mdns services array

esphome/components/mdns/__init__.py

@@ -90,12 +90,38 @@ async def to_code(config):
 
     cg.add_define("USE_MDNS")
 
+    # Count how many services we'll have at compile time
+    service_count = 0
+
+    # Check if API is enabled (USE_API is defined by api component)
+    if "api" in CORE.config:
+        service_count += 1
+
+    # Check if Prometheus is enabled (USE_PROMETHEUS is defined by prometheus component)
+    if "prometheus" in CORE.config:
+        service_count += 1
+
+    # Check if Web Server is enabled (USE_WEBSERVER is defined by web_server component)
+    if "web_server" in CORE.config:
+        service_count += 1
+
+    # Count extra services from config
+    extra_service_count = len(config.get(CONF_SERVICES, []))
+    if extra_service_count > 0:
+        service_count += extra_service_count
+        cg.add_define("USE_MDNS_EXTRA_SERVICES")
+        cg.add_define("MDNS_EXTRA_SERVICE_COUNT", extra_service_count)
+
+    # If no services, we'll add a fallback HTTP service
+    if service_count == 0:
+        service_count = 1
+
+    # Define the total service count
+    cg.add_define("MDNS_SERVICE_COUNT", service_count)
+
     var = cg.new_Pvariable(config[CONF_ID])
     await cg.register_component(var, config)
 
-    if config[CONF_SERVICES]:
-        cg.add_define("USE_MDNS_EXTRA_SERVICES")
-
     for service in config[CONF_SERVICES]:
         txt = [
             cg.StructInitializer(

esphome/components/mdns/mdns_component.cpp

@@ -24,7 +24,8 @@ static const char *const TAG = "mdns";
 void MDNSComponent::compile_records_() {
   this->hostname_ = App.get_name();
 
-  this->services_.clear();
+  this->service_count_ = 0;
+
 #ifdef USE_API
   if (api::global_api_server != nullptr) {
     MDNSService service{};
@@ -80,7 +81,7 @@ void MDNSComponent::compile_records_() {
     service.txt_records.push_back({"package_import_url", dashboard_import::get_package_import_url()});
 #endif
 
-    this->services_.push_back(service);
+    this->services_[this->service_count_++] = service;
   }
 #endif  // USE_API
 
@@ -90,7 +91,7 @@ void MDNSComponent::compile_records_() {
     service.service_type = "_prometheus-http";
     service.proto = "_tcp";
     service.port = USE_WEBSERVER_PORT;
-    this->services_.push_back(service);
+    this->services_[this->service_count_++] = service;
   }
 #endif
 
@@ -100,15 +101,17 @@ void MDNSComponent::compile_records_() {
     service.service_type = "_http";
     service.proto = "_tcp";
     service.port = USE_WEBSERVER_PORT;
-    this->services_.push_back(service);
+    this->services_[this->service_count_++] = service;
   }
 #endif
 
 #ifdef USE_MDNS_EXTRA_SERVICES
-  this->services_.insert(this->services_.end(), this->services_extra_.begin(), this->services_extra_.end());
+  for (const auto &extra_service : this->services_extra_) {
+    this->services_[this->service_count_++] = extra_service;
+  }
 #endif
 
-  if (this->services_.empty()) {
+  if (this->service_count_ == 0) {
     // Publish "http" service if not using native API
     // This is just to have *some* mDNS service so that .local resolution works
     MDNSService service{};
@@ -116,7 +119,7 @@ void MDNSComponent::compile_records_() {
     service.proto = "_tcp";
     service.port = USE_WEBSERVER_PORT;
     service.txt_records.push_back({"version", ESPHOME_VERSION});
-    this->services_.push_back(service);
+    this->services_[this->service_count_++] = service;
   }
 }
 
@@ -126,7 +129,8 @@ void MDNSComponent::dump_config() {
                 "  Hostname: %s",
                 this->hostname_.c_str());
   ESP_LOGV(TAG, "  Services:");
-  for (const auto &service : this->services_) {
+  for (size_t i = 0; i < this->service_count_; i++) {
+    const auto &service = this->services_[i];
     ESP_LOGV(TAG, "  - %s, %s, %d", service.service_type.c_str(), service.proto.c_str(),
              const_cast<TemplatableValue<uint16_t> &>(service.port).value());
     for (const auto &record : service.txt_records) {
@@ -136,8 +140,6 @@ void MDNSComponent::dump_config() {
   }
 }
 
-std::vector<MDNSService> MDNSComponent::get_services() { return this->services_; }
-
 }  // namespace mdns
 }  // namespace esphome
 #endif

esphome/components/mdns/mdns_component.h

@@ -1,6 +1,7 @@
 #pragma once
 #include "esphome/core/defines.h"
 #ifdef USE_MDNS
+#include <array>
 #include <string>
 #include <vector>
 #include "esphome/core/automation.h"
@@ -39,7 +40,8 @@ class MDNSComponent : public Component {
   void add_extra_service(MDNSService service) { services_extra_.push_back(std::move(service)); }
 #endif
 
-  std::vector<MDNSService> get_services();
+  const std::array<MDNSService, MDNS_SERVICE_COUNT> &get_services() const { return this->services_; }
+  size_t get_service_count() const { return this->service_count_; }
 
   void on_shutdown() override;
 
@@ -47,7 +49,8 @@ class MDNSComponent : public Component {
 #ifdef USE_MDNS_EXTRA_SERVICES
   std::vector<MDNSService> services_extra_{};
 #endif
-  std::vector<MDNSService> services_{};
+  std::array<MDNSService, MDNS_SERVICE_COUNT> services_{};
+  size_t service_count_{0};  // Track how many services are actually populated
   std::string hostname_;
   void compile_records_();
 };

esphome/components/openthread/openthread.cpp

@@ -125,11 +125,14 @@ void OpenThreadSrpComponent::setup() {
     return;
   }
 
-  // Copy the mdns services to our local instance so that the c_str pointers remain valid for the lifetime of this
-  // component
-  this->mdns_services_ = this->mdns_->get_services();
-  ESP_LOGD(TAG, "Setting up SRP services. count = %d\n", this->mdns_services_.size());
-  for (const auto &service : this->mdns_services_) {
+  // Get the mdns services directly from the component
+  // No lifetime concerns since OpenThread runs after MDNS component (enforced by get_setup_priority)
+  // and the services array in MDNS component lives for the entire application lifetime
+  const auto &services = this->mdns_->get_services();
+  size_t service_count = this->mdns_->get_service_count();
+  ESP_LOGD(TAG, "Setting up SRP services. count = %d\n", service_count);
+  for (size_t i = 0; i < service_count; i++) {
+    const auto &service = services[i];
     otSrpClientBuffersServiceEntry *entry = otSrpClientBuffersAllocateService(instance);
     if (!entry) {
       ESP_LOGW(TAG, "Failed to allocate service entry");

esphome/components/openthread/openthread.h

@@ -46,7 +46,6 @@ class OpenThreadSrpComponent : public Component {
 
  protected:
   esphome::mdns::MDNSComponent *mdns_{nullptr};
-  std::vector<esphome::mdns::MDNSService> mdns_services_;
   std::vector<std::unique_ptr<uint8_t[]>> memory_pool_;
   void *pool_alloc_(size_t size);
 };