defer payload attribute computation (#14644)

* defer payload attribute computation

* fire payload event on skipped slots

* changelog

* fix test and missing version attr

* fix lint

* deepsource

* mv head block lookup for missed slots to streamer

---------

Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>

consensus-types/payload-attribute/BUILD.bazel

@@ -10,8 +10,12 @@ go_library(
     importpath = "github.com/prysmaticlabs/prysm/v5/consensus-types/payload-attribute",
     visibility = ["//visibility:public"],
     deps = [
+        "//beacon-chain/state:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//consensus-types:go_default_library",
         "//consensus-types/blocks:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
+        "//consensus-types/primitives:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//runtime/version:go_default_library",
         "@com_github_pkg_errors//:go_default_library",

consensus-types/payload-attribute/getters.go

@@ -38,6 +38,16 @@ func (a *data) Withdrawals() ([]*enginev1.Withdrawal, error) {
 	return a.withdrawals, nil
 }
 
+func (a *data) ParentBeaconBlockRoot() ([]byte, error) {
+	if len(a.parentBeaconBlockRoot) == 0 {
+		return nil, errNoParentRoot
+	}
+	if a.version < version.Deneb {
+		return nil, consensus_types.ErrNotSupported("ParentBeaconBlockRoot", a.version)
+	}
+	return a.parentBeaconBlockRoot, nil
+}
+
 // PbV1 returns the payload attribute in version 1.
 func (a *data) PbV1() (*enginev1.PayloadAttributes, error) {
 	if a == nil {
@@ -97,6 +107,9 @@ func (a *data) PbV3() (*enginev1.PayloadAttributesV3, error) {
 
 // IsEmpty returns whether the given payload attribute is empty
 func (a *data) IsEmpty() bool {
+	if a == nil {
+		return true
+	}
 	if len(a.PrevRandao()) != 0 {
 		return false
 	}

consensus-types/payload-attribute/interface.go

@@ -10,6 +10,7 @@ type Attributer interface {
 	Timestamp() uint64
 	SuggestedFeeRecipient() []byte
 	Withdrawals() ([]*enginev1.Withdrawal, error)
+	ParentBeaconBlockRoot() ([]byte, error)
 	PbV1() (*enginev1.PayloadAttributes, error)
 	PbV2() (*enginev1.PayloadAttributesV2, error)
 	PbV3() (*enginev1.PayloadAttributesV3, error)

consensus-types/payload-attribute/types.go

@@ -2,7 +2,11 @@ package payloadattribute
 
 import (
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	field_params "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 )
@@ -23,6 +27,7 @@ type data struct {
 var (
 	errNilPayloadAttribute         = errors.New("received nil payload attribute")
 	errUnsupportedPayloadAttribute = errors.New("unsupported payload attribute")
+	errNoParentRoot                = errors.New("parent root is empty")
 )
 
 // New returns a new payload attribute with the given input object.
@@ -89,3 +94,16 @@ func initPayloadAttributeFromV3(a *enginev1.PayloadAttributesV3) (Attributer, er
 		parentBeaconBlockRoot: a.ParentBeaconBlockRoot,
 	}, nil
 }
+
+// EventData holds the values for a PayloadAttributes event.
+type EventData struct {
+	ProposerIndex     primitives.ValidatorIndex
+	ProposalSlot      primitives.Slot
+	ParentBlockNumber uint64
+	ParentBlockRoot   []byte
+	ParentBlockHash   []byte
+	Attributer        Attributer
+	HeadState         state.BeaconState
+	HeadBlock         interfaces.ReadOnlySignedBeaconBlock
+	HeadRoot          [field_params.RootLength]byte
+}