[wifi] Use StringRef and std::span in WiFiConnectStateListener to avoid allocations (#12672)

esphome/components/wifi/wifi_component.h

@@ -6,7 +6,9 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/helpers.h"
+#include "esphome/core/string_ref.h"
 
+#include <span>
 #include <string>
 #include <vector>
 
@@ -274,7 +276,7 @@ class WiFiScanResultsListener {
  */
 class WiFiConnectStateListener {
  public:
-  virtual void on_wifi_connect_state(const std::string &ssid, const bssid_t &bssid) = 0;
+  virtual void on_wifi_connect_state(StringRef ssid, std::span<const uint8_t, 6> bssid) = 0;
 };
 
 /** Listener interface for WiFi power save mode changes.

esphome/components/wifi/wifi_component_esp8266.cpp

@@ -526,7 +526,7 @@ void WiFiComponent::wifi_event_callback(System_Event_t *event) {
       s_sta_connected = true;
 #ifdef USE_WIFI_LISTENERS
       for (auto *listener : global_wifi_component->connect_state_listeners_) {
-        listener->on_wifi_connect_state(global_wifi_component->wifi_ssid(), global_wifi_component->wifi_bssid());
+        listener->on_wifi_connect_state(StringRef(buf, it.ssid_len), it.bssid);
       }
       // For static IP configurations, GOT_IP event may not fire, so notify IP listeners here
 #ifdef USE_WIFI_MANUAL_IP
@@ -559,8 +559,9 @@ void WiFiComponent::wifi_event_callback(System_Event_t *event) {
       s_sta_connected = false;
       s_sta_connecting = false;
 #ifdef USE_WIFI_LISTENERS
+      static constexpr uint8_t EMPTY_BSSID[6] = {};
       for (auto *listener : global_wifi_component->connect_state_listeners_) {
-        listener->on_wifi_connect_state("", bssid_t({0, 0, 0, 0, 0, 0}));
+        listener->on_wifi_connect_state(StringRef(), EMPTY_BSSID);
       }
 #endif
       break;

esphome/components/wifi/wifi_component_esp_idf.cpp

@@ -737,7 +737,7 @@ void WiFiComponent::wifi_process_event_(IDFWiFiEvent *data) {
     s_sta_connected = true;
 #ifdef USE_WIFI_LISTENERS
     for (auto *listener : this->connect_state_listeners_) {
-      listener->on_wifi_connect_state(this->wifi_ssid(), this->wifi_bssid());
+      listener->on_wifi_connect_state(StringRef(buf, it.ssid_len), it.bssid);
     }
     // For static IP configurations, GOT_IP event may not fire, so notify IP listeners here
 #ifdef USE_WIFI_MANUAL_IP
@@ -772,8 +772,9 @@ void WiFiComponent::wifi_process_event_(IDFWiFiEvent *data) {
     s_sta_connecting = false;
     error_from_callback_ = true;
 #ifdef USE_WIFI_LISTENERS
+    static constexpr uint8_t EMPTY_BSSID[6] = {};
     for (auto *listener : this->connect_state_listeners_) {
-      listener->on_wifi_connect_state("", bssid_t({0, 0, 0, 0, 0, 0}));
+      listener->on_wifi_connect_state(StringRef(), EMPTY_BSSID);
     }
 #endif
 

esphome/components/wifi/wifi_component_libretiny.cpp

@@ -303,7 +303,7 @@ void WiFiComponent::wifi_event_callback_(esphome_wifi_event_id_t event, esphome_
                format_mac_address_pretty(it.bssid).c_str(), it.channel, get_auth_mode_str(it.authmode));
 #ifdef USE_WIFI_LISTENERS
       for (auto *listener : this->connect_state_listeners_) {
-        listener->on_wifi_connect_state(this->wifi_ssid(), this->wifi_bssid());
+        listener->on_wifi_connect_state(StringRef(buf, it.ssid_len), it.bssid);
       }
       // For static IP configurations, GOT_IP event may not fire, so notify IP listeners here
 #ifdef USE_WIFI_MANUAL_IP
@@ -357,8 +357,9 @@ void WiFiComponent::wifi_event_callback_(esphome_wifi_event_id_t event, esphome_
 
       s_sta_connecting = false;
 #ifdef USE_WIFI_LISTENERS
+      static constexpr uint8_t EMPTY_BSSID[6] = {};
       for (auto *listener : this->connect_state_listeners_) {
-        listener->on_wifi_connect_state("", bssid_t({0, 0, 0, 0, 0, 0}));
+        listener->on_wifi_connect_state(StringRef(), EMPTY_BSSID);
       }
 #endif
       break;

esphome/components/wifi/wifi_component_pico_w.cpp

@@ -256,8 +256,10 @@ void WiFiComponent::wifi_loop_() {
     s_sta_was_connected = true;
     ESP_LOGV(TAG, "Connected");
 #ifdef USE_WIFI_LISTENERS
+    String ssid = WiFi.SSID();
+    bssid_t bssid = this->wifi_bssid();
     for (auto *listener : this->connect_state_listeners_) {
-      listener->on_wifi_connect_state(this->wifi_ssid(), this->wifi_bssid());
+      listener->on_wifi_connect_state(StringRef(ssid.c_str(), ssid.length()), bssid);
     }
     // For static IP configurations, notify IP listeners immediately as the IP is already configured
 #ifdef USE_WIFI_MANUAL_IP
@@ -275,8 +277,9 @@ void WiFiComponent::wifi_loop_() {
     s_sta_had_ip = false;
     ESP_LOGV(TAG, "Disconnected");
 #ifdef USE_WIFI_LISTENERS
+    static constexpr uint8_t EMPTY_BSSID[6] = {};
     for (auto *listener : this->connect_state_listeners_) {
-      listener->on_wifi_connect_state("", bssid_t({0, 0, 0, 0, 0, 0}));
+      listener->on_wifi_connect_state(StringRef(), EMPTY_BSSID);
     }
 #endif
   }

esphome/components/wifi_info/wifi_info_text_sensor.cpp

@@ -103,8 +103,8 @@ void SSIDWiFiInfo::setup() { wifi::global_wifi_component->add_connect_state_list
 
 void SSIDWiFiInfo::dump_config() { LOG_TEXT_SENSOR("", "SSID", this); }
 
-void SSIDWiFiInfo::on_wifi_connect_state(const std::string &ssid, const wifi::bssid_t &bssid) {
+void SSIDWiFiInfo::on_wifi_connect_state(StringRef ssid, std::span<const uint8_t, 6> bssid) {
-  this->publish_state(ssid);
+  this->publish_state(ssid.str());
 }
 
 /****************
@@ -115,7 +115,7 @@ void BSSIDWiFiInfo::setup() { wifi::global_wifi_component->add_connect_state_lis
 
 void BSSIDWiFiInfo::dump_config() { LOG_TEXT_SENSOR("", "BSSID", this); }
 
-void BSSIDWiFiInfo::on_wifi_connect_state(const std::string &ssid, const wifi::bssid_t &bssid) {
+void BSSIDWiFiInfo::on_wifi_connect_state(StringRef ssid, std::span<const uint8_t, 6> bssid) {
   char buf[18] = "unknown";
   if (mac_address_is_valid(bssid.data())) {
     format_mac_addr_upper(bssid.data(), buf);

esphome/components/wifi_info/wifi_info_text_sensor.h

@@ -2,10 +2,12 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/helpers.h"
+#include "esphome/core/string_ref.h"
 #include "esphome/components/text_sensor/text_sensor.h"
 #include "esphome/components/wifi/wifi_component.h"
 #ifdef USE_WIFI
 #include <array>
+#include <span>
 
 namespace esphome::wifi_info {
 
@@ -52,7 +54,7 @@ class SSIDWiFiInfo final : public Component, public text_sensor::TextSensor, pub
   void dump_config() override;
 
   // WiFiConnectStateListener interface
-  void on_wifi_connect_state(const std::string &ssid, const wifi::bssid_t &bssid) override;
+  void on_wifi_connect_state(StringRef ssid, std::span<const uint8_t, 6> bssid) override;
 };
 
 class BSSIDWiFiInfo final : public Component, public text_sensor::TextSensor, public wifi::WiFiConnectStateListener {
@@ -61,7 +63,7 @@ class BSSIDWiFiInfo final : public Component, public text_sensor::TextSensor, pu
   void dump_config() override;
 
   // WiFiConnectStateListener interface
-  void on_wifi_connect_state(const std::string &ssid, const wifi::bssid_t &bssid) override;
+  void on_wifi_connect_state(StringRef ssid, std::span<const uint8_t, 6> bssid) override;
 };
 
 class PowerSaveModeWiFiInfo final : public Component,

esphome/components/wifi_signal/wifi_signal_sensor.h

@@ -2,9 +2,11 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/helpers.h"
+#include "esphome/core/string_ref.h"
 #include "esphome/components/sensor/sensor.h"
 #include "esphome/components/wifi/wifi_component.h"
 #ifdef USE_WIFI
+#include <span>
 namespace esphome::wifi_signal {
 
 #ifdef USE_WIFI_LISTENERS
@@ -28,7 +30,7 @@ class WiFiSignalSensor : public sensor::Sensor, public PollingComponent {
 
 #ifdef USE_WIFI_LISTENERS
   // WiFiConnectStateListener interface - update RSSI immediately on connect
-  void on_wifi_connect_state(const std::string &ssid, const wifi::bssid_t &bssid) override { this->update(); }
+  void on_wifi_connect_state(StringRef ssid, std::span<const uint8_t, 6> bssid) override { this->update(); }
 #endif
 };