pss/outbox: refactored outbox into own package, touched pss_tests and pss to accommodate changes

Author: aperonam

pss/outbox/message.go

@@ -0,0 +1,19 @@
+package outbox
+
+import (
+	"time"
+
+	"github.com/ethersphere/swarm/pss/message"
+)
+
+type outboxMsg struct {
+	msg       *message.Message
+	startedAt time.Time
+}
+
+func NewOutboxMessage(msg *message.Message) *outboxMsg {
+	return &outboxMsg{
+		msg:       msg,
+		startedAt: time.Now(),
+	}
+}

pss/outbox/mock.go

@@ -0,0 +1,32 @@
+package outbox
+
+import (
+	"github.com/ethersphere/swarm/log"
+	"github.com/ethersphere/swarm/pss/message"
+)
+
+const (
+	defaultOutboxCapacity = 100000
+)
+
+var mockForwardFunction = func(msg *message.Message) error {
+	log.Debug("Forwarded message", "msg", msg)
+	return nil
+}
+
+func NewMock(config *Config) (outboxMock *Outbox) {
+	if config == nil {
+		config = &Config{
+			NumberSlots: defaultOutboxCapacity,
+			Forward:     mockForwardFunction,
+		}
+	} else {
+		if config.Forward == nil {
+			config.Forward = mockForwardFunction
+		}
+		if config.NumberSlots == 0 {
+			config.NumberSlots = defaultOutboxCapacity
+		}
+	}
+	return NewOutbox(config)
+}

pss/outbox/outbox.go

@@ -0,0 +1,110 @@
+package outbox
+
+import (
+	"errors"
+
+	"github.com/ethereum/go-ethereum/metrics"
+	"github.com/ethersphere/swarm/log"
+	"github.com/ethersphere/swarm/pss/message"
+)
+
+type Config struct {
+	NumberSlots int
+	Forward     forwardFunction
+}
+
+type Outbox struct {
+	forwardFunc forwardFunction
+	queue       []*outboxMsg
+	slots       chan int
+	process     chan int
+	stopC       chan struct{}
+}
+
+type forwardFunction func(msg *message.Message) error
+
+var ErrOutboxFull = errors.New("outbox full")
+
+func NewOutbox(config *Config) *Outbox {
+	outbox := &Outbox{
+		forwardFunc: config.Forward,
+		queue:       make([]*outboxMsg, config.NumberSlots),
+		slots:       make(chan int, config.NumberSlots),
+		process:     make(chan int),
+		stopC:       make(chan struct{}),
+	}
+	// fill up outbox slots
+	for i := 0; i < cap(outbox.slots); i++ {
+		outbox.slots <- i
+	}
+	return outbox
+}
+
+func (o *Outbox) Start() {
+	log.Info("Starting outbox")
+	go o.processOutbox()
+}
+
+func (o *Outbox) Stop() {
+	log.Info("Stopping outbox")
+	close(o.stopC)
+}
+
+// Enqueue a new element in the outbox if there is any slot available.
+// Then send it to process. This method is blocking in the process channel!
+func (o *Outbox) Enqueue(outboxMsg *outboxMsg) error {
+	// first we try to obtain a slot in the outbox
+	select {
+	case slot := <-o.slots:
+		o.queue[slot] = outboxMsg
+		metrics.GetOrRegisterGauge("pss.outbox.len", nil).Update(int64(o.len()))
+		// we send this message slot to process
+		select {
+		case <-o.stopC:
+		case o.process <- slot:
+		}
+		return nil
+	default:
+		metrics.GetOrRegisterCounter("pss.enqueue.outbox.full", nil).Inc(1)
+		return ErrOutboxFull
+	}
+}
+
+//ProcessOutbox starts a routine that tries to forward messages present in the outbox queue
+func (o *Outbox) processOutbox() {
+	for slot := range o.process {
+		go func(slot int) {
+			msg := o.queue[slot]
+			metrics.GetOrRegisterResettingTimer("pss.handle.outbox", nil).UpdateSince(msg.startedAt)
+			if err := o.forwardFunc(msg.msg); err != nil {
+				metrics.GetOrRegisterCounter("pss.forward.err", nil).Inc(1)
+				log.Debug(err.Error())
+				// requeue the message for processing
+				o.requeue(slot)
+				log.Debug("Message requeued", "slot", slot)
+				return
+			}
+			//message processed, free the outbox slot
+			o.free(slot)
+			metrics.GetOrRegisterGauge("pss.outbox.len", nil).Update(int64(o.len()))
+		}(slot)
+	}
+}
+
+func (o *Outbox) free(slot int) {
+	select {
+	case <-o.stopC:
+	case o.slots <- slot:
+	}
+
+}
+
+func (o *Outbox) requeue(slot int) {
+	select {
+	case <-o.stopC:
+	case o.process <- slot:
+	}
+}
+func (o *Outbox) len() int {
+	return cap(o.slots) - len(o.slots)
+}

pss/outbox/outbox_test.go

@@ -0,0 +1,77 @@
+package outbox_test
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/ethersphere/swarm/pss/message"
+	"github.com/ethersphere/swarm/pss/outbox"
+)
+
+func TestOutbox(t *testing.T) {
+
+	outboxCapacity := 2
+	failed := make([]interface{}, 0)
+	failedC := make(chan struct{})
+	successC := make(chan struct{})
+	continueC := make(chan struct{})
+
+	forwardFail := false
+
+	mockForwardFunction := func(msg *message.Message) error {
+		if !forwardFail {
+			successC <- struct{}{}
+			return nil
+		} else {
+			failed = append(failed, msg)
+			failedC <- struct{}{}
+			<-continueC
+			return errors.New("forced test error forwarding message")
+		}
+	}
+
+	testOutbox := outbox.NewMock(&outbox.Config{
+		NumberSlots: outboxCapacity,
+		Forward:     mockForwardFunction,
+	})
+
+	testOutbox.Start()
+	defer testOutbox.Stop()
+
+	err := testOutbox.Enqueue(testOutboxMessage)
+	if err != nil {
+		t.Fatalf("unexpected error enqueueing, %v", err)
+	}
+
+	//We wait for the forward function to success
+	<-successC
+
+	forwardFail = true
+
+	err = testOutbox.Enqueue(testOutboxMessage)
+	if err != nil {
+		t.Fatalf("unexpected error enqueueing, %v", err)
+	}
+	//We wait for the forward function to fail
+	<-failedC
+
+	failedMessages := len(failed)
+	if failedMessages != 1 {
+		t.Fatalf("unexpected number of failed messages, got %v, wanted 1", failedMessages)
+	}
+
+	// The message will be retried once we send to continueC, so first, we change the forward function
+	forwardFail = false
+	continueC <- struct{}{}
+
+	//We wait for the retry and success
+	<-successC
+}
+
+var testOutboxMessage = outbox.NewOutboxMessage(&message.Message{
+	To:      nil,
+	Flags:   message.Flags{},
+	Expire:  0,
+	Topic:   message.Topic{},
+	Payload: nil,
+})

pss/outbox/outbox_whitebox_test.go

@@ -0,0 +1,51 @@
+package outbox
+
+import (
+	"testing"
+
+	"github.com/ethersphere/swarm/pss/message"
+)
+
+func TestFullOutbox(t *testing.T) {
+
+	outboxCapacity := 2
+	processC := make(chan struct{})
+	successForward := func(msg *message.Message) error {
+		<-processC
+		return nil
+	}
+
+	testOutbox := NewMock(&Config{
+		NumberSlots: outboxCapacity,
+		Forward:     successForward,
+	})
+	testOutbox.Start()
+	defer testOutbox.Stop()
+
+	err := testOutbox.Enqueue(testOutboxMessage)
+	if err != nil {
+		t.Fatalf("unexpected error enqueueing, %v", err)
+	}
+
+	err = testOutbox.Enqueue(testOutboxMessage)
+	if err != nil {
+		t.Fatalf("unexpected error enqueueing, %v", err)
+	}
+	//As we haven't signaled processC, the messages are still in the outbox
+	err = testOutbox.Enqueue(testOutboxMessage)
+	if err != ErrOutboxFull {
+		t.Fatalf("unexpected error, got %v, wanted %v", err, ErrOutboxFull)
+	}
+	processC <- struct{}{}
+
+	//There should be a slot again in the outbox to enqueue
+	<-testOutbox.slots
+}
+
+var testOutboxMessage = NewOutboxMessage(&message.Message{
+	To:      nil,
+	Flags:   message.Flags{},
+	Expire:  0,
+	Topic:   message.Topic{},
+	Payload: nil,
+})