node_api.h

/******************************************************************************
 * Experimental prototype for demonstrating VM agnostic and ABI stable API
 * for native modules to use instead of using Nan and V8 APIs directly.
 *
 * The current status is "Experimental" and should not be used for
 * production applications.  The API is still subject to change
 * and as an experimental feature is NOT subject to semver.
 *
 ******************************************************************************/
#ifndef SRC_NODE_API_H_
#define SRC_NODE_API_H_

#include <stddef.h>
#include <stdbool.h>
#include "node_api_types.h"

#ifdef _WIN32
  #ifdef BUILDING_NODE_EXTENSION
    #ifdef EXTERNAL_NAPI
      // Building external N-API, or native module against external N-API
      #define NAPI_EXTERN /* nothing */
    #else
      // Building native module against node with built-in N-API
      #define NAPI_EXTERN __declspec(dllimport)
    #endif
  #else
    // Building node with built-in N-API
    #define NAPI_EXTERN __declspec(dllexport)
  #endif
#else
  #define NAPI_EXTERN /* nothing */
#endif

#ifdef _WIN32
# define NAPI_MODULE_EXPORT __declspec(dllexport)
#else
# define NAPI_MODULE_EXPORT __attribute__((visibility("default")))
#endif


typedef void (*napi_addon_register_func)(napi_env env,
                                         napi_value exports,
                                         napi_value module,
                                         void* priv);

typedef struct {
  int nm_version;
  unsigned int nm_flags;
  const char* nm_filename;
  napi_addon_register_func nm_register_func;
  const char* nm_modname;
  void* nm_priv;
  void* reserved[4];
} napi_module;

#define NAPI_MODULE_VERSION  1

#if defined(_MSC_VER)
#pragma section(".CRT$XCU", read)
#define NAPI_C_CTOR(fn)                                                     \
  static void __cdecl fn(void);                                             \
  __declspec(dllexport, allocate(".CRT$XCU")) void(__cdecl * fn##_)(void) = \
      fn;                                                                   \
  static void __cdecl fn(void)
#else
#define NAPI_C_CTOR(fn)                              \
  static void fn(void) __attribute__((constructor)); \
  static void fn(void)
#endif

#ifdef __cplusplus
#define EXTERN_C_START extern "C" {
#define EXTERN_C_END }
#else
#define EXTERN_C_START
#define EXTERN_C_END
#endif

#define NAPI_MODULE_X(modname, regfunc, priv, flags)                  \
  EXTERN_C_START                                                      \
    static napi_module _module =                                      \
    {                                                                 \
      NAPI_MODULE_VERSION,                                            \
      flags,                                                          \
      __FILE__,                                                       \
      regfunc,                                                        \
      #modname,                                                       \
      priv,                                                           \
      {0},                                                            \
    };                                                                \
    NAPI_C_CTOR(_register_ ## modname) {                              \
      napi_module_register(&_module);                                 \
    }                                                                 \
  EXTERN_C_END

#define NAPI_MODULE(modname, regfunc) \
  NAPI_MODULE_X(modname, regfunc, NULL, 0)

EXTERN_C_START

NAPI_EXTERN void napi_module_register(napi_module* mod);

NAPI_EXTERN napi_status
napi_get_last_error_info(napi_env env,
                         const napi_extended_error_info** result);

// Getters for defined singletons
NAPI_EXTERN napi_status napi_get_undefined(napi_env env, napi_value* result);
NAPI_EXTERN napi_status napi_get_null(napi_env env, napi_value* result);
NAPI_EXTERN napi_status napi_get_global(napi_env env, napi_value* result);
NAPI_EXTERN napi_status napi_get_boolean(napi_env env,
                                         bool value,
                                         napi_value* result);

// Methods to create Primitive types/Objects
NAPI_EXTERN napi_status napi_create_object(napi_env env, napi_value* result);
NAPI_EXTERN napi_status napi_create_array(napi_env env, napi_value* result);
NAPI_EXTERN napi_status napi_create_array_with_length(napi_env env,
                                                      size_t length,
                                                      napi_value* result);
NAPI_EXTERN napi_status napi_create_number(napi_env env,
                                           double value,
                                           napi_value* result);
NAPI_EXTERN napi_status napi_create_string_utf8(napi_env env,
                                                const char* str,
                                                size_t length,
                                                napi_value* result);
NAPI_EXTERN napi_status napi_create_string_utf16(napi_env env,
                                                 const char16_t* str,
                                                 size_t length,
                                                 napi_value* result);
NAPI_EXTERN napi_status napi_create_symbol(napi_env env,
                                           napi_value description,
                                           napi_value* result);
NAPI_EXTERN napi_status napi_create_function(napi_env env,
                                             const char* utf8name,
                                             napi_callback cb,
                                             void* data,
                                             napi_value* result);
NAPI_EXTERN napi_status napi_create_error(napi_env env,
                                          napi_value msg,
                                          napi_value* result);
NAPI_EXTERN napi_status napi_create_type_error(napi_env env,
                                               napi_value msg,
                                               napi_value* result);
NAPI_EXTERN napi_status napi_create_range_error(napi_env env,
                                                napi_value msg,
                                                napi_value* result);

// Methods to get the the native napi_value from Primitive type
NAPI_EXTERN napi_status napi_typeof(napi_env env,
                                    napi_value value,
                                    napi_valuetype* result);
NAPI_EXTERN napi_status napi_get_value_double(napi_env env,
                                              napi_value value,
                                              double* result);
NAPI_EXTERN napi_status napi_get_value_int32(napi_env env,
                                             napi_value value,
                                             int32_t* result);
NAPI_EXTERN napi_status napi_get_value_uint32(napi_env env,
                                              napi_value value,
                                              uint32_t* result);
NAPI_EXTERN napi_status napi_get_value_int64(napi_env env,
                                             napi_value value,
                                             int64_t* result);
NAPI_EXTERN napi_status napi_get_value_bool(napi_env env,
                                            napi_value value,
                                            bool* result);

// Gets the number of CHARACTERS in the string.
NAPI_EXTERN napi_status napi_get_value_string_length(napi_env env,
                                                     napi_value value,
                                                     size_t* result);

// Copies UTF-8 encoded bytes from a string into a buffer.
NAPI_EXTERN napi_status napi_get_value_string_utf8(napi_env env,
                                                   napi_value value,
                                                   char* buf,
                                                   size_t bufsize,
                                                   size_t* result);

// Copies UTF-16 encoded bytes from a string into a buffer.
NAPI_EXTERN napi_status napi_get_value_string_utf16(napi_env env,
                                                    napi_value value,
                                                    char16_t* buf,
                                                    size_t bufsize,
                                                    size_t* result);

// Methods to coerce values
// These APIs may execute user scripts
NAPI_EXTERN napi_status napi_coerce_to_bool(napi_env env,
                                            napi_value value,
                                            napi_value* result);
NAPI_EXTERN napi_status napi_coerce_to_number(napi_env env,
                                              napi_value value,
                                              napi_value* result);
NAPI_EXTERN napi_status napi_coerce_to_object(napi_env env,
                                              napi_value value,
                                              napi_value* result);
NAPI_EXTERN napi_status napi_coerce_to_string(napi_env env,
                                              napi_value value,
                                              napi_value* result);

// Methods to work with Objects
NAPI_EXTERN napi_status napi_get_prototype(napi_env env,
                                           napi_value object,
                                           napi_value* result);
NAPI_EXTERN napi_status napi_get_property_names(napi_env env,
                                                napi_value object,
                                                napi_value* result);
NAPI_EXTERN napi_status napi_set_property(napi_env env,
                                          napi_value object,
                                          napi_value key,
                                          napi_value value);
NAPI_EXTERN napi_status napi_has_property(napi_env env,
                                          napi_value object,
                                          napi_value key,
                                          bool* result);
NAPI_EXTERN napi_status napi_get_property(napi_env env,
                                          napi_value object,
                                          napi_value key,
                                          napi_value* result);
NAPI_EXTERN napi_status napi_set_named_property(napi_env env,
                                          napi_value object,
                                          const char* utf8name,
                                          napi_value value);
NAPI_EXTERN napi_status napi_has_named_property(napi_env env,
                                          napi_value object,
                                          const char* utf8name,
                                          bool* result);
NAPI_EXTERN napi_status napi_get_named_property(napi_env env,
                                          napi_value object,
                                          const char* utf8name,
                                          napi_value* result);
NAPI_EXTERN napi_status napi_set_element(napi_env env,
                                         napi_value object,
                                         uint32_t index,
                                         napi_value value);
NAPI_EXTERN napi_status napi_has_element(napi_env env,
                                         napi_value object,
                                         uint32_t index,
                                         bool* result);
NAPI_EXTERN napi_status napi_get_element(napi_env env,
                                         napi_value object,
                                         uint32_t index,
                                         napi_value* result);
NAPI_EXTERN napi_status
napi_define_properties(napi_env env,
                       napi_value object,
                       size_t property_count,
                       const napi_property_descriptor* properties);

// Methods to work with Arrays
NAPI_EXTERN napi_status napi_is_array(napi_env env,
                                      napi_value value,
                                      bool* result);
NAPI_EXTERN napi_status napi_get_array_length(napi_env env,
                                              napi_value value,
                                              uint32_t* result);

// Methods to compare values
NAPI_EXTERN napi_status napi_strict_equals(napi_env env,
                                           napi_value lhs,
                                           napi_value rhs,
                                           bool* result);

// Methods to work with Functions
NAPI_EXTERN napi_status napi_call_function(napi_env env,
                                           napi_value recv,
                                           napi_value func,
                                           size_t argc,
                                           const napi_value* argv,
                                           napi_value* result);
NAPI_EXTERN napi_status napi_new_instance(napi_env env,
                                          napi_value constructor,
                                          size_t argc,
                                          const napi_value* argv,
                                          napi_value* result);
NAPI_EXTERN napi_status napi_instanceof(napi_env env,
                                        napi_value object,
                                        napi_value constructor,
                                        bool* result);

// Napi version of node::MakeCallback(...)
NAPI_EXTERN napi_status napi_make_callback(napi_env env,
                                           napi_value recv,
                                           napi_value func,
                                           size_t argc,
                                           const napi_value* argv,
                                           napi_value* result);

// Methods to work with napi_callbacks

// Gets all callback info in a single call. (Ugly, but faster.)
NAPI_EXTERN napi_status napi_get_cb_info(
    napi_env env,               // [in] NAPI environment handle
    napi_callback_info cbinfo,  // [in] Opaque callback-info handle
    size_t* argc,      // [in-out] Specifies the size of the provided argv array
                       // and receives the actual count of args.
    napi_value* argv,  // [out] Array of values
    napi_value* thisArg,  // [out] Receives the JS 'this' arg for the call
    void** data);         // [out] Receives the data pointer for the callback.

NAPI_EXTERN napi_status napi_get_cb_args_length(napi_env env,
                                                napi_callback_info cbinfo,
                                                size_t* result);
NAPI_EXTERN napi_status napi_get_cb_args(napi_env env,
                                         napi_callback_info cbinfo,
                                         napi_value* buf,
                                         size_t bufsize);
NAPI_EXTERN napi_status napi_get_cb_this(napi_env env,
                                         napi_callback_info cbinfo,
                                         napi_value* result);

NAPI_EXTERN napi_status napi_get_cb_data(napi_env env,
                                         napi_callback_info cbinfo,
                                         void** result);
NAPI_EXTERN napi_status napi_is_construct_call(napi_env env,
                                               napi_callback_info cbinfo,
                                               bool* result);
NAPI_EXTERN napi_status napi_set_return_value(napi_env env,
                                              napi_callback_info cbinfo,
                                              napi_value value);
NAPI_EXTERN napi_status
napi_define_class(napi_env env,
                  const char* utf8name,
                  napi_callback constructor,
                  void* data,
                  size_t property_count,
                  const napi_property_descriptor* properties,
                  napi_value* result);

// Methods to work with external data objects
NAPI_EXTERN napi_status napi_wrap(napi_env env,
                                  napi_value js_object,
                                  void* native_object,
                                  napi_finalize finalize_cb,
                                  void* finalize_hint,
                                  napi_ref* result);
NAPI_EXTERN napi_status napi_unwrap(napi_env env,
                                    napi_value js_object,
                                    void** result);
NAPI_EXTERN napi_status napi_create_external(napi_env env,
                                             void* data,
                                             napi_finalize finalize_cb,
                                             void* finalize_hint,
                                             napi_value* result);
NAPI_EXTERN napi_status napi_get_value_external(napi_env env,
                                                napi_value value,
                                                void** result);

// Methods to control object lifespan

// Set initial_refcount to 0 for a weak reference, >0 for a strong reference.
NAPI_EXTERN napi_status napi_create_reference(napi_env env,
                                              napi_value value,
                                              uint32_t initial_refcount,
                                              napi_ref* result);

// Deletes a reference. The referenced value is released, and may
// be GC'd unless there are other references to it.
NAPI_EXTERN napi_status napi_delete_reference(napi_env env, napi_ref ref);

// Increments the reference count, optionally returning the resulting count.
// After this call the  reference will be a strong reference because its
// refcount is >0, and the referenced object is effectively "pinned".
// Calling this when the refcount is 0 and the object is unavailable
// results in an error.
NAPI_EXTERN napi_status napi_reference_ref(napi_env env,
                                           napi_ref ref,
                                           uint32_t* result);

// Decrements the reference count, optionally returning the resulting count.
// If the result is 0 the reference is now weak and the object may be GC'd
// at any time if there are no other references. Calling this when the
// refcount is already 0 results in an error.
NAPI_EXTERN napi_status napi_reference_unref(napi_env env,
                                             napi_ref ref,
                                             uint32_t* result);

// Attempts to get a referenced value. If the reference is weak,
// the value might no longer be available, in that case the call
// is still successful but the result is NULL.
NAPI_EXTERN napi_status napi_get_reference_value(napi_env env,
                                                 napi_ref ref,
                                                 napi_value* result);

NAPI_EXTERN napi_status napi_open_handle_scope(napi_env env,
                                               napi_handle_scope* result);
NAPI_EXTERN napi_status napi_close_handle_scope(napi_env env,
                                                napi_handle_scope scope);
NAPI_EXTERN napi_status
napi_open_escapable_handle_scope(napi_env env,
                                 napi_escapable_handle_scope* result);
NAPI_EXTERN napi_status
napi_close_escapable_handle_scope(napi_env env,
                                  napi_escapable_handle_scope scope);

NAPI_EXTERN napi_status napi_escape_handle(napi_env env,
                                           napi_escapable_handle_scope scope,
                                           napi_value escapee,
                                           napi_value* result);

// Methods to support error handling
NAPI_EXTERN napi_status napi_throw(napi_env env, napi_value error);
NAPI_EXTERN napi_status napi_throw_error(napi_env env, const char* msg);
NAPI_EXTERN napi_status napi_throw_type_error(napi_env env, const char* msg);
NAPI_EXTERN napi_status napi_throw_range_error(napi_env env, const char* msg);
NAPI_EXTERN napi_status napi_is_error(napi_env env,
                                      napi_value value,
                                      bool* result);

// Methods to support catching exceptions
NAPI_EXTERN napi_status napi_is_exception_pending(napi_env env, bool* result);
NAPI_EXTERN napi_status napi_get_and_clear_last_exception(napi_env env,
                                                          napi_value* result);

// Methods to provide node::Buffer functionality with napi types
NAPI_EXTERN napi_status napi_create_buffer(napi_env env,
                                           size_t length,
                                           void** data,
                                           napi_value* result);
NAPI_EXTERN napi_status napi_create_external_buffer(napi_env env,
                                                    size_t length,
                                                    void* data,
                                                    napi_finalize finalize_cb,
                                                    void* finalize_hint,
                                                    napi_value* result);
NAPI_EXTERN napi_status napi_create_buffer_copy(napi_env env,
                                                size_t length,
                                                const void* data,
                                                void** result_data,
                                                napi_value* result);
NAPI_EXTERN napi_status napi_is_buffer(napi_env env,
                                       napi_value value,
                                       bool* result);
NAPI_EXTERN napi_status napi_get_buffer_info(napi_env env,
                                             napi_value value,
                                             void** data,
                                             size_t* length);

// Methods to work with array buffers and typed arrays
NAPI_EXTERN napi_status napi_is_arraybuffer(napi_env env,
                                            napi_value value,
                                            bool* result);
NAPI_EXTERN napi_status napi_create_arraybuffer(napi_env env,
                                                size_t byte_length,
                                                void** data,
                                                napi_value* result);
NAPI_EXTERN napi_status
napi_create_external_arraybuffer(napi_env env,
                                 void* external_data,
                                 size_t byte_length,
                                 napi_finalize finalize_cb,
                                 void* finalize_hint,
                                 napi_value* result);
NAPI_EXTERN napi_status napi_get_arraybuffer_info(napi_env env,
                                                  napi_value arraybuffer,
                                                  void** data,
                                                  size_t* byte_length);
NAPI_EXTERN napi_status napi_is_typedarray(napi_env env,
                                           napi_value value,
                                           bool* result);
NAPI_EXTERN napi_status napi_create_typedarray(napi_env env,
                                               napi_typedarray_type type,
                                               size_t length,
                                               napi_value arraybuffer,
                                               size_t byte_offset,
                                               napi_value* result);
NAPI_EXTERN napi_status napi_get_typedarray_info(napi_env env,
                                                 napi_value typedarray,
                                                 napi_typedarray_type* type,
                                                 size_t* length,
                                                 void** data,
                                                 napi_value* arraybuffer,
                                                 size_t* byte_offset);
EXTERN_C_END

#endif  // SRC_NODE_API_H__