[api] Optimize APINoiseContext memory usage by removing shared_ptr overhead

esphome/components/api/api_connection.cpp

@@ -90,8 +90,8 @@ static const int CAMERA_STOP_STREAM = 5000;
 APIConnection::APIConnection(std::unique_ptr<socket::Socket> sock, APIServer *parent)
     : parent_(parent), initial_state_iterator_(this), list_entities_iterator_(this) {
 #if defined(USE_API_PLAINTEXT) && defined(USE_API_NOISE)
-  auto noise_ctx = parent->get_noise_ctx();
+  auto &noise_ctx = parent->get_noise_ctx();
-  if (noise_ctx->has_psk()) {
+  if (noise_ctx.has_psk()) {
     this->helper_ =
         std::unique_ptr<APIFrameHelper>{new APINoiseFrameHelper(std::move(sock), noise_ctx, &this->client_info_)};
   } else {

esphome/components/api/api_frame_helper_noise.cpp

@@ -527,7 +527,7 @@ APIError APINoiseFrameHelper::init_handshake_() {
   if (aerr != APIError::OK)
     return aerr;
 
-  const auto &psk = ctx_->get_psk();
+  const auto &psk = this->ctx_.get_psk();
   err = noise_handshakestate_set_pre_shared_key(handshake_, psk.data(), psk.size());
   aerr = handle_noise_error_(err, LOG_STR("noise_handshakestate_set_pre_shared_key"),
                              APIError::HANDSHAKESTATE_SETUP_FAILED);

esphome/components/api/api_frame_helper_noise.h

@@ -9,9 +9,8 @@ namespace esphome::api {
 
 class APINoiseFrameHelper final : public APIFrameHelper {
  public:
-  APINoiseFrameHelper(std::unique_ptr<socket::Socket> socket, std::shared_ptr<APINoiseContext> ctx,
+  APINoiseFrameHelper(std::unique_ptr<socket::Socket> socket, APINoiseContext &ctx, const ClientInfo *client_info)
-                      const ClientInfo *client_info)
+      : APIFrameHelper(std::move(socket), client_info), ctx_(ctx) {
-      : APIFrameHelper(std::move(socket), client_info), ctx_(std::move(ctx)) {
     // Noise header structure:
     // Pos 0: indicator (0x01)
     // Pos 1-2: encrypted payload size (16-bit big-endian)
@@ -41,8 +40,8 @@ class APINoiseFrameHelper final : public APIFrameHelper {
   NoiseCipherState *send_cipher_{nullptr};
   NoiseCipherState *recv_cipher_{nullptr};
 
-  // Shared pointer (8 bytes on 32-bit = 4 bytes control block pointer + 4 bytes object pointer)
+  // Reference to noise context (4 bytes on 32-bit)
-  std::shared_ptr<APINoiseContext> ctx_;
+  APINoiseContext &ctx_;
 
   // Vector (12 bytes on 32-bit)
   std::vector<uint8_t> prologue_;

esphome/components/api/api_server.cpp

@@ -227,8 +227,8 @@ void APIServer::dump_config() {
                 "  Max connections: %u",
                 network::get_use_address(), this->port_, this->listen_backlog_, this->max_connections_);
 #ifdef USE_API_NOISE
-  ESP_LOGCONFIG(TAG, "  Noise encryption: %s", YESNO(this->noise_ctx_->has_psk()));
+  ESP_LOGCONFIG(TAG, "  Noise encryption: %s", YESNO(this->noise_ctx_.has_psk()));
-  if (!this->noise_ctx_->has_psk()) {
+  if (!this->noise_ctx_.has_psk()) {
     ESP_LOGCONFIG(TAG, "  Supports encryption: YES");
   }
 #else
@@ -493,7 +493,7 @@ bool APIServer::save_noise_psk(psk_t psk, bool make_active) {
   ESP_LOGW(TAG, "Key set in YAML");
   return false;
 #else
-  auto &old_psk = this->noise_ctx_->get_psk();
+  auto &old_psk = this->noise_ctx_.get_psk();
   if (std::equal(old_psk.begin(), old_psk.end(), psk.begin())) {
     ESP_LOGW(TAG, "New PSK matches old");
     return true;

esphome/components/api/api_server.h

@@ -54,8 +54,8 @@ class APIServer : public Component, public Controller {
 #ifdef USE_API_NOISE
   bool save_noise_psk(psk_t psk, bool make_active = true);
   bool clear_noise_psk(bool make_active = true);
-  void set_noise_psk(psk_t psk) { noise_ctx_->set_psk(psk); }
+  void set_noise_psk(psk_t psk) { this->noise_ctx_.set_psk(psk); }
-  std::shared_ptr<APINoiseContext> get_noise_ctx() { return noise_ctx_; }
+  APINoiseContext &get_noise_ctx() { return this->noise_ctx_; }
 #endif  // USE_API_NOISE
 
   void handle_disconnect(APIConnection *conn);
@@ -228,7 +228,7 @@ class APIServer : public Component, public Controller {
   // 7 bytes used, 1 byte padding
 
 #ifdef USE_API_NOISE
-  std::shared_ptr<APINoiseContext> noise_ctx_ = std::make_shared<APINoiseContext>();
+  APINoiseContext noise_ctx_;
   ESPPreferenceObject noise_pref_;
 #endif  // USE_API_NOISE
 };

esphome/components/mdns/mdns_component.cpp

@@ -119,7 +119,7 @@ void MDNSComponent::compile_records_(StaticVector<MDNSService, MDNS_SERVICE_COUN
     MDNS_STATIC_CONST_CHAR(TXT_API_ENCRYPTION, "api_encryption");
     MDNS_STATIC_CONST_CHAR(TXT_API_ENCRYPTION_SUPPORTED, "api_encryption_supported");
     MDNS_STATIC_CONST_CHAR(NOISE_ENCRYPTION, "Noise_NNpsk0_25519_ChaChaPoly_SHA256");
-    bool has_psk = api::global_api_server->get_noise_ctx()->has_psk();
+    bool has_psk = api::global_api_server->get_noise_ctx().has_psk();
     const char *encryption_key = has_psk ? TXT_API_ENCRYPTION : TXT_API_ENCRYPTION_SUPPORTED;
     txt_records.push_back({MDNS_STR(encryption_key), MDNS_STR(NOISE_ENCRYPTION)});
 #endif

esphome/components/mqtt/mqtt_client.cpp

@@ -140,7 +140,7 @@ void MQTTClientComponent::send_device_info_() {
 #endif
 
 #ifdef USE_API_NOISE
-        root[api::global_api_server->get_noise_ctx()->has_psk() ? "api_encryption" : "api_encryption_supported"] =
+        root[api::global_api_server->get_noise_ctx().has_psk() ? "api_encryption" : "api_encryption_supported"] =
             "Noise_NNpsk0_25519_ChaChaPoly_SHA256";
 #endif
       },