win32-api/dist/lib/helper.js

FFI definitions of windows win32 api for node-ffi

import * as ffi from 'ffi'
import { Config } from 'win32-def'
const dllInst = new Map() // for DLL.load() with settings.singleton === true

export function load(dllName, dllFuncs, fns, settings) {
    const st = parse_settings(settings)

    if (st && st.singleton) {
        let inst = get_inst_by_name(dllName)

        if (!inst) {
            inst = ffi.Library(dllName, gen_api_opts(dllFuncs, fns))
            set_inst_by_name(dllName, inst)
        }
        return inst
    }
    else {
        return ffi.Library(dllName, gen_api_opts(dllFuncs, fns))
    }
}
// generate function definitions via converting macro windows data type (like PVOID) to the expected value
export function gen_api_opts(dllFuncs, fns) {
    const ret = {}

    if (fns && Array.isArray(fns) && fns.length) {
        for (const fn of fns) {
            const ps = dllFuncs[fn]

            if (ps) {
                Object.defineProperty(ret, fn, {
                    value: ps,
                    writable: false,
                    enumerable: true,
                    configurable: false,
                })
            }
        }
    }
    else {
        for (const fn of Object.keys(dllFuncs)) {
            const ps = dllFuncs[fn]

            Object.defineProperty(ret, fn, {
                value: ps,
                writable: false,
                enumerable: true,
                configurable: false,
            })
        }
    }
    return ret
}
function get_inst_by_name(dllName) {
    return dllInst.get(dllName)
}
function set_inst_by_name(dllName, inst) {
    dllInst.set(dllName, inst)
}
function parse_settings(settings) {
    const st = Object.assign({}, Config.settingsDefault)

    if (typeof settings !== 'undefined' && settings && Object.keys(settings).length) {
        Object.assign(st, settings)
    }
    return st
}