From c5af298bc2f3a62cc7794e16ab4084e17c8259da Mon Sep 17 00:00:00 2001
From: axelKingsley <axel.kingsley@gmail.com>
Date: Thu, 26 Sep 2024 14:41:36 -0500
Subject: [PATCH] refactor Pointer method on iterator

---
 .../supervisor/backend/db/logs/iterator.go          |  7 ++++---
 op-supervisor/supervisor/backend/db/logs/state.go   | 13 +++++++++----
 op-supervisor/supervisor/backend/safety/views.go    | 12 +-----------
 3 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/op-supervisor/supervisor/backend/db/logs/iterator.go b/op-supervisor/supervisor/backend/db/logs/iterator.go
index 8cac703df217..f9e65c41e890 100644
--- a/op-supervisor/supervisor/backend/db/logs/iterator.go
+++ b/op-supervisor/supervisor/backend/db/logs/iterator.go
@@ -8,12 +8,13 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 
 	"github.com/ethereum-optimism/optimism/op-supervisor/supervisor/backend/db/entrydb"
+	"github.com/ethereum-optimism/optimism/op-supervisor/supervisor/backend/db/heads"
 	"github.com/ethereum-optimism/optimism/op-supervisor/supervisor/types"
 )
 
 type IteratorState interface {
 	NextIndex() entrydb.EntryIdx
-	Pointer() (hash common.Hash, num uint64, timestamp uint64, logsSince uint32, ok bool)
+	HeadPointer() (heads.HeadPointer, error)
 	SealedBlock() (hash common.Hash, num uint64, ok bool)
 	InitMessage() (hash common.Hash, logIndex uint32, ok bool)
 	ExecMessage() *types.ExecutingMessage
@@ -166,6 +167,6 @@ func (i *iterator) ExecMessage() *types.ExecutingMessage {
 	return i.current.ExecMessage()
 }
 
-func (i *iterator) Pointer() (hash common.Hash, num uint64, timestamp uint64, logsSince uint32, ok bool) {
-	return i.current.Pointer()
+func (i *iterator) HeadPointer() (heads.HeadPointer, error) {
+	return i.current.HeadPointer()
 }
diff --git a/op-supervisor/supervisor/backend/db/logs/state.go b/op-supervisor/supervisor/backend/db/logs/state.go
index 8937ca683851..df63f96e3599 100644
--- a/op-supervisor/supervisor/backend/db/logs/state.go
+++ b/op-supervisor/supervisor/backend/db/logs/state.go
@@ -9,6 +9,7 @@ import (
 
 	"github.com/ethereum-optimism/optimism/op-service/eth"
 	"github.com/ethereum-optimism/optimism/op-supervisor/supervisor/backend/db/entrydb"
+	"github.com/ethereum-optimism/optimism/op-supervisor/supervisor/backend/db/heads"
 	"github.com/ethereum-optimism/optimism/op-supervisor/supervisor/types"
 )
 
@@ -126,12 +127,16 @@ func (l *logContext) ExecMessage() *types.ExecutingMessage {
 	return nil
 }
 
-func (l *logContext) Pointer() (hash common.Hash, num uint64, timestamp uint64, logsSince uint32, ok bool) {
+func (l *logContext) HeadPointer() (heads.HeadPointer, error) {
 	if l.need != 0 {
-		ok = false
-		return
+		return heads.HeadPointer{}, errors.New("cannot provide head pointer while state is incomplete")
 	}
-	return l.blockHash, l.blockNum, l.timestamp, l.logsSince, true
+	return heads.HeadPointer{
+		LastSealedBlockHash: l.blockHash,
+		LastSealedBlockNum:  l.blockNum,
+		LastSealedTimestamp: l.timestamp,
+		LogsSince:           l.logsSince,
+	}, nil
 }
 
 // ApplyEntry applies an entry on top of the current state.
diff --git a/op-supervisor/supervisor/backend/safety/views.go b/op-supervisor/supervisor/backend/safety/views.go
index 6f14da84afeb..cdaabf614602 100644
--- a/op-supervisor/supervisor/backend/safety/views.go
+++ b/op-supervisor/supervisor/backend/safety/views.go
@@ -2,7 +2,6 @@ package safety
 
 import (
 	"errors"
-	"fmt"
 
 	"github.com/ethereum-optimism/optimism/op-service/eth"
 	"github.com/ethereum-optimism/optimism/op-supervisor/supervisor/backend/db/heads"
@@ -22,16 +21,7 @@ type View struct {
 }
 
 func (vi *View) Cross() (heads.HeadPointer, error) {
-	parentHash, parentNum, timestamp, logsSince, ok := vi.iter.Pointer()
-	if !ok {
-		return heads.HeadPointer{}, fmt.Errorf("no db content yet: %w", logs.ErrFuture)
-	}
-	return heads.HeadPointer{
-		LastSealedBlockHash: parentHash,
-		LastSealedBlockNum:  parentNum,
-		LastSealedTimestamp: timestamp,
-		LogsSince:           logsSince,
-	}, nil
+	return vi.iter.HeadPointer()
 }
 
 func (vi *View) Local() (heads.HeadPointer, error) {