[climate] Add zero-copy support for API custom fan mode and preset commands (#12402)

esphome/components/api/api.proto

@@ -1091,11 +1091,11 @@ message ClimateCommandRequest {
   bool has_swing_mode = 14;
   ClimateSwingMode swing_mode = 15;
   bool has_custom_fan_mode = 16;
-  string custom_fan_mode = 17;
+  string custom_fan_mode = 17 [(pointer_to_buffer) = true];
   bool has_preset = 18;
   ClimatePreset preset = 19;
   bool has_custom_preset = 20;
-  string custom_preset = 21;
+  string custom_preset = 21 [(pointer_to_buffer) = true];
   bool has_target_humidity = 22;
   float target_humidity = 23;
   uint32 device_id = 24 [(field_ifdef) = "USE_DEVICES"];

esphome/components/api/api_connection.cpp

@@ -712,11 +712,11 @@ void APIConnection::climate_command(const ClimateCommandRequest &msg) {
   if (msg.has_fan_mode)
     call.set_fan_mode(static_cast<climate::ClimateFanMode>(msg.fan_mode));
   if (msg.has_custom_fan_mode)
-    call.set_fan_mode(msg.custom_fan_mode);
+    call.set_fan_mode(reinterpret_cast<const char *>(msg.custom_fan_mode), msg.custom_fan_mode_len);
   if (msg.has_preset)
     call.set_preset(static_cast<climate::ClimatePreset>(msg.preset));
   if (msg.has_custom_preset)
-    call.set_preset(msg.custom_preset);
+    call.set_preset(reinterpret_cast<const char *>(msg.custom_preset), msg.custom_preset_len);
   if (msg.has_swing_mode)
     call.set_swing_mode(static_cast<climate::ClimateSwingMode>(msg.swing_mode));
   call.perform();

esphome/components/api/api_pb2.cpp

@@ -1392,12 +1392,18 @@ bool ClimateCommandRequest::decode_varint(uint32_t field_id, ProtoVarInt value)
 }
 bool ClimateCommandRequest::decode_length(uint32_t field_id, ProtoLengthDelimited value) {
   switch (field_id) {
-    case 17:
-      this->custom_fan_mode = value.as_string();
+    case 17: {
+      // Use raw data directly to avoid allocation
+      this->custom_fan_mode = value.data();
+      this->custom_fan_mode_len = value.size();
       break;
-    case 21:
-      this->custom_preset = value.as_string();
+    }
+    case 21: {
+      // Use raw data directly to avoid allocation
+      this->custom_preset = value.data();
+      this->custom_preset_len = value.size();
       break;
+    }
     default:
       return false;
   }

esphome/components/api/api_pb2.h

@@ -1475,7 +1475,7 @@ class ClimateStateResponse final : public StateResponseProtoMessage {
 class ClimateCommandRequest final : public CommandProtoMessage {
  public:
   static constexpr uint8_t MESSAGE_TYPE = 48;
-  static constexpr uint8_t ESTIMATED_SIZE = 84;
+  static constexpr uint8_t ESTIMATED_SIZE = 104;
 #ifdef HAS_PROTO_MESSAGE_DUMP
   const char *message_name() const override { return "climate_command_request"; }
 #endif
@@ -1492,11 +1492,13 @@ class ClimateCommandRequest final : public CommandProtoMessage {
   bool has_swing_mode{false};
   enums::ClimateSwingMode swing_mode{};
   bool has_custom_fan_mode{false};
-  std::string custom_fan_mode{};
+  const uint8_t *custom_fan_mode{nullptr};
+  uint16_t custom_fan_mode_len{0};
   bool has_preset{false};
   enums::ClimatePreset preset{};
   bool has_custom_preset{false};
-  std::string custom_preset{};
+  const uint8_t *custom_preset{nullptr};
+  uint16_t custom_preset_len{0};
   bool has_target_humidity{false};
   float target_humidity{0.0f};
 #ifdef HAS_PROTO_MESSAGE_DUMP

esphome/components/api/api_pb2_dump.cpp

@@ -1374,11 +1374,15 @@ void ClimateCommandRequest::dump_to(std::string &out) const {
   dump_field(out, "has_swing_mode", this->has_swing_mode);
   dump_field(out, "swing_mode", static_cast<enums::ClimateSwingMode>(this->swing_mode));
   dump_field(out, "has_custom_fan_mode", this->has_custom_fan_mode);
-  dump_field(out, "custom_fan_mode", this->custom_fan_mode);
+  out.append("  custom_fan_mode: ");
+  out.append(format_hex_pretty(this->custom_fan_mode, this->custom_fan_mode_len));
+  out.append("\n");
   dump_field(out, "has_preset", this->has_preset);
   dump_field(out, "preset", static_cast<enums::ClimatePreset>(this->preset));
   dump_field(out, "has_custom_preset", this->has_custom_preset);
-  dump_field(out, "custom_preset", this->custom_preset);
+  out.append("  custom_preset: ");
+  out.append(format_hex_pretty(this->custom_preset, this->custom_preset_len));
+  out.append("\n");
   dump_field(out, "has_target_humidity", this->has_target_humidity);
   dump_field(out, "target_humidity", this->target_humidity);
 #ifdef USE_DEVICES

esphome/components/climate/climate.cpp

@@ -2,6 +2,7 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/controller_registry.h"
 #include "esphome/core/macros.h"
+#include <strings.h>
 
 namespace esphome::climate {
 
@@ -190,24 +191,30 @@ ClimateCall &ClimateCall::set_fan_mode(ClimateFanMode fan_mode) {
 }
 
 ClimateCall &ClimateCall::set_fan_mode(const char *custom_fan_mode) {
+  return this->set_fan_mode(custom_fan_mode, strlen(custom_fan_mode));
+}
+
+ClimateCall &ClimateCall::set_fan_mode(const std::string &fan_mode) {
+  return this->set_fan_mode(fan_mode.data(), fan_mode.size());
+}
+
+ClimateCall &ClimateCall::set_fan_mode(const char *custom_fan_mode, size_t len) {
   // Check if it's a standard enum mode first
   for (const auto &mode_entry : CLIMATE_FAN_MODES_BY_STR) {
-    if (str_equals_case_insensitive(custom_fan_mode, mode_entry.str)) {
+    if (strncasecmp(custom_fan_mode, mode_entry.str, len) == 0 && mode_entry.str[len] == '\0') {
       return this->set_fan_mode(static_cast<ClimateFanMode>(mode_entry.value));
     }
   }
   // Find the matching pointer from parent climate device
-  if (const char *mode_ptr = this->parent_->find_custom_fan_mode_(custom_fan_mode)) {
+  if (const char *mode_ptr = this->parent_->find_custom_fan_mode_(custom_fan_mode, len)) {
     this->custom_fan_mode_ = mode_ptr;
     this->fan_mode_.reset();
     return *this;
   }
-  ESP_LOGW(TAG, "'%s' - Unrecognized fan mode %s", this->parent_->get_name().c_str(), custom_fan_mode);
+  ESP_LOGW(TAG, "'%s' - Unrecognized fan mode %.*s", this->parent_->get_name().c_str(), (int) len, custom_fan_mode);
   return *this;
 }
 
-ClimateCall &ClimateCall::set_fan_mode(const std::string &fan_mode) { return this->set_fan_mode(fan_mode.c_str()); }
-
 ClimateCall &ClimateCall::set_fan_mode(optional<std::string> fan_mode) {
   if (fan_mode.has_value()) {
     this->set_fan_mode(fan_mode.value());
@@ -222,24 +229,30 @@ ClimateCall &ClimateCall::set_preset(ClimatePreset preset) {
 }
 
 ClimateCall &ClimateCall::set_preset(const char *custom_preset) {
+  return this->set_preset(custom_preset, strlen(custom_preset));
+}
+
+ClimateCall &ClimateCall::set_preset(const std::string &preset) {
+  return this->set_preset(preset.data(), preset.size());
+}
+
+ClimateCall &ClimateCall::set_preset(const char *custom_preset, size_t len) {
   // Check if it's a standard enum preset first
   for (const auto &preset_entry : CLIMATE_PRESETS_BY_STR) {
-    if (str_equals_case_insensitive(custom_preset, preset_entry.str)) {
+    if (strncasecmp(custom_preset, preset_entry.str, len) == 0 && preset_entry.str[len] == '\0') {
       return this->set_preset(static_cast<ClimatePreset>(preset_entry.value));
     }
   }
   // Find the matching pointer from parent climate device
-  if (const char *preset_ptr = this->parent_->find_custom_preset_(custom_preset)) {
+  if (const char *preset_ptr = this->parent_->find_custom_preset_(custom_preset, len)) {
     this->custom_preset_ = preset_ptr;
     this->preset_.reset();
     return *this;
   }
-  ESP_LOGW(TAG, "'%s' - Unrecognized preset %s", this->parent_->get_name().c_str(), custom_preset);
+  ESP_LOGW(TAG, "'%s' - Unrecognized preset %.*s", this->parent_->get_name().c_str(), (int) len, custom_preset);
   return *this;
 }
 
-ClimateCall &ClimateCall::set_preset(const std::string &preset) { return this->set_preset(preset.c_str()); }
-
 ClimateCall &ClimateCall::set_preset(optional<std::string> preset) {
   if (preset.has_value()) {
     this->set_preset(preset.value());
@@ -688,11 +701,19 @@ bool Climate::set_custom_preset_(const char *preset) {
 void Climate::clear_custom_preset_() { this->custom_preset_ = nullptr; }
 
 const char *Climate::find_custom_fan_mode_(const char *custom_fan_mode) {
-  return this->get_traits().find_custom_fan_mode_(custom_fan_mode);
+  return this->find_custom_fan_mode_(custom_fan_mode, strlen(custom_fan_mode));
+}
+
+const char *Climate::find_custom_fan_mode_(const char *custom_fan_mode, size_t len) {
+  return this->get_traits().find_custom_fan_mode_(custom_fan_mode, len);
 }
 
 const char *Climate::find_custom_preset_(const char *custom_preset) {
-  return this->get_traits().find_custom_preset_(custom_preset);
+  return this->find_custom_preset_(custom_preset, strlen(custom_preset));
+}
+
+const char *Climate::find_custom_preset_(const char *custom_preset, size_t len) {
+  return this->get_traits().find_custom_preset_(custom_preset, len);
 }
 
 void Climate::dump_traits_(const char *tag) {

esphome/components/climate/climate.h

@@ -78,6 +78,8 @@ class ClimateCall {
   ClimateCall &set_fan_mode(optional<std::string> fan_mode);
   /// Set the custom fan mode of the climate device.
   ClimateCall &set_fan_mode(const char *custom_fan_mode);
+  /// Set the custom fan mode of the climate device (zero-copy API path).
+  ClimateCall &set_fan_mode(const char *custom_fan_mode, size_t len);
   /// Set the swing mode of the climate device.
   ClimateCall &set_swing_mode(ClimateSwingMode swing_mode);
   /// Set the swing mode of the climate device.
@@ -94,6 +96,8 @@ class ClimateCall {
   ClimateCall &set_preset(optional<std::string> preset);
   /// Set the custom preset of the climate device.
   ClimateCall &set_preset(const char *custom_preset);
+  /// Set the custom preset of the climate device (zero-copy API path).
+  ClimateCall &set_preset(const char *custom_preset, size_t len);
 
   void perform();
 
@@ -290,9 +294,11 @@ class Climate : public EntityBase {
 
   /// Find and return the matching custom fan mode pointer from traits, or nullptr if not found.
   const char *find_custom_fan_mode_(const char *custom_fan_mode);
+  const char *find_custom_fan_mode_(const char *custom_fan_mode, size_t len);
 
   /// Find and return the matching custom preset pointer from traits, or nullptr if not found.
   const char *find_custom_preset_(const char *custom_preset);
+  const char *find_custom_preset_(const char *custom_preset, size_t len);
 
   /** Get the default traits of this climate device.
    *

esphome/components/climate/climate_traits.h

@@ -20,18 +20,22 @@ using ClimatePresetMask = FiniteSetMask<ClimatePreset, DefaultBitPolicy<ClimateP
 
 // Lightweight linear search for small vectors (1-20 items) of const char* pointers
 // Avoids std::find template overhead
-inline bool vector_contains(const std::vector<const char *> &vec, const char *value) {
+inline bool vector_contains(const std::vector<const char *> &vec, const char *value, size_t len) {
   for (const char *item : vec) {
-    if (strcmp(item, value) == 0)
+    if (strncmp(item, value, len) == 0 && item[len] == '\0')
       return true;
   }
   return false;
 }
 
+inline bool vector_contains(const std::vector<const char *> &vec, const char *value) {
+  return vector_contains(vec, value, strlen(value));
+}
+
 // Find and return matching pointer from vector, or nullptr if not found
-inline const char *vector_find(const std::vector<const char *> &vec, const char *value) {
+inline const char *vector_find(const std::vector<const char *> &vec, const char *value, size_t len) {
   for (const char *item : vec) {
-    if (strcmp(item, value) == 0)
+    if (strncmp(item, value, len) == 0 && item[len] == '\0')
       return item;
   }
   return nullptr;
@@ -257,13 +261,19 @@ class ClimateTraits {
   /// Find and return the matching custom fan mode pointer from supported modes, or nullptr if not found
   /// This is protected as it's an implementation detail - use Climate::find_custom_fan_mode_() instead
   const char *find_custom_fan_mode_(const char *custom_fan_mode) const {
-    return vector_find(this->supported_custom_fan_modes_, custom_fan_mode);
+    return this->find_custom_fan_mode_(custom_fan_mode, strlen(custom_fan_mode));
+  }
+  const char *find_custom_fan_mode_(const char *custom_fan_mode, size_t len) const {
+    return vector_find(this->supported_custom_fan_modes_, custom_fan_mode, len);
   }
 
   /// Find and return the matching custom preset pointer from supported presets, or nullptr if not found
   /// This is protected as it's an implementation detail - use Climate::find_custom_preset_() instead
   const char *find_custom_preset_(const char *custom_preset) const {
-    return vector_find(this->supported_custom_presets_, custom_preset);
+    return this->find_custom_preset_(custom_preset, strlen(custom_preset));
+  }
+  const char *find_custom_preset_(const char *custom_preset, size_t len) const {
+    return vector_find(this->supported_custom_presets_, custom_preset, len);
   }
 
   uint32_t feature_flags_{0};