node-ffi experiment

t1.cpp

// g++ -O3 -pie -shared t1.cpp -o t1.dll

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

extern "C" {
  __declspec(dllexport)
  void callme(char ***out, char *out2) {
    char s[2][3][6] = {{"one", "two", "three"}, {"four", "five", "six"}};
    printf("%s\n", s[1][1]);
    memcpy(out, s, sizeof(s));
    memcpy(out2, s[1][0], sizeof(s[1][0]));
  }
}

t1.js

var ffi = require('ffi'),
    ref = require('ref'),
    ArrayType = require('ref-array');

var Str = ArrayType('char');
var StringArray = ArrayType(Str);
var StringArrayArray = ArrayType(StringArray);

var dll = ffi.Library('t1.dll', {
  'callme': [ 'void' , [ StringArrayArray, ref.refType('string') ] ]
});

//var r = new StringArrayArray([new StringArray([new Str(6), new Str(6), new Str(6)]),
//                              new StringArray([new Str(6), new Str(6), new Str(6)])]);
var r = new Buffer(6*3*2);
var r2 = ref.alloc(ref.refType('string'), null);

dll.callme.async(r, r2, function (err, res) {
//dll.callme(r, r2);
  console.log(r);
  console.log(ref.readCString(r, 4*6));
  console.log(ref.readCString(r2, 0));
});

t1_test.cpp

// g++ -O3 t1_test.cpp -o t1_test

#include <windows.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

typedef void (CALLBACK* callme)(char***, char*);

int main(int argc, char* argv[]) {
  HMODULE handle = LoadLibrary("t1.dll");
  printf("handle: %ld\n", handle);
  callme dll = (callme)GetProcAddress(handle, "callme");
  printf("dll: %ld\n", dll);

  char a[2][3][6];
  char b[6];
  dll((char***)a, b);
  printf ("returned: %s %s\n", a[1][1], b);
  FreeLibrary(handle);
  return 0;
}