[lock] Store lock state strings in flash on ESP8266 (#12163)

esphome/components/lock/lock.cpp

@@ -7,21 +7,21 @@ namespace esphome::lock {
 
 static const char *const TAG = "lock";
 
-const char *lock_state_to_string(LockState state) {
+const LogString *lock_state_to_string(LockState state) {
   switch (state) {
     case LOCK_STATE_LOCKED:
-      return "LOCKED";
+      return LOG_STR("LOCKED");
     case LOCK_STATE_UNLOCKED:
-      return "UNLOCKED";
+      return LOG_STR("UNLOCKED");
     case LOCK_STATE_JAMMED:
-      return "JAMMED";
+      return LOG_STR("JAMMED");
     case LOCK_STATE_LOCKING:
-      return "LOCKING";
+      return LOG_STR("LOCKING");
     case LOCK_STATE_UNLOCKING:
-      return "UNLOCKING";
+      return LOG_STR("UNLOCKING");
     case LOCK_STATE_NONE:
     default:
-      return "UNKNOWN";
+      return LOG_STR("UNKNOWN");
   }
 }
 
@@ -52,7 +52,7 @@ void Lock::publish_state(LockState state) {
 
   this->state = state;
   this->rtc_.save(&this->state);
-  ESP_LOGD(TAG, "'%s': Sending state %s", this->name_.c_str(), lock_state_to_string(state));
+  ESP_LOGD(TAG, "'%s': Sending state %s", this->name_.c_str(), LOG_STR_ARG(lock_state_to_string(state)));
   this->state_callback_.call();
 #if defined(USE_LOCK) && defined(USE_CONTROLLER_REGISTRY)
   ControllerRegistry::notify_lock_update(this);
@@ -65,8 +65,7 @@ void LockCall::perform() {
   ESP_LOGD(TAG, "'%s' - Setting", this->parent_->get_name().c_str());
   this->validate_();
   if (this->state_.has_value()) {
-    const char *state_s = lock_state_to_string(*this->state_);
-    ESP_LOGD(TAG, "  State: %s", state_s);
+    ESP_LOGD(TAG, "  State: %s", LOG_STR_ARG(lock_state_to_string(*this->state_)));
   }
   this->parent_->control(*this);
 }
@@ -74,7 +73,7 @@ void LockCall::validate_() {
   if (this->state_.has_value()) {
     auto state = *this->state_;
     if (!this->parent_->traits.supports_state(state)) {
-      ESP_LOGW(TAG, "  State %s is not supported by this device!", lock_state_to_string(*this->state_));
+      ESP_LOGW(TAG, "  State %s is not supported by this device!", LOG_STR_ARG(lock_state_to_string(*this->state_)));
       this->state_.reset();
     }
   }

esphome/components/lock/lock.h

@@ -30,7 +30,10 @@ enum LockState : uint8_t {
   LOCK_STATE_LOCKING = 4,
   LOCK_STATE_UNLOCKING = 5
 };
-const char *lock_state_to_string(LockState state);
+const LogString *lock_state_to_string(LockState state);
+
+/// Maximum length of lock state string (including null terminator): "UNLOCKING" = 10
+static constexpr size_t LOCK_STATE_STR_SIZE = 10;
 
 class LockTraits {
  public:

esphome/components/mqtt/mqtt_lock.cpp

@@ -48,8 +48,14 @@ void MQTTLockComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfi
 bool MQTTLockComponent::send_initial_state() { return this->publish_state(); }
 
 bool MQTTLockComponent::publish_state() {
-  std::string payload = lock_state_to_string(this->lock_->state);
-  return this->publish(this->get_state_topic_(), payload);
+#ifdef USE_STORE_LOG_STR_IN_FLASH
+  char buf[LOCK_STATE_STR_SIZE];
+  strncpy_P(buf, (PGM_P) lock_state_to_string(this->lock_->state), sizeof(buf) - 1);
+  buf[sizeof(buf) - 1] = '\0';
+  return this->publish(this->get_state_topic_(), buf);
+#else
+  return this->publish(this->get_state_topic_(), LOG_STR_ARG(lock_state_to_string(this->lock_->state)));
+#endif
 }
 
 }  // namespace mqtt

esphome/components/web_server/web_server.cpp

@@ -1334,7 +1334,7 @@ std::string WebServer::climate_json(climate::Climate *obj, JsonDetail start_conf
   const auto traits = obj->get_traits();
   int8_t target_accuracy = traits.get_target_temperature_accuracy_decimals();
   int8_t current_accuracy = traits.get_current_temperature_accuracy_decimals();
-  char buf[16];
+  char buf[PSTR_LOCAL_SIZE];
 
   if (start_config == DETAIL_ALL) {
     JsonArray opt = root["modes"].to<JsonArray>();
@@ -1484,7 +1484,8 @@ std::string WebServer::lock_json(lock::Lock *obj, lock::LockState value, JsonDet
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
-  set_json_icon_state_value(root, obj, "lock", lock::lock_state_to_string(value), value, start_config);
+  char buf[PSTR_LOCAL_SIZE];
+  set_json_icon_state_value(root, obj, "lock", PSTR_LOCAL(lock::lock_state_to_string(value)), value, start_config);
   if (start_config == DETAIL_ALL) {
     this->add_sorting_info_(root, obj);
   }
@@ -1645,7 +1646,7 @@ std::string WebServer::alarm_control_panel_json(alarm_control_panel::AlarmContro
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
-  char buf[16];
+  char buf[PSTR_LOCAL_SIZE];
   set_json_icon_state_value(root, obj, "alarm-control-panel", PSTR_LOCAL(alarm_control_panel_state_to_string(value)),
                             value, start_config);
   if (start_config == DETAIL_ALL) {