So close, but cannot get it to work (elaborate snippets inside)!

[LennardF1989]

I looked very closely at how Atom implements electron-link, but I for the world cannot get it to work... It also seems like almost none is actually using this, which is a shame, because it's a pretty cool feature. Hence I'm going to document what I have done, so others can learn from it and save themselves a day of work. Anyway, some help would be very much appreciated to get it running. I feel like I'm close, but I'm just not seeing what I'm missing...

I made a snapshot.js which contains the following:

if(false) {
   require("./native");
   require("./main");
}

The two files from above are the only two I need a snapshot from. I guarded them with an if(false) so I have complete control when to load them.

I use the following compile.js, roughly based on Atom, but very simplied:

const electronLink = require("electron-link");
const fs = require("fs");
const vm = require("vm");
const path = require("path");
const childProcess = require("child_process");

let processedFiles = 0;

const snapshotScriptPath = "./cache/snapshot_generated.js";

electronLink({
    baseDirPath: "./app",
    mainPath: "./app/snapshot.js",
    cachePath: "./cache",
    shouldExcludeModule: (modulePath) => {
        console.log(modulePath);
        
        return !modulePath.endsWith("native.js") && !modulePath.endsWith("main.js");
    }
}).then(function (snapshotScript) {
    fs.writeFileSync(snapshotScriptPath, snapshotScript);

    vm.runInNewContext(snapshotScript, undefined, { filename: snapshotScriptPath, displayErrors: true });

    var mksnapshotPath = path.join('.', 'node_modules', 'electron-mksnapshot', 'bin', 'mksnapshot');

    childProcess.execFileSync(mksnapshotPath, [snapshotScriptPath, "--startup_blob", "./app/snapshot_blob.bin"]);
}).catch((error) => {
    console.log(error);
});

The two files from the snapshot.js are of the following format:

module.exports = function() {
    //Do stuff
}

My startup.js, which is set in package.json, does the following:

var main;

if (typeof snapshotResult !== 'undefined') {
    snapshotResult.setGlobals(global, process, global, {}, console, require);

    main = snapshotResult.customRequire("./main");
}
else {
    main = require("./main");
}

main();

main() effectively runs the module.exports from before, creates a BrowserWindow with a preload-script, which in turn requires native.js in a similar fashion.

Everything works fine when trying out using electron app from the CLI. But after building, and replacing the default snapshot_blob.bin, it simply does not work, at all.

Can someone please point out what I'm missing?

PS. I also notice, when I open the snapshot_blob.bin with notepad, the whole generated snapshot.js is fully readable, kind of defeating the point of compiling it (other than speed). What's up with that?

[astoilkov]

Hi @LennardF1989,

Did you figure out how to make electron-link work? I have successfully made the snapshot_blob.bin but there seems to no difference in performance. In both cases, the app load time is around 450ms.

[adaml881]

Hi, have either of you had any progress with this?

[HZSamir]

3 years later. Does anyone have any idea how to use this thing?