Exactly, so why not a single Worker that does everything?

HHello, I’m Allie!Exactly, so why not a single Worker that does everything?

J

how you will use htmlrewriter to parse html and store it in a var?

I think we can only store a htmlrewriter response if we use it in a service worker and make a hit from parent

J

Jadugar_Jaggu•3/4/24, 3:24 PM

is there another way of doing it?

JJadugar_Jaggu how you will use htmlrewriter to parse html and store it in a var? I think we ...

H

Hello, I’m Allie!OP•3/4/24, 3:25 PM

Why would you need to store it? Why not just stream it back to the client once it has been modified?

HHello, I’m Allie!Why would you need to store it? Why not just stream it back to the client once i...

J

Jadugar_Jaggu•3/4/24, 3:26 PM

it depends on the use cases. Maybe he doesn't want to stream it to the client.

Cloudflare workers are very powerful, can do many things with it

HHello, I’m Allie!Exactly, so why not a single Worker that does everything?

V

vakno•3/4/24, 3:36 PM

because the implementation would look much cleaner and organized code wise, also i think there might be problems with some responses

Vvakno because the implementation would look much cleaner and organized code wise, also...

H

Hello, I’m Allie!OP•3/4/24, 3:42 PM

I would note too that this will cost more, since you would have to invoke 2+ Workers

HHello, I’m Allie!I would note too that this will cost more, since you would have to invoke 2+ Wor...

V

vakno•3/4/24, 3:46 PM

you are right. So basically the best solution is to combine all into one?

Vvakno you are right. So basically the best solution is to combine all into one?

H

Hello, I’m Allie!OP•3/4/24, 3:51 PM

Imo, yes. It should also make it (marginally) faster

R

Rahul Raikwar•3/4/24, 4:06 PM

How can fix this - Error: Failed to publish your Function. Got error: Your Functions script is over the 1 MiB size limit (workers.api.error.script_too_large)

Vvakno ok so i have 100 urls, on some i need to change meta titles, on some i need to c...

I

Isaac McFadyen•3/4/24, 4:07 PM

There's also a limit of 100 workers on an account so you actually couldn't do this without Workers for Platforms (which generally requires an Enterprise plan).

I

Isaac McFadyen•3/4/24, 4:07 PM

And I don't think you could bind 720 workers without WfP even if you could create them all.

RRahul Raikwar How can fix this - Error: Failed to publish your Function. Got error: Your Funct...

C

Chaika•3/4/24, 4:11 PM

Either make your script smaller, or upgrade to Workers Paid which is 10 MiB max

C

Chaika•3/4/24, 4:11 PM

You're using nextjs or some framework?

M

Mitya•3/4/24, 4:15 PM

Hey all. If I have a shared JS file, let's say

global.js

global.js

, containing a

{}

{}

, which multiple scripts import and hook things onto, will this leak/bleed into multiple requests to my worker given Node's import caching, or will it be isolated to just the current request?

MMitya Hey all. If I have a shared JS file, let's say `global.js`, containing a `{}`, w...

I

Isaac McFadyen•3/4/24, 4:22 PM

When Workers are deployed the files are bundled automatically into each Worker, they're not actually imported at runtime. So to answer your question, they'll be completely isolated for each Worker.

However they won't be isolated by each request - if you mutate a variable then that variable will stay mutated on the next request if the user hits the same server, which is likely if the user is the same but is unlikely if two different users or even different browsers are requesting the Worker.

CChaika You're using nextjs or some framework?

R

Rahul Raikwar•3/4/24, 4:25 PM

Yes next js

IIsaac McFadyen When Workers are deployed the files are bundled automatically into each Worker, ...

M

Mitya•3/4/24, 4:26 PM

Thanks for the advice, much appreciated. If the leakage occurs within multiple requests for the same user, that's fine, but you're saying I can rely on non-leakage between different users?

Basically my use case is that a request sends a QS param, let's say

foo=1

foo=1

, and I want to hook that onto a global object so other files can use it, rather than laboriously having to pass it around to all functions. But the next request may send QS

foo=2

foo=2

. Sounds like I'll be OK based on what you say. (But presumably in a non-serverless/Worker environment this would be problematic?)

MMitya Thanks for the advice, much appreciated. If the leakage occurs within multiple r...

H

Hello, I’m Allie!OP•3/4/24, 4:29 PM

You can’t be guaranteed that it will/won’t ever leak

MMitya Thanks for the advice, much appreciated. If the leakage occurs within multiple r...

I

Isaac McFadyen•3/4/24, 4:29 PM

So basically a global variable is stored per server (called a "metal"). Cloudflare has many many metals so it's unlikely that one user will hit the same metal, but it's very much possible especially in smaller datacenters with only a few metals. I'd not rely on users hitting different metals and just write any code with the idea that it might leak between users if they hit the same metal.

C

Chaika•3/4/24, 4:31 PM

(the other way I'd view it is eventually if you scale up/become big enough it's going to happen more and more, unlikely at small scale sure but still bad idea)

M

Mitya•3/4/24, 4:32 PM

Interesting - thanks very much. So if I can't hook things onto a global object, for the reasons you guys have said, is my only remaining option to explicitly pass around info between concerns (middleware/controllers/helpers) or is there some other way I'm missing?

M

Mitya•3/4/24, 4:32 PM

(I come from PHP land, where everything is isolated per request, even globals.)

MMitya Interesting - thanks very much. So if I can't hook things onto a global object, ...

H

Hello, I’m Allie!OP•3/4/24, 4:35 PM

If it is only per-request storage you need, you could use https://developers.cloudflare.com/workers/runtime-apis/nodejs/asynclocalstorage

Cloudflare Docs

AsyncLocalStorage · Cloudflare Workers docs

Cloudflare Workers provides an implementation of a subset of the Node.js AsyncLocalStorage API for creating in-memory stores that remain coherent …

M

Mitya•3/4/24, 4:45 PM

Oh, interesting. Presumably good old, synchronous, browser-style

globalObject.localStorage

globalObject.localStorage

wouldn't work? If so, using AsyncLocalStorage, am I right that it would look something like this, to store a global property for later reading downstream?
Upstream file:

import { AsyncLocalStorage } from 'node:async_hooks';
const fooStore = new AsyncLocalStorage();
fooStore.run('bar'); //<-- running in some async middleware

import { AsyncLocalStorage } from 'node:async_hooks';
const fooStore = new AsyncLocalStorage();
fooStore.run('bar'); //<-- running in some async middleware

import { AsyncLocalStorage } from 'node:async_hooks';
const fooStore = new AsyncLocalStorage();
fooStore.run('bar'); //<-- running in some async middleware

import { AsyncLocalStorage } from 'node:async_hooks';
const fooStore = new AsyncLocalStorage();
fooStore.run('bar'); //<-- running in some async middleware

Downstream file:

import { AsyncLocalStorage } from 'node:async_hooks';
const fooStore = new AsyncLocalStorage();
const fooVal = fooStore.getStore(); //"bar"

import { AsyncLocalStorage } from 'node:async_hooks';
const fooStore = new AsyncLocalStorage();
const fooVal = fooStore.getStore(); //"bar"

import { AsyncLocalStorage } from 'node:async_hooks';
const fooStore = new AsyncLocalStorage();
const fooVal = fooStore.getStore(); //"bar"

import { AsyncLocalStorage } from 'node:async_hooks';
const fooStore = new AsyncLocalStorage();
const fooVal = fooStore.getStore(); //"bar"

JJadugar_Jaggu hey guys is anyone familiar with this issue? I am facing it right after automati...

C

Chaika•3/4/24, 4:46 PM

Thanks for reporting. I would watch this incident for further updates on the issue, and try again when it is resolved:
https://www.cloudflarestatus.com/incidents/3q7sg3tpp7qv

Issues changing CPU Limit for Cloudflare Workers and Pages

MMitya Oh, interesting. Presumably good old, synchronous, browser-style `globalObject.l...

K

kian•3/4/24, 4:46 PM

import { AsyncLocalStorage } from "node:async_hooks";

const asyncLocalStorage = new AsyncLocalStorage();

async function doStuff() {
  const { req, env, ctx } = asyncLocalStorage.getStore();

  const obj = await env.KV.get("foo");

  // ...
}

export default {
  async fetch(req, env, ctx) {
    return asyncLocalStorage.run({ req, env, ctx }, async () => {
      await doStuff();

      return new Response("Hello World!");
    });
  },
};

import { AsyncLocalStorage } from "node:async_hooks";

const asyncLocalStorage = new AsyncLocalStorage();

async function doStuff() {
  const { req, env, ctx } = asyncLocalStorage.getStore();

  const obj = await env.KV.get("foo");

  // ...
}

export default {
  async fetch(req, env, ctx) {
    return asyncLocalStorage.run({ req, env, ctx }, async () => {
      await doStuff();

      return new Response("Hello World!");
    });
  },
};

import { AsyncLocalStorage } from "node:async_hooks";

const asyncLocalStorage = new AsyncLocalStorage();

async function doStuff() {
  const { req, env, ctx } = asyncLocalStorage.getStore();

  const obj = await env.KV.get("foo");

  // ...
}

export default {
  async fetch(req, env, ctx) {
    return asyncLocalStorage.run({ req, env, ctx }, async () => {
      await doStuff();

      return new Response("Hello World!");
    });
  },
};

import { AsyncLocalStorage } from "node:async_hooks";

const asyncLocalStorage = new AsyncLocalStorage();

async function doStuff() {
  const { req, env, ctx } = asyncLocalStorage.getStore();

  const obj = await env.KV.get("foo");

  // ...
}

export default {
  async fetch(req, env, ctx) {
    return asyncLocalStorage.run({ req, env, ctx }, async () => {
      await doStuff();

      return new Response("Hello World!");
    });
  },
};

K

kian•3/4/24, 4:47 PM

run

run

takes the object you want to store, and then a callback

M

Mitya•3/4/24, 4:49 PM

Thanks @kian . So I was nearly there but just need to pass an object? And presumably the callback is optional if all I'm doing is writing to the store for future use, rather than, as per the docs example, sending a response once write is complete?

K

kian•3/4/24, 4:49 PM

Doesn't necessarily have to be an object

K

kian•3/4/24, 4:49 PM

Can be a string, number, array, etc

M

Mitya•3/4/24, 4:50 PM

Yeah... so my original effort would work? (I passed just a string value there, not an object.) But is the general flow correct? Appreciate the help.

K

kian•3/4/24, 4:50 PM

run

run

requires the callback

K

kian•3/4/24, 4:50 PM

The idea is that it runs that function async within a 'context'

K

kian•3/4/24, 4:50 PM

and the store for that context is what you passed as the first arg

M

Mitya•3/4/24, 4:51 PM

Ah... then I'm struggling a little. You're saying

mystore.run({foo: bar})

mystore.run({foo: bar})

is insufficient to write to the storage? If so, what would any callback I passed actually "do", if all I want to do is write for later reading?

K

kian•3/4/24, 4:58 PM

The storage is only available within the function passed to

run

run

K

kian•3/4/24, 4:59 PM

i.e in my case, I put everything inside the function I pass to

run

run

and return my Response there

K

kian•3/4/24, 4:59 PM

Everything else can now do

asyncLocalStorage.getStore();

asyncLocalStorage.getStore();

to access req, env, ctx

M

Mitya•3/4/24, 5:00 PM

OK, that makes sense. But does this mean that downstream files/functions in other files will not be able to access the storage value because they're not running in

run()

run()

's callback?

Say file A (middleware) wants to write a value to storage. That middleware then hands over to a controller (file B), which then calls a helper function in file C. Is it possible files B/C to access the storage value written by file A?

M

Mitya•3/4/24, 5:01 PM

Sorry - this is all new to me and I'm having a little difficulty. I do appreciate the help.

K

kian•3/4/24, 5:03 PM

Do you have a minimal example of the layout/middleware? It might be easier if I adapt that to use AsyncLocalStorage and you can see how it works.

M

Mitya•3/4/24, 5:05 PM

Sure. I'm using itty-router. So:

import fooApi from '../controllers/foo'
router.post('/foo/bar', async req => {
  const resp = fooApi.bar(); //e.g. "hello world"
  return resp;
})

import fooApi from '../controllers/foo'
router.post('/foo/bar', async req => {
  const resp = fooApi.bar(); //e.g. "hello world"
  return resp;
})

import fooApi from '../controllers/foo'
router.post('/foo/bar', async req => {
  const resp = fooApi.bar(); //e.g. "hello world"
  return resp;
})

import fooApi from '../controllers/foo'
router.post('/foo/bar', async req => {
  const resp = fooApi.bar(); //e.g. "hello world"
  return resp;
})

I'd like to be able to set a local storage value in that middleware, but have my function at

fooApi.bar()

fooApi.bar()

(in

controllers/foo.js

controllers/foo.js

) be able to access that stored value.

M

Mitya•3/4/24, 5:06 PM

controllers/foo

controllers/foo

:

export default {
  bar: () => {
    //how to access local storage value in here? I'm not in the middleware's storage.run() callback at this point...
  }
};

export default {
  bar: () => {
    //how to access local storage value in here? I'm not in the middleware's storage.run() callback at this point...
  }
};

export default {
  bar: () => {
    //how to access local storage value in here? I'm not in the middleware's storage.run() callback at this point...
  }
};

export default {
  bar: () => {
    //how to access local storage value in here? I'm not in the middleware's storage.run() callback at this point...
  }
};

K

kian•3/4/24, 5:15 PM

export const als = new AsyncLocalStorage();

router.get("/", async () => {
    return als.run("foo", async () => {
        const resp = foo.bar();
        return new Response(resp);
    });
});

export const als = new AsyncLocalStorage();

router.get("/", async () => {
    return als.run("foo", async () => {
        const resp = foo.bar();
        return new Response(resp);
    });
});

export const als = new AsyncLocalStorage();

router.get("/", async () => {
    return als.run("foo", async () => {
        const resp = foo.bar();
        return new Response(resp);
    });
});

export const als = new AsyncLocalStorage();

router.get("/", async () => {
    return als.run("foo", async () => {
        const resp = foo.bar();
        return new Response(resp);
    });
});

import { als } from ".";

export default {
    bar: () => {
        return als.getStore();
    },
};

import { als } from ".";

export default {
    bar: () => {
        return als.getStore();
    },
};

import { als } from ".";

export default {
    bar: () => {
        return als.getStore();
    },
};

import { als } from ".";

export default {
    bar: () => {
        return als.getStore();
    },
};

K

kian•3/4/24, 5:15 PM

Admittedly it's not ideal with multiple modules as you have to pass around the top-level

als

als

Kkian ```js export const als = new AsyncLocalStorage(); router.get("/", async () => {...

H

Hello, I’m Allie!OP•3/4/24, 5:16 PM

I forget, can’t you shim the storage onto GlobalScope?

K

kian•3/4/24, 5:17 PM

I wonder if

globalThis.als = new AsyncLocalStorage

globalThis.als = new AsyncLocalStorage

would work

K

kian•3/4/24, 5:17 PM

:blobcatthonking:

Kkian I wonder if `globalThis.als = new AsyncLocalStorage` would work

H

Hello, I’m Allie!OP•3/4/24, 5:17 PM

https://tenor.com/view/great-minds-think-like-smile-smart-gif-14683105

Tenor

M

Mitya•3/4/24, 5:17 PM

That would be great if so (but if it does, couldn't I just hook my data onto

globalThis

globalThis

in the first place and bypass ALS?)

Exactly, so why not a single Worker that does everything?

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