[voice_assistant] Replace timer unordered_map with vector to eliminate per-tick heap allocation (#13857)

esphome/components/voice_assistant/__init__.py

@@ -371,7 +371,12 @@ async def to_code(config):
     if on_timer_tick := config.get(CONF_ON_TIMER_TICK):
         await automation.build_automation(
             var.get_timer_tick_trigger(),
-            [(cg.std_vector.template(Timer), "timers")],
+            [
+                (
+                    cg.std_vector.template(Timer).operator("const").operator("ref"),
+                    "timers",
+                )
+            ],
             on_timer_tick,
         )
         has_timers = True

esphome/components/voice_assistant/voice_assistant.cpp

@@ -859,35 +859,43 @@ void VoiceAssistant::on_audio(const api::VoiceAssistantAudio &msg) {
 }
 
 void VoiceAssistant::on_timer_event(const api::VoiceAssistantTimerEventResponse &msg) {
-  Timer timer = {
+  // Find existing timer or add a new one
-      .id = msg.timer_id,
+  auto it = this->timers_.begin();
-      .name = msg.name,
+  for (; it != this->timers_.end(); ++it) {
-      .total_seconds = msg.total_seconds,
+    if (it->id == msg.timer_id)
-      .seconds_left = msg.seconds_left,
+      break;
-      .is_active = msg.is_active,
+  }
-  };
+  if (it == this->timers_.end()) {
-  this->timers_[timer.id] = timer;
+    this->timers_.push_back({});
+    it = this->timers_.end() - 1;
+  }
+  it->id = msg.timer_id;
+  it->name = msg.name;
+  it->total_seconds = msg.total_seconds;
+  it->seconds_left = msg.seconds_left;
+  it->is_active = msg.is_active;
+
   char timer_buf[Timer::TO_STR_BUFFER_SIZE];
   ESP_LOGD(TAG,
            "Timer Event\n"
            "  Type: %" PRId32 "\n"
            "  %s",
-           msg.event_type, timer.to_str(timer_buf));
+           msg.event_type, it->to_str(timer_buf));
 
   switch (msg.event_type) {
     case api::enums::VOICE_ASSISTANT_TIMER_STARTED:
-      this->timer_started_trigger_.trigger(timer);
+      this->timer_started_trigger_.trigger(*it);
       break;
     case api::enums::VOICE_ASSISTANT_TIMER_UPDATED:
-      this->timer_updated_trigger_.trigger(timer);
+      this->timer_updated_trigger_.trigger(*it);
       break;
     case api::enums::VOICE_ASSISTANT_TIMER_CANCELLED:
-      this->timer_cancelled_trigger_.trigger(timer);
+      this->timer_cancelled_trigger_.trigger(*it);
-      this->timers_.erase(timer.id);
+      this->timers_.erase(it);
       break;
     case api::enums::VOICE_ASSISTANT_TIMER_FINISHED:
-      this->timer_finished_trigger_.trigger(timer);
+      this->timer_finished_trigger_.trigger(*it);
-      this->timers_.erase(timer.id);
+      this->timers_.erase(it);
       break;
   }
 
@@ -901,16 +909,12 @@ void VoiceAssistant::on_timer_event(const api::VoiceAssistantTimerEventResponse
 }
 
 void VoiceAssistant::timer_tick_() {
-  std::vector<Timer> res;
+  for (auto &timer : this->timers_) {
-  res.reserve(this->timers_.size());
-  for (auto &pair : this->timers_) {
-    auto &timer = pair.second;
     if (timer.is_active && timer.seconds_left > 0) {
       timer.seconds_left--;
     }
-    res.push_back(timer);
   }
-  this->timer_tick_trigger_.trigger(res);
+  this->timer_tick_trigger_.trigger(this->timers_);
 }
 
 void VoiceAssistant::on_announce(const api::VoiceAssistantAnnounceRequest &msg) {

esphome/components/voice_assistant/voice_assistant.h

@@ -24,7 +24,6 @@
 #include "esphome/components/socket/socket.h"
 
 #include <span>
-#include <unordered_map>
 #include <vector>
 
 namespace esphome {
@@ -226,9 +225,9 @@ class VoiceAssistant : public Component {
   Trigger<Timer> *get_timer_updated_trigger() { return &this->timer_updated_trigger_; }
   Trigger<Timer> *get_timer_cancelled_trigger() { return &this->timer_cancelled_trigger_; }
   Trigger<Timer> *get_timer_finished_trigger() { return &this->timer_finished_trigger_; }
-  Trigger<std::vector<Timer>> *get_timer_tick_trigger() { return &this->timer_tick_trigger_; }
+  Trigger<const std::vector<Timer> &> *get_timer_tick_trigger() { return &this->timer_tick_trigger_; }
   void set_has_timers(bool has_timers) { this->has_timers_ = has_timers; }
-  const std::unordered_map<std::string, Timer> &get_timers() const { return this->timers_; }
+  const std::vector<Timer> &get_timers() const { return this->timers_; }
 
  protected:
   bool allocate_buffers_();
@@ -267,13 +266,13 @@ class VoiceAssistant : public Component {
 
   api::APIConnection *api_client_{nullptr};
 
-  std::unordered_map<std::string, Timer> timers_;
+  std::vector<Timer> timers_;
   void timer_tick_();
   Trigger<Timer> timer_started_trigger_;
   Trigger<Timer> timer_finished_trigger_;
   Trigger<Timer> timer_updated_trigger_;
   Trigger<Timer> timer_cancelled_trigger_;
-  Trigger<std::vector<Timer>> timer_tick_trigger_;
+  Trigger<const std::vector<Timer> &> timer_tick_trigger_;
   bool has_timers_{false};
   bool timer_tick_running_{false};
 

tests/components/voice_assistant/common-idf.yaml

@@ -68,3 +68,24 @@ voice_assistant:
     - logger.log:
         format: "Voice assistant error - code %s, message: %s"
         args: [code.c_str(), message.c_str()]
+  on_timer_started:
+    - logger.log:
+        format: "Timer started: %s"
+        args: [timer.id.c_str()]
+  on_timer_updated:
+    - logger.log:
+        format: "Timer updated: %s"
+        args: [timer.id.c_str()]
+  on_timer_cancelled:
+    - logger.log:
+        format: "Timer cancelled: %s"
+        args: [timer.id.c_str()]
+  on_timer_finished:
+    - logger.log:
+        format: "Timer finished: %s"
+        args: [timer.id.c_str()]
+  on_timer_tick:
+    - lambda: |-
+        for (auto &timer : timers) {
+          ESP_LOGD("timer", "Timer %s: %" PRIu32 "s left", timer.name.c_str(), timer.seconds_left);
+        }

tests/components/voice_assistant/common.yaml

@@ -58,3 +58,24 @@ voice_assistant:
     - logger.log:
         format: "Voice assistant error - code %s, message: %s"
         args: [code.c_str(), message.c_str()]
+  on_timer_started:
+    - logger.log:
+        format: "Timer started: %s"
+        args: [timer.id.c_str()]
+  on_timer_updated:
+    - logger.log:
+        format: "Timer updated: %s"
+        args: [timer.id.c_str()]
+  on_timer_cancelled:
+    - logger.log:
+        format: "Timer cancelled: %s"
+        args: [timer.id.c_str()]
+  on_timer_finished:
+    - logger.log:
+        format: "Timer finished: %s"
+        args: [timer.id.c_str()]
+  on_timer_tick:
+    - lambda: |-
+        for (auto &timer : timers) {
+          ESP_LOGD("timer", "Timer %s: %" PRIu32 "s left", timer.name.c_str(), timer.seconds_left);
+        }