c++cnode.jsnode.js-napi

Calling a C function with Node.js N-API shows output not expected


I'm new to Node.js N-API. Let me go straight to the question.

I'm trying to call a C function Camellia_Ekeygen with N-API, but the output of the function m_uKttWork is different from calling the same function directly with C++ code.

Here're the codes and outputs for references.

Using N-API

module.cpp

#include <node_api.h>
#include "camellia.h"

napi_value MyFunction(napi_env env, napi_callback_info info) {
    typedef unsigned int KEY_TABLE_TYPE[68];
    typedef unsigned char BYTE;

    BYTE m_byCurrentWorkKey[16] {};
    KEY_TABLE_TYPE m_uKttWork {};

    napi_status status;

    Camellia_Ekeygen( 128, m_byCurrentWorkKey, m_uKttWork );

    napi_value result;
    status = napi_create_array(env, &result);

    napi_value num_result;
    for (int i = 0; i < 68; i++) {
        status = napi_create_uint32(env, m_uKttWork[i], &num_result);
        status = napi_set_element(env, result, i, num_result);
    }

    return result;
}

napi_value Init(napi_env env, napi_value exports) {
    napi_status status;
    napi_value fn;

    status = napi_create_function(env, NULL, 0, MyFunction, NULL, &fn);
    status = napi_set_named_property(env, exports, "my_function", fn);

    return exports;
}

NAPI_MODULE(NODE_GYP_MODULE_NAME, Init)

module.js

const addon = require('./build/Release/module');
console.log(addon.my_function());

Output

$ node module.js
[ 0,
  0,
  0,
  0,
  1827423791,
  382301878,
  1852628593,
  3123771802,
  0,
  0,
  0,
  0,
  588766488,
  3143317110,
  1865976676,
  2093823798,
  4002168422,
  2604339595,
  1169317293,
  2610640796,
  0,
  0,
  0,
  0,
  523455949,
  2294675270,
  0,
  0,
  2800143847,
  4221767577,
  1724826722,
  292329323,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  1169317293,
  2610640796,
  4002168422,
  2604339595,
  0,
  0,
  0,
  0,
  3143317110,
  1865976676,
  2093823798,
  588766488,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0,
  0 ]
(node:3475) Warning: N-API is an experimental feature and could change at any time.
$ 

Calling Camellia_Ekeygen directly

test.cpp

#include <iostream>
#include "camellia.h"

int main() {
    typedef unsigned char BYTE;
    typedef unsigned int KEY_TABLE_TYPE[68];

    BYTE m_byCurrentWorkKey[16] {};
    KEY_TABLE_TYPE m_uKttWork {};

    Camellia_Ekeygen( 128, m_byCurrentWorkKey, m_uKttWork );

    for (int i = 0; i < 68; i++) {
        std::cout << m_uKttWork[i] << " ";
    }

    std::cout << "\n";
}

Output

$ g++ -std=c++11 -o test test.cpp Camellia.c 
$ ./test 
382301878 1827423791 0 0 1546120148 3860271694 623942010 872017868 1546120148 3860271694 1290497688 4155529454 4122759699 2305910053 1290497688 4155529454 2604339595 4002168422 2610640796 1169317293 4283709980 2844888938 4139420567 2122284241 0 0 3011048906 3223194901 2723350903 3007290908 1170374237 3194057156 0 0 0 0 1821862673 456472600 694825438 3002140226 3073371509 739572990 694825438 3002140226 3073371509 739572990 3672780383 4194169671 1865976676 3143317110 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
$ 

Is there anything I should be looking at in this case?? I've been looking for clues in these few days but still have no idea so far. Any troubleshooting direction or reference is appreciated.


Solution

  • I'm sure now the Camellia_Ekeygen actually called was not the one in the C++ source file I provided.

    I renamed the function to Camellia_Ekeygen1 in module.cpp, camellia.h and the C++ source file and then the output was expected.

    Thanks a lot for your time reading this.