我试图连接monetdb与node.js.我有一个简单的(20行)c程序,可以使用mapi库查询moentdb.
我可以使用这些库为node.js构建一些东西(模块/插件),它使用这些库并连接到monetdb吗？
(使用odbc是一种选择,但它有其自身的缺点.)
Update1：
node-ffi非常棒.我能够很容易地创建一个fetch表程序. (例如,我添加了我的工作代码.)
所以,如果我有3个选项
1. ODBC
2. node-ffi
3.一个c程序,用于获取数据库数据并通过套接字侦听来自node.js的连接
在性能方面,这是更好的实现选择,如果我没有多少时间为node.js开发插件
var ffi = require("ffi");
var libmylibrary = ffi.Library('/usr/local/lib/libmapi.so',{
"mapi_connect":["int",["string",'int',"string","string"]],"mapi_query":['int',["int","mapi_fetch_row":["int",["int"]],"mapi_fetch_field":["string","int"]]
});
var res = libmylibrary.mapi_connect("localhost",50000,"monetdb","sql","demo");
console.log(res);
var ret=libmylibrary.mapi_query(res,"select * from table");
while(libmylibrary.mapi_fetch_row(ret)){
console.log(libmylibrary.mapi_fetch_field(ret,0));
console.log(libmylibrary.mapi_fetch_field(ret,1));
}
There is non-trivial overhead associated with FFI calls. Comparing a hard-coded binding version of strtoul() to an FFI version of strtoul() shows that the native hard-coded binding is orders of magnitude faster. So don’t just use the C version of a function just because it’s faster. There’s a significant cost in FFI calls,so make them worth it.
换句话说,FFI有效,但速度很慢.如果您只是需要打几个电话,这很好,但如果您需要频繁拨打电话,这是非常糟糕的消息.
你需要做的是写一个addon.插件是C模块,为C和C库提供粘合剂. (仅仅因为你必须在C中编写插件并不意味着你不能从插件中调用纯C代码！)
节点docs提供了大量可以帮助您入门的示例.如果你正在使用Windows,here’s some tips来设置VS.
如果对C库的调用是阻塞的,则需要使它们异步. libuv provides a thread pool you can do the work on.
