Add Debug Forkchoice endpoint support

api/v1/forkchoice.go

@@ -0,0 +1,237 @@
+// Copyright © 2020, 2021 Attestant Limited.
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v1
+
+import (
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/attestantio/go-eth2-client/spec/phase0"
+	"github.com/pkg/errors"
+)
+
+// ForkChoice is the data regarding the node's current fork choice context.
+type ForkChoice struct {
+	// JustifiedCheckpoint is the current justified checkpoint.
+	JustifiedCheckpoint phase0.Checkpoint
+	// FInalizedCheckpoint is the current finalized checkpoint.
+	FinalizedCheckpoint phase0.Checkpoint
+	// ForkChoiceNodes contains the fork choice nodes.
+	ForkChoiceNodes []*ForkChoiceNode
+}
+
+// MarshalJSON implements json.Marshaler.
+func (f *ForkChoice) MarshalJSON() ([]byte, error) {
+	return json.Marshal(&forkChoiceJSON{
+		JustifiedCheckpoint: &f.JustifiedCheckpoint,
+		FinalizedCheckpoint: &f.FinalizedCheckpoint,
+		ForkChoiceNodes:     f.ForkChoiceNodes,
+	})
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (f *ForkChoice) UnmarshalJSON(input []byte) error {
+	var err error
+
+	var forkChoiceJSON forkChoiceJSON
+	if err = json.Unmarshal(input, &forkChoiceJSON); err != nil {
+		return errors.Wrap(err, "invalid JSON")
+	}
+
+	if forkChoiceJSON.JustifiedCheckpoint == nil {
+		return errors.New("justified checkpoint missing")
+	}
+	f.JustifiedCheckpoint = *forkChoiceJSON.JustifiedCheckpoint
+
+	if forkChoiceJSON.FinalizedCheckpoint == nil {
+		return errors.New("finalized checkpoint missing")
+	}
+	f.FinalizedCheckpoint = *forkChoiceJSON.FinalizedCheckpoint
+
+	if forkChoiceJSON.ForkChoiceNodes == nil {
+		return errors.New("fork choice nodes missing")
+	}
+	f.ForkChoiceNodes = forkChoiceJSON.ForkChoiceNodes
+
+	return nil
+}
+
+// String returns a string version of the structure.
+func (f *ForkChoice) String() string {
+	data, err := json.Marshal(f)
+	if err != nil {
+		return fmt.Sprintf("ERR: %v", err)
+	}
+	return string(data)
+}
+
+// forkChoiceJSON is the json representation of the struct.
+type forkChoiceJSON struct {
+	JustifiedCheckpoint *phase0.Checkpoint `json:"justified_checkpoint"`
+	FinalizedCheckpoint *phase0.Checkpoint `json:"finalized_checkpoint"`
+	ForkChoiceNodes     []*ForkChoiceNode  `json:"fork_choice_nodes"`
+}
+
+type ForkChoiceNodeValidity string
+
+const (
+	ForkChoiceNodeValidityInvalid    ForkChoiceNodeValidity = "INVALID"
+	ForkChoiceNodeValidityValid      ForkChoiceNodeValidity = "VALID"
+	ForkChoiceNodeValidityOptimistic ForkChoiceNodeValidity = "OPTIMISTIC"
+)
+
+func parseForkChoiceValidity(input string) (ForkChoiceNodeValidity, error) {
+	switch input {
+	case "INVALID":
+		return ForkChoiceNodeValidityInvalid, nil
+	case "VALID":
+		return ForkChoiceNodeValidityValid, nil
+	case "OPTIMISTIC":
+		return ForkChoiceNodeValidityOptimistic, nil
+	default:
+		return "", errors.New(fmt.Sprintf("invalid value for fork choice node validity: %s", input))
+	}
+}
+
+type ForkChoiceNode struct {
+	// Slot is the slot of the node.
+	Slot phase0.Slot
+	// BlockRoot is the block root of the node.
+	BlockRoot phase0.Root
+	// ParentRoot is the parent root of the node.
+	ParentRoot phase0.Root
+	// JustifiedEpcih is the justified epoch of the node.
+	JustifiedEpoch phase0.Epoch
+	// FinalizedEpoch is the finalized epoch of the node.
+	FinalizedEpoch phase0.Epoch
+	// Weight is the weight of the node.
+	Weight uint64
+	// Validity is the validity of the node.
+	Validity ForkChoiceNodeValidity
+	// ExecutiionBlockHash is the execution block hash of the node.
+	ExecutionBlockHash phase0.Root
+	// ExtraData is the extra data of the node.
+	ExtraData interface{}
+}
+
+// forkChoiceNodeJSON is the json representation of the struct.
+type forkChoiceNodeJSON struct {
+	Slot               string      `json:"slot"`
+	BlockRoot          string      `json:"block_root"`
+	ParentRoot         string      `json:"parent_root"`
+	JustifiedEpoch     string      `json:"justified_epoch"`
+	FinalizedEpoch     string      `json:"finalized_epoch"`
+	Weight             string      `json:"weight"`
+	Validity           string      `json:"validity"`
+	ExecutionBlockHash string      `json:"execution_block_hash"`
+	ExtraData          interface{} `json:"extra_data,omitempty"`
+}
+
+// MarshalJSON implements json.Marshaler.
+func (f *ForkChoiceNode) MarshalJSON() ([]byte, error) {
+	return json.Marshal(&forkChoiceNodeJSON{
+		Slot:               fmt.Sprintf("%d", f.Slot),
+		BlockRoot:          fmt.Sprintf("%#x", f.BlockRoot),
+		ParentRoot:         fmt.Sprintf("%#x", f.ParentRoot),
+		JustifiedEpoch:     fmt.Sprintf("%d", f.JustifiedEpoch),
+		FinalizedEpoch:     fmt.Sprintf("%d", f.FinalizedEpoch),
+		Weight:             fmt.Sprintf("%d", f.Weight),
+		Validity:           string(f.Validity),
+		ExecutionBlockHash: fmt.Sprintf("%#x", f.ExecutionBlockHash),
+		ExtraData:          f.ExtraData,
+	})
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (f *ForkChoiceNode) UnmarshalJSON(input []byte) error {
+	var err error
+
+	var forkChoiceNodeJSON forkChoiceNodeJSON
+	if err = json.Unmarshal(input, &forkChoiceNodeJSON); err != nil {
+		return errors.Wrap(err, "invalid JSON")
+	}
+
+	slot, err := strconv.ParseUint(forkChoiceNodeJSON.Slot, 10, 64)
+	if err != nil {
+		return errors.Wrap(err, fmt.Sprintf("invalid value for slot: %s", forkChoiceNodeJSON.Slot))
+	}
+	f.Slot = phase0.Slot(slot)
+
+	blockRoot, err := hex.DecodeString(strings.TrimPrefix(forkChoiceNodeJSON.BlockRoot, "0x"))
+	if err != nil {
+		return errors.Wrap(err, fmt.Sprintf("invalid value for block root: %s", forkChoiceNodeJSON.BlockRoot))
+	}
+	if len(blockRoot) != rootLength {
+		return fmt.Errorf("incorrect length %d for block root", len(blockRoot))
+	}
+	copy(f.BlockRoot[:], blockRoot)
+
+	parentRoot, err := hex.DecodeString(strings.TrimPrefix(forkChoiceNodeJSON.ParentRoot, "0x"))
+	if err != nil {
+		return errors.Wrap(err, fmt.Sprintf("invalid value for parent root: %s", forkChoiceNodeJSON.ParentRoot))
+	}
+	if len(parentRoot) != rootLength {
+		return fmt.Errorf("incorrect length %d for parent root", len(parentRoot))
+	}
+	copy(f.ParentRoot[:], parentRoot)
+
+	justifiedEpoch, err := strconv.ParseUint(forkChoiceNodeJSON.JustifiedEpoch, 10, 64)
+	if err != nil {
+		return errors.Wrap(err, fmt.Sprintf("invalid value for justified epoch: %s", forkChoiceNodeJSON.JustifiedEpoch))
+	}
+	f.JustifiedEpoch = phase0.Epoch(justifiedEpoch)
+
+	finalizedEpoch, err := strconv.ParseUint(forkChoiceNodeJSON.FinalizedEpoch, 10, 64)
+	if err != nil {
+		return errors.Wrap(err, fmt.Sprintf("invalid value for finalized epoch: %s", forkChoiceNodeJSON.FinalizedEpoch))
+	}
+	f.FinalizedEpoch = phase0.Epoch(finalizedEpoch)
+
+	weight, err := strconv.ParseUint(forkChoiceNodeJSON.Weight, 10, 64)
+	if err != nil {
+		return errors.Wrap(err, fmt.Sprintf("invalid value for weight: %s", forkChoiceNodeJSON.Weight))
+	}
+	f.Weight = weight
+
+	validity, err := parseForkChoiceValidity(forkChoiceNodeJSON.Validity)
+	if err != nil {
+		return errors.Wrap(err, fmt.Sprintf("invalid value for validity: %s", forkChoiceNodeJSON.Validity))
+	}
+	f.Validity = validity
+
+	executionBlockHash, err := hex.DecodeString(strings.TrimPrefix(forkChoiceNodeJSON.ExecutionBlockHash, "0x"))
+	if err != nil {
+		return errors.Wrap(err, fmt.Sprintf("invalid value for execution block hash: %s", forkChoiceNodeJSON.ExecutionBlockHash))
+	}
+	if len(executionBlockHash) != rootLength {
+		return fmt.Errorf("incorrect length %d for execution block hash", len(executionBlockHash))
+	}
+	copy(f.ExecutionBlockHash[:], executionBlockHash)
+
+	f.ExtraData = forkChoiceNodeJSON.ExtraData
+
+	return nil
+}
+
+// String returns a string version of the structure.
+func (f *ForkChoiceNode) String() string {
+	data, err := json.Marshal(f)
+	if err != nil {
+		return fmt.Sprintf("ERR: %v", err)
+	}
+	return string(data)
+}