Reserve memory for component and platform vectors (#9042)

esphome/components/alarm_control_panel/__init__.py

@@ -235,6 +235,7 @@ async def register_alarm_control_panel(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_alarm_control_panel(var))
+    CORE.register_platform_component("alarm_control_panel", var)
     await setup_alarm_control_panel_core_(var, config)
 
 

esphome/components/binary_sensor/__init__.py

@@ -554,6 +554,7 @@ async def register_binary_sensor(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_binary_sensor(var))
+    CORE.register_platform_component("binary_sensor", var)
     await setup_binary_sensor_core_(var, config)
 
 

esphome/components/button/__init__.py

@@ -108,6 +108,7 @@ async def register_button(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_button(var))
+    CORE.register_platform_component("button", var)
     await setup_button_core_(var, config)
 
 

esphome/components/climate/__init__.py

@@ -443,6 +443,7 @@ async def register_climate(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_climate(var))
+    CORE.register_platform_component("climate", var)
     await setup_climate_core_(var, config)
 
 

esphome/components/cover/__init__.py

@@ -189,6 +189,7 @@ async def register_cover(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_cover(var))
+    CORE.register_platform_component("cover", var)
     await setup_cover_core_(var, config)
 
 

esphome/components/datetime/__init__.py

@@ -158,7 +158,9 @@ async def setup_datetime_core_(var, config):
 async def register_datetime(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
-    cg.add(getattr(cg.App, f"register_{config[CONF_TYPE].lower()}")(var))
+    entity_type = config[CONF_TYPE].lower()
+    cg.add(getattr(cg.App, f"register_{entity_type}")(var))
+    CORE.register_platform_component(entity_type, var)
     await setup_datetime_core_(var, config)
     cg.add_define(f"USE_DATETIME_{config[CONF_TYPE]}")
 

esphome/components/event/__init__.py

@@ -113,6 +113,7 @@ async def register_event(var, config, *, event_types: list[str]):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_event(var))
+    CORE.register_platform_component("event", var)
     await setup_event_core_(var, config, event_types=event_types)
 
 

esphome/components/fan/__init__.py

@@ -296,6 +296,7 @@ async def register_fan(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_fan(var))
+    CORE.register_platform_component("fan", var)
     await setup_fan_core_(var, config)
 
 

esphome/components/light/__init__.py

@@ -37,7 +37,7 @@ from esphome.const import (
     CONF_WEB_SERVER,
     CONF_WHITE,
 )
-from esphome.core import coroutine_with_priority
+from esphome.core import CORE, coroutine_with_priority
 from esphome.cpp_generator import MockObjClass
 from esphome.cpp_helpers import setup_entity
 
@@ -270,6 +270,7 @@ async def setup_light_core_(light_var, output_var, config):
 async def register_light(output_var, config):
     light_var = cg.new_Pvariable(config[CONF_ID], output_var)
     cg.add(cg.App.register_light(light_var))
+    CORE.register_platform_component("light", light_var)
     await cg.register_component(light_var, config)
     await setup_light_core_(light_var, output_var, config)
 

esphome/components/lock/__init__.py

@@ -115,6 +115,7 @@ async def register_lock(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_lock(var))
+    CORE.register_platform_component("lock", var)
     await _setup_lock_core(var, config)
 
 

esphome/components/media_player/__init__.py

@@ -103,6 +103,7 @@ async def register_media_player(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_media_player(var))
+    CORE.register_platform_component("media_player", var)
     await setup_media_player_core_(var, config)
 
 

esphome/components/number/__init__.py

@@ -277,6 +277,7 @@ async def register_number(
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_number(var))
+    CORE.register_platform_component("number", var)
     await setup_number_core_(
         var, config, min_value=min_value, max_value=max_value, step=step
     )

esphome/components/select/__init__.py

@@ -111,6 +111,7 @@ async def register_select(var, config, *, options: list[str]):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_select(var))
+    CORE.register_platform_component("select", var)
     await setup_select_core_(var, config, options=options)
 
 

esphome/components/sensor/__init__.py

@@ -167,7 +167,6 @@ DEVICE_CLASSES = [
 ]
 
 _LOGGER = logging.getLogger(__name__)
-
 sensor_ns = cg.esphome_ns.namespace("sensor")
 StateClasses = sensor_ns.enum("StateClass")
 STATE_CLASSES = {
@@ -840,6 +839,7 @@ async def register_sensor(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_sensor(var))
+    CORE.register_platform_component("sensor", var)
     await setup_sensor_core_(var, config)
 
 

esphome/components/switch/__init__.py

@@ -159,6 +159,7 @@ async def register_switch(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_switch(var))
+    CORE.register_platform_component("switch", var)
     await setup_switch_core_(var, config)
 
 

esphome/components/text/__init__.py

@@ -126,6 +126,7 @@ async def register_text(
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_text(var))
+    CORE.register_platform_component("text", var)
     await setup_text_core_(
         var, config, min_length=min_length, max_length=max_length, pattern=pattern
     )

esphome/components/text_sensor/__init__.py

@@ -215,6 +215,7 @@ async def register_text_sensor(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_text_sensor(var))
+    CORE.register_platform_component("text_sensor", var)
     await setup_text_sensor_core_(var, config)
 
 

esphome/components/update/__init__.py

@@ -111,6 +111,7 @@ async def register_update(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_update(var))
+    CORE.register_platform_component("update", var)
     await setup_update_core_(var, config)
 
 

esphome/components/valve/__init__.py

@@ -163,6 +163,7 @@ async def register_valve(var, config):
     if not CORE.has_id(config[CONF_ID]):
         var = cg.Pvariable(config[CONF_ID], var)
     cg.add(cg.App.register_valve(var))
+    CORE.register_platform_component("valve", var)
     await _setup_valve_core(var, config)
 
 

esphome/core/__init__.py

@@ -1,3 +1,4 @@
+from collections import defaultdict
 import logging
 import math
 import os
@@ -516,6 +517,9 @@ class EsphomeCore:
         self.loaded_platforms: set[str] = set()
         # A set of component IDs to track what Component subclasses are declared
         self.component_ids = set()
+        # Dict to track platform entity counts for pre-allocation
+        # Key: platform name (e.g. "sensor", "binary_sensor"), Value: count
+        self.platform_counts: defaultdict[str, int] = defaultdict(int)
         # Whether ESPHome was started in verbose mode
         self.verbose = False
         # Whether ESPHome was started in quiet mode
@@ -545,6 +549,7 @@ class EsphomeCore:
         self.platformio_options = {}
         self.loaded_integrations = set()
         self.component_ids = set()
+        self.platform_counts = defaultdict(int)
         PIN_SCHEMA_REGISTRY.reset()
 
     @property
@@ -669,16 +674,17 @@ class EsphomeCore:
     def using_esp_idf(self):
         return self.target_framework == "esp-idf"
 
-    def add_job(self, func, *args, **kwargs):
+    def add_job(self, func, *args, **kwargs) -> None:
         self.event_loop.add_job(func, *args, **kwargs)
 
-    def flush_tasks(self):
+    def flush_tasks(self) -> None:
         try:
             self.event_loop.flush_tasks()
         except RuntimeError as e:
             raise EsphomeError(str(e)) from e
 
-    def add(self, expression):
+    def add(self, expression, prepend=False) -> "Statement":
+        """Add an expression or statement to the main setup() block."""
         from esphome.cpp_generator import Expression, Statement, statement
 
         if isinstance(expression, Expression):
@@ -688,11 +694,14 @@ class EsphomeCore:
                 f"Add '{expression}' must be expression or statement, not {type(expression)}"
             )
 
-        self.main_statements.append(expression)
+        if prepend:
+            self.main_statements.insert(0, expression)
+        else:
+            self.main_statements.append(expression)
         _LOGGER.debug("Adding: %s", expression)
         return expression
 
-    def add_global(self, expression, prepend=False):
+    def add_global(self, expression, prepend=False) -> "Statement":
         from esphome.cpp_generator import Expression, Statement, statement
 
         if isinstance(expression, Expression):
@@ -822,6 +831,14 @@ class EsphomeCore:
     def has_id(self, id):
         return id in self.variables
 
+    def register_platform_component(self, platform_name: str, var) -> None:
+        """Register a component for a platform and track its count.
+
+        :param platform_name: The name of the platform (e.g., 'sensor', 'binary_sensor')
+        :param var: The variable (component) being registered (currently unused but kept for future use)
+        """
+        self.platform_counts[platform_name] += 1
+
     @property
     def cpp_main_section(self):
         from esphome.cpp_generator import statement

esphome/core/application.h

@@ -198,6 +198,73 @@ class Application {
   void register_update(update::UpdateEntity *update) { this->updates_.push_back(update); }
 #endif
 
+  /// Reserve space for components to avoid memory fragmentation
+  void reserve_components(size_t count) { this->components_.reserve(count); }
+
+#ifdef USE_BINARY_SENSOR
+  void reserve_binary_sensor(size_t count) { this->binary_sensors_.reserve(count); }
+#endif
+#ifdef USE_SWITCH
+  void reserve_switch(size_t count) { this->switches_.reserve(count); }
+#endif
+#ifdef USE_BUTTON
+  void reserve_button(size_t count) { this->buttons_.reserve(count); }
+#endif
+#ifdef USE_SENSOR
+  void reserve_sensor(size_t count) { this->sensors_.reserve(count); }
+#endif
+#ifdef USE_TEXT_SENSOR
+  void reserve_text_sensor(size_t count) { this->text_sensors_.reserve(count); }
+#endif
+#ifdef USE_FAN
+  void reserve_fan(size_t count) { this->fans_.reserve(count); }
+#endif
+#ifdef USE_COVER
+  void reserve_cover(size_t count) { this->covers_.reserve(count); }
+#endif
+#ifdef USE_CLIMATE
+  void reserve_climate(size_t count) { this->climates_.reserve(count); }
+#endif
+#ifdef USE_LIGHT
+  void reserve_light(size_t count) { this->lights_.reserve(count); }
+#endif
+#ifdef USE_NUMBER
+  void reserve_number(size_t count) { this->numbers_.reserve(count); }
+#endif
+#ifdef USE_DATETIME_DATE
+  void reserve_date(size_t count) { this->dates_.reserve(count); }
+#endif
+#ifdef USE_DATETIME_TIME
+  void reserve_time(size_t count) { this->times_.reserve(count); }
+#endif
+#ifdef USE_DATETIME_DATETIME
+  void reserve_datetime(size_t count) { this->datetimes_.reserve(count); }
+#endif
+#ifdef USE_SELECT
+  void reserve_select(size_t count) { this->selects_.reserve(count); }
+#endif
+#ifdef USE_TEXT
+  void reserve_text(size_t count) { this->texts_.reserve(count); }
+#endif
+#ifdef USE_LOCK
+  void reserve_lock(size_t count) { this->locks_.reserve(count); }
+#endif
+#ifdef USE_VALVE
+  void reserve_valve(size_t count) { this->valves_.reserve(count); }
+#endif
+#ifdef USE_MEDIA_PLAYER
+  void reserve_media_player(size_t count) { this->media_players_.reserve(count); }
+#endif
+#ifdef USE_ALARM_CONTROL_PANEL
+  void reserve_alarm_control_panel(size_t count) { this->alarm_control_panels_.reserve(count); }
+#endif
+#ifdef USE_EVENT
+  void reserve_event(size_t count) { this->events_.reserve(count); }
+#endif
+#ifdef USE_UPDATE
+  void reserve_update(size_t count) { this->updates_.reserve(count); }
+#endif
+
   /// Register the component in this Application instance.
   template<class C> C *register_component(C *c) {
     static_assert(std::is_base_of<Component, C>::value, "Only Component subclasses can be registered");

esphome/core/config.py

@@ -329,6 +329,12 @@ async def _add_automations(config):
         await automation.build_automation(trigger, [], conf)
 
 
+@coroutine_with_priority(-100.0)
+async def _add_platform_reserves() -> None:
+    for platform_name, count in sorted(CORE.platform_counts.items()):
+        cg.add(cg.RawStatement(f"App.reserve_{platform_name}({count});"), prepend=True)
+
+
 @coroutine_with_priority(100.0)
 async def to_code(config):
     cg.add_global(cg.global_ns.namespace("esphome").using)
@@ -347,6 +353,12 @@ async def to_code(config):
             config[CONF_NAME_ADD_MAC_SUFFIX],
         )
     )
+    # Reserve space for components to avoid reallocation during registration
+    cg.add(
+        cg.RawStatement(f"App.reserve_components({len(CORE.component_ids)});"),
+    )
+
+    CORE.add_job(_add_platform_reserves)
 
     CORE.add_job(_add_automations, config)
 

esphome/cpp_generator.py

@@ -579,13 +579,13 @@ def new_Pvariable(id_: ID, *args: SafeExpType) -> Pvariable:
     return Pvariable(id_, rhs)
 
 
-def add(expression: Expression | Statement):
+def add(expression: Expression | Statement, prepend: bool = False):
     """Add an expression to the codegen section.
 
     After this is called, the given given expression will
     show up in the setup() function after this has been called.
     """
-    CORE.add(expression)
+    CORE.add(expression, prepend)
 
 
 def add_global(expression: SafeExpType | Statement, prepend: bool = False):