[light] Store effect names in flash (const char*) to save RAM (#11487)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

esphome/components/adalight/adalight_light_effect.cpp

@@ -9,7 +9,7 @@ static const char *const TAG = "adalight_light_effect";
 static const uint32_t ADALIGHT_ACK_INTERVAL = 1000;
 static const uint32_t ADALIGHT_RECEIVE_TIMEOUT = 1000;
 
-AdalightLightEffect::AdalightLightEffect(const std::string &name) : AddressableLightEffect(name) {}
+AdalightLightEffect::AdalightLightEffect(const char *name) : AddressableLightEffect(name) {}
 
 void AdalightLightEffect::start() {
   AddressableLightEffect::start();

esphome/components/adalight/adalight_light_effect.h

@@ -11,7 +11,7 @@ namespace adalight {
 
 class AdalightLightEffect : public light::AddressableLightEffect, public uart::UARTDevice {
  public:
-  AdalightLightEffect(const std::string &name);
+  AdalightLightEffect(const char *name);
 
   void start() override;
   void stop() override;

esphome/components/e131/e131.cpp

@@ -80,8 +80,8 @@ void E131Component::add_effect(E131AddressableLightEffect *light_effect) {
     return;
   }
 
-  ESP_LOGD(TAG, "Registering '%s' for universes %d-%d.", light_effect->get_name().c_str(),
-           light_effect->get_first_universe(), light_effect->get_last_universe());
+  ESP_LOGD(TAG, "Registering '%s' for universes %d-%d.", light_effect->get_name(), light_effect->get_first_universe(),
+           light_effect->get_last_universe());
 
   light_effects_.insert(light_effect);
 
@@ -95,8 +95,8 @@ void E131Component::remove_effect(E131AddressableLightEffect *light_effect) {
     return;
   }
 
-  ESP_LOGD(TAG, "Unregistering '%s' for universes %d-%d.", light_effect->get_name().c_str(),
-           light_effect->get_first_universe(), light_effect->get_last_universe());
+  ESP_LOGD(TAG, "Unregistering '%s' for universes %d-%d.", light_effect->get_name(), light_effect->get_first_universe(),
+           light_effect->get_last_universe());
 
   light_effects_.erase(light_effect);
 

esphome/components/e131/e131_addressable_light_effect.cpp

@@ -9,7 +9,7 @@ namespace e131 {
 static const char *const TAG = "e131_addressable_light_effect";
 static const int MAX_DATA_SIZE = (sizeof(E131Packet::values) - 1);
 
-E131AddressableLightEffect::E131AddressableLightEffect(const std::string &name) : AddressableLightEffect(name) {}
+E131AddressableLightEffect::E131AddressableLightEffect(const char *name) : AddressableLightEffect(name) {}
 
 int E131AddressableLightEffect::get_data_per_universe() const { return get_lights_per_universe() * channels_; }
 
@@ -58,8 +58,8 @@ bool E131AddressableLightEffect::process_(int universe, const E131Packet &packet
       std::min(it->size(), std::min(output_offset + get_lights_per_universe(), output_offset + packet.count - 1));
   auto *input_data = packet.values + 1;
 
-  ESP_LOGV(TAG, "Applying data for '%s' on %d universe, for %" PRId32 "-%d.", get_name().c_str(), universe,
-           output_offset, output_end);
+  ESP_LOGV(TAG, "Applying data for '%s' on %d universe, for %" PRId32 "-%d.", get_name(), universe, output_offset,
+           output_end);
 
   switch (channels_) {
     case E131_MONO:

esphome/components/e131/e131_addressable_light_effect.h

@@ -13,7 +13,7 @@ enum E131LightChannels { E131_MONO = 1, E131_RGB = 3, E131_RGBW = 4 };
 
 class E131AddressableLightEffect : public light::AddressableLightEffect {
  public:
-  E131AddressableLightEffect(const std::string &name);
+  E131AddressableLightEffect(const char *name);
 
   void start() override;
   void stop() override;

esphome/components/light/addressable_light_effect.h

@@ -30,7 +30,7 @@ inline static uint8_t half_sin8(uint8_t v) { return sin16_c(uint16_t(v) * 128u)
 
 class AddressableLightEffect : public LightEffect {
  public:
-  explicit AddressableLightEffect(const std::string &name) : LightEffect(name) {}
+  explicit AddressableLightEffect(const char *name) : LightEffect(name) {}
   void start_internal() override {
     this->get_addressable_()->set_effect_active(true);
     this->get_addressable_()->clear_effect_data();
@@ -57,8 +57,7 @@ class AddressableLightEffect : public LightEffect {
 
 class AddressableLambdaLightEffect : public AddressableLightEffect {
  public:
-  AddressableLambdaLightEffect(const std::string &name,
-                               std::function<void(AddressableLight &, Color, bool initial_run)> f,
+  AddressableLambdaLightEffect(const char *name, std::function<void(AddressableLight &, Color, bool initial_run)> f,
                                uint32_t update_interval)
       : AddressableLightEffect(name), f_(std::move(f)), update_interval_(update_interval) {}
   void start() override { this->initial_run_ = true; }
@@ -81,7 +80,7 @@ class AddressableLambdaLightEffect : public AddressableLightEffect {
 
 class AddressableRainbowLightEffect : public AddressableLightEffect {
  public:
-  explicit AddressableRainbowLightEffect(const std::string &name) : AddressableLightEffect(name) {}
+  explicit AddressableRainbowLightEffect(const char *name) : AddressableLightEffect(name) {}
   void apply(AddressableLight &it, const Color &current_color) override {
     ESPHSVColor hsv;
     hsv.value = 255;
@@ -112,7 +111,7 @@ struct AddressableColorWipeEffectColor {
 
 class AddressableColorWipeEffect : public AddressableLightEffect {
  public:
-  explicit AddressableColorWipeEffect(const std::string &name) : AddressableLightEffect(name) {}
+  explicit AddressableColorWipeEffect(const char *name) : AddressableLightEffect(name) {}
   void set_colors(const std::initializer_list<AddressableColorWipeEffectColor> &colors) { this->colors_ = colors; }
   void set_add_led_interval(uint32_t add_led_interval) { this->add_led_interval_ = add_led_interval; }
   void set_reverse(bool reverse) { this->reverse_ = reverse; }
@@ -165,7 +164,7 @@ class AddressableColorWipeEffect : public AddressableLightEffect {
 
 class AddressableScanEffect : public AddressableLightEffect {
  public:
-  explicit AddressableScanEffect(const std::string &name) : AddressableLightEffect(name) {}
+  explicit AddressableScanEffect(const char *name) : AddressableLightEffect(name) {}
   void set_move_interval(uint32_t move_interval) { this->move_interval_ = move_interval; }
   void set_scan_width(uint32_t scan_width) { this->scan_width_ = scan_width; }
   void apply(AddressableLight &it, const Color &current_color) override {
@@ -202,7 +201,7 @@ class AddressableScanEffect : public AddressableLightEffect {
 
 class AddressableTwinkleEffect : public AddressableLightEffect {
  public:
-  explicit AddressableTwinkleEffect(const std::string &name) : AddressableLightEffect(name) {}
+  explicit AddressableTwinkleEffect(const char *name) : AddressableLightEffect(name) {}
   void apply(AddressableLight &addressable, const Color &current_color) override {
     const uint32_t now = millis();
     uint8_t pos_add = 0;
@@ -244,7 +243,7 @@ class AddressableTwinkleEffect : public AddressableLightEffect {
 
 class AddressableRandomTwinkleEffect : public AddressableLightEffect {
  public:
-  explicit AddressableRandomTwinkleEffect(const std::string &name) : AddressableLightEffect(name) {}
+  explicit AddressableRandomTwinkleEffect(const char *name) : AddressableLightEffect(name) {}
   void apply(AddressableLight &it, const Color &current_color) override {
     const uint32_t now = millis();
     uint8_t pos_add = 0;
@@ -293,7 +292,7 @@ class AddressableRandomTwinkleEffect : public AddressableLightEffect {
 
 class AddressableFireworksEffect : public AddressableLightEffect {
  public:
-  explicit AddressableFireworksEffect(const std::string &name) : AddressableLightEffect(name) {}
+  explicit AddressableFireworksEffect(const char *name) : AddressableLightEffect(name) {}
   void start() override {
     auto &it = *this->get_addressable_();
     it.all() = Color::BLACK;
@@ -342,7 +341,7 @@ class AddressableFireworksEffect : public AddressableLightEffect {
 
 class AddressableFlickerEffect : public AddressableLightEffect {
  public:
-  explicit AddressableFlickerEffect(const std::string &name) : AddressableLightEffect(name) {}
+  explicit AddressableFlickerEffect(const char *name) : AddressableLightEffect(name) {}
   void apply(AddressableLight &it, const Color &current_color) override {
     const uint32_t now = millis();
     const uint8_t intensity = this->intensity_;

esphome/components/light/base_light_effects.h

@@ -17,7 +17,7 @@ inline static float random_cubic_float() {
 /// Pulse effect.
 class PulseLightEffect : public LightEffect {
  public:
-  explicit PulseLightEffect(const std::string &name) : LightEffect(name) {}
+  explicit PulseLightEffect(const char *name) : LightEffect(name) {}
 
   void apply() override {
     const uint32_t now = millis();
@@ -60,7 +60,7 @@ class PulseLightEffect : public LightEffect {
 /// Random effect. Sets random colors every 10 seconds and slowly transitions between them.
 class RandomLightEffect : public LightEffect {
  public:
-  explicit RandomLightEffect(const std::string &name) : LightEffect(name) {}
+  explicit RandomLightEffect(const char *name) : LightEffect(name) {}
 
   void apply() override {
     const uint32_t now = millis();
@@ -112,7 +112,7 @@ class RandomLightEffect : public LightEffect {
 
 class LambdaLightEffect : public LightEffect {
  public:
-  LambdaLightEffect(const std::string &name, std::function<void(bool initial_run)> f, uint32_t update_interval)
+  LambdaLightEffect(const char *name, std::function<void(bool initial_run)> f, uint32_t update_interval)
       : LightEffect(name), f_(std::move(f)), update_interval_(update_interval) {}
 
   void start() override { this->initial_run_ = true; }
@@ -138,7 +138,7 @@ class LambdaLightEffect : public LightEffect {
 
 class AutomationLightEffect : public LightEffect {
  public:
-  AutomationLightEffect(const std::string &name) : LightEffect(name) {}
+  AutomationLightEffect(const char *name) : LightEffect(name) {}
   void stop() override { this->trig_->stop_action(); }
   void apply() override {
     if (!this->trig_->is_action_running()) {
@@ -163,7 +163,7 @@ struct StrobeLightEffectColor {
 
 class StrobeLightEffect : public LightEffect {
  public:
-  explicit StrobeLightEffect(const std::string &name) : LightEffect(name) {}
+  explicit StrobeLightEffect(const char *name) : LightEffect(name) {}
   void apply() override {
     const uint32_t now = millis();
     if (now - this->last_switch_ < this->colors_[this->at_color_].duration)
@@ -198,7 +198,7 @@ class StrobeLightEffect : public LightEffect {
 
 class FlickerLightEffect : public LightEffect {
  public:
-  explicit FlickerLightEffect(const std::string &name) : LightEffect(name) {}
+  explicit FlickerLightEffect(const char *name) : LightEffect(name) {}
 
   void apply() override {
     LightColorValues remote = this->state_->remote_values;

esphome/components/light/light_call.cpp

@@ -156,7 +156,7 @@ void LightCall::perform() {
     if (this->effect_ == 0u) {
       effect_s = "None";
     } else {
-      effect_s = this->parent_->effects_[this->effect_ - 1]->get_name().c_str();
+      effect_s = this->parent_->effects_[this->effect_ - 1]->get_name();
     }
 
     if (publish) {
@@ -511,7 +511,7 @@ LightCall &LightCall::set_effect(const std::string &effect) {
   for (uint32_t i = 0; i < this->parent_->effects_.size(); i++) {
     LightEffect *e = this->parent_->effects_[i];
 
-    if (strcasecmp(effect.c_str(), e->get_name().c_str()) == 0) {
+    if (strcasecmp(effect.c_str(), e->get_name()) == 0) {
       this->set_effect(i + 1);
       found = true;
       break;

esphome/components/light/light_effect.h

@@ -1,7 +1,5 @@
 #pragma once
 
-#include <utility>
-
 #include "esphome/core/component.h"
 
 namespace esphome {
@@ -11,7 +9,7 @@ class LightState;
 
 class LightEffect {
  public:
-  explicit LightEffect(std::string name) : name_(std::move(name)) {}
+  explicit LightEffect(const char *name) : name_(name) {}
 
   /// Initialize this LightEffect. Will be called once after creation.
   virtual void start() {}
@@ -24,7 +22,11 @@ class LightEffect {
   /// Apply this effect. Use the provided state for starting transitions, ...
   virtual void apply() = 0;
 
-  const std::string &get_name() { return this->name_; }
+  /**
+   * Returns the name of this effect.
+   * The returned pointer is valid for the lifetime of the program and must not be freed.
+   */
+  const char *get_name() const { return this->name_; }
 
   /// Internal method called by the LightState when this light effect is registered in it.
   virtual void init() {}
@@ -47,7 +49,7 @@ class LightEffect {
 
  protected:
   LightState *state_{nullptr};
-  std::string name_;
+  const char *name_;
 
   /// Internal method to find this effect's index in the parent light's effect list.
   uint32_t get_index_in_parent_() const;

esphome/components/light/light_state.h

@@ -177,7 +177,7 @@ class LightState : public EntityBase, public Component {
       return 0;
     }
     for (size_t i = 0; i < this->effects_.size(); i++) {
-      if (strcasecmp(effect_name.c_str(), this->effects_[i]->get_name().c_str()) == 0) {
+      if (strcasecmp(effect_name.c_str(), this->effects_[i]->get_name()) == 0) {
         return i + 1;  // Effects are 1-indexed in active_effect_index_
       }
     }

esphome/components/wled/wled_light_effect.cpp

@@ -28,7 +28,7 @@ const int DEFAULT_BLANK_TIME = 1000;
 
 static const char *const TAG = "wled_light_effect";
 
-WLEDLightEffect::WLEDLightEffect(const std::string &name) : AddressableLightEffect(name) {}
+WLEDLightEffect::WLEDLightEffect(const char *name) : AddressableLightEffect(name) {}
 
 void WLEDLightEffect::start() {
   AddressableLightEffect::start();

esphome/components/wled/wled_light_effect.h

@@ -15,7 +15,7 @@ namespace wled {
 
 class WLEDLightEffect : public light::AddressableLightEffect {
  public:
-  WLEDLightEffect(const std::string &name);
+  WLEDLightEffect(const char *name);
 
   void start() override;
   void stop() override;