[mqtt] Use StringRef to avoid string copies in discovery (#11731)

esphome/components/mqtt/mqtt_alarm_control_panel.cpp

@@ -36,7 +36,7 @@ void MQTTAlarmControlPanelComponent::setup() {
     } else if (strcasecmp(payload.c_str(), "TRIGGERED") == 0) {
       call.triggered();
     } else {
-      ESP_LOGW(TAG, "'%s': Received unknown command payload %s", this->friendly_name().c_str(), payload.c_str());
+      ESP_LOGW(TAG, "'%s': Received unknown command payload %s", this->friendly_name_().c_str(), payload.c_str());
     }
     call.perform();
   });

esphome/components/mqtt/mqtt_binary_sensor.cpp

@@ -30,9 +30,12 @@ MQTTBinarySensorComponent::MQTTBinarySensorComponent(binary_sensor::BinarySensor
 }
 
 void MQTTBinarySensorComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
-  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
+  // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-  if (!this->binary_sensor_->get_device_class().empty())
+  const auto device_class = this->binary_sensor_->get_device_class_ref();
-    root[MQTT_DEVICE_CLASS] = this->binary_sensor_->get_device_class();
+  if (!device_class.empty()) {
+    root[MQTT_DEVICE_CLASS] = device_class;
+  }
+  // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
   if (this->binary_sensor_->is_status_binary_sensor())
     root[MQTT_PAYLOAD_ON] = mqtt::global_mqtt_client->get_availability().payload_available;
   if (this->binary_sensor_->is_status_binary_sensor())

esphome/components/mqtt/mqtt_button.cpp

@@ -20,7 +20,7 @@ void MQTTButtonComponent::setup() {
     if (payload == "PRESS") {
       this->button_->press();
     } else {
-      ESP_LOGW(TAG, "'%s': Received unknown status payload: %s", this->friendly_name().c_str(), payload.c_str());
+      ESP_LOGW(TAG, "'%s': Received unknown status payload: %s", this->friendly_name_().c_str(), payload.c_str());
       this->status_momentary_warning("state", 5000);
     }
   });
@@ -33,8 +33,9 @@ void MQTTButtonComponent::dump_config() {
 void MQTTButtonComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   config.state_topic = false;
-  if (!this->button_->get_device_class().empty()) {
+  const auto device_class = this->button_->get_device_class_ref();
-    root[MQTT_DEVICE_CLASS] = this->button_->get_device_class();
+  if (!device_class.empty()) {
+    root[MQTT_DEVICE_CLASS] = device_class;
   }
   // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
 }

esphome/components/mqtt/mqtt_component.cpp

@@ -64,11 +64,11 @@ bool MQTTComponent::send_discovery_() {
   const MQTTDiscoveryInfo &discovery_info = global_mqtt_client->get_discovery_info();
 
   if (discovery_info.clean) {
-    ESP_LOGV(TAG, "'%s': Cleaning discovery", this->friendly_name().c_str());
+    ESP_LOGV(TAG, "'%s': Cleaning discovery", this->friendly_name_().c_str());
     return global_mqtt_client->publish(this->get_discovery_topic_(discovery_info), "", 0, this->qos_, true);
   }
 
-  ESP_LOGV(TAG, "'%s': Sending discovery", this->friendly_name().c_str());
+  ESP_LOGV(TAG, "'%s': Sending discovery", this->friendly_name_().c_str());
 
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   return global_mqtt_client->publish_json(
@@ -85,12 +85,16 @@ bool MQTTComponent::send_discovery_() {
         }
 
         // Fields from EntityBase
-        root[MQTT_NAME] = this->get_entity()->has_own_name() ? this->friendly_name() : "";
+        root[MQTT_NAME] = this->get_entity()->has_own_name() ? this->friendly_name_() : "";
 
-        if (this->is_disabled_by_default())
+        if (this->is_disabled_by_default_())
           root[MQTT_ENABLED_BY_DEFAULT] = false;
-        if (!this->get_icon().empty())
+        // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-          root[MQTT_ICON] = this->get_icon();
+        const auto icon_ref = this->get_icon_ref_();
+        if (!icon_ref.empty()) {
+          root[MQTT_ICON] = icon_ref;
+        }
+        // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
 
         const auto entity_category = this->get_entity()->get_entity_category();
         switch (entity_category) {
@@ -122,7 +126,7 @@ bool MQTTComponent::send_discovery_() {
         const MQTTDiscoveryInfo &discovery_info = global_mqtt_client->get_discovery_info();
         if (discovery_info.unique_id_generator == MQTT_MAC_ADDRESS_UNIQUE_ID_GENERATOR) {
           char friendly_name_hash[9];
-          sprintf(friendly_name_hash, "%08" PRIx32, fnv1_hash(this->friendly_name()));
+          sprintf(friendly_name_hash, "%08" PRIx32, fnv1_hash(this->friendly_name_()));
           friendly_name_hash[8] = 0;  // ensure the hash-string ends with null
           root[MQTT_UNIQUE_ID] = get_mac_address() + "-" + this->component_type() + "-" + friendly_name_hash;
         } else {
@@ -184,7 +188,7 @@ bool MQTTComponent::is_discovery_enabled() const {
 }
 
 std::string MQTTComponent::get_default_object_id_() const {
-  return str_sanitize(str_snake_case(this->friendly_name()));
+  return str_sanitize(str_snake_case(this->friendly_name_()));
 }
 
 void MQTTComponent::subscribe(const std::string &topic, mqtt_callback_t callback, uint8_t qos) {
@@ -268,9 +272,9 @@ void MQTTComponent::schedule_resend_state() { this->resend_state_ = true; }
 bool MQTTComponent::is_connected_() const { return global_mqtt_client->is_connected(); }
 
 // Pull these properties from EntityBase if not overridden
-std::string MQTTComponent::friendly_name() const { return this->get_entity()->get_name(); }
+std::string MQTTComponent::friendly_name_() const { return this->get_entity()->get_name(); }
-std::string MQTTComponent::get_icon() const { return this->get_entity()->get_icon(); }
+StringRef MQTTComponent::get_icon_ref_() const { return this->get_entity()->get_icon_ref(); }
-bool MQTTComponent::is_disabled_by_default() const { return this->get_entity()->is_disabled_by_default(); }
+bool MQTTComponent::is_disabled_by_default_() const { return this->get_entity()->is_disabled_by_default(); }
 bool MQTTComponent::is_internal() {
   if (this->has_custom_state_topic_) {
     // If the custom state_topic is null, return true as it is internal and should not publish

esphome/components/mqtt/mqtt_component.h

@@ -165,13 +165,13 @@ class MQTTComponent : public Component {
   virtual const EntityBase *get_entity() const = 0;
 
   /// Get the friendly name of this MQTT component.
-  virtual std::string friendly_name() const;
+  std::string friendly_name_() const;
 
-  /// Get the icon field of this component
+  /// Get the icon field of this component as StringRef
-  virtual std::string get_icon() const;
+  StringRef get_icon_ref_() const;
 
   /// Get whether the underlying Entity is disabled by default
-  virtual bool is_disabled_by_default() const;
+  bool is_disabled_by_default_() const;
 
   /// Get the MQTT topic that new states will be shared to.
   std::string get_state_topic_() const;

esphome/components/mqtt/mqtt_cover.cpp

@@ -67,9 +67,12 @@ void MQTTCoverComponent::dump_config() {
   }
 }
 void MQTTCoverComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
-  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
+  // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-  if (!this->cover_->get_device_class().empty())
+  const auto device_class = this->cover_->get_device_class_ref();
-    root[MQTT_DEVICE_CLASS] = this->cover_->get_device_class();
+  if (!device_class.empty()) {
+    root[MQTT_DEVICE_CLASS] = device_class;
+  }
+  // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
 
   auto traits = this->cover_->get_traits();
   if (traits.get_is_assumed_state()) {

esphome/components/mqtt/mqtt_event.cpp

@@ -21,8 +21,12 @@ void MQTTEventComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConf
   for (const auto &event_type : this->event_->get_event_types())
     event_types.add(event_type);
 
-  if (!this->event_->get_device_class().empty())
+  // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-    root[MQTT_DEVICE_CLASS] = this->event_->get_device_class();
+  const auto device_class = this->event_->get_device_class_ref();
+  if (!device_class.empty()) {
+    root[MQTT_DEVICE_CLASS] = device_class;
+  }
+  // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
 
   config.command_topic = false;
 }

esphome/components/mqtt/mqtt_fan.cpp

@@ -24,15 +24,15 @@ void MQTTFanComponent::setup() {
     auto val = parse_on_off(payload.c_str());
     switch (val) {
       case PARSE_ON:
-        ESP_LOGD(TAG, "'%s' Turning Fan ON.", this->friendly_name().c_str());
+        ESP_LOGD(TAG, "'%s' Turning Fan ON.", this->friendly_name_().c_str());
         this->state_->turn_on().perform();
         break;
       case PARSE_OFF:
-        ESP_LOGD(TAG, "'%s' Turning Fan OFF.", this->friendly_name().c_str());
+        ESP_LOGD(TAG, "'%s' Turning Fan OFF.", this->friendly_name_().c_str());
         this->state_->turn_off().perform();
         break;
       case PARSE_TOGGLE:
-        ESP_LOGD(TAG, "'%s' Toggling Fan.", this->friendly_name().c_str());
+        ESP_LOGD(TAG, "'%s' Toggling Fan.", this->friendly_name_().c_str());
         this->state_->toggle().perform();
         break;
       case PARSE_NONE:
@@ -48,11 +48,11 @@ void MQTTFanComponent::setup() {
       auto val = parse_on_off(payload.c_str(), "forward", "reverse");
       switch (val) {
         case PARSE_ON:
-          ESP_LOGD(TAG, "'%s': Setting direction FORWARD", this->friendly_name().c_str());
+          ESP_LOGD(TAG, "'%s': Setting direction FORWARD", this->friendly_name_().c_str());
           this->state_->make_call().set_direction(fan::FanDirection::FORWARD).perform();
           break;
         case PARSE_OFF:
-          ESP_LOGD(TAG, "'%s': Setting direction REVERSE", this->friendly_name().c_str());
+          ESP_LOGD(TAG, "'%s': Setting direction REVERSE", this->friendly_name_().c_str());
           this->state_->make_call().set_direction(fan::FanDirection::REVERSE).perform();
           break;
         case PARSE_TOGGLE:
@@ -75,11 +75,11 @@ void MQTTFanComponent::setup() {
                       auto val = parse_on_off(payload.c_str(), "oscillate_on", "oscillate_off");
                       switch (val) {
                         case PARSE_ON:
-                          ESP_LOGD(TAG, "'%s': Setting oscillating ON", this->friendly_name().c_str());
+                          ESP_LOGD(TAG, "'%s': Setting oscillating ON", this->friendly_name_().c_str());
                           this->state_->make_call().set_oscillating(true).perform();
                           break;
                         case PARSE_OFF:
-                          ESP_LOGD(TAG, "'%s': Setting oscillating OFF", this->friendly_name().c_str());
+                          ESP_LOGD(TAG, "'%s': Setting oscillating OFF", this->friendly_name_().c_str());
                           this->state_->make_call().set_oscillating(false).perform();
                           break;
                         case PARSE_TOGGLE:

esphome/components/mqtt/mqtt_lock.cpp

@@ -24,7 +24,7 @@ void MQTTLockComponent::setup() {
     } else if (strcasecmp(payload.c_str(), "OPEN") == 0) {
       this->lock_->open();
     } else {
-      ESP_LOGW(TAG, "'%s': Received unknown status payload: %s", this->friendly_name().c_str(), payload.c_str());
+      ESP_LOGW(TAG, "'%s': Received unknown status payload: %s", this->friendly_name_().c_str(), payload.c_str());
       this->status_momentary_warning("state", 5000);
     }
   });

esphome/components/mqtt/mqtt_number.cpp

@@ -44,8 +44,11 @@ void MQTTNumberComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryCon
   root[MQTT_MIN] = traits.get_min_value();
   root[MQTT_MAX] = traits.get_max_value();
   root[MQTT_STEP] = traits.get_step();
-  if (!this->number_->traits.get_unit_of_measurement().empty())
+  // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-    root[MQTT_UNIT_OF_MEASUREMENT] = this->number_->traits.get_unit_of_measurement();
+  const auto unit_of_measurement = this->number_->traits.get_unit_of_measurement_ref();
+  if (!unit_of_measurement.empty()) {
+    root[MQTT_UNIT_OF_MEASUREMENT] = unit_of_measurement;
+  }
   switch (this->number_->traits.get_mode()) {
     case NUMBER_MODE_AUTO:
       break;
@@ -56,8 +59,11 @@ void MQTTNumberComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryCon
       root[MQTT_MODE] = "slider";
       break;
   }
-  if (!this->number_->traits.get_device_class().empty())
+  const auto device_class = this->number_->traits.get_device_class_ref();
-    root[MQTT_DEVICE_CLASS] = this->number_->traits.get_device_class();
+  if (!device_class.empty()) {
+    root[MQTT_DEVICE_CLASS] = device_class;
+  }
+  // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
 
   config.command_topic = true;
 }

esphome/components/mqtt/mqtt_sensor.cpp

@@ -44,13 +44,17 @@ void MQTTSensorComponent::set_expire_after(uint32_t expire_after) { this->expire
 void MQTTSensorComponent::disable_expire_after() { this->expire_after_ = 0; }
 
 void MQTTSensorComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
-  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
+  // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-  if (!this->sensor_->get_device_class().empty()) {
+  const auto device_class = this->sensor_->get_device_class_ref();
-    root[MQTT_DEVICE_CLASS] = this->sensor_->get_device_class();
+  if (!device_class.empty()) {
+    root[MQTT_DEVICE_CLASS] = device_class;
   }
 
-  if (!this->sensor_->get_unit_of_measurement().empty())
+  const auto unit_of_measurement = this->sensor_->get_unit_of_measurement_ref();
-    root[MQTT_UNIT_OF_MEASUREMENT] = this->sensor_->get_unit_of_measurement();
+  if (!unit_of_measurement.empty()) {
+    root[MQTT_UNIT_OF_MEASUREMENT] = unit_of_measurement;
+  }
+  // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
 
   if (this->get_expire_after() > 0)
     root[MQTT_EXPIRE_AFTER] = this->get_expire_after() / 1000;

esphome/components/mqtt/mqtt_switch.cpp

@@ -29,7 +29,7 @@ void MQTTSwitchComponent::setup() {
         break;
       case PARSE_NONE:
       default:
-        ESP_LOGW(TAG, "'%s': Received unknown status payload: %s", this->friendly_name().c_str(), payload.c_str());
+        ESP_LOGW(TAG, "'%s': Received unknown status payload: %s", this->friendly_name_().c_str(), payload.c_str());
         this->status_momentary_warning("state", 5000);
         break;
     }

esphome/components/mqtt/mqtt_text_sensor.cpp

@@ -15,10 +15,12 @@ using namespace esphome::text_sensor;
 
 MQTTTextSensor::MQTTTextSensor(TextSensor *sensor) : sensor_(sensor) {}
 void MQTTTextSensor::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
-  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
+  // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-  if (!this->sensor_->get_device_class().empty()) {
+  const auto device_class = this->sensor_->get_device_class_ref();
-    root[MQTT_DEVICE_CLASS] = this->sensor_->get_device_class();
+  if (!device_class.empty()) {
+    root[MQTT_DEVICE_CLASS] = device_class;
   }
+  // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
   config.command_topic = false;
 }
 void MQTTTextSensor::setup() {

esphome/components/mqtt/mqtt_update.cpp

@@ -20,7 +20,7 @@ void MQTTUpdateComponent::setup() {
     if (payload == "INSTALL") {
       this->update_->perform();
     } else {
-      ESP_LOGW(TAG, "'%s': Received unknown update payload: %s", this->friendly_name().c_str(), payload.c_str());
+      ESP_LOGW(TAG, "'%s': Received unknown update payload: %s", this->friendly_name_().c_str(), payload.c_str());
       this->status_momentary_warning("state", 5000);
     }
   });

esphome/components/mqtt/mqtt_valve.cpp

@@ -49,10 +49,12 @@ void MQTTValveComponent::dump_config() {
   }
 }
 void MQTTValveComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
-  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
+  // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-  if (!this->valve_->get_device_class().empty()) {
+  const auto device_class = this->valve_->get_device_class_ref();
-    root[MQTT_DEVICE_CLASS] = this->valve_->get_device_class();
+  if (!device_class.empty()) {
+    root[MQTT_DEVICE_CLASS] = device_class;
   }
+  // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
 
   auto traits = this->valve_->get_traits();
   if (traits.get_is_assumed_state()) {