model_data.h

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#pragma once
 
#ifdef USE_ESP32
 
#include <cstddef>
#include <cstdint>
#include "esphome/core/helpers.h"
 
namespace esphome::micro_wake_word {
 
// Owns the buffer holding a runtime-downloaded TFLite model. The buffer prefers PSRAM but falls back to
// internal RAM, so a device without PSRAM can still hold a single model. It is filled over HTTP, checked
// for integrity by the caller (SHA256) and for a usable TFLite header here, then kept alive for the
// lifetime of the WakeWordModel that uses it. Only ever held behind a std::shared_ptr, so copies and
// moves are disabled.
class ModelData {
 public:
  ModelData() = default;
  ~ModelData();
 
  // Non-copyable, non-movable
  ModelData(const ModelData &) = delete;
  ModelData &operator=(const ModelData &) = delete;
  ModelData(ModelData &&) = delete;
  ModelData &operator=(ModelData &&) = delete;
 
  // Allocate memory for model
  bool allocate(size_t size);
 
  // Get stable pointer for TFLite (only valid after validate_and_mark_ready())
  const uint8_t *get_model_pointer() const;
 
  // Get writable pointer for downloading (invalidates the model)
  uint8_t *get_write_pointer();
 
  // Validate TFLite model and mark as ready for use
  bool validate_and_mark_ready();
 
  // Check if model is valid and ready for use
  bool is_valid() const { return this->valid_; }
 
  // Get size of model data
  size_t size() const { return this->size_; }
 
  // Check if memory is allocated
  bool is_allocated() const { return this->data_ != nullptr; }
 
 protected:
  // Deallocate memory
  void deallocate_();
 
  uint8_t *data_{nullptr};
  size_t size_{0};
  bool valid_{false};
  RAMAllocator<uint8_t> allocator_{RAMAllocator<uint8_t>::NONE};
};
 
}  // namespace esphome::micro_wake_word
 
#endif  // USE_ESP32