state-diff configs & kv functions (#15903)

* state-diff configs

* state diff kv functions

* potuz's comments

* Update config.go

* fix merge conflicts

* apply bazel's suggestion and fix some bugs

* preston's feedback

cmd/beacon-chain/flags/BUILD.bazel

@@ -18,7 +18,9 @@ go_library(
     ],
     deps = [
         "//cmd:go_default_library",
+        "//config/features:go_default_library",
         "//config/params:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@com_github_urfave_cli_v2//:go_default_library",
     ],
@@ -26,7 +28,13 @@ go_library(
 
 go_test(
     name = "go_default_test",
-    srcs = ["api_module_test.go"],
+    srcs = [
+        "api_module_test.go",
+        "config_test.go",
+    ],
     embed = [":go_default_library"],
-    deps = ["//testing/assert:go_default_library"],
+    deps = [
+        "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
+    ],
 )

cmd/beacon-chain/flags/base.go

@@ -345,4 +345,10 @@ var (
 		Usage: "Maximum number of signatures to batch verify at once for beacon attestation p2p gossip.",
 		Value: 1000,
 	}
+	// StateDiffExponents defines the state diff tree hierarchy levels.
+	StateDiffExponents = &cli.IntSliceFlag{
+		Name:  "state-diff-exponents",
+		Usage: "A comma-separated list of exponents (of 2) in decreasing order, defining the state diff hierarchy levels. The last exponent must be greater than or equal to 5.",
+		Value: cli.NewIntSlice(21, 18, 16, 13, 11, 9, 5),
+	}
 )

cmd/beacon-chain/flags/config.go

@@ -2,9 +2,13 @@ package flags
 
 import (
 	"github.com/OffchainLabs/prysm/v7/cmd"
+	"github.com/OffchainLabs/prysm/v7/config/features"
+	"github.com/pkg/errors"
 	"github.com/urfave/cli/v2"
 )
 
+const maxStateDiffExponents = 30
+
 // GlobalFlags specifies all the global flags for the
 // beacon node.
 type GlobalFlags struct {
@@ -19,6 +23,7 @@ type GlobalFlags struct {
 	BlobBatchLimitBurstFactor       int
 	DataColumnBatchLimit            int
 	DataColumnBatchLimitBurstFactor int
+	StateDiffExponents              []int
 }
 
 var globalConfig *GlobalFlags
@@ -38,7 +43,7 @@ func Init(c *GlobalFlags) {
 
 // ConfigureGlobalFlags initializes the global config.
 // based on the provided cli context.
-func ConfigureGlobalFlags(ctx *cli.Context) {
+func ConfigureGlobalFlags(ctx *cli.Context) error {
 	cfg := &GlobalFlags{}
 
 	if ctx.Bool(SubscribeToAllSubnets.Name) {
@@ -51,6 +56,18 @@ func ConfigureGlobalFlags(ctx *cli.Context) {
 		cfg.SubscribeAllDataSubnets = true
 	}
 
+	// State-diff-exponents
+	cfg.StateDiffExponents = ctx.IntSlice(StateDiffExponents.Name)
+	if features.Get().EnableStateDiff {
+		if err := validateStateDiffExponents(cfg.StateDiffExponents); err != nil {
+			return err
+		}
+	} else {
+		if ctx.IsSet(StateDiffExponents.Name) {
+			log.Warn("--state-diff-exponents is set but --enable-state-diff is not; the value will be ignored.")
+		}
+	}
+
 	cfg.BlockBatchLimit = ctx.Int(BlockBatchLimit.Name)
 	cfg.BlockBatchLimitBurstFactor = ctx.Int(BlockBatchLimitBurstFactor.Name)
 	cfg.BlobBatchLimit = ctx.Int(BlobBatchLimit.Name)
@@ -63,6 +80,7 @@ func ConfigureGlobalFlags(ctx *cli.Context) {
 	configureMinimumPeers(ctx, cfg)
 
 	Init(cfg)
+	return nil
 }
 
 // MaxDialIsActive checks if the user has enabled the max dial flag.
@@ -78,3 +96,26 @@ func configureMinimumPeers(ctx *cli.Context, cfg *GlobalFlags) {
 		cfg.MinimumSyncPeers = maxPeers
 	}
 }
+
+// validateStateDiffExponents validates the provided exponents for state diffs with these constraints in mind:
+//   - Must contain between 1 and 15 values.
+//   - Exponents must be in strictly decreasing order.
+//   - Every exponent must be <= 30. (2^30 slots is more than 300 years at 12s slots)
+//   - The last (smallest) exponent must be >= 5. (This ensures diffs are at least 1 epoch apart)
+func validateStateDiffExponents(exponents []int) error {
+	length := len(exponents)
+	if length == 0 || length > 15 {
+		return errors.New("state diff exponents must contain between 1 and 15 values")
+	}
+	if exponents[length-1] < 5 {
+		return errors.New("the last state diff exponent must be at least 5")
+	}
+	prev := maxStateDiffExponents + 1
+	for _, exp := range exponents {
+		if exp >= prev {
+			return errors.New("state diff exponents must be in strictly decreasing order, and each exponent must be <= 30")
+		}
+		prev = exp
+	}
+	return nil
+}

cmd/beacon-chain/flags/config_test.go

@@ -0,0 +1,39 @@
+package flags
+
+import (
+	"strconv"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v7/testing/require"
+)
+
+func TestValidateStateDiffExponents(t *testing.T) {
+	tests := []struct {
+		exponents []int
+		wantErr   bool
+		errMsg    string
+	}{
+		{exponents: []int{0, 1, 2}, wantErr: true, errMsg: "at least 5"},
+		{exponents: []int{1, 2, 3}, wantErr: true, errMsg: "at least 5"},
+		{exponents: []int{9, 8, 4}, wantErr: true, errMsg: "at least 5"},
+		{exponents: []int{3, 4, 5}, wantErr: true, errMsg: "decreasing"},
+		{exponents: []int{15, 14, 14, 12, 11}, wantErr: true, errMsg: "decreasing"},
+		{exponents: []int{15, 14, 13, 12, 11}, wantErr: false},
+		{exponents: []int{21, 18, 16, 13, 11, 9, 5}, wantErr: false},
+		{exponents: []int{30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 18, 16, 13, 11, 9, 5}, wantErr: true, errMsg: "between 1 and 15 values"},
+		{exponents: []int{}, wantErr: true, errMsg: "between 1 and 15 values"},
+		{exponents: []int{30, 18, 16, 13, 11, 9, 5}, wantErr: false},
+		{exponents: []int{31, 18, 16, 13, 11, 9, 5}, wantErr: true, errMsg: "<= 30"},
+	}
+
+	for i, tt := range tests {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			err := validateStateDiffExponents(tt.exponents)
+			if tt.wantErr {
+				require.ErrorContains(t, tt.errMsg, err)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}