From 25a68e9339e9cde478df7db195d6c40b6e59292c Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Sat, 7 Mar 2026 08:22:09 -1000
Subject: [PATCH] [api] Inline capacity check in ProtoByteBuffer::resize()

Avoid calling reserve() when capacity is already sufficient.
After warmup, resize() becomes just a compare + store with no
function call overhead on the hot path.
---
 esphome/components/api/proto.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/esphome/components/api/proto.h b/esphome/components/api/proto.h
index 48e5497e811..845c614e3cd 100644
--- a/esphome/components/api/proto.h
+++ b/esphome/components/api/proto.h
@@ -262,7 +262,8 @@ class ProtoByteBuffer {
     }
   }
   void resize(size_t n) {
-    this->reserve(n);
+    if (n > this->capacity_)
+      this->reserve(n);
     this->size_ = n;  // no zero-fill
   }
   uint8_t *data() { return this->data_.get(); }