react-native-vision-camera/cpp/JSITypedArray.h

//
//  JSITypedArray.h
//  VisionCamera
//
//  Created by Marc Rousavy on 21.02.23.
//  Copyright © 2023 mrousavy. All rights reserved.
//


// Copied & Adapted from https://github.com/expo/expo/blob/main/packages/expo-gl/common/EXTypedArrayApi.h
// Credits to Expo

#pragma once

#include <jsi/jsi.h>

namespace jsi = facebook::jsi;

namespace vision {

enum class TypedArrayKind {
  Int8Array,
  Int16Array,
  Int32Array,
  Uint8Array,
  Uint8ClampedArray,
  Uint16Array,
  Uint32Array,
  Float32Array,
  Float64Array,
};

template <TypedArrayKind T>
class TypedArray;

template <TypedArrayKind T>
struct typedArrayTypeMap;
template <>
struct typedArrayTypeMap<TypedArrayKind::Int8Array> {
  typedef int8_t type;
};
template <>
struct typedArrayTypeMap<TypedArrayKind::Int16Array> {
  typedef int16_t type;
};
template <>
struct typedArrayTypeMap<TypedArrayKind::Int32Array> {
  typedef int32_t type;
};
template <>
struct typedArrayTypeMap<TypedArrayKind::Uint8Array> {
  typedef uint8_t type;
};
template <>
struct typedArrayTypeMap<TypedArrayKind::Uint8ClampedArray> {
  typedef uint8_t type;
};
template <>
struct typedArrayTypeMap<TypedArrayKind::Uint16Array> {
  typedef uint16_t type;
};
template <>
struct typedArrayTypeMap<TypedArrayKind::Uint32Array> {
  typedef uint32_t type;
};
template <>
struct typedArrayTypeMap<TypedArrayKind::Float32Array> {
  typedef float type;
};
template <>
struct typedArrayTypeMap<TypedArrayKind::Float64Array> {
  typedef double type;
};

// Instance of this class will invalidate PropNameIDCache when destructor is called.
// Attach this object to global in specific jsi::Runtime to make sure lifecycle of
// the cache object is connected to the lifecycle of the js runtime
class InvalidateCacheOnDestroy : public jsi::HostObject {
 public:
  InvalidateCacheOnDestroy(jsi::Runtime &runtime);
  virtual ~InvalidateCacheOnDestroy();
  virtual jsi::Value get(jsi::Runtime &, const jsi::PropNameID &name) {
    return jsi::Value::null();
  }
  virtual void set(jsi::Runtime &, const jsi::PropNameID &name, const jsi::Value &value) {}
  virtual std::vector<jsi::PropNameID> getPropertyNames(jsi::Runtime &rt) {
    return {};
  }

 private:
  uintptr_t key;
};

class TypedArrayBase : public jsi::Object {
 public:
  template <TypedArrayKind T>
  using ContentType = typename typedArrayTypeMap<T>::type;

  TypedArrayBase(jsi::Runtime &, size_t, TypedArrayKind);
  TypedArrayBase(jsi::Runtime &, const jsi::Object &);
  TypedArrayBase(TypedArrayBase &&) = default;
  TypedArrayBase &operator=(TypedArrayBase &&) = default;

  TypedArrayKind getKind(jsi::Runtime &runtime) const;

  template <TypedArrayKind T>
  TypedArray<T> get(jsi::Runtime &runtime) const &;
  template <TypedArrayKind T>
  TypedArray<T> get(jsi::Runtime &runtime) &&;
  template <TypedArrayKind T>
  TypedArray<T> as(jsi::Runtime &runtime) const &;
  template <TypedArrayKind T>
  TypedArray<T> as(jsi::Runtime &runtime) &&;

  size_t size(jsi::Runtime &runtime) const;
  size_t length(jsi::Runtime &runtime) const;
  size_t byteLength(jsi::Runtime &runtime) const;
  size_t byteOffset(jsi::Runtime &runtime) const;
  bool hasBuffer(jsi::Runtime &runtime) const;

  std::vector<uint8_t> toVector(jsi::Runtime &runtime);
  jsi::ArrayBuffer getBuffer(jsi::Runtime &runtime) const;

 private:
  template <TypedArrayKind>
  friend class TypedArray;
};

bool isTypedArray(jsi::Runtime &runtime, const jsi::Object &jsObj);
TypedArrayBase getTypedArray(jsi::Runtime &runtime, const jsi::Object &jsObj);

std::vector<uint8_t> arrayBufferToVector(jsi::Runtime &runtime, jsi::Object &jsObj);
void arrayBufferUpdate(
    jsi::Runtime &runtime,
    jsi::ArrayBuffer &buffer,
    std::vector<uint8_t> data,
    size_t offset);

template <TypedArrayKind T>
class TypedArray : public TypedArrayBase {
 public:
  TypedArray(jsi::Runtime &runtime, size_t size);
  TypedArray(jsi::Runtime &runtime, std::vector<ContentType<T>> data);
  TypedArray(TypedArrayBase &&base);
  TypedArray(TypedArray &&) = default;
  TypedArray &operator=(TypedArray &&) = default;

  std::vector<ContentType<T>> toVector(jsi::Runtime &runtime);
  void update(jsi::Runtime &runtime, const std::vector<ContentType<T>> &data);
  void updateUnsafe(jsi::Runtime &runtime, ContentType<T> *data, size_t length);
  uint8_t* data(jsi::Runtime &runtime);
};

template <TypedArrayKind T>
TypedArray<T> TypedArrayBase::get(jsi::Runtime &runtime) const & {
  assert(getKind(runtime) == T);
  (void)runtime; // when assert is disabled we need to mark this as used
  return TypedArray<T>(jsi::Value(runtime, jsi::Value(runtime, *this).asObject(runtime)));
}

template <TypedArrayKind T>
TypedArray<T> TypedArrayBase::get(jsi::Runtime &runtime) && {
  assert(getKind(runtime) == T);
  (void)runtime; // when assert is disabled we need to mark this as used
  return TypedArray<T>(std::move(*this));
}

template <TypedArrayKind T>
TypedArray<T> TypedArrayBase::as(jsi::Runtime &runtime) const & {
  if (getKind(runtime) != T) {
    throw jsi::JSError(runtime, "Object is not a TypedArray");
  }
  return get<T>(runtime);
}

template <TypedArrayKind T>
TypedArray<T> TypedArrayBase::as(jsi::Runtime &runtime) && {
  if (getKind(runtime) != T) {
    throw jsi::JSError(runtime, "Object is not a TypedArray");
  }
  return std::move(*this).get<T>(runtime);
}
} // namespace vision