check src or output changed by mtime and fileSize cache.
const {SgStatCache} = require("sgstatcache");
const cache = new SgStatCache("mycachefile");
cache.load(); // if not exist, it returns false;
// check file is change, make new file
if (!cache.isSameAsLast("src.cpp") || !cache.isSameAsLast("src.o")) {
// to something to make src.cpp to src.o
cache.update("src.cpp");
cache.update("src.o");
}
cache.save(); // save file stat to end