supernode/p2p: cache validator lookups to cut handshake gRPC reads

pkg/lumera/validator.go

@@ -3,36 +3,117 @@ package lumera
 import (
 	"context"
 	"fmt"
+	"time"
 
 	sntypes "github.com/LumeraProtocol/lumera/x/supernode/v1/types"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
+	ristretto "github.com/dgraph-io/ristretto/v2"
+	"golang.org/x/sync/singleflight"
 )
 
+const (
+	// Expect up to ~100 live keys; use TinyLFU counters ~10x.
+	cacheNumCounters = 1_000
+	// With per-item cost of 1, cap total items to 100.
+	cacheMaxCost     = 100
+	cacheBufferItems = 64
+	cacheItemCost    = 1
+	cacheTTL         = time.Hour
+)
+
+func newStringCache[T any]() *ristretto.Cache[string, T] {
+	c, _ := ristretto.NewCache(&ristretto.Config[string, T]{
+		NumCounters: cacheNumCounters,
+		MaxCost:     cacheMaxCost,
+		BufferItems: cacheBufferItems,
+	})
+	return c
+}
+
 type SecureKeyExchangeValidator struct {
-	lumeraClient Client
+	lumeraClient   Client
+	accountCache   *ristretto.Cache[string, *authtypes.QueryAccountInfoResponse]
+	supernodeCache *ristretto.Cache[string, *sntypes.SuperNode]
+	sf             singleflight.Group
 }
 
 func NewSecureKeyExchangeValidator(lumeraClient Client) *SecureKeyExchangeValidator {
 	return &SecureKeyExchangeValidator{
-		lumeraClient: lumeraClient,
+		lumeraClient:   lumeraClient,
+		accountCache:   newStringCache[*authtypes.QueryAccountInfoResponse](),
+		supernodeCache: newStringCache[*sntypes.SuperNode](),
 	}
 }
 
 func (v *SecureKeyExchangeValidator) AccountInfoByAddress(ctx context.Context, addr string) (*authtypes.QueryAccountInfoResponse, error) {
-	accountInfo, err := v.lumeraClient.Auth().AccountInfoByAddress(ctx, addr)
+	if v.accountCache != nil {
+		if val, ok := v.accountCache.Get(addr); ok && val != nil {
+			return val, nil
+		}
+	}
+
+	// Deduplicate concurrent fetches for the same address
+	res, err, _ := v.sf.Do("acct:"+addr, func() (any, error) {
+		// Double-check cache inside singleflight window (cheap and safe)
+		if v.accountCache != nil {
+			if val, ok := v.accountCache.Get(addr); ok && val != nil {
+				return val, nil
+			}
+		}
+
+		accountInfo, err := v.lumeraClient.Auth().AccountInfoByAddress(ctx, addr)
+		if err != nil {
+			return nil, fmt.Errorf("failed to get account info: %w", err)
+		}
+		if accountInfo != nil && v.accountCache != nil {
+			v.accountCache.SetWithTTL(addr, accountInfo, cacheItemCost, cacheTTL)
+		}
+		return accountInfo, nil
+	})
 	if err != nil {
-		return nil, fmt.Errorf("failed to get account info: %w", err)
+		return nil, err
+	}
+	ai, _ := res.(*authtypes.QueryAccountInfoResponse)
+	if ai == nil {
+		return nil, fmt.Errorf("account info is nil")
 	}
-	return accountInfo, nil
+	return ai, nil
 }
 
 func (v *SecureKeyExchangeValidator) GetSupernodeBySupernodeAddress(ctx context.Context, address string) (*sntypes.SuperNode, error) {
-	supernodeInfo, err := v.lumeraClient.SuperNode().GetSupernodeBySupernodeAddress(ctx, address)
+	if v.supernodeCache != nil {
+		if val, ok := v.supernodeCache.Get(address); ok && val != nil {
+			return val, nil
+		}
+	}
+
+	// Deduplicate concurrent fetches for the same supernode address
+	res, err, _ := v.sf.Do("sn:"+address, func() (any, error) {
+		// Double-check cache inside singleflight window
+		if v.supernodeCache != nil {
+			if val, ok := v.supernodeCache.Get(address); ok && val != nil {
+				return val, nil
+			}
+		}
+
+		supernodeInfo, err := v.lumeraClient.SuperNode().GetSupernodeBySupernodeAddress(ctx, address)
+		if err != nil {
+			return nil, fmt.Errorf("failed to get supernode info: %w", err)
+		}
+		if supernodeInfo == nil {
+			return nil, fmt.Errorf("supernode info is nil")
+		}
+		if v.supernodeCache != nil {
+			v.supernodeCache.SetWithTTL(address, supernodeInfo, cacheItemCost, cacheTTL)
+		}
+		return supernodeInfo, nil
+	})
 	if err != nil {
-		return nil, fmt.Errorf("failed to get supernode info: %w", err)
+		return nil, err
 	}
-	if supernodeInfo == nil {
+	sn, _ := res.(*sntypes.SuperNode)
+	if sn == nil {
 		return nil, fmt.Errorf("supernode info is nil")
 	}
-	return supernodeInfo, nil
+	return sn, nil
 }