[select] Add zero-copy support for API select commands (#12329)

esphome/components/api/api.proto

@@ -1195,7 +1195,7 @@ message SelectCommandRequest {
   option (base_class) = "CommandProtoMessage";
 
   fixed32 key = 1;
-  string state = 2;
+  string state = 2 [(pointer_to_buffer) = true];
   uint32 device_id = 3 [(field_ifdef) = "USE_DEVICES"];
 }
 

esphome/components/api/api_connection.cpp

@@ -902,7 +902,7 @@ uint16_t APIConnection::try_send_select_info(EntityBase *entity, APIConnection *
 }
 void APIConnection::select_command(const SelectCommandRequest &msg) {
   ENTITY_COMMAND_MAKE_CALL(select::Select, select, select)
-  call.set_option(msg.state);
+  call.set_option(reinterpret_cast<const char *>(msg.state), msg.state_len);
   call.perform();
 }
 #endif

esphome/components/api/api_pb2.cpp

@@ -1569,9 +1569,12 @@ bool SelectCommandRequest::decode_varint(uint32_t field_id, ProtoVarInt value) {
 }
 bool SelectCommandRequest::decode_length(uint32_t field_id, ProtoLengthDelimited value) {
   switch (field_id) {
-    case 2:
-      this->state = value.as_string();
+    case 2: {
+      // Use raw data directly to avoid allocation
+      this->state = value.data();
+      this->state_len = value.size();
       break;
+    }
     default:
       return false;
   }

esphome/components/api/api_pb2.h

@@ -1604,11 +1604,12 @@ class SelectStateResponse final : public StateResponseProtoMessage {
 class SelectCommandRequest final : public CommandProtoMessage {
  public:
   static constexpr uint8_t MESSAGE_TYPE = 54;
-  static constexpr uint8_t ESTIMATED_SIZE = 18;
+  static constexpr uint8_t ESTIMATED_SIZE = 28;
 #ifdef HAS_PROTO_MESSAGE_DUMP
   const char *message_name() const override { return "select_command_request"; }
 #endif
-  std::string state{};
+  const uint8_t *state{nullptr};
+  uint16_t state_len{0};
 #ifdef HAS_PROTO_MESSAGE_DUMP
   void dump_to(std::string &out) const override;
 #endif

esphome/components/api/api_pb2_dump.cpp

@@ -1453,7 +1453,9 @@ void SelectStateResponse::dump_to(std::string &out) const {
 void SelectCommandRequest::dump_to(std::string &out) const {
   MessageDumpHelper helper(out, "SelectCommandRequest");
   dump_field(out, "key", this->key);
-  dump_field(out, "state", this->state);
+  out.append("  state: ");
+  out.append(format_hex_pretty(this->state, this->state_len));
+  out.append("\n");
 #ifdef USE_DEVICES
   dump_field(out, "device_id", this->device_id);
 #endif

esphome/components/select/select.cpp

@@ -56,12 +56,10 @@ size_t Select::size() const {
   return options.size();
 }
 
-optional<size_t> Select::index_of(const std::string &option) const { return this->index_of(option.c_str()); }
-
-optional<size_t> Select::index_of(const char *option) const {
+optional<size_t> Select::index_of(const char *option, size_t len) const {
   const auto &options = traits.get_options();
   for (size_t i = 0; i < options.size(); i++) {
-    if (strcmp(options[i], option) == 0) {
+    if (strncmp(options[i], option, len) == 0 && options[i][len] == '\0') {
       return i;
     }
   }

esphome/components/select/select.h

@@ -62,8 +62,9 @@ class Select : public EntityBase {
   size_t size() const;
 
   /// Find the (optional) index offset of the provided option value.
-  optional<size_t> index_of(const std::string &option) const;
-  optional<size_t> index_of(const char *option) const;
+  optional<size_t> index_of(const char *option, size_t len) const;
+  optional<size_t> index_of(const std::string &option) const { return this->index_of(option.data(), option.size()); }
+  optional<size_t> index_of(const char *option) const { return this->index_of(option, strlen(option)); }
 
   /// Return the (optional) index offset of the currently active option.
   optional<size_t> active_index() const;

esphome/components/select/select_call.cpp

@@ -6,9 +6,7 @@ namespace esphome::select {
 
 static const char *const TAG = "select";
 
-SelectCall &SelectCall::set_option(const std::string &option) { return this->with_option(option); }
-
-SelectCall &SelectCall::set_option(const char *option) { return this->with_option(option); }
+SelectCall &SelectCall::set_option(const char *option, size_t len) { return this->with_option(option, len); }
 
 SelectCall &SelectCall::set_index(size_t index) { return this->with_index(index); }
 
@@ -32,12 +30,10 @@ SelectCall &SelectCall::with_cycle(bool cycle) {
   return *this;
 }
 
-SelectCall &SelectCall::with_option(const std::string &option) { return this->with_option(option.c_str()); }
-
-SelectCall &SelectCall::with_option(const char *option) {
+SelectCall &SelectCall::with_option(const char *option, size_t len) {
   this->operation_ = SELECT_OP_SET;
   // Find the option index - this validates the option exists
-  this->index_ = this->parent_->index_of(option);
+  this->index_ = this->parent_->index_of(option, len);
   return *this;
 }
 

esphome/components/select/select_call.h

@@ -20,8 +20,9 @@ class SelectCall {
   explicit SelectCall(Select *parent) : parent_(parent) {}
   void perform();
 
-  SelectCall &set_option(const std::string &option);
-  SelectCall &set_option(const char *option);
+  SelectCall &set_option(const char *option, size_t len);
+  SelectCall &set_option(const std::string &option) { return this->set_option(option.data(), option.size()); }
+  SelectCall &set_option(const char *option) { return this->set_option(option, strlen(option)); }
   SelectCall &set_index(size_t index);
 
   SelectCall &select_next(bool cycle);
@@ -31,8 +32,9 @@ class SelectCall {
 
   SelectCall &with_operation(SelectOperation operation);
   SelectCall &with_cycle(bool cycle);
-  SelectCall &with_option(const std::string &option);
-  SelectCall &with_option(const char *option);
+  SelectCall &with_option(const char *option, size_t len);
+  SelectCall &with_option(const std::string &option) { return this->with_option(option.data(), option.size()); }
+  SelectCall &with_option(const char *option) { return this->with_option(option, strlen(option)); }
   SelectCall &with_index(size_t index);
 
  protected: