[esp32_ble_server] Optimize manufacturer_data storage to reduce memory overhead

esphome/components/esp32_ble/ble.cpp

@@ -68,6 +68,10 @@ void ESP32BLE::advertising_set_service_data(const std::vector<uint8_t> &data) {
 }
 
 void ESP32BLE::advertising_set_manufacturer_data(const std::vector<uint8_t> &data) {
+  this->advertising_set_manufacturer_data(std::span<const uint8_t>(data));
+}
+
+void ESP32BLE::advertising_set_manufacturer_data(std::span<const uint8_t> data) {
   this->advertising_init_();
   this->advertising_->set_manufacturer_data(data);
   this->advertising_start();

esphome/components/esp32_ble/ble.h

@@ -118,6 +118,7 @@ class ESP32BLE : public Component {
   void advertising_start();
   void advertising_set_service_data(const std::vector<uint8_t> &data);
   void advertising_set_manufacturer_data(const std::vector<uint8_t> &data);
+  void advertising_set_manufacturer_data(std::span<const uint8_t> data);
   void advertising_set_appearance(uint16_t appearance) { this->appearance_ = appearance; }
   void advertising_set_service_data_and_name(std::span<const uint8_t> data, bool include_name);
   void advertising_add_service_uuid(ESPBTUUID uuid);

esphome/components/esp32_ble/ble_advertising.cpp

@@ -59,6 +59,10 @@ void BLEAdvertising::set_service_data(const std::vector<uint8_t> &data) {
 }
 
 void BLEAdvertising::set_manufacturer_data(const std::vector<uint8_t> &data) {
+  this->set_manufacturer_data(std::span<const uint8_t>(data));
+}
+
+void BLEAdvertising::set_manufacturer_data(std::span<const uint8_t> data) {
   delete[] this->advertising_data_.p_manufacturer_data;
   this->advertising_data_.p_manufacturer_data = nullptr;
   this->advertising_data_.manufacturer_len = data.size();

esphome/components/esp32_ble/ble_advertising.h

@@ -35,6 +35,7 @@ class BLEAdvertising {
   void set_scan_response(bool scan_response) { this->scan_response_ = scan_response; }
   void set_min_preferred_interval(uint16_t interval) { this->advertising_data_.min_interval = interval; }
   void set_manufacturer_data(const std::vector<uint8_t> &data);
+  void set_manufacturer_data(std::span<const uint8_t> data);
   void set_appearance(uint16_t appearance) { this->advertising_data_.appearance = appearance; }
   void set_service_data(const std::vector<uint8_t> &data);
   void set_service_data(std::span<const uint8_t> data);

esphome/components/esp32_ble_server/ble_server.cpp

@@ -99,7 +99,8 @@ bool BLEServer::can_proceed() { return this->is_running() || !this->parent_->is_
 
 void BLEServer::restart_advertising_() {
   if (this->is_running()) {
-    this->parent_->advertising_set_manufacturer_data(this->manufacturer_data_);
+    this->parent_->advertising_set_manufacturer_data(
+        std::span<const uint8_t>(this->manufacturer_data_.get(), this->manufacturer_data_length_));
   }
 }
 

esphome/components/esp32_ble_server/ble_server.h

@@ -35,7 +35,11 @@ class BLEServer : public Component, public GATTsEventHandler, public BLEStatusEv
   bool is_running();
 
   void set_manufacturer_data(const std::vector<uint8_t> &data) {
-    this->manufacturer_data_ = data;
+    this->manufacturer_data_length_ = data.size();
+    this->manufacturer_data_.reset(data.empty() ? nullptr : new uint8_t[data.size()]);
+    if (!data.empty()) {
+      memcpy(this->manufacturer_data_.get(), data.data(), data.size());
+    }
     this->restart_advertising_();
   }
 
@@ -87,24 +91,27 @@ class BLEServer : public Component, public GATTsEventHandler, public BLEStatusEv
   void remove_client_(uint16_t conn_id);
   void dispatch_callbacks_(CallbackType type, uint16_t conn_id);
 
+  // 4-byte aligned (pointers and vectors on 32-bit)
   std::vector<CallbackEntry> callbacks_;
-
-  std::vector<uint8_t> manufacturer_data_{};
-  esp_gatt_if_t gatts_if_{0};
-  bool registered_{false};
-
-  uint16_t clients_[USE_ESP32_BLE_MAX_CONNECTIONS]{};
-  uint8_t client_count_{0};
   std::vector<ServiceEntry> services_{};
   std::vector<BLEService *> services_to_start_{};
+  std::unique_ptr<uint8_t[]> manufacturer_data_{};
   BLEService *device_information_service_{};
 
+  // 2-byte aligned
+  uint16_t clients_[USE_ESP32_BLE_MAX_CONNECTIONS]{};
+
+  // 1-byte aligned
+  uint8_t manufacturer_data_length_{0};
+  uint8_t client_count_{0};
+  esp_gatt_if_t gatts_if_{0};
   enum State : uint8_t {
     INIT = 0x00,
     REGISTERING,
     STARTING_SERVICE,
     RUNNING,
   } state_{INIT};
+  bool registered_{false};
 };
 
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)