first commit

internal/nostr/relay.go

@@ -0,0 +1,51 @@
+package nostr
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	gn "github.com/nbd-wtf/go-nostr"
+)
+
+// Pool is a small relay-connection pool.
+type Pool struct {
+	mu      sync.Mutex
+	relays  []string
+	active  map[string]*gn.Relay
+}
+
+func NewPool(urls []string) *Pool {
+	return &Pool{relays: urls, active: map[string]*gn.Relay{}}
+}
+
+func (p *Pool) URLs() []string { return p.relays }
+
+func (p *Pool) Connect(ctx context.Context, url string) (*gn.Relay, error) {
+	p.mu.Lock()
+	if r, ok := p.active[url]; ok && r.IsConnected() {
+		p.mu.Unlock()
+		return r, nil
+	}
+	p.mu.Unlock()
+
+	dialCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
+	defer cancel()
+	r, err := gn.RelayConnect(dialCtx, url)
+	if err != nil {
+		return nil, err
+	}
+	p.mu.Lock()
+	p.active[url] = r
+	p.mu.Unlock()
+	return r, nil
+}
+
+func (p *Pool) Close() {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	for _, r := range p.active {
+		_ = r.Close()
+	}
+	p.active = map[string]*gn.Relay{}
+}