len(names))
+			}
+			infos := make([]nats.ObjectStore, 0)
+			for info := range js.BucketsInfo() {
+				infos = append(infos, info)
+			}
+			if len(infos) != test.bucketsNum {
+				t.Fatalf("Invalid number of streams; want: %d; got: %d", test.bucketsNum, len(infos))
+			}
+		})
+	}
+}