stategen: Pre-populate bls pubkey cache as part of stategen's Resume function (#11482)

* Pre-populate bls pubkey cache as part of state gen's Resume function. This adds some helpers and a benchmark to blst

* Do it async

* fix missing import

* lint

---------

Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>
Co-authored-by: rauljordan <raul@prysmaticlabs.com>

crypto/bls/blst/BUILD.bazel

@@ -34,6 +34,7 @@ go_test(
         "public_key_test.go",
         "secret_key_test.go",
         "signature_test.go",
+        "test_helper_test.go",
     ],
     embed = [":go_default_library"],
     deps = [

crypto/bls/blst/public_key.go

@@ -12,7 +12,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/crypto/bls/common"
 )
 
-var maxKeys = 1000000
+var maxKeys = 1_000_000
 var pubkeyCache = lruwrpr.New(maxKeys)
 
 // PublicKey used in the BLS signature scheme.

crypto/bls/blst/public_key_test.go

@@ -97,3 +97,27 @@ func TestPublicKeysEmpty(t *testing.T) {
 	_, err := blst.AggregatePublicKeys(pubs)
 	require.ErrorContains(t, "nil or empty public keys", err)
 }
+
+func BenchmarkPublicKeyFromBytes(b *testing.B) {
+	priv, err := blst.RandKey()
+	require.NoError(b, err)
+	pubkey := priv.PublicKey()
+	pubkeyBytes := pubkey.Marshal()
+
+	b.Run("cache on", func(b *testing.B) {
+		blst.EnableCaches()
+		for i := 0; i < b.N; i++ {
+			_, err := blst.PublicKeyFromBytes(pubkeyBytes)
+			require.NoError(b, err)
+		}
+	})
+
+	b.Run("cache off", func(b *testing.B) {
+		blst.DisableCaches()
+		for i := 0; i < b.N; i++ {
+			_, err := blst.PublicKeyFromBytes(pubkeyBytes)
+			require.NoError(b, err)
+		}
+	})
+
+}

crypto/bls/blst/test_helper_test.go

@@ -0,0 +1,13 @@
+package blst
+
+// Note: These functions are for tests to access private globals, such as pubkeyCache.
+
+// DisableCaches sets the cache sizes to 0.
+func DisableCaches() {
+	pubkeyCache.Resize(0)
+}
+
+// EnableCaches sets the cache sizes to the default values.
+func EnableCaches() {
+	pubkeyCache.Resize(maxKeys)
+}