test/node-api/test_buffer/test_buffer.c

#include <stdlib.h>
#include <string.h>
#include <node_api.h>
#include "../../js-native-api/common.h"

static const char theText[] =
    "Lorem ipsum dolor sit amet, consectetur adipiscing elit.";

static int deleterCallCount = 0;
static void deleteTheText(napi_env env, void* data, void* finalize_hint) {
  NODE_API_ASSERT_RETURN_VOID(
      env, data != NULL && strcmp(data, theText) == 0, "invalid data");
  (void)finalize_hint;
  free(data);
  deleterCallCount++;
}

static void noopDeleter(napi_env env, void* data, void* finalize_hint) {
  NODE_API_ASSERT_RETURN_VOID(
      env, data != NULL && strcmp(data, theText) == 0, "invalid data");
  (void)finalize_hint;
  deleterCallCount++;
}

static void malignDeleter(napi_env env, void* data, void* finalize_hint) {
  NODE_API_ASSERT_RETURN_VOID(env, data != NULL && strcmp(data, theText) == 0, "invalid data");
  napi_ref finalizer_ref = (napi_ref)finalize_hint;
  napi_value js_finalizer;
  napi_value recv;
  NODE_API_CALL_RETURN_VOID(env, napi_get_reference_value(env, finalizer_ref, &js_finalizer));
  NODE_API_CALL_RETURN_VOID(env, napi_get_global(env, &recv));
  NODE_API_CALL_RETURN_VOID(env, napi_call_function(env, recv, js_finalizer, 0, NULL, NULL));
  NODE_API_CALL_RETURN_VOID(env, napi_delete_reference(env, finalizer_ref));
}

static napi_value newBuffer(napi_env env, napi_callback_info info) {
  napi_value theBuffer;
  char* theCopy;
  const unsigned int kBufferSize = sizeof(theText);

  NODE_API_CALL(env,
      napi_create_buffer(
          env, sizeof(theText), (void**)(&theCopy), &theBuffer));
  NODE_API_ASSERT(env, theCopy, "Failed to copy static text for newBuffer");
  memcpy(theCopy, theText, kBufferSize);

  return theBuffer;
}

static napi_value newExternalBuffer(napi_env env, napi_callback_info info) {
  napi_value theBuffer;
  char* theCopy = strdup(theText);
  NODE_API_ASSERT(
      env, theCopy, "Failed to copy static text for newExternalBuffer");
  NODE_API_CALL(env,
      napi_create_external_buffer(
          env, sizeof(theText), theCopy, deleteTheText,
          NULL /* finalize_hint */, &theBuffer));

  return theBuffer;
}

static napi_value getDeleterCallCount(napi_env env, napi_callback_info info) {
  napi_value callCount;
  NODE_API_CALL(env, napi_create_int32(env, deleterCallCount, &callCount));
  return callCount;
}

static napi_value copyBuffer(napi_env env, napi_callback_info info) {
  napi_value theBuffer;
  NODE_API_CALL(env, napi_create_buffer_copy(
      env, sizeof(theText), theText, NULL, &theBuffer));
  return theBuffer;
}

static napi_value bufferHasInstance(napi_env env, napi_callback_info info) {
  size_t argc = 1;
  napi_value args[1];
  NODE_API_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
  NODE_API_ASSERT(env, argc == 1, "Wrong number of arguments");
  napi_value theBuffer = args[0];
  bool hasInstance;
  napi_valuetype theType;
  NODE_API_CALL(env, napi_typeof(env, theBuffer, &theType));
  NODE_API_ASSERT(env,
      theType == napi_object, "bufferHasInstance: instance is not an object");
  NODE_API_CALL(env, napi_is_buffer(env, theBuffer, &hasInstance));
  NODE_API_ASSERT(env, hasInstance, "bufferHasInstance: instance is not a buffer");
  napi_value returnValue;
  NODE_API_CALL(env, napi_get_boolean(env, hasInstance, &returnValue));
  return returnValue;
}

static napi_value bufferInfo(napi_env env, napi_callback_info info) {
  size_t argc = 1;
  napi_value args[1];
  NODE_API_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
  NODE_API_ASSERT(env, argc == 1, "Wrong number of arguments");
  napi_value theBuffer = args[0];
  char *bufferData;
  napi_value returnValue;
  size_t bufferLength;
  NODE_API_CALL(env,
      napi_get_buffer_info(
          env, theBuffer, (void**)(&bufferData), &bufferLength));
  NODE_API_CALL(env, napi_get_boolean(env,
      !strcmp(bufferData, theText) && bufferLength == sizeof(theText),
      &returnValue));
  return returnValue;
}

static napi_value staticBuffer(napi_env env, napi_callback_info info) {
  napi_value theBuffer;
  NODE_API_CALL(env,
      napi_create_external_buffer(
          env, sizeof(theText), (void*)theText, noopDeleter,
          NULL /* finalize_hint */, &theBuffer));
  return theBuffer;
}

static napi_value malignFinalizerBuffer(napi_env env, napi_callback_info info) {
  size_t argc = 1;
  napi_value args[1];
  NODE_API_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
  NODE_API_ASSERT(env, argc == 1, "Wrong number of arguments");
  napi_value finalizer = args[0];
  napi_valuetype finalizer_valuetype;
  NODE_API_CALL(env, napi_typeof(env, finalizer, &finalizer_valuetype));
  NODE_API_ASSERT(env, finalizer_valuetype == napi_function, "Wrong type of first argument");
  napi_ref finalizer_ref;
  NODE_API_CALL(env, napi_create_reference(env, finalizer, 1, &finalizer_ref));

  napi_value theBuffer;
  NODE_API_CALL(
      env,
      napi_create_external_buffer(env,
                                  sizeof(theText),
                                  (void*)theText,
                                  malignDeleter,
                                  finalizer_ref,  // finalize_hint
                                  &theBuffer));
  return theBuffer;
}

static napi_value Init(napi_env env, napi_value exports) {
  napi_value theValue;

  NODE_API_CALL(env,
      napi_create_string_utf8(env, theText, sizeof(theText), &theValue));
  NODE_API_CALL(env,
      napi_set_named_property(env, exports, "theText", theValue));

  napi_property_descriptor methods[] = {
    DECLARE_NODE_API_PROPERTY("newBuffer", newBuffer),
    DECLARE_NODE_API_PROPERTY("newExternalBuffer", newExternalBuffer),
    DECLARE_NODE_API_PROPERTY("getDeleterCallCount", getDeleterCallCount),
    DECLARE_NODE_API_PROPERTY("copyBuffer", copyBuffer),
    DECLARE_NODE_API_PROPERTY("bufferHasInstance", bufferHasInstance),
    DECLARE_NODE_API_PROPERTY("bufferInfo", bufferInfo),
    DECLARE_NODE_API_PROPERTY("staticBuffer", staticBuffer),
    DECLARE_NODE_API_PROPERTY("malignFinalizerBuffer", malignFinalizerBuffer),
  };

  NODE_API_CALL(env, napi_define_properties(
      env, exports, sizeof(methods) / sizeof(methods[0]), methods));

  return exports;
}

NAPI_MODULE(NODE_GYP_MODULE_NAME, Init)