From b5bc478a38b045c4616f38231a69ce90e8aff044 Mon Sep 17 00:00:00 2001
From: Mikhail Bezoyan <mbezoyan@twitter.com>
Date: Mon, 30 Sep 2024 08:29:16 +0000
Subject: [PATCH] [util-core] Avoid unnecessary allocations in
 ByteArray.extract

Unapply in pattern matching creates a tuple and unnecessarily boxes integers. Rewriting it in a more imperative style for efficiency.

Differential Revision: https://phabricator.twitter.biz/D1173579
---
 util-core/src/main/scala/com/twitter/io/Buf.scala | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/util-core/src/main/scala/com/twitter/io/Buf.scala b/util-core/src/main/scala/com/twitter/io/Buf.scala
index f942c6b09d..051de125da 100644
--- a/util-core/src/main/scala/com/twitter/io/Buf.scala
+++ b/util-core/src/main/scala/com/twitter/io/Buf.scala
@@ -778,13 +778,15 @@ object Buf {
        *
        * A copy may be performed if necessary.
        */
-      def extract(buf: Buf): Array[Byte] = Buf.ByteArray.coerce(buf) match {
-        case Buf.ByteArray.Owned(bytes, 0, end) if end == bytes.length =>
-          bytes
-        case Buf.ByteArray.Shared(bytes) =>
+      def extract(buf: Buf): Array[Byte] = {
+        val byteArray = Buf.ByteArray.coerce(buf)
+        if (byteArray.begin == 0 && byteArray.end == byteArray.bytes.length) {
+          byteArray.bytes
+        } else {
           // If the unsafe version included offsets, we need to create a new array
           // containing only the relevant bytes.
-          bytes
+          byteArray.copiedByteArray
+        }
       }
     }