api: add pss client facing apis (#686)

* add pss websocket api for opening a persistent connection for incoming messages on a given topic
* add pss message send api to send outgoing messages

cmd/internal/file/io_test.go

@@ -156,7 +156,7 @@ func newTestServer(t *testing.T, storer storage.Storer) *url.URL {
 	t.Helper()
 	logger := logging.New(ioutil.Discard, 0)
 	store := statestore.NewStateStore()
-	s := api.New(tags.NewTags(store, logger), storer, nil, logger, nil, api.Options{})
+	s := api.New(tags.NewTags(store, logger), storer, nil, nil, logger, nil, api.Options{})
 	ts := httptest.NewServer(s)
 	srvUrl, err := url.Parse(ts.URL)
 	if err != nil {

go.mod

@@ -15,6 +15,7 @@ require (
 	github.com/gopherjs/gopherjs v0.0.0-20200217142428-fce0ec30dd00 // indirect
 	github.com/gorilla/handlers v1.4.2
 	github.com/gorilla/mux v1.7.4
+	github.com/gorilla/websocket v1.4.2
 	github.com/ipfs/go-log/v2 v2.1.1 // indirect
 	github.com/kr/text v0.2.0 // indirect
 	github.com/libp2p/go-libp2p v0.10.0

pkg/api/api.go

@@ -7,13 +7,16 @@ package api
 import (
 	"errors"
 	"fmt"
+	"io"
 	"net/http"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/ethersphere/bee/pkg/logging"
 	m "github.com/ethersphere/bee/pkg/metrics"
+	"github.com/ethersphere/bee/pkg/pss"
 	"github.com/ethersphere/bee/pkg/resolver"
 	"github.com/ethersphere/bee/pkg/storage"
 	"github.com/ethersphere/bee/pkg/swarm"
@@ -37,22 +40,28 @@ var (
 type Service interface {
 	http.Handler
 	m.Collector
+	io.Closer
 }
 
 type server struct {
 	Tags     *tags.Tags
 	Storer   storage.Storer
 	Resolver resolver.Interface
+	Pss      pss.Interface
 	Logger   logging.Logger
 	Tracer   *tracing.Tracer
 	Options
 	http.Handler
 	metrics metrics
+
+	wsWg sync.WaitGroup // wait for all websockets to close on exit
+	quit chan struct{}
 }
 
 type Options struct {
 	CORSAllowedOrigins []string
 	GatewayMode        bool
+	WsPingPeriod       time.Duration
 }
 
 const (
@@ -61,15 +70,17 @@ const (
 )
 
 // New will create a and initialize a new API service.
-func New(tags *tags.Tags, storer storage.Storer, resolver resolver.Interface, logger logging.Logger, tracer *tracing.Tracer, o Options) Service {
+func New(tags *tags.Tags, storer storage.Storer, resolver resolver.Interface, pss pss.Interface, logger logging.Logger, tracer *tracing.Tracer, o Options) Service {
 	s := &server{
 		Tags:     tags,
 		Storer:   storer,
 		Resolver: resolver,
+		Pss:      pss,
 		Options:  o,
 		Logger:   logger,
 		Tracer:   tracer,
 		metrics:  newMetrics(),
+		quit:     make(chan struct{}),
 	}
 
 	s.setupRouting()
@@ -77,6 +88,26 @@ func New(tags *tags.Tags, storer storage.Storer, resolver resolver.Interface, lo
 	return s
 }
 
+// Close hangs up running websockets on shutdown.
+func (s *server) Close() error {
+	s.Logger.Info("api shutting down")
+	close(s.quit)
+
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		s.wsWg.Wait()
+	}()
+
+	select {
+	case <-done:
+	case <-time.After(5 * time.Second):
+		return errors.New("api shutting down with open websockets")
+	}
+
+	return nil
+}
+
 // getOrCreateTag attempts to get the tag if an id is supplied, and returns an error if it does not exist.
 // If no id is supplied, it will attempt to create a new tag with a generated name and return it.
 func (s *server) getOrCreateTag(tagUid string) (*tags.Tag, bool, error) {

pkg/api/api_test.go

@@ -11,39 +11,50 @@ import (
 	"net/http/httptest"
 	"net/url"
 	"testing"
+	"time"
 
 	"github.com/ethersphere/bee/pkg/api"
 	"github.com/ethersphere/bee/pkg/logging"
+	"github.com/ethersphere/bee/pkg/pss"
 	"github.com/ethersphere/bee/pkg/resolver"
 	resolverMock "github.com/ethersphere/bee/pkg/resolver/mock"
 	"github.com/ethersphere/bee/pkg/storage"
 	"github.com/ethersphere/bee/pkg/swarm"
 	"github.com/ethersphere/bee/pkg/tags"
+	"github.com/gorilla/websocket"
 	"resenje.org/web"
 )
 
 type testServerOptions struct {
 	Storer       storage.Storer
 	Resolver     resolver.Interface
+	Pss          pss.Interface
+	WsPath       string
 	Tags         *tags.Tags
 	GatewayMode  bool
+	WsPingPeriod time.Duration
 	Logger       logging.Logger
 }
 
-func newTestServer(t *testing.T, o testServerOptions) *http.Client {
+func newTestServer(t *testing.T, o testServerOptions) (*http.Client, *websocket.Conn, string) {
 	if o.Logger == nil {
 		o.Logger = logging.New(ioutil.Discard, 0)
 	}
 	if o.Resolver == nil {
 		o.Resolver = resolverMock.NewResolver()
 	}
-	s := api.New(o.Tags, o.Storer, o.Resolver, o.Logger, nil, api.Options{
+	if o.WsPingPeriod == 0 {
+		o.WsPingPeriod = 60 * time.Second
+	}
+	s := api.New(o.Tags, o.Storer, o.Resolver, o.Pss, o.Logger, nil, api.Options{
 		GatewayMode:  o.GatewayMode,
+		WsPingPeriod: o.WsPingPeriod,
 	})
 	ts := httptest.NewServer(s)
 	t.Cleanup(ts.Close)
 
-	return &http.Client{
+	var (
+		httpClient = &http.Client{
 			Transport: web.RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
 				u, err := url.Parse(ts.URL + r.URL.String())
 				if err != nil {
@@ -53,6 +64,19 @@ func newTestServer(t *testing.T, o testServerOptions) *http.Client {
 				return ts.Client().Transport.RoundTrip(r)
 			}),
 		}
+		conn *websocket.Conn
+		err  error
+	)
+
+	if o.WsPath != "" {
+		u := url.URL{Scheme: "ws", Host: ts.Listener.Addr().String(), Path: o.WsPath}
+		conn, _, err = websocket.DefaultDialer.Dial(u.String(), nil)
+		if err != nil {
+			t.Fatalf("dial: %v. url %v", err, u.String())
+		}
+
+	}
+	return httpClient, conn, ts.Listener.Addr().String()
 }
 
 func TestParseName(t *testing.T) {
@@ -116,7 +140,7 @@ func TestParseName(t *testing.T) {
 				}))
 		}
 
-		s := api.New(nil, nil, tC.res, tC.log, nil, api.Options{}).(*api.Server)
+		s := api.New(nil, nil, tC.res, nil, tC.log, nil, api.Options{}).(*api.Server)
 
 		t.Run(tC.desc, func(t *testing.T) {
 			got, err := s.ResolveNameOrAddress(tC.name)

pkg/api/bytes_test.go

@@ -6,11 +6,12 @@ package api_test
 
 import (
 	"bytes"
-	statestore "github.com/ethersphere/bee/pkg/statestore/mock"
 	"io/ioutil"
 	"net/http"
 	"testing"
 
+	statestore "github.com/ethersphere/bee/pkg/statestore/mock"
+
 	"github.com/ethersphere/bee/pkg/api"
 	"github.com/ethersphere/bee/pkg/jsonhttp"
 	"github.com/ethersphere/bee/pkg/jsonhttp/jsonhttptest"
@@ -31,7 +32,7 @@ func TestBytes(t *testing.T) {
 		mockStorer     = mock.NewStorer()
 		mockStatestore = statestore.NewStateStore()
 		logger         = logging.New(ioutil.Discard, 0)
-		client         = newTestServer(t, testServerOptions{
+		client, _, _   = newTestServer(t, testServerOptions{
 			Storer: mockStorer,
 			Tags:   tags.NewTags(mockStatestore, logger),
 			Logger: logging.New(ioutil.Discard, 5),

pkg/api/bzz_test.go

@@ -9,7 +9,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	statestore "github.com/ethersphere/bee/pkg/statestore/mock"
 	"io"
 	"io/ioutil"
 	"mime"
@@ -17,6 +16,8 @@ import (
 	"strings"
 	"testing"
 
+	statestore "github.com/ethersphere/bee/pkg/statestore/mock"
+
 	"github.com/ethersphere/bee/pkg/collection/entry"
 	"github.com/ethersphere/bee/pkg/file/pipeline"
 	"github.com/ethersphere/bee/pkg/jsonhttp"
@@ -36,7 +37,7 @@ func TestBzz(t *testing.T) {
 		ctx                 = context.Background()
 		mockStatestore      = statestore.NewStateStore()
 		logger              = logging.New(ioutil.Discard, 0)
-		client              = newTestServer(t, testServerOptions{
+		client, _, _        = newTestServer(t, testServerOptions{
 			Storer: storer,
 			Tags:   tags.NewTags(mockStatestore, logger),
 			Logger: logging.New(ioutil.Discard, 5),

pkg/api/chunk_test.go

@@ -6,13 +6,14 @@ package api_test
 
 import (
 	"bytes"
-	"github.com/ethersphere/bee/pkg/logging"
-	statestore "github.com/ethersphere/bee/pkg/statestore/mock"
 	"io"
 	"io/ioutil"
 	"net/http"
 	"testing"
 
+	"github.com/ethersphere/bee/pkg/logging"
+	statestore "github.com/ethersphere/bee/pkg/statestore/mock"
+
 	"github.com/ethersphere/bee/pkg/tags"
 
 	"github.com/ethersphere/bee/pkg/api"
@@ -41,7 +42,7 @@ func TestChunkUploadDownload(t *testing.T) {
 		logger               = logging.New(ioutil.Discard, 0)
 		tag                  = tags.NewTags(mockStatestore, logger)
 		mockValidatingStorer = mock.NewStorer(mock.WithValidator(mockValidator))
-		client               = newTestServer(t, testServerOptions{
+		client, _, _         = newTestServer(t, testServerOptions{
 			Storer: mockValidatingStorer,
 			Tags:   tag,
 		})

pkg/api/dirs_test.go

@@ -35,7 +35,7 @@ func TestDirs(t *testing.T) {
 		storer               = mock.NewStorer()
 		mockStatestore       = statestore.NewStateStore()
 		logger               = logging.New(ioutil.Discard, 0)
-		client               = newTestServer(t, testServerOptions{
+		client, _, _         = newTestServer(t, testServerOptions{
 			Storer: storer,
 			Tags:   tags.NewTags(mockStatestore, logger),
 			Logger: logging.New(ioutil.Discard, 5),

pkg/api/file_test.go

@@ -8,7 +8,6 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	statestore "github.com/ethersphere/bee/pkg/statestore/mock"
 	"io"
 	"io/ioutil"
 	"mime"
@@ -18,6 +17,8 @@ import (
 	"strings"
 	"testing"
 
+	statestore "github.com/ethersphere/bee/pkg/statestore/mock"
+
 	"github.com/ethersphere/bee/pkg/api"
 	"github.com/ethersphere/bee/pkg/jsonhttp"
 	"github.com/ethersphere/bee/pkg/jsonhttp/jsonhttptest"
@@ -35,7 +36,7 @@ func TestFiles(t *testing.T) {
 		simpleData           = []byte("this is a simple text")
 		mockStatestore       = statestore.NewStateStore()
 		logger               = logging.New(ioutil.Discard, 0)
-		client               = newTestServer(t, testServerOptions{
+		client, _, _         = newTestServer(t, testServerOptions{
 			Storer: mock.NewStorer(),
 			Tags:   tags.NewTags(mockStatestore, logger),
 		})
@@ -338,7 +339,7 @@ func TestRangeRequests(t *testing.T) {
 		t.Run(upload.name, func(t *testing.T) {
 			mockStatestore := statestore.NewStateStore()
 			logger := logging.New(ioutil.Discard, 0)
-			client := newTestServer(t, testServerOptions{
+			client, _, _ := newTestServer(t, testServerOptions{
 				Storer: mock.NewStorer(),
 				Tags:   tags.NewTags(mockStatestore, logger),
 				Logger: logging.New(ioutil.Discard, 5),

pkg/api/gatewaymode_test.go

@@ -20,7 +20,7 @@ import (
 
 func TestGatewayMode(t *testing.T) {
 	logger := logging.New(ioutil.Discard, 0)
-	client := newTestServer(t, testServerOptions{
+	client, _, _ := newTestServer(t, testServerOptions{
 		Storer:      mock.NewStorer(),
 		Tags:        tags.NewTags(statestore.NewStateStore(), logger),
 		Logger:      logger,

pkg/api/pin_test.go

@@ -37,7 +37,7 @@ func TestPinChunkHandler(t *testing.T) {
 		logger               = logging.New(ioutil.Discard, 0)
 		tag                  = tags.NewTags(mockStatestore, logger)
 
-		client = newTestServer(t, testServerOptions{
+		client, _, _ = newTestServer(t, testServerOptions{
 			Storer: mockValidatingStorer,
 			Tags:   tag,
 			Logger: logger,

pkg/api/pss.go

+// Copyright 2020 The Swarm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package api
+
+import (
+	"context"
+	"encoding/hex"
+	"io/ioutil"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/ethersphere/bee/pkg/jsonhttp"
+	"github.com/ethersphere/bee/pkg/swarm"
+	"github.com/ethersphere/bee/pkg/trojan"
+	"github.com/gorilla/mux"
+	"github.com/gorilla/websocket"
+)
+
+var (
+	upgrader = websocket.Upgrader{
+		ReadBufferSize:  swarm.ChunkSize,
+		WriteBufferSize: swarm.ChunkSize,
+	}
+	writeDeadline   = 4 * time.Second // write deadline. should be smaller than the shutdown timeout on api close
+	targetMaxLength = 2               // max target length in bytes, in order to prevent grieving by excess computation
+)
+
+type PssMessage struct {
+	Topic   string
+	Message string
+}
+
+func (s *server) pssPostHandler(w http.ResponseWriter, r *http.Request) {
+	t := mux.Vars(r)["topic"]
+	topic := trojan.NewTopic(t)
+
+	tg := mux.Vars(r)["targets"]
+	var targets trojan.Targets
+	tgts := strings.Split(tg, ",")
+
+	for _, v := range tgts {
+		target, err := hex.DecodeString(v)
+		if err != nil || len(target) > targetMaxLength {
+			s.Logger.Debugf("pss send: bad targets: %v", err)
+			s.Logger.Error("pss send: bad targets")
+			jsonhttp.BadRequest(w, nil)
+			return
+		}
+		targets = append(targets, target)
+	}
+
+	payload, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		s.Logger.Debugf("pss read payload: %v", err)
+		s.Logger.Error("pss read payload")
+		jsonhttp.InternalServerError(w, nil)
+		return
+	}
+
+	err = s.Pss.Send(r.Context(), targets, topic, payload)
+	if err != nil {
+		s.Logger.Debugf("pss send payload: %v. topic: %s", err, t)
+		s.Logger.Error("pss send payload")
+		jsonhttp.InternalServerError(w, nil)
+		return
+	}
+
+	jsonhttp.OK(w, nil)
+}
+
+func (s *server) pssWsHandler(w http.ResponseWriter, r *http.Request) {
+	conn, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		s.Logger.Debugf("pss ws: upgrade: %v", err)
+		s.Logger.Error("pss ws: cannot upgrade")
+		jsonhttp.InternalServerError(w, nil)
+		return
+	}
+
+	t := mux.Vars(r)["topic"]
+	s.wsWg.Add(1)
+	go s.pumpWs(conn, t)
+}
+
+func (s *server) pumpWs(conn *websocket.Conn, t string) {
+	defer s.wsWg.Done()
+
+	var (
+		dataC  = make(chan []byte)
+		gone   = make(chan struct{})
+		topic  = trojan.NewTopic(t)
+		ticker = time.NewTicker(s.WsPingPeriod)
+		err    error
+	)
+	defer func() {
+		ticker.Stop()
+		_ = conn.Close()
+	}()
+	cleanup := s.Pss.Register(topic, func(_ context.Context, m *trojan.Message) {
+		dataC <- m.Payload
+	})
+
+	defer cleanup()
+
+	conn.SetCloseHandler(func(code int, text string) error {
+		s.Logger.Debugf("pss handler: client gone. code %d message %s", code, text)
+		close(gone)
+		return nil
+	})
+
+	for {
+		select {
+		case b := <-dataC:
+			err = conn.SetWriteDeadline(time.Now().Add(writeDeadline))
+			if err != nil {
+				s.Logger.Debugf("pss set write deadline: %v", err)
+				return
+			}
+
+			err = conn.WriteMessage(websocket.BinaryMessage, b)
+			if err != nil {
+				s.Logger.Debugf("pss write to websocket: %v", err)
+				return
+			}
+
+		case <-s.quit:
+			// shutdown
+			err = conn.SetWriteDeadline(time.Now().Add(writeDeadline))
+			if err != nil {
+				s.Logger.Debugf("pss set write deadline: %v", err)
+				return
+			}
+			err = conn.WriteMessage(websocket.CloseMessage, []byte{})
+			if err != nil {
+				s.Logger.Debugf("pss write close message: %v", err)
+			}
+			return
+		case <-gone:
+			// client gone
+			return
+		case <-ticker.C:
+			err = conn.SetWriteDeadline(time.Now().Add(writeDeadline))
+			if err != nil {
+				s.Logger.Debugf("pss set write deadline: %v", err)
+				return
+			}
+			if err = conn.WriteMessage(websocket.PingMessage, nil); err != nil {
+				// error encountered while pinging client. client probably gone
+				return
+			}
+		}
+	}
+}

pkg/api/pss_test.go

+// Copyright 2020 The Swarm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package api_test
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/ethersphere/bee/pkg/jsonhttp"
+	"github.com/ethersphere/bee/pkg/jsonhttp/jsonhttptest"
+	"github.com/ethersphere/bee/pkg/logging"
+	"github.com/ethersphere/bee/pkg/pss"
+	"github.com/ethersphere/bee/pkg/pushsync"
+	"github.com/ethersphere/bee/pkg/storage/mock"
+	"github.com/ethersphere/bee/pkg/swarm"
+	"github.com/ethersphere/bee/pkg/trojan"
+	"github.com/gorilla/websocket"
+)
+
+var (
+	target  = trojan.Target([]byte{1})
+	targets = trojan.Targets([]trojan.Target{target})
+	payload = []byte("testdata")
+	topic   = trojan.NewTopic("testtopic")
+	timeout = 10 * time.Second
+)
+
+// creates a single websocket handler for an arbitrary topic, and receives a message
+func TestPssWebsocketSingleHandler(t *testing.T) {
+	var (
+		pss, cl, _ = newPssTest(t, opts{})
+		msgContent = make([]byte, len(payload))
+		tc         swarm.Chunk
+		mtx        sync.Mutex
+		done       = make(chan struct{})
+	)
+
+	err := cl.SetReadDeadline(time.Now().Add(timeout))
+	if err != nil {
+		t.Fatal(err)
+	}
+	cl.SetReadLimit(swarm.ChunkSize)
+
+	defer close(done)
+	go waitReadMessage(t, &mtx, cl, msgContent, done)
+	m, err := trojan.NewMessage(topic, payload)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tc, err = m.Wrap(context.Background(), targets)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = pss.TryUnwrap(context.Background(), tc)
+	if err != nil {
+		t.Fatal(err)
+	}
+	waitMessage(t, msgContent, payload, &mtx)
+}
+
+func TestPssWebsocketSingleHandlerDeregister(t *testing.T) {
+	// create a new pss instance, register a handle through ws, call
+	// pss.TryUnwrap with a chunk designated for this handler and expect
+	// the handler to be notified
+	var (
+		pss, cl, _ = newPssTest(t, opts{})
+		msgContent = make([]byte, len(payload))
+		tc         swarm.Chunk
+		mtx        sync.Mutex
+		done       = make(chan struct{})
+	)
+
+	err := cl.SetReadDeadline(time.Now().Add(timeout))
+
+	if err != nil {
+		t.Fatal(err)
+	}
+	cl.SetReadLimit(swarm.ChunkSize)
+	defer close(done)
+	go waitReadMessage(t, &mtx, cl, msgContent, done)
+	m, err := trojan.NewMessage(topic, payload)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tc, err = m.Wrap(context.Background(), targets)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// close the websocket before calling pss with the message
+	err = cl.WriteMessage(websocket.CloseMessage, []byte{})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = pss.TryUnwrap(context.Background(), tc)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	waitMessage(t, msgContent, nil, &mtx)
+}
+
+func TestPssWebsocketMultiHandler(t *testing.T) {
+	var (
+		pss, cl, listener = newPssTest(t, opts{})
+		u                 = url.URL{Scheme: "ws", Host: listener, Path: "/pss/subscribe/testtopic"}
+		cl2, _, err       = websocket.DefaultDialer.Dial(u.String(), nil)
+
+		msgContent  = make([]byte, len(payload))
+		msgContent2 = make([]byte, len(payload))
+		tc          swarm.Chunk
+		mtx         sync.Mutex
+		done        = make(chan struct{})
+	)
+	if err != nil {
+		t.Fatalf("dial: %v. url %v", err, u.String())
+	}
+
+	err = cl.SetReadDeadline(time.Now().Add(timeout))
+	if err != nil {
+		t.Fatal(err)
+	}
+	cl.SetReadLimit(swarm.ChunkSize)
+
+	defer close(done)
+	go waitReadMessage(t, &mtx, cl, msgContent, done)
+	go waitReadMessage(t, &mtx, cl2, msgContent2, done)
+	m, err := trojan.NewMessage(topic, payload)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tc, err = m.Wrap(context.Background(), targets)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// close the websocket before calling pss with the message
+	err = cl.WriteMessage(websocket.CloseMessage, []byte{})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = pss.TryUnwrap(context.Background(), tc)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	waitMessage(t, msgContent, nil, &mtx)
+	waitMessage(t, msgContent2, nil, &mtx)
+}
+
+// TestPssSend tests that the pss message sending over http works correctly.
+func TestPssSend(t *testing.T) {
+	var (
+		logger = logging.New(ioutil.Discard, 0)
+
+		mtx             sync.Mutex
+		recievedTargets trojan.Targets
+		recievedTopic   trojan.Topic
+		recievedBytes   []byte
+		done            bool
+
+		sendFn = func(_ context.Context, targets trojan.Targets, topic trojan.Topic, bytes []byte) error {
+			mtx.Lock()
+			recievedTargets = targets
+			recievedTopic = topic
+			recievedBytes = bytes
+			done = true
+			mtx.Unlock()
+			return nil
+		}
+
+		pss          = newMockPss(sendFn)
+		client, _, _ = newTestServer(t, testServerOptions{
+			Pss:    pss,
+			Storer: mock.NewStorer(),
+			Logger: logger,
+		})
+
+		targets   = fmt.Sprintf("[[%d]]", 0x12)
+		topic     = "testtopic"
+		hasher    = swarm.NewHasher()
+		_, err    = hasher.Write([]byte(topic))
+		topicHash = hasher.Sum(nil)
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Run("err - bad targets", func(t *testing.T) {
+		jsonhttptest.Request(t, client, http.MethodPost, "/pss/send/to/badtarget", http.StatusBadRequest,
+			jsonhttptest.WithRequestBody(bytes.NewReader(payload)),
+			jsonhttptest.WithExpectedJSONResponse(jsonhttp.StatusResponse{
+				Message: "Bad Request",
+				Code:    http.StatusBadRequest,
+			}),
+		)
+	})
+
+	t.Run("ok", func(t *testing.T) {
+		jsonhttptest.Request(t, client, http.MethodPost, "/pss/send/testtopic/12", http.StatusOK,
+			jsonhttptest.WithRequestBody(bytes.NewReader(payload)),
+			jsonhttptest.WithExpectedJSONResponse(jsonhttp.StatusResponse{
+				Message: "OK",
+				Code:    http.StatusOK,
+			}),
+		)
+		waitDone(t, &mtx, &done)
+		if !bytes.Equal(recievedBytes, payload) {
+			t.Fatalf("payload mismatch. want %v got %v", payload, recievedBytes)
+		}
+		if targets != fmt.Sprint(recievedTargets) {
+			t.Fatalf("targets mismatch. want %v got %v", targets, recievedTargets)
+		}
+		if string(topicHash) != string(recievedTopic[:]) {
+			t.Fatalf("topic mismatch. want %v got %v", topic, string(recievedTopic[:]))
+		}
+	})
+}
+
+// TestPssPingPong tests that the websocket api adheres to the websocket standard
+// and sends ping-pong messages to keep the connection alive.
+// The test opens a websocket, keeps it alive for 500ms, then receives a pss message.
+func TestPssPingPong(t *testing.T) {
+	var (
+		pss, cl, _ = newPssTest(t, opts{pingPeriod: 90 * time.Millisecond})
+
+		msgContent = make([]byte, len(payload))
+		tc         swarm.Chunk
+		mtx        sync.Mutex
+		pongWait   = 1 * time.Millisecond
+		done       = make(chan struct{})
+	)
+
+	cl.SetReadLimit(swarm.ChunkSize)
+	err := cl.SetReadDeadline(time.Now().Add(pongWait))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer close(done)
+	go waitReadMessage(t, &mtx, cl, msgContent, done)
+
+	m, err := trojan.NewMessage(topic, payload)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tc, err = m.Wrap(context.Background(), targets)
+	if err != nil {
+		t.Fatal(err)
+	}
+	time.Sleep(500 * time.Millisecond) // wait to see that the websocket is kept alive
+
+	err = pss.TryUnwrap(context.Background(), tc)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	waitMessage(t, msgContent, nil, &mtx)
+}
+
+func waitReadMessage(t *testing.T, mtx *sync.Mutex, cl *websocket.Conn, targetContent []byte, done <-chan struct{}) {
+	t.Helper()
+	timeout := time.After(timeout)
+	for {
+		select {
+		case <-done:
+			return
+		case <-timeout:
+			t.Errorf("timed out waiting for message")
+			return
+		default:
+		}
+
+		msgType, message, err := cl.ReadMessage()
+		if err != nil {
+			return
+		}
+		if msgType == websocket.PongMessage {
+			// ignore pings
+			continue
+		}
+
+		if message != nil {
+			mtx.Lock()
+			copy(targetContent, message)
+			mtx.Unlock()
+		}
+		time.Sleep(50 * time.Millisecond)
+	}
+}
+
+func waitDone(t *testing.T, mtx *sync.Mutex, done *bool) {
+	for i := 0; i < 10; i++ {
+		mtx.Lock()
+		if *done {
+			mtx.Unlock()
+			return
+		}
+		mtx.Unlock()
+		time.Sleep(50 * time.Millisecond)
+	}
+	t.Fatal("timed out waiting for send")
+}
+
+func waitMessage(t *testing.T, data, expData []byte, mtx *sync.Mutex) {
+	ttl := time.After(timeout)
+	for {
+		select {
+		case <-ttl:
+			if expData == nil {
+				return
+			}
+			t.Fatal("timed out waiting for pss message")
+		default:
+		}
+		mtx.Lock()
+		if bytes.Equal(data, expData) {
+			mtx.Unlock()
+			return
+		}
+		mtx.Unlock()
+		time.Sleep(100 * time.Millisecond)
+	}
+}
+
+type opts struct {
+	pingPeriod time.Duration
+}
+
+func newPssTest(t *testing.T, o opts) (pss.Interface, *websocket.Conn, string) {
+	var (
+		logger = logging.New(ioutil.Discard, 0)
+		pss    = pss.New(logger)
+	)
+	if o.pingPeriod == 0 {
+		o.pingPeriod = 10 * time.Second
+	}
+	_, cl, listener := newTestServer(t, testServerOptions{
+		Pss:          pss,
+		WsPath:       "/pss/subscribe/testtopic",
+		Storer:       mock.NewStorer(),
+		Logger:       logger,
+		WsPingPeriod: o.pingPeriod,
+	})
+	return pss, cl, listener
+}
+
+type pssSendFn func(context.Context, trojan.Targets, trojan.Topic, []byte) error
+type mpss struct {
+	f pssSendFn
+}
+
+func newMockPss(f pssSendFn) *mpss {
+	return &mpss{f}
+}
+
+// Send arbitrary byte slice with the given topic to Targets.
+func (m *mpss) Send(ctx context.Context, targets trojan.Targets, topic trojan.Topic, bytes []byte) error {
+	return m.f(ctx, targets, topic, bytes)
+}
+
+// Register a Handler for a given Topic.
+func (m *mpss) Register(_ trojan.Topic, _ pss.Handler) func() {
+	panic("not implemented") // TODO: Implement
+}
+
+// TryUnwrap tries to unwrap a wrapped trojan message.
+func (m *mpss) TryUnwrap(_ context.Context, _ swarm.Chunk) error {
+	panic("not implemented") // TODO: Implement
+}
+
+func (m *mpss) SetPushSyncer(pushSyncer pushsync.PushSyncer) {
+	panic("not implemented") // TODO: Implement
+}
+
+func (m *mpss) Close() error {
+	panic("not implemented") // TODO: Implement
+}

pkg/api/router.go

@@ -90,6 +90,15 @@ func (s *server) setupRouting() {
 		),
 	})
 
+	handle(router, "/pss/send/{topic}/{targets}", jsonhttp.MethodHandler{
+		"POST": web.ChainHandlers(
+			jsonhttp.NewMaxBodyBytesHandler(swarm.ChunkSize),
+			web.FinalHandlerFunc(s.pssPostHandler),
+		),
+	})
+
+	handle(router, "/pss/subscribe/{topic}", http.HandlerFunc(s.pssWsHandler))
+
 	handle(router, "/tags", web.ChainHandlers(
 		s.gatewayModeForbidEndpointHandler,
 		web.FinalHandler(jsonhttp.MethodHandler{

pkg/api/tag_test.go

@@ -8,14 +8,15 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"github.com/ethersphere/bee/pkg/logging"
-	statestore "github.com/ethersphere/bee/pkg/statestore/mock"
 	"io/ioutil"
 	"net/http"
 	"strconv"
 	"strings"
 	"testing"
 
+	"github.com/ethersphere/bee/pkg/logging"
+	statestore "github.com/ethersphere/bee/pkg/statestore/mock"
+
 	"github.com/ethersphere/bee/pkg/api"
 	"github.com/ethersphere/bee/pkg/jsonhttp"
 	"github.com/ethersphere/bee/pkg/jsonhttp/jsonhttptest"
@@ -46,7 +47,7 @@ func TestTags(t *testing.T) {
 		logger             = logging.New(ioutil.Discard, 0)
 		tag                = tags.NewTags(mockStatestore, logger)
 		mockPusher         = mp.NewMockPusher(tag)
-		client             = newTestServer(t, testServerOptions{
+		client, _, _       = newTestServer(t, testServerOptions{
 			Storer: mock.NewStorer(),
 			Tags:   tag,
 		})

pkg/logging/http_access.go

@@ -5,6 +5,7 @@
 package logging
 
 import (
+	"bufio"
 	"net"
 	"net/http"
 	"time"
@@ -89,6 +90,10 @@ func (l *responseLogger) Flush() {
 	l.w.(http.Flusher).Flush()
 }
 
+func (l *responseLogger) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	return l.w.(http.Hijacker).Hijack()
+}
+
 func (l *responseLogger) CloseNotify() <-chan bool {
 	// staticcheck SA1019 CloseNotifier interface is required by gorilla compress handler
 	// nolint:staticcheck

pkg/node/node.go

@@ -54,6 +54,7 @@ import (
 type Bee struct {
 	p2pService            io.Closer
 	p2pCancel             context.CancelFunc
+	apiCloser             io.Closer
 	apiServer             *http.Server
 	debugAPIServer        *http.Server
 	resolverCloser        io.Closer
@@ -66,6 +67,8 @@ type Bee struct {
 	pusherCloser          io.Closer
 	pullerCloser          io.Closer
 	pullSyncCloser        io.Closer
+	pssCloser             io.Closer
+	recoveryHandleCleanup func()
 }
 
 type Options struct {
@@ -247,7 +250,8 @@ func NewBee(addr string, swarmAddress swarm.Address, keystore keystore.Service,
 	}
 
 	// instantiate the pss object
-	psss := pss.New(logger, nil)
+	psss := pss.New(logger)
+	b.pssCloser = psss
 
 	var ns storage.Storer
 	if o.GlobalPinningEnabled {
@@ -262,7 +266,7 @@ func NewBee(addr string, swarmAddress swarm.Address, keystore keystore.Service,
 	pushSyncProtocol := pushsync.New(p2ps, storer, kad, tagg, psss.TryUnwrap, logger, acc, accounting.NewFixedPricer(swarmAddress, 10))
 
 	// set the pushSyncer in the PSS
-	psss.WithPushSyncer(pushSyncProtocol)
+	psss.SetPushSyncer(pushSyncProtocol)
 
 	if err = p2ps.AddProtocol(pushSyncProtocol.Protocol()); err != nil {
 		return nil, fmt.Errorf("pushsync service: %w", err)
@@ -271,7 +275,7 @@ func NewBee(addr string, swarmAddress swarm.Address, keystore keystore.Service,
 	if o.GlobalPinningEnabled {
 		// register function for chunk repair upon receiving a trojan message
 		chunkRepairHandler := recovery.NewRepairHandler(ns, logger, pushSyncProtocol)
-		psss.Register(recovery.RecoveryTopic, chunkRepairHandler)
+		b.recoveryHandleCleanup = psss.Register(recovery.RecoveryTopic, chunkRepairHandler)
 	}
 
 	pushSyncPusher := pusher.New(storer, kad, pushSyncProtocol, tagg, logger)
@@ -299,9 +303,10 @@ func NewBee(addr string, swarmAddress swarm.Address, keystore keystore.Service,
 	var apiService api.Service
 	if o.APIAddr != "" {
 		// API server
-		apiService = api.New(tagg, ns, multiResolver, logger, tracer, api.Options{
+		apiService = api.New(tagg, ns, multiResolver, psss, logger, tracer, api.Options{
 			CORSAllowedOrigins: o.CORSAllowedOrigins,
 			GatewayMode:        o.GatewayMode,
+			WsPingPeriod:       60 * time.Second,
 		})
 		apiListener, err := net.Listen("tcp", o.APIAddr)
 		if err != nil {
@@ -323,6 +328,7 @@ func NewBee(addr string, swarmAddress swarm.Address, keystore keystore.Service,
 		}()
 
 		b.apiServer = apiServer
+		b.apiCloser = apiService
 	}
 
 	if o.DebugAPIAddr != "" {
@@ -373,6 +379,12 @@ func NewBee(addr string, swarmAddress swarm.Address, keystore keystore.Service,
 func (b *Bee) Shutdown(ctx context.Context) error {
 	errs := new(multiError)
 
+	if b.apiCloser != nil {
+		if err := b.apiCloser.Close(); err != nil {
+			errs.add(fmt.Errorf("api: %w", err))
+		}
+	}
+
 	var eg errgroup.Group
 	if b.apiServer != nil {
 		eg.Go(func() error {
@@ -395,6 +407,10 @@ func (b *Bee) Shutdown(ctx context.Context) error {
 		errs.add(err)
 	}
 
+	if b.recoveryHandleCleanup != nil {
+		b.recoveryHandleCleanup()
+	}
+
 	if err := b.pusherCloser.Close(); err != nil {
 		errs.add(fmt.Errorf("pusher: %w", err))
 	}
@@ -407,6 +423,10 @@ func (b *Bee) Shutdown(ctx context.Context) error {
 		errs.add(fmt.Errorf("pull sync: %w", err))
 	}
 
+	if err := b.pssCloser.Close(); err != nil {
+		errs.add(fmt.Errorf("pss: %w", err))
+	}
+
 	b.p2pCancel()
 	if err := b.p2pService.Close(); err != nil {
 		errs.add(fmt.Errorf("p2p server: %w", err))

pkg/pss/pss.go

@@ -8,6 +8,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io"
 	"sync"
 
 	"github.com/ethersphere/bee/pkg/logging"
@@ -22,54 +23,67 @@ var (
 )
 
 type Interface interface {
-	Send(ctx context.Context, targets trojan.Targets, topic trojan.Topic, payload []byte) error
-	Register(topic trojan.Topic, hndlr Handler)
-	GetHandler(topic trojan.Topic) Handler
-	TryUnwrap(ctx context.Context, c swarm.Chunk) error
-	WithPushSyncer(pushSyncer pushsync.PushSyncer)
+	// Send arbitrary byte slice with the given topic to Targets.
+	Send(context.Context, trojan.Targets, trojan.Topic, []byte) error
+	// Register a Handler for a given Topic.
+	Register(trojan.Topic, Handler) func()
+	// TryUnwrap tries to unwrap a wrapped trojan message.
+	TryUnwrap(context.Context, swarm.Chunk) error
+
+	SetPushSyncer(pushSyncer pushsync.PushSyncer)
+	io.Closer
 }
 
-// pss is the top-level struct, which takes care of message sending
 type pss struct {
 	pusher     pushsync.PushSyncer
-	handlers   map[trojan.Topic]Handler
-	handlersMu sync.RWMutex
+	handlers   map[trojan.Topic][]*Handler
+	handlersMu sync.Mutex
 	metrics    metrics
 	logger     logging.Logger
+	quit       chan struct{}
 }
 
-// New inits the pss struct with the storer
-func New(logger logging.Logger, pusher pushsync.PushSyncer) Interface {
+// New returns a new pss service.
+func New(logger logging.Logger) Interface {
 	return &pss{
 		logger:   logger,
-		pusher:   pusher,
-		handlers: make(map[trojan.Topic]Handler),
+		handlers: make(map[trojan.Topic][]*Handler),
 		metrics:  newMetrics(),
+		quit:     make(chan struct{}),
 	}
 }
 
-func (ps *pss) WithPushSyncer(pushSyncer pushsync.PushSyncer) {
+func (ps *pss) Close() error {
+	close(ps.quit)
+	ps.handlersMu.Lock()
+	defer ps.handlersMu.Unlock()
+
+	ps.handlers = make(map[trojan.Topic][]*Handler) //unset handlers on shutdown
+
+	return nil
+}
+
+func (ps *pss) SetPushSyncer(pushSyncer pushsync.PushSyncer) {
 	ps.pusher = pushSyncer
 }
 
-// Handler defines code to be executed upon reception of a trojan message
-type Handler func(context.Context, *trojan.Message) error
+// Handler defines code to be executed upon reception of a trojan message.
+type Handler func(context.Context, *trojan.Message)
 
 // Send constructs a padded message with topic and payload,
-// wraps it in a trojan chunk such that one of the targets is a prefix of the chunk address
-// uses push-sync to deliver message
+// wraps it in a trojan chunk such that one of the targets is a prefix of the chunk address.
+// Uses push-sync to deliver message.
 func (p *pss) Send(ctx context.Context, targets trojan.Targets, topic trojan.Topic, payload []byte) error {
 	p.metrics.TotalMessagesSentCounter.Inc()
 
-	//construct Trojan Chunk
 	m, err := trojan.NewMessage(topic, payload)
 	if err != nil {
 		return err
 	}
+
 	var tc swarm.Chunk
 	tc, err = m.Wrap(ctx, targets)
 	if err != nil {
-
 		return err
 	}
 
@@ -81,33 +95,69 @@ func (p *pss) Send(ctx context.Context, targets trojan.Targets, topic trojan.Top
 	return nil
 }
 
-// Register allows the definition of a Handler func for a specific topic on the pss struct
-func (p *pss) Register(topic trojan.Topic, hndlr Handler) {
+// Register allows the definition of a Handler func for a specific topic on the pss struct.
+func (p *pss) Register(topic trojan.Topic, handler Handler) (cleanup func()) {
+	p.handlersMu.Lock()
+	defer p.handlersMu.Unlock()
+
+	p.handlers[topic] = append(p.handlers[topic], &handler)
+
+	return func() {
 		p.handlersMu.Lock()
 		defer p.handlersMu.Unlock()
-	p.handlers[topic] = hndlr
+
+		h := p.handlers[topic]
+		for i := 0; i < len(h); i++ {
+			if h[i] == &handler {
+				p.handlers[topic] = append(h[:i], h[i+1:]...)
+				return
+			}
+		}
+	}
 }
 
-// TryUnwrap allows unwrapping a chunk as a trojan message and calling its handler func based on its topic
+// TryUnwrap allows unwrapping a chunk as a trojan message and calling its handlers based on the topic.
 func (p *pss) TryUnwrap(ctx context.Context, c swarm.Chunk) error {
-
 	if !trojan.IsPotential(c) {
 		return nil
 	}
-	m, err := trojan.Unwrap(c) // if err occurs unwrapping, there will be no handler
+	m, err := trojan.Unwrap(c)
 	if err != nil {
 		return err
 	}
-	h := p.GetHandler(m.Topic)
+	h := p.getHandlers(m.Topic)
 	if h == nil {
 		return fmt.Errorf("topic %v, %w", m.Topic, ErrNoHandler)
 	}
-	return h(ctx, m)
+
+	ctx, cancel := context.WithCancel(ctx)
+	done := make(chan struct{})
+	var wg sync.WaitGroup
+	go func() {
+		defer cancel()
+		select {
+		case <-p.quit:
+		case <-done:
+		}
+	}()
+	for _, hh := range h {
+		wg.Add(1)
+		go func(hh Handler) {
+			defer wg.Done()
+			hh(ctx, m)
+		}(*hh)
+	}
+	go func() {
+		wg.Wait()
+		close(done)
+	}()
+
+	return nil
 }
 
-// GetHandler returns the Handler func registered in pss for the given topic
-func (p *pss) GetHandler(topic trojan.Topic) Handler {
-	p.handlersMu.RLock()
-	defer p.handlersMu.RUnlock()
+func (p *pss) getHandlers(topic trojan.Topic) []*Handler {
+	p.handlersMu.Lock()
+	defer p.handlersMu.Unlock()
+
 	return p.handlers[topic]
 }

pkg/pss/pss_test.go

@@ -8,7 +8,10 @@ import (
 	"bytes"
 	"context"
 	"io/ioutil"
+	"runtime"
+	"sync"
 	"testing"
+	"time"
 
 	"github.com/ethersphere/bee/pkg/logging"
 	"github.com/ethersphere/bee/pkg/pss"
@@ -21,7 +24,7 @@ import (
 // TestSend creates a trojan chunk and sends it using push sync
 func TestSend(t *testing.T) {
 	var err error
-	ctx := context.TODO()
+	ctx := context.Background()
 
 	// create a mock pushsync service to push the chunk to its destination
 	var receipt *pushsync.Receipt
@@ -35,7 +38,8 @@ func TestSend(t *testing.T) {
 		return rcpt, nil
 	})
 
-	pss := pss.New(logging.New(ioutil.Discard, 0), pushSyncService)
+	pss := pss.New(logging.New(ioutil.Discard, 0))
+	pss.SetPushSyncer(pushSyncService)
 
 	target := trojan.Target([]byte{1}) // arbitrary test target
 	targets := trojan.Targets([]trojan.Target{target})
@@ -64,54 +68,12 @@ func TestSend(t *testing.T) {
 	}
 }
 
-// TestRegister verifies that handler funcs are able to be registered correctly in pss
-func TestRegister(t *testing.T) {
-	pss := pss.New(logging.New(ioutil.Discard, 0), nil)
-
-	handlerVerifier := 0 // test variable to check handler funcs are correctly retrieved
-
-	// register first handler
-	testHandler := func(ctx context.Context, m *trojan.Message) error {
-		handlerVerifier = 1
-		return nil
-	}
-	testTopic := trojan.NewTopic("FIRST_HANDLER")
-	pss.Register(testTopic, testHandler)
-
-	registeredHandler := pss.GetHandler(testTopic)
-	err := registeredHandler(context.Background(), &trojan.Message{}) // call handler to verify the retrieved func is correct
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if handlerVerifier != 1 {
-		t.Fatalf("unexpected handler retrieved, verifier variable should be 1 but is %d instead", handlerVerifier)
-	}
-
-	// register second handler
-	testHandler = func(ctx context.Context, m *trojan.Message) error {
-		handlerVerifier = 2
-		return nil
-	}
-	testTopic = trojan.NewTopic("SECOND_HANDLER")
-	pss.Register(testTopic, testHandler)
-
-	registeredHandler = pss.GetHandler(testTopic)
-	err = registeredHandler(context.Background(), &trojan.Message{}) // call handler to verify the retrieved func is correct
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if handlerVerifier != 2 {
-		t.Fatalf("unexpected handler retrieved, verifier variable should be 2 but is %d instead", handlerVerifier)
-	}
-}
-
 // TestDeliver verifies that registering a handler on pss for a given topic and then submitting a trojan chunk with said topic to it
 // results in the execution of the expected handler func
 func TestDeliver(t *testing.T) {
-	pss := pss.New(logging.New(ioutil.Discard, 0), nil)
-	ctx := context.TODO()
+	pss := pss.New(logging.New(ioutil.Discard, 0))
+	ctx := context.Background()
+	var mtx sync.Mutex
 
 	// test message
 	topic := trojan.NewTopic("footopic")
@@ -130,9 +92,10 @@ func TestDeliver(t *testing.T) {
 
 	// create and register handler
 	var tt trojan.Topic // test variable to check handler func was correctly called
-	hndlr := func(ctx context.Context, m *trojan.Message) error {
-		tt = m.Topic // copy the message topic to the test variable
-		return nil
+	hndlr := func(ctx context.Context, m *trojan.Message) {
+		mtx.Lock()
+		copy(tt[:], m.Topic[:]) // copy the message topic to the test variable
+		mtx.Unlock()
 	}
 	pss.Register(topic, hndlr)
 
@@ -141,28 +104,125 @@ func TestDeliver(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if tt != msg.Topic {
-		t.Fatalf("unexpected result for pss Deliver func, expected test variable to have a value of %v but is %v instead", msg.Topic, tt)
+	runtime.Gosched() // schedule the handler goroutine
+	for i := 0; i < 10; i++ {
+		mtx.Lock()
+
+		eq := bytes.Equal(tt[:], msg.Topic[:])
+		mtx.Unlock()
+		if eq {
+			return
+		}
+		<-time.After(50 * time.Millisecond)
 	}
+	t.Fatalf("unexpected result for pss Deliver func, expected test variable to have a value of %v but is %v instead", msg.Topic, tt)
 }
 
-func TestHandler(t *testing.T) {
-	pss := pss.New(logging.New(ioutil.Discard, 0), nil)
-	testTopic := trojan.NewTopic("TEST_TOPIC")
+// TestRegister verifies that handler funcs are able to be registered correctly in pss
+func TestRegister(t *testing.T) {
+	var (
+		pss     = pss.New(logging.New(ioutil.Discard, 0))
+		h1Calls = 0
+		h2Calls = 0
+		h3Calls = 0
+		mtx     sync.Mutex
+
+		topic1  = trojan.NewTopic("one")
+		topic2  = trojan.NewTopic("two")
+		payload = []byte("payload")
+		target  = trojan.Target([]byte{1})
+		targets = trojan.Targets([]trojan.Target{target})
+
+		h1 = func(_ context.Context, m *trojan.Message) {
+			mtx.Lock()
+			defer mtx.Unlock()
+			h1Calls++
+		}
+
+		h2 = func(_ context.Context, m *trojan.Message) {
+			mtx.Lock()
+			defer mtx.Unlock()
+			h2Calls++
+		}
+
+		h3 = func(_ context.Context, m *trojan.Message) {
+			mtx.Lock()
+			defer mtx.Unlock()
+			h3Calls++
+		}
+	)
+	_ = pss.Register(topic1, h1)
+	_ = pss.Register(topic2, h2)
+
+	// send a message on topic1, check that only h1 is called
+	msg, err := trojan.NewMessage(topic1, payload)
+	if err != nil {
+		t.Fatal(err)
+	}
+	c, err := msg.Wrap(context.Background(), targets)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = pss.TryUnwrap(context.Background(), c)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ensureCalls(t, &mtx, &h1Calls, 1)
+	ensureCalls(t, &mtx, &h2Calls, 0)
 
-	// verify handler is null
-	if pss.GetHandler(testTopic) != nil {
-		t.Errorf("handler should be null")
+	// register another topic handler on the same topic
+	cleanup := pss.Register(topic1, h3)
+	err = pss.TryUnwrap(context.Background(), c)
+	if err != nil {
+		t.Fatal(err)
 	}
 
-	// register first handler
-	testHandler := func(ctx context.Context, m *trojan.Message) error { return nil }
+	ensureCalls(t, &mtx, &h1Calls, 2)
+	ensureCalls(t, &mtx, &h2Calls, 0)
+	ensureCalls(t, &mtx, &h3Calls, 1)
 
-	// set handler for test topic
-	pss.Register(testTopic, testHandler)
+	cleanup() // remove the last handler
 
-	if pss.GetHandler(testTopic) == nil {
-		t.Errorf("handler should be registered")
+	err = pss.TryUnwrap(context.Background(), c)
+	if err != nil {
+		t.Fatal(err)
 	}
 
+	ensureCalls(t, &mtx, &h1Calls, 3)
+	ensureCalls(t, &mtx, &h2Calls, 0)
+	ensureCalls(t, &mtx, &h3Calls, 1)
+
+	msg, err = trojan.NewMessage(topic2, payload)
+	if err != nil {
+		t.Fatal(err)
+	}
+	c, err = msg.Wrap(context.Background(), targets)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = pss.TryUnwrap(context.Background(), c)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ensureCalls(t, &mtx, &h1Calls, 3)
+	ensureCalls(t, &mtx, &h2Calls, 1)
+	ensureCalls(t, &mtx, &h3Calls, 1)
+}
+
+func ensureCalls(t *testing.T, mtx *sync.Mutex, calls *int, exp int) {
+	t.Helper()
+
+	for i := 0; i < 10; i++ {
+		mtx.Lock()
+		if *calls == exp {
+			mtx.Unlock()
+			return
+		}
+		mtx.Unlock()
+		<-time.After(100 * time.Millisecond)
+	}
+	t.Fatal("timed out waiting for value")
 }

pkg/pushsync/mock/mock.go

@@ -11,14 +11,18 @@ import (
 	"github.com/ethersphere/bee/pkg/swarm"
 )
 
-type PushSync struct {
+type mock struct {
 	sendChunk func(ctx context.Context, chunk swarm.Chunk) (*pushsync.Receipt, error)
 }
 
-func New(sendChunk func(ctx context.Context, chunk swarm.Chunk) (*pushsync.Receipt, error)) *PushSync {
-	return &PushSync{sendChunk: sendChunk}
+func New(sendChunk func(ctx context.Context, chunk swarm.Chunk) (*pushsync.Receipt, error)) pushsync.PushSyncer {
+	return &mock{sendChunk: sendChunk}
 }
 
-func (s *PushSync) PushChunkToClosest(ctx context.Context, chunk swarm.Chunk) (*pushsync.Receipt, error) {
+func (s *mock) PushChunkToClosest(ctx context.Context, chunk swarm.Chunk) (*pushsync.Receipt, error) {
 	return s.sendChunk(ctx, chunk)
 }
+
+func (s *mock) Close() error {
+	return nil
+}

pkg/recovery/export_test.go

-// Copyright 2020 The Swarm Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package recovery
-
-var (
-	ErrChunkNotPresent = errChunkNotPresent
-)

pkg/recovery/repair.go

@@ -6,7 +6,6 @@ package recovery
 
 import (
 	"context"
-	"errors"
 
 	"github.com/ethersphere/bee/pkg/logging"
 	"github.com/ethersphere/bee/pkg/pss"
@@ -26,10 +25,6 @@ var (
 	RecoveryTopic = trojan.NewTopic(RecoveryTopicText)
 )
 
-var (
-	errChunkNotPresent = errors.New("chunk repair: chunk not present in local store for repairing")
-)
-
 // RecoveryHook defines code to be executed upon failing to retrieve chunks.
 type RecoveryHook func(chunkAddress swarm.Address, targets trojan.Targets) error
 
@@ -50,32 +45,31 @@ func NewRecoveryHook(pss PssSender) RecoveryHook {
 
 // NewRepairHandler creates a repair function to re-upload globally pinned chunks to the network with the given store.
 func NewRepairHandler(s storage.Storer, logger logging.Logger, pushSyncer pushsync.PushSyncer) pss.Handler {
-	return func(ctx context.Context, m *trojan.Message) error {
+	return func(ctx context.Context, m *trojan.Message) {
 		chAddr := m.Payload
 
 		// check if the chunk exists in the local store and proceed.
 		// otherwise the Get will trigger a unnecessary network retrieve
 		exists, err := s.Has(ctx, swarm.NewAddress(chAddr))
 		if err != nil {
-			return err
+			return
 		}
 		if !exists {
-			return errChunkNotPresent
+			return
 		}
 
 		// retrieve the chunk from the local store
 		ch, err := s.Get(ctx, storage.ModeGetRequest, swarm.NewAddress(chAddr))
 		if err != nil {
 			logger.Tracef("chunk repair: error while getting chunk for repairing: %v", err)
-			return err
+			return
 		}
 
 		// push the chunk using push sync so that it reaches it destination in network
 		_, err = pushSyncer.PushChunkToClosest(ctx, ch)
 		if err != nil {
 			logger.Tracef("chunk repair: error while sending chunk or receiving receipt: %v", err)
-			return err
+			return
 		}
-		return nil
 	}
 }

pkg/recovery/repair_test.go

@@ -155,10 +155,7 @@ func TestNewRepairHandler(t *testing.T) {
 		}
 
 		// invoke the chunk repair handler
-		err = repairHandler(context.Background(), &msg)
-		if err != nil {
-			t.Fatal(err)
-		}
+		repairHandler(context.Background(), &msg)
 
 		// check if receipt is received
 		if receipt == nil {
@@ -200,10 +197,7 @@ func TestNewRepairHandler(t *testing.T) {
 		}
 
 		// invoke the chunk repair handler
-		err = repairHandler(context.Background(), &msg)
-		if !errors.Is(err, recovery.ErrChunkNotPresent) {
-			t.Fatal(err)
-		}
+		repairHandler(context.Background(), &msg)
 
 		if pushServiceCalled {
 			t.Fatal("push service called even if the chunk is not present")
@@ -243,10 +237,7 @@ func TestNewRepairHandler(t *testing.T) {
 		}
 
 		// invoke the chunk repair handler
-		err = repairHandler(context.Background(), &msg)
-		if err != nil && err != receiptError {
-			t.Fatal(err)
-		}
+		repairHandler(context.Background(), &msg)
 
 		if receiptError == nil {
 			t.Fatal("pushsync did not generate a receipt error")