From b9a9689aae1d366dc0071131b7bbe6d91fb7d2aa Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Wed, 18 Sep 2024 10:35:29 +0100
Subject: [PATCH] [PERF] Chunk encoding: simplify writeByte

Rather than append a zero then set the value at that position, append the value.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
---
 tsdb/chunkenc/bstream.go | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tsdb/chunkenc/bstream.go b/tsdb/chunkenc/bstream.go
index f9668c68c..6e01798f7 100644
--- a/tsdb/chunkenc/bstream.go
+++ b/tsdb/chunkenc/bstream.go
@@ -95,10 +95,8 @@ func (b *bstream) writeByte(byt byte) {
 	// Complete the last byte with the leftmost b.count bits from byt.
 	b.stream[i] |= byt >> (8 - b.count)
 
-	b.stream = append(b.stream, 0)
-	i++
 	// Write the remainder, if any.
-	b.stream[i] = byt << b.count
+	b.stream = append(b.stream, byt<<b.count)
 }
 
 // writeBits writes the nbits right-most bits of u to the stream