Merge remote-tracking branch 'upstream/bluetooth_no_allocate' into integration

esphome/components/api/api.proto

@@ -1465,7 +1465,7 @@ message BluetoothDeviceRequest {
 
   uint64 address = 1;
   BluetoothDeviceRequestType request_type = 2;
-  bool has_address_type = 3;
+  bool has_address_type = 3;  // Deprecated, should be removed in 2027.8 - https://github.com/esphome/esphome/pull/10318
   uint32 address_type = 4;
 }
 
@@ -1571,7 +1571,7 @@ message BluetoothGATTWriteRequest {
   uint32 handle = 2;
   bool response = 3;
 
-  bytes data = 4;
+  bytes data = 4 [(pointer_to_buffer) = true];
 }
 
 message BluetoothGATTReadDescriptorRequest {
@@ -1591,7 +1591,7 @@ message BluetoothGATTWriteDescriptorRequest {
   uint64 address = 1;
   uint32 handle = 2;
 
-  bytes data = 3;
+  bytes data = 3 [(pointer_to_buffer) = true];
 }
 
 message BluetoothGATTNotifyRequest {

esphome/components/api/api_options.proto

@@ -32,6 +32,13 @@ extend google.protobuf.FieldOptions {
     optional string fixed_array_size_define = 50010;
     optional string fixed_array_with_length_define = 50011;
 
+    // pointer_to_buffer: Use pointer instead of array for fixed-size byte fields
+    // When set, the field will be declared as a pointer (const uint8_t *data)
+    // instead of an array (uint8_t data[N]). This allows zero-copy on decode
+    // by pointing directly to the protobuf buffer. The buffer must remain valid
+    // until the message is processed (which is guaranteed for stack-allocated messages).
+    optional bool pointer_to_buffer = 50012 [default=false];
+
     // container_pointer: Zero-copy optimization for repeated fields.
     //
     // When container_pointer is set on a repeated field, the generated message will

esphome/components/api/api_pb2.cpp

@@ -2028,9 +2028,12 @@ bool BluetoothGATTWriteRequest::decode_varint(uint32_t field_id, ProtoVarInt val
 }
 bool BluetoothGATTWriteRequest::decode_length(uint32_t field_id, ProtoLengthDelimited value) {
   switch (field_id) {
-    case 4:
-      this->data = value.as_string();
+    case 4: {
+      // Use raw data directly to avoid allocation
+      this->data = value.data();
+      this->data_len = value.size();
       break;
+    }
     default:
       return false;
   }
@@ -2064,9 +2067,12 @@ bool BluetoothGATTWriteDescriptorRequest::decode_varint(uint32_t field_id, Proto
 }
 bool BluetoothGATTWriteDescriptorRequest::decode_length(uint32_t field_id, ProtoLengthDelimited value) {
   switch (field_id) {
-    case 3:
-      this->data = value.as_string();
+    case 3: {
+      // Use raw data directly to avoid allocation
+      this->data = value.data();
+      this->data_len = value.size();
       break;
+    }
     default:
       return false;
   }

esphome/components/api/api_pb2.h

@@ -1985,14 +1985,15 @@ class BluetoothGATTReadResponse final : public ProtoMessage {
 class BluetoothGATTWriteRequest final : public ProtoDecodableMessage {
  public:
   static constexpr uint8_t MESSAGE_TYPE = 75;
-  static constexpr uint8_t ESTIMATED_SIZE = 19;
+  static constexpr uint8_t ESTIMATED_SIZE = 29;
 #ifdef HAS_PROTO_MESSAGE_DUMP
   const char *message_name() const override { return "bluetooth_gatt_write_request"; }
 #endif
   uint64_t address{0};
   uint32_t handle{0};
   bool response{false};
-  std::string data{};
+  const uint8_t *data{nullptr};
+  uint16_t data_len{0};
 #ifdef HAS_PROTO_MESSAGE_DUMP
   void dump_to(std::string &out) const override;
 #endif
@@ -2020,13 +2021,14 @@ class BluetoothGATTReadDescriptorRequest final : public ProtoDecodableMessage {
 class BluetoothGATTWriteDescriptorRequest final : public ProtoDecodableMessage {
  public:
   static constexpr uint8_t MESSAGE_TYPE = 77;
-  static constexpr uint8_t ESTIMATED_SIZE = 17;
+  static constexpr uint8_t ESTIMATED_SIZE = 27;
 #ifdef HAS_PROTO_MESSAGE_DUMP
   const char *message_name() const override { return "bluetooth_gatt_write_descriptor_request"; }
 #endif
   uint64_t address{0};
   uint32_t handle{0};
-  std::string data{};
+  const uint8_t *data{nullptr};
+  uint16_t data_len{0};
 #ifdef HAS_PROTO_MESSAGE_DUMP
   void dump_to(std::string &out) const override;
 #endif

esphome/components/api/api_pb2_dump.cpp

@@ -1649,7 +1649,7 @@ void BluetoothGATTWriteRequest::dump_to(std::string &out) const {
   dump_field(out, "handle", this->handle);
   dump_field(out, "response", this->response);
   out.append("  data: ");
-  out.append(format_hex_pretty(reinterpret_cast<const uint8_t *>(this->data.data()), this->data.size()));
+  out.append(format_hex_pretty(this->data, this->data_len));
   out.append("\n");
 }
 void BluetoothGATTReadDescriptorRequest::dump_to(std::string &out) const {
@@ -1662,7 +1662,7 @@ void BluetoothGATTWriteDescriptorRequest::dump_to(std::string &out) const {
   dump_field(out, "address", this->address);
   dump_field(out, "handle", this->handle);
   out.append("  data: ");
-  out.append(format_hex_pretty(reinterpret_cast<const uint8_t *>(this->data.data()), this->data.size()));
+  out.append(format_hex_pretty(this->data, this->data_len));
   out.append("\n");
 }
 void BluetoothGATTNotifyRequest::dump_to(std::string &out) const {

esphome/components/api/proto.h

@@ -182,6 +182,10 @@ class ProtoLengthDelimited {
   explicit ProtoLengthDelimited(const uint8_t *value, size_t length) : value_(value), length_(length) {}
   std::string as_string() const { return std::string(reinterpret_cast<const char *>(this->value_), this->length_); }
 
+  // Direct access to raw data without string allocation
+  const uint8_t *data() const { return this->value_; }
+  size_t size() const { return this->length_; }
+
   /**
    * Decode the length-delimited data into an existing ProtoDecodableMessage instance.
    *

esphome/components/bluetooth_proxy/bluetooth_connection.cpp

@@ -514,7 +514,8 @@ esp_err_t BluetoothConnection::read_characteristic(uint16_t handle) {
   return this->check_and_log_error_("esp_ble_gattc_read_char", err);
 }
 
-esp_err_t BluetoothConnection::write_characteristic(uint16_t handle, const std::string &data, bool response) {
+esp_err_t BluetoothConnection::write_characteristic(uint16_t handle, const uint8_t *data, size_t length,
+                                                    bool response) {
   if (!this->connected()) {
     this->log_gatt_not_connected_("write", "characteristic");
     return ESP_GATT_NOT_CONNECTED;
@@ -523,7 +524,7 @@ esp_err_t BluetoothConnection::write_characteristic(uint16_t handle, const std::
            handle);
 
   esp_err_t err =
-      esp_ble_gattc_write_char(this->gattc_if_, this->conn_id_, handle, data.size(), (uint8_t *) data.data(),
+      esp_ble_gattc_write_char(this->gattc_if_, this->conn_id_, handle, length, const_cast<uint8_t *>(data),
                                response ? ESP_GATT_WRITE_TYPE_RSP : ESP_GATT_WRITE_TYPE_NO_RSP, ESP_GATT_AUTH_REQ_NONE);
   return this->check_and_log_error_("esp_ble_gattc_write_char", err);
 }
@@ -540,7 +541,7 @@ esp_err_t BluetoothConnection::read_descriptor(uint16_t handle) {
   return this->check_and_log_error_("esp_ble_gattc_read_char_descr", err);
 }
 
-esp_err_t BluetoothConnection::write_descriptor(uint16_t handle, const std::string &data, bool response) {
+esp_err_t BluetoothConnection::write_descriptor(uint16_t handle, const uint8_t *data, size_t length, bool response) {
   if (!this->connected()) {
     this->log_gatt_not_connected_("write", "descriptor");
     return ESP_GATT_NOT_CONNECTED;
@@ -549,7 +550,7 @@ esp_err_t BluetoothConnection::write_descriptor(uint16_t handle, const std::stri
            handle);
 
   esp_err_t err = esp_ble_gattc_write_char_descr(
-      this->gattc_if_, this->conn_id_, handle, data.size(), (uint8_t *) data.data(),
+      this->gattc_if_, this->conn_id_, handle, length, const_cast<uint8_t *>(data),
       response ? ESP_GATT_WRITE_TYPE_RSP : ESP_GATT_WRITE_TYPE_NO_RSP, ESP_GATT_AUTH_REQ_NONE);
   return this->check_and_log_error_("esp_ble_gattc_write_char_descr", err);
 }

esphome/components/bluetooth_proxy/bluetooth_connection.h

@@ -18,9 +18,9 @@ class BluetoothConnection final : public esp32_ble_client::BLEClientBase {
   esp32_ble_tracker::AdvertisementParserType get_advertisement_parser_type() override;
 
   esp_err_t read_characteristic(uint16_t handle);
-  esp_err_t write_characteristic(uint16_t handle, const std::string &data, bool response);
+  esp_err_t write_characteristic(uint16_t handle, const uint8_t *data, size_t length, bool response);
   esp_err_t read_descriptor(uint16_t handle);
-  esp_err_t write_descriptor(uint16_t handle, const std::string &data, bool response);
+  esp_err_t write_descriptor(uint16_t handle, const uint8_t *data, size_t length, bool response);
 
   esp_err_t notify_characteristic(uint16_t handle, bool enable);
 

esphome/components/bluetooth_proxy/bluetooth_proxy.cpp

@@ -305,7 +305,7 @@ void BluetoothProxy::bluetooth_gatt_write(const api::BluetoothGATTWriteRequest &
     return;
   }
 
-  auto err = connection->write_characteristic(msg.handle, msg.data, msg.response);
+  auto err = connection->write_characteristic(msg.handle, msg.data, msg.data_len, msg.response);
   if (err != ESP_OK) {
     this->send_gatt_error(msg.address, msg.handle, err);
   }
@@ -331,7 +331,7 @@ void BluetoothProxy::bluetooth_gatt_write_descriptor(const api::BluetoothGATTWri
     return;
   }
 
-  auto err = connection->write_descriptor(msg.handle, msg.data, true);
+  auto err = connection->write_descriptor(msg.handle, msg.data, msg.data_len, true);
   if (err != ESP_OK) {
     this->send_gatt_error(msg.address, msg.handle, err);
   }

esphome/components/mmc5603/mmc5603.cpp

@@ -128,21 +128,21 @@ void MMC5603Component::update() {
   raw_x |= buffer[1] << 4;
   raw_x |= buffer[2] << 0;
 
-  const float x = 0.0625 * (raw_x - 524288);
+  const float x = 0.00625 * (raw_x - 524288);
 
   int32_t raw_y = 0;
   raw_y |= buffer[3] << 12;
   raw_y |= buffer[4] << 4;
   raw_y |= buffer[5] << 0;
 
-  const float y = 0.0625 * (raw_y - 524288);
+  const float y = 0.00625 * (raw_y - 524288);
 
   int32_t raw_z = 0;
   raw_z |= buffer[6] << 12;
   raw_z |= buffer[7] << 4;
   raw_z |= buffer[8] << 0;
 
-  const float z = 0.0625 * (raw_z - 524288);
+  const float z = 0.00625 * (raw_z - 524288);
 
   const float heading = atan2f(0.0f - x, y) * 180.0f / M_PI;
   ESP_LOGD(TAG, "Got x=%0.02fµT y=%0.02fµT z=%0.02fµT heading=%0.01f°", x, y, z, heading);