[esp32_ble_server][esp32_improv] Eliminate unnecessary heap allocations (#11569)

esphome/components/esp32_ble_server/__init__.py

@@ -461,7 +461,9 @@ async def parse_value(value_config, args):
     if isinstance(value, str):
         value = list(value.encode(value_config[CONF_STRING_ENCODING]))
     if isinstance(value, list):
-        return cg.std_vector.template(cg.uint8)(value)
+        # Generate initializer list {1, 2, 3} instead of std::vector<uint8_t>({1, 2, 3})
+        # This calls the set_value(std::initializer_list<uint8_t>) overload
+        return cg.ArrayInitializer(*value)
     val = cg.RawExpression(f"{value_config[CONF_TYPE]}({cg.safe_exp(value)})")
     return ByteBuffer_ns.wrap(val, value_config[CONF_ENDIANNESS])
 

esphome/components/esp32_ble_server/ble_characteristic.cpp

@@ -35,13 +35,18 @@ BLECharacteristic::BLECharacteristic(const ESPBTUUID uuid, uint32_t properties)
 
 void BLECharacteristic::set_value(ByteBuffer buffer) { this->set_value(buffer.get_data()); }
 
-void BLECharacteristic::set_value(const std::vector<uint8_t> &buffer) {
+void BLECharacteristic::set_value(std::vector<uint8_t> &&buffer) {
   xSemaphoreTake(this->set_value_lock_, 0L);
-  this->value_ = buffer;
+  this->value_ = std::move(buffer);
   xSemaphoreGive(this->set_value_lock_);
 }
+
+void BLECharacteristic::set_value(std::initializer_list<uint8_t> data) {
+  this->set_value(std::vector<uint8_t>(data));  // Delegate to move overload
+}
+
 void BLECharacteristic::set_value(const std::string &buffer) {
-  this->set_value(std::vector<uint8_t>(buffer.begin(), buffer.end()));
+  this->set_value(std::vector<uint8_t>(buffer.begin(), buffer.end()));  // Delegate to move overload
 }
 
 void BLECharacteristic::notify() {

esphome/components/esp32_ble_server/ble_characteristic.h

@@ -33,7 +33,8 @@ class BLECharacteristic {
   ~BLECharacteristic();
 
   void set_value(ByteBuffer buffer);
-  void set_value(const std::vector<uint8_t> &buffer);
+  void set_value(std::vector<uint8_t> &&buffer);
+  void set_value(std::initializer_list<uint8_t> data);
   void set_value(const std::string &buffer);
 
   void set_broadcast_property(bool value);

esphome/components/esp32_ble_server/ble_descriptor.cpp

@@ -46,15 +46,17 @@ void BLEDescriptor::do_create(BLECharacteristic *characteristic) {
   this->state_ = CREATING;
 }
 
-void BLEDescriptor::set_value(std::vector<uint8_t> buffer) {
+void BLEDescriptor::set_value(std::vector<uint8_t> &&buffer) { this->set_value_impl_(buffer.data(), buffer.size()); }
-  size_t length = buffer.size();
 
+void BLEDescriptor::set_value(std::initializer_list<uint8_t> data) { this->set_value_impl_(data.begin(), data.size()); }
+
+void BLEDescriptor::set_value_impl_(const uint8_t *data, size_t length) {
   if (length > this->value_.attr_max_len) {
     ESP_LOGE(TAG, "Size %d too large, must be no bigger than %d", length, this->value_.attr_max_len);
     return;
   }
   this->value_.attr_len = length;
-  memcpy(this->value_.attr_value, buffer.data(), length);
+  memcpy(this->value_.attr_value, data, length);
 }
 
 void BLEDescriptor::gatts_event_handler(esp_gatts_cb_event_t event, esp_gatt_if_t gatts_if,

esphome/components/esp32_ble_server/ble_descriptor.h

@@ -27,7 +27,8 @@ class BLEDescriptor {
   void do_create(BLECharacteristic *characteristic);
   ESPBTUUID get_uuid() const { return this->uuid_; }
 
-  void set_value(std::vector<uint8_t> buffer);
+  void set_value(std::vector<uint8_t> &&buffer);
+  void set_value(std::initializer_list<uint8_t> data);
   void set_value(ByteBuffer buffer) { this->set_value(buffer.get_data()); }
 
   void gatts_event_handler(esp_gatts_cb_event_t event, esp_gatt_if_t gatts_if, esp_ble_gatts_cb_param_t *param);
@@ -42,6 +43,8 @@ class BLEDescriptor {
   }
 
  protected:
+  void set_value_impl_(const uint8_t *data, size_t length);
+
   BLECharacteristic *characteristic_{nullptr};
   ESPBTUUID uuid_;
   uint16_t handle_{0xFFFF};

esphome/components/esp32_improv/esp32_improv_component.cpp

@@ -270,8 +270,8 @@ void ESP32ImprovComponent::set_error_(improv::Error error) {
   }
 }
 
-void ESP32ImprovComponent::send_response_(std::vector<uint8_t> &response) {
+void ESP32ImprovComponent::send_response_(std::vector<uint8_t> &&response) {
-  this->rpc_response_->set_value(ByteBuffer::wrap(response));
+  this->rpc_response_->set_value(std::move(response));
   if (this->state_ != improv::STATE_STOPPED)
     this->rpc_response_->notify();
 }
@@ -409,10 +409,8 @@ void ESP32ImprovComponent::check_wifi_connection_() {
       }
     }
 #endif
-    // Pass to build_rpc_response using vector constructor from iterators to avoid extra copies
+    this->send_response_(improv::build_rpc_response(improv::WIFI_SETTINGS,
-    std::vector<uint8_t> data = improv::build_rpc_response(
+                                                    std::vector<std::string>(url_strings, url_strings + url_count)));
-        improv::WIFI_SETTINGS, std::vector<std::string>(url_strings, url_strings + url_count));
-    this->send_response_(data);
   } else if (this->is_active() && this->state_ != improv::STATE_PROVISIONED) {
     ESP_LOGD(TAG, "WiFi provisioned externally");
   }

esphome/components/esp32_improv/esp32_improv_component.h

@@ -109,7 +109,7 @@ class ESP32ImprovComponent : public Component, public improv_base::ImprovBase {
   void set_state_(improv::State state, bool update_advertising = true);
   void set_error_(improv::Error error);
   improv::State get_initial_state_() const;
-  void send_response_(std::vector<uint8_t> &response);
+  void send_response_(std::vector<uint8_t> &&response);
   void process_incoming_data_();
   void on_wifi_connect_timeout_();
   void check_wifi_connection_();