/
pubsub.go
189 lines (154 loc) · 3.8 KB
/
pubsub.go
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package pubsubcoreapi
import (
"context"
"sync"
"time"
coreapi "github.com/ipfs/interface-go-ipfs-core"
options "github.com/ipfs/interface-go-ipfs-core/options"
"github.com/libp2p/go-libp2p/core/peer"
"go.opentelemetry.io/otel/trace"
"go.uber.org/zap"
"berty.tech/go-orbit-db/events"
"berty.tech/go-orbit-db/iface"
"berty.tech/go-orbit-db/pubsub"
)
type psTopic struct {
topic string
ps *coreAPIPubSub
members []peer.ID
muMembers sync.RWMutex
}
func (p *psTopic) Publish(ctx context.Context, message []byte) error {
return p.ps.api.PubSub().Publish(ctx, p.topic, message)
}
func (p *psTopic) Peers(_ context.Context) ([]peer.ID, error) {
p.muMembers.RLock()
members := p.members
p.muMembers.RUnlock()
return members, nil
}
func (p *psTopic) peersDiff(ctx context.Context) (joining, leaving []peer.ID, err error) {
p.muMembers.RLock()
oldMembers := map[peer.ID]struct{}{}
for _, m := range p.members {
oldMembers[m] = struct{}{}
}
p.muMembers.RUnlock()
all, err := p.ps.api.PubSub().Peers(ctx, options.PubSub.Topic(p.topic))
if err != nil {
return nil, nil, err
}
for _, m := range all {
if _, ok := oldMembers[m]; !ok {
joining = append(joining, m)
} else {
delete(oldMembers, m)
}
}
for m := range oldMembers {
leaving = append(leaving, m)
}
p.muMembers.Lock()
p.members = all
p.muMembers.Unlock()
return joining, leaving, nil
}
func (p *psTopic) WatchPeers(ctx context.Context) (<-chan events.Event, error) {
ch := make(chan events.Event, 32)
go func() {
defer close(ch)
for {
joining, leaving, err := p.peersDiff(ctx)
if err != nil {
p.ps.logger.Error("", zap.Error(err))
return
}
for _, pid := range joining {
ch <- pubsub.NewEventPeerJoin(pid, p.Topic())
}
for _, pid := range leaving {
ch <- pubsub.NewEventPeerLeave(pid, p.Topic())
}
select {
case <-ctx.Done():
return
case <-time.After(p.ps.pollInterval):
continue
}
}
}()
return ch, nil
}
func (p *psTopic) WatchMessages(ctx context.Context) (<-chan *iface.EventPubSubMessage, error) {
sub, err := p.ps.api.PubSub().Subscribe(ctx, p.topic)
if err != nil {
return nil, err
}
ch := make(chan *iface.EventPubSubMessage, 128)
go func() {
defer close(ch)
for {
msg, err := sub.Next(ctx)
if err != nil {
switch err {
case context.Canceled, context.DeadlineExceeded:
p.ps.logger.Debug("watch message ended",
zap.String("topic", p.topic),
zap.Error(err))
default:
p.ps.logger.Error("error while retrieving pubsub message",
zap.String("topic", p.topic),
zap.Error(err))
}
return
}
if msg.From() == p.ps.id {
continue
}
ch <- pubsub.NewEventMessage(msg.Data())
}
}()
return ch, nil
}
func (p *psTopic) Topic() string {
return p.topic
}
type coreAPIPubSub struct {
api coreapi.CoreAPI
logger *zap.Logger
id peer.ID
pollInterval time.Duration
tracer trace.Tracer
topics map[string]*psTopic
muTopics sync.Mutex
}
func (c *coreAPIPubSub) TopicSubscribe(_ context.Context, topic string) (iface.PubSubTopic, error) {
c.muTopics.Lock()
defer c.muTopics.Unlock()
if t, ok := c.topics[topic]; ok {
return t, nil
}
c.topics[topic] = &psTopic{
topic: topic,
ps: c,
}
return c.topics[topic], nil
}
func NewPubSub(api coreapi.CoreAPI, id peer.ID, pollInterval time.Duration, logger *zap.Logger, tracer trace.Tracer) iface.PubSubInterface {
if logger == nil {
logger = zap.NewNop()
}
if tracer == nil {
tracer = trace.NewNoopTracerProvider().Tracer("")
}
return &coreAPIPubSub{
topics: map[string]*psTopic{},
api: api,
id: id,
logger: logger,
pollInterval: pollInterval,
tracer: tracer,
}
}
var _ iface.PubSubInterface = &coreAPIPubSub{}
var _ iface.PubSubTopic = &psTopic{}