From 837dd46adffe2f6dbb4184f54b5a34b79acb8bec Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Fri, 27 Jun 2025 08:56:54 +0200
Subject: [PATCH] Reduce component_iterator memory usage (#9205)

---
 esphome/core/component_iterator.cpp | 2 +-
 esphome/core/component_iterator.h   | 6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/esphome/core/component_iterator.cpp b/esphome/core/component_iterator.cpp
index da593340c1..b06c964b7c 100644
--- a/esphome/core/component_iterator.cpp
+++ b/esphome/core/component_iterator.cpp
@@ -375,7 +375,7 @@ void ComponentIterator::advance() {
   }
 
   if (advance_platform) {
-    this->state_ = static_cast<IteratorState>(static_cast<uint32_t>(this->state_) + 1);
+    this->state_ = static_cast<IteratorState>(static_cast<uint8_t>(this->state_) + 1);
     this->at_ = 0;
   } else if (success) {
     this->at_++;
diff --git a/esphome/core/component_iterator.h b/esphome/core/component_iterator.h
index 9e187f6c57..4b41872db7 100644
--- a/esphome/core/component_iterator.h
+++ b/esphome/core/component_iterator.h
@@ -93,7 +93,9 @@ class ComponentIterator {
   virtual bool on_end();
 
  protected:
-  enum class IteratorState {
+  // Iterates over all ESPHome entities (sensors, switches, lights, etc.)
+  // Supports up to 256 entity types and up to 65,535 entities of each type
+  enum class IteratorState : uint8_t {
     NONE = 0,
     BEGIN,
 #ifdef USE_BINARY_SENSOR
@@ -167,7 +169,7 @@ class ComponentIterator {
 #endif
     MAX,
   } state_{IteratorState::NONE};
-  size_t at_{0};
+  uint16_t at_{0};  // Supports up to 65,535 entities per type
   bool include_internal_{false};
 };