Firehose working

pkg/pipe/pipe.go

@@ -0,0 +1,144 @@
+package pipe
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"slices"
+	"time"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+var (
+	relevantKinds = []int{
+		nostr.KindProfileMetadata,
+		nostr.KindFollowList,
+	}
+
+	defaultRelays = []string{
+		"wss://purplepag.es",
+		"wss://njump.me",
+		"wss://relay.snort.social",
+		"wss://relay.damus.io",
+		"wss://relay.primal.net",
+		"wss://relay.nostr.band",
+		"wss://nostr-pub.wellorder.net",
+		"wss://relay.nostr.net",
+		"wss://nostr.lu.ke",
+		"wss://nostr.at",
+		"wss://e.nos.lol",
+		"wss://nostr.lopp.social",
+		"wss://nostr.vulpem.com",
+		"wss://relay.nostr.bg",
+		"wss://wot.utxo.one",
+		"wss://nostrelites.org",
+		"wss://wot.nostr.party",
+		"wss://wot.sovbit.host",
+		"wss://wot.girino.org",
+		"wss://relay.lnau.net",
+		"wss://wot.siamstr.com",
+		"wss://wot.sudocarlos.com",
+		"wss://relay.otherstuff.fyi",
+		"wss://relay.lexingtonbitcoin.org",
+		"wss://wot.azzamo.net",
+		"wss://wot.swarmstr.com",
+		"wss://zap.watch",
+		"wss://satsage.xyz",
+	}
+)
+
+type FirehoseConfig struct {
+	Relays []string
+	Offset time.Duration
+}
+
+func NewFirehoseConfig() FirehoseConfig {
+	return FirehoseConfig{
+		Relays: defaultRelays,
+		Offset: 10 * time.Second,
+	}
+}
+
+func (c FirehoseConfig) Since() *nostr.Timestamp {
+	since := nostr.Timestamp(time.Now().Add(-c.Offset).Unix())
+	return &since
+}
+
+func (c FirehoseConfig) Print() {
+	fmt.Printf("Firehose\n")
+	fmt.Printf("  Relays: %v\n", c.Relays)
+	fmt.Printf("  Offset: %v\n", c.Offset)
+}
+
+type PubkeyChecker interface {
+	Exists(ctx context.Context, pubkey string) (bool, error)
+}
+
+// buffer is a minimalistic ring buffer used to keep track of the latest event IDs
+type buffer struct {
+	IDs      []string
+	capacity int
+	write    int
+}
+
+func newBuffer(capacity int) *buffer {
+	return &buffer{
+		IDs:      make([]string, capacity),
+		capacity: capacity,
+	}
+}
+
+func (b *buffer) Add(ID string) {
+	b.IDs[b.write] = ID
+	b.write = (b.write + 1) % b.capacity
+}
+
+func (b *buffer) Contains(ID string) bool {
+	return slices.Contains(b.IDs, ID)
+}
+
+// Firehose connects to a list of relays and pulls [relevantKinds] events that are newer than [FirehoseConfig.Since].
+// It discards events from unknown pubkeys as an anti-spam mechanism.
+func Firehose(ctx context.Context, config FirehoseConfig, check PubkeyChecker, send func(e *nostr.Event) error) {
+	pool := nostr.NewSimplePool(ctx)
+	defer close(pool)
+
+	filter := nostr.Filter{
+		Kinds: relevantKinds,
+		Since: config.Since(),
+	}
+
+	seen := newBuffer(2048)
+	for event := range pool.SubscribeMany(ctx, config.Relays, filter) {
+
+		if seen.Contains(event.ID) {
+			// event already seen, skip
+			continue
+		}
+		seen.Add(event.ID)
+
+		exists, err := check.Exists(ctx, event.PubKey)
+		if err != nil {
+			log.Printf("Firehose: %v", err)
+			continue
+		}
+
+		if !exists {
+			// event from unknown pubkey, skip
+			continue
+		}
+
+		if err := send(event.Event); err != nil {
+			log.Printf("Firehose: %v", err)
+		}
+	}
+}
+
+// Close iterates over the relays in the pool and closes all connections.
+func close(pool *nostr.SimplePool) {
+	pool.Relays.Range(func(_ string, relay *nostr.Relay) bool {
+		relay.Close()
+		return true
+	})
+}

pkg/pipe/pipe_test.go

@@ -0,0 +1,41 @@
+package pipe
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+var (
+	ctx = context.Background()
+
+	pip = "f683e87035f7ad4f44e0b98cfbd9537e16455a92cd38cefc4cb31db7557f5ef2"
+)
+
+// Manually change pip's follow list and see if the events gets printed. Works only with `go test`
+func TestFirehose(t *testing.T) {
+	ctx, cancel := context.WithTimeout(ctx, time.Second*20)
+	defer cancel()
+
+	checker := mockChecker{pubkey: pip}
+	config := FirehoseConfig{Relays: defaultRelays}
+	Firehose(ctx, config, checker, print)
+}
+
+type mockChecker struct {
+	pubkey string
+}
+
+func (c mockChecker) Exists(ctx context.Context, pubkey string) (bool, error) {
+	return pubkey == c.pubkey, nil
+}
+
+func print(e *nostr.Event) error {
+	fmt.Printf("\nevent ID: %v", e.ID)
+	fmt.Printf("\nevent pubkey: %v", e.PubKey)
+	fmt.Printf("\nevent kind: %d\n", e.Kind)
+	return nil
+}