v0.23.0

• Add napi_create_external_arraybuffer, the ArrayBuffer memory is copy from wasm, use emnapi_sync_memory to sync memory between wasm and JavaScript, use runtime method $emnapiSyncMemory on JavaScript side

  void finalizer(napi_env env, void* finalize_data, void* finalize_hint) {
     free(finalize_data);
  }
  
  napi_value createExternalArraybuffer(napi_env env, napi_callback_info info) {
    uint8_t* external_data = malloc(3);
    external_data[0] = 0;
    external_data[1] = 1;
    external_data[2] = 2;
    napi_value array_buffer;
    napi_create_external_arraybuffer(env, external_data, 3, finalizer, NULL, &array_buffer);
  
    external_data[0] = 3; // JavaScript ArrayBuffer memory will not change
    emnapi_sync_memory(env, array_buffer, 0, external_data, NAPI_AUTO_LENGTH, false);
    // after sync memory, new Uint8Array(array_buffer)[0] === 3
  
    return array_buffer;
  }

  declare function emnapiSyncMemory (
    arrayBufferOrView: ArrayBuffer | ArrayBufferView,
    offset?: number,
    pointer?: number,
    len?: number,
    js_to_wasm?: boolean
  ): void
  
  const array_buffer = Module.emnapiExports.createExternalArraybuffer()
  new Uint8Array(array_buffer)[1] === 4
  Module.emnapiSyncMemory(array_buffer, 0, 0, -1, true)

• ArrayBuffer related API always return data pointer, the memory could be a copy from JavaScript ArrayBuffer, use emnapi_get_memory_address to check if the memory should be released by user,

  • napi_create_arraybuffer
  • napi_get_arraybuffer_info
  • napi_get_typedarray_info
  • napi_get_dataview_info

  void* data;
  napi_get_typedarray_info(env, typedarray, NULL, NULL, &data, NULL, NULL);
  
  void* address;
  emnapi_ownership ownership;
  bool runtime_allocated;
  emnapi_get_memory_address(env, typedarray, &address, &ownership, &runtime_allocated);
  assert(address == data);
  if (data != NULL && runtime_allocated && ownership == emnapi_userland) {
    // user should free data
    // free(data);
  }