nodejs与c/c++交互目前主流的方式有两种,node addon c++ 和 node-ffi .
1、node addon c++
1)nodejs从c语言读取数据
addon.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
typedef struct
{
double lon;
double lat;
}gps_info_t;
gps_info_t* gps;
void get_gps_shm_init(void)
{
gps = (gps_info_t *)malloc(sizeof(gps_info_t));
}
Napi::Object CreateObject(const Napi::CallbackInfo& info) {
Napi::Env env = info.Env();
Napi::Object obj = Napi::Object::New(env);
gps->lon = 55.5;
gps->lat = 66.6;
printf("send lon: %f\n", gps->lon);
printf("send lat: %f\n", gps->lat);
obj.Set(Napi::String::New(env, "lon"), gps->lon);
obj.Set(Napi::String::New(env, "lat"), gps->lat);
return obj;
}
Napi::Object Init(Napi::Env env, Napi::Object exports) {
get_gps_shm_init();
return Napi::Function::New(env, CreateObject, "createObject");
}
NODE_API_MODULE(addon, Init)
addon.js
var addon = require('bindings')('addon');
var obj = addon('gps');
console.log(obj.lon);
console.log(obj.lat);
module.exports.obj = obj;
2)nodejs向c语言写数据
addon.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
typedef struct
{
char *user_name;
char *passwd;
char *dev_id;
}user_info_t;
user_info_t* user;
void put_user_info_shm_init(void)
{
user = (user_info_t *)malloc(sizeof(user_info_t));
user->user_name = (char*)malloc(32*sizeof(char));
user->passwd = (char*)malloc(32*sizeof(char));
user->dev_id = (char*)malloc(32*sizeof(char));
}
Napi::Object CreateObject(const Napi::CallbackInfo& info) {
Napi::Env env = info.Env();
Napi::Object obj = Napi::Object::New(env);
memset(user->user_name, 0, 32);
memset(user->passwd, 0, 32);
memset(user->dev_id, 0, 32);
memcpy(user->user_name, info[0].ToString(), 32);
memcpy(user->passwd, info[1].ToString(), 32);
memcpy(user->dev_id, info[2].ToString(), 32);
printf("recv user info (user_name): %s\n", user->user_name);
printf("recv user info (passwd): %s\n", user->passwd);
printf("recv user info (dev_id): %s\n", user->dev_id);
return obj;
}
Napi::Object Init(Napi::Env env, Napi::Object exports) {
put_user_info_shm_init();
return Napi::Function::New(env, CreateObject, "createObject");
}
NODE_API_MODULE(addon, Init)
addon.js
var addon = require('bindings')('addon');
var user_info = {
user_name = 'zdd';
passwd = '123';
dev_id = '65535'
}
var obj = addon(user_info.user_name,user_info.passwd,user_info.dev_id);
module.exports.user_info = user_info;
nodejs的C/C++拓展,将c/c++源码编译成js模板库
ubuntu下编译
node-gyp configure
node-gyp buildnode addon.js
交叉编译
export CC=arm-linux-gnueabihf-gcc
export CXX=arm-linux-gnueabihf-g++
export LD=arm-linux-gnueabihf-ld
export RAINLIB=arm-linux-gnueabihf-rainlib
export AR=arm-linux-gnueabihf-ar
export LINK=arm-linux-gnueabihf-g++
node-gyp configure --arch=arm
node-gyp buildnode addon.js
2、node-ffi
1)nodejs从c语言读取数据
factorial.c
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#if defined(WIN32) || defined(_WIN32)
#define EXPORT __declspec(dllexport)
#else
#define EXPORT
#endif
typedef struct
{
double lon;
double lat;
}gps_info_t;
gps_info_t* gps;
void get_gps_shm_init(void)
{
gps = (gps_info_t *)malloc(sizeof(gps_info_t));
}
EXPORT gps_info_t* get_gps_info(void) {
get_gps_shm_init();
gps->lon = 55.5;
gps->lat = 55.5;return gps;
}
factorial.js
var ffi = require('../node-ffi-master/')
var refStruct = require('ref-struct');
var refArray = require('ref-array');
var ref = require('ref');
//gps date struct
var gps = refStruct({
'lon':ref.types.double,
'lat':ref.types.double,
});
var gpsStructArrayType = refArray(gps);
var gps_info = gpsStructArrayType(10);
var libfactorial = ffi.Library('./libfactorial', {
'get_gps_info': [ gpsStructArrayType, [ 'void' ] ],
});
gps_info = libfactorial.get_gps_info(0)
console.log('Your output: ' + gps_info[0].lon)
console.log('Your output: ' + gps_info[0].lat)
2)nodejs向c语言写数据
factorial.c
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#if defined(WIN32) || defined(_WIN32)
#define EXPORT __declspec(dllexport)
#else
#define EXPORT
#endif
typedef struct
{
char *user_name;
char *passwd;
char *dev_id;
}user_info_t;
user_info_t* user;
void put_user_info_shm_init(void)
{
user = (user_info_t *)malloc(sizeof(user_info_t));
user->user_name = (char*)malloc(32*sizeof(char));
user->passwd = (char*)malloc(32*sizeof(char));
user->dev_id = (char*)malloc(32*sizeof(char));
}
EXPORT void put_user_info(user_info_t* user_info) {
put_user_info_shm_init();
printf("get userinfo(user_name):%s",user_info->user_name);
printf("get userinfo(user_name):%s",user_info->passwd);
printf("get userinfo(user_name):%s",user_info->dev_id);
}
factorial.js
var ffi = require('../node-ffi-master/')
var refStruct = require('ref-struct');
var refArray = require('ref-array');
var ref = require('ref');
//ui date struct
var user = refStruct({
'user_name':'string',
'passwd':'string',
'dev_id':'string',
});
var userStructArrayType = refArray(user);
var user_info = userStructArrayType(1);
user_info[0].user_name = 'zdd';
user_info[0].passwd = '123';
user_info[0].dev_id = '65535';
var libfactorial = ffi.Library('./libfactorial', {
'put_user_info': [ 'void', [ userStructArrayType ] ]
});
libfactorial.put_user_info(user_info)
console.log('Your input: ' + user_info[0].user_name)
console.log('Your input: ' + user_info[0].passwd)
console.log('Your input: ' + user_info[0].dev_id)
gcc / arm-linux-gnueabihf-gcc -shared -fpic factorial.c -o libfactorial.so
node factorial.js
上面两种方式写了个demo放在github上了
https://github.com/zhoudd1/nodejs_call_c_cc
3、还有一种小众化的方式
通过child_process 方式调用EXE进程来实现数据交互。
var cp= require('child_process');
//同步的方式letout = cp.execFileSync("testdll.exe", ["arg1","arg2"],{});
//异步的方式
cp.execFile("testdll.exe", ["arg1","arg2"], {}, (error, stdout, stderr) => {
console.log(stdout);
})
这种方式NODE 会接管stdout 和 stderr ,exe中把结果通过 printf 输出。
缺点:需要先生成EXE,EXE 中调用 DLL/so 并且返回结果。
优点:不需要配置 FFI,不受DLL/so 的影响