From 610d0be5ed9ac5438ebc82c46ee8bc71502051e5 Mon Sep 17 00:00:00 2001
From: Tristan Wilson <twilson@offchainlabs.com>
Date: Wed, 28 Feb 2024 13:25:51 -0800
Subject: [PATCH] Simplify impl of batch type switching logic

The ring buffer was not necessary, a simple counter will suffice to
implement the same logic.
---
 arbnode/batch_poster.go      | 14 ++++----
 arbnode/batch_poster_test.go | 70 ------------------------------------
 2 files changed, 8 insertions(+), 76 deletions(-)
 delete mode 100644 arbnode/batch_poster_test.go

diff --git a/arbnode/batch_poster.go b/arbnode/batch_poster.go
index 40d51e0192..bb5b05d1e4 100644
--- a/arbnode/batch_poster.go
+++ b/arbnode/batch_poster.go
@@ -91,7 +91,7 @@ type BatchPoster struct {
 	dataPoster         *dataposter.DataPoster
 	redisLock          *redislock.Simple
 	messagesPerBatch   *arbmath.MovingAverage[uint64]
-	batch4844History   *BoolRing
+	non4844BatchCount  int // Count of consecutive non-4844 batches posted
 	// This is an atomic variable that should only be accessed atomically.
 	// An estimate of the number of batches we want to post but haven't yet.
 	// This doesn't include batches which we don't want to post yet due to the L1 bounds.
@@ -311,7 +311,6 @@ func NewBatchPoster(ctx context.Context, opts *BatchPosterOpts) (*BatchPoster, e
 		bridgeAddr:         opts.DeployInfo.Bridge,
 		daWriter:           opts.DAWriter,
 		redisLock:          redisLock,
-		batch4844History:   NewBoolRing(16),
 	}
 	b.messagesPerBatch, err = arbmath.NewMovingAverage[uint64](20)
 	if err != nil {
@@ -976,9 +975,8 @@ func (b *BatchPoster) maybePostSequencerBatch(ctx context.Context) (bool, error)
 					// "address already reserved". This logic makes sure that, if there is a backlog,
 					// that enough non-4844 batches have been posted to fill a block before switching.
 					if backlog == 0 ||
-						b.batch4844History.Empty() ||
-						b.batch4844History.Peek() ||
-						b.batch4844History.All(false) {
+						b.non4844BatchCount == 0 ||
+						b.non4844BatchCount > 16 {
 						blobFeePerByte := eip4844.CalcBlobFee(eip4844.CalcExcessBlobGas(*latestHeader.ExcessBlobGas, *latestHeader.BlobGasUsed))
 						blobFeePerByte.Mul(blobFeePerByte, blobTxBlobGasPerBlob)
 						blobFeePerByte.Div(blobFeePerByte, usableBytesInBlob)
@@ -1225,7 +1223,11 @@ func (b *BatchPoster) maybePostSequencerBatch(ctx context.Context) (bool, error)
 	recentlyHitL1Bounds := time.Since(b.lastHitL1Bounds) < config.PollInterval*3
 	postedMessages := b.building.msgCount - batchPosition.MessageCount
 	b.messagesPerBatch.Update(uint64(postedMessages))
-	b.batch4844History.Update(b.building.use4844)
+	if b.building.use4844 {
+		b.non4844BatchCount = 0
+	} else {
+		b.non4844BatchCount++
+	}
 	unpostedMessages := msgCount - b.building.msgCount
 	messagesPerBatch := b.messagesPerBatch.Average()
 	if messagesPerBatch == 0 {
diff --git a/arbnode/batch_poster_test.go b/arbnode/batch_poster_test.go
deleted file mode 100644
index 15c9ae0c05..0000000000
--- a/arbnode/batch_poster_test.go
+++ /dev/null
@@ -1,70 +0,0 @@
-// Copyright 2024, Offchain Labs, Inc.
-// For license information, see https://github.com/nitro/blob/master/LICENSE
-
-package arbnode
-
-import "testing"
-
-func TestBoolRing(t *testing.T) {
-	b := NewBoolRing(3)
-	if !b.Empty() {
-		Fail(t, "not empty as expected")
-	}
-
-	b.Update(true)
-	if !b.Peek() {
-		Fail(t, "Peek returned wrong value")
-	}
-	if b.All(true) {
-		Fail(t, "All shouldn't be true if buffer is not full")
-	}
-
-	b.Update(true)
-	if !b.Peek() {
-		Fail(t, "Peek returned wrong value")
-	}
-	if b.All(true) {
-		Fail(t, "All shouldn't be true if buffer is not full")
-	}
-
-	b.Update(true)
-	if !b.Peek() {
-		Fail(t, "Peek returned wrong value")
-	}
-	if !b.All(true) {
-		Fail(t, "Buffer was full of true, All(true) should be true")
-	}
-
-	b.Update(false)
-	if b.Peek() {
-		Fail(t, "Peek returned wrong value")
-	}
-	if b.All(true) {
-		Fail(t, "Buffer is not full of true")
-	}
-
-	b.Update(true)
-	if !b.Peek() {
-		Fail(t, "Peek returned wrong value")
-	}
-	if b.All(true) {
-		Fail(t, "Buffer is not full of true")
-	}
-
-	b.Update(true)
-	if !b.Peek() {
-		Fail(t, "Peek returned wrong value")
-	}
-	if b.All(true) {
-		Fail(t, "Buffer is not full of true")
-	}
-
-	b.Update(true)
-	if !b.Peek() {
-		Fail(t, "Peek returned wrong value")
-	}
-	if !b.All(true) {
-		Fail(t, "Buffer was full of true, All(true) should be true")
-	}
-
-}