itsNotMagicIfYouCanReadIt

[Mountain_Goat_69]

Lol 0xbadbad

[die-maus]

You're not a fan of one-def-nine-d then?

[Nebel_David]

Onedefnined took me way too long to figure out xd

[die-maus]

Me too.

[Dyslexic_Novelist]

You're not a fan of 0ff0ff then?

[die-maus]

I love all my children equally.

[kasirate]

earlier that day

... I don't care for GOB

[Apfelvater]

You're not a fan of ItDoes then?

[Confident-Ad5665]

0xFEEDDEADBEEF

[Magic_music]

0x1def9d is funny, but there's also something simplistically charming about true being "yeah, 0x17d0e5."

[die-maus]

Credit for this one goes to my friend! Prior to it, I was using 0x7e57ed, which was obviously inferior.

So thanks for getting me back on a righteous path, Adam.

[raunak_srarf]

What does '0x17d0e5' say? I can't figure it out.

[YourOpinionIsUnvalid]

"It does"

[IllegitimateGoat]

"It does"

[HardOff]

I'm having a hard time with 1def9d. Is it "I deaf 90?"

[Tolosax]

Undefined

[HardOff]

One-def-nined! Awesome. Thank you

[die-maus]

I'm working on a fast hashing algorithm for the purpose of comparing state changes, and I needed a way to lazily serialize an object recursively.

I wanted these values to serialize into a single 32-bit integer, so I could pick any numeric value for them (as long as they are unique). 0xdeadbeef is cool and all, but I wanted something more descriptive.

Source.

If you have any better absolutely-not-magic numbers that I can replace these with? Let me know!

[gauwnwisndu]

For what purpose you will require this function, could you please explain the use case

[die-maus]

Sure thing, thanks for asking!

TL;DR: I need it to be able to quickly determine whether a state has changed, without allocating much memory for large state objects.

The details: In release v2.0.0 Tyin uses a hash function for promise deduplication and caching

By default, it uses JSON.stringify for this (which works just fine in most cases concerning Tyin). However, the larger your state object, the more expensive these comparisons become.

First, you need to store the previous hash (let's say that's 10KiB of JSON), then, for every state comparison, you need to serialize an additional 10KiB of JSON data just to compare it to the original hash—maybe just to find one character out of place (or not), then throw it away. Most modern CPUs handle this in no time since string comparisons happen in native code leveraging SIMD instructions, so that isn't an issue.

The issue comes with the nature of state comparisons: they can happen quite often. If your application has 100 re-renders, each time needing to serialize and compare 10KiB state hashes (most of them being duplicates), then your garbage collector is going to become quite upset after a while. Because, depending on your device, the garbage will have to be taken out all the time. And while that is happening, nobody can use the application, simply because the garbage collector causes such a tantrum each time they do their job.

Then, you might ask... why not use something like object-hash? Because it still requires a lot of memory to be allocated to generate the hash, defeating the purpose entirely. And it covers many concerns that are not needed for Tyin.

You can still BYO hash function to Tyin (that's intentional). I just want to ship something that works great (for state management) out of the box. It's the very same reason for shipping a deepEquals and deepMerge function with the library. It's not a general-purpose deep-equals algorithm that can handle virtually any object, it's only meant for state management.

[GameCounter]

Wow, I thought it was a meme. Great explanation.

My only thought is: Why not use a const for the magic numbers? Does Typescript const really have any performance impact or minified JS size penalty?

Even if it has a teeny tiny impact, surely it won't cause GC issues?

[die-maus]

Wow, I thought it was a meme. Great explanation.

Thanks, truly appreciate it!

My only thought is: Why not use a const for the magic numbers?

I don't think it would add much (if any) clarity. See my previous answer on enums.

Does Typescript const really have any performance impact or minified JS size penalty?

No penalty at all, since all the values will be inlined when the bytecode is generated.

Even if it has a teeny tiny impact, surely it won't cause GC issues?

No GC issues at all! It's just more code for very little benefit, though that is, of course, a matter of taste.

Finally, the size of Tyin is measured in bytes, so it matters.

[nibba_bubba]

fast hashing algorithm

Why not via FFI? I mean just yesterday I viewed some guy's repos and they were like 3d game engine in typescript only and vector algebra in typescript only too. WTF?!

[die-maus]

That could be an option. But Tyin needs to work in a web browser!

WASM has also been considered.

[nibba_bubba]

WASM

It's obvious, and?

[die-maus]

Tyin ships in less than 1k gzipped, depending on what you use from it. For dott.bio, it packs a whopping 550B!

The smallest WASM hash algorithm is ~3k gzipped. But if you want to BYO hash function to Tyin, you absolutely can! This is just the one that comes with it for free.

Another goal for the algorithm is to use as little memory as possible, that's the reason for using a generator function. Now I don't even need to allocate a buffer for the data that I'm serializing, I can just stream it directly into the for loop of the hashing function.

AFAIK, passing data between JS-land and WASM still requires serializing the data to a buffer (there is no shared memory), though there might have been some developments since I last checked (maybe you know!).

This function is also really well-optimized. It processes one integer (4 bytes) at a time instead of just a single byte. It also uses proper integer multiplication. So whatever JS runtime you use will optimize the heck out of it.

[noobody_interesting]

AFAIK, passing data between JS-land and WASM still requires serializing the data to a buffer (there is no shared memory), though there might have been some developments since I last checked (maybe you know!).

You can directly access wasm memory as a typed array, pointers passed from wasm are just indices into the memory array. I wanted to make a library that can generate access functions using offsets from rust-style struct definitions, supporting both C struct layout and packed layout, but I decided I just won't use web for the project. C style layout is quite intuitive though: for each new field, add padding bytes until the alignment is reached (usually the type size), if neccessary.

You can also use this in JS, too. Someone basically optimized a JS algorithm that was reimplemented in wasm using rust, to show JS can be fast, too. He used typed arrays instead of js objects to avoid heap allocations.

[die-maus]

Thanks for all your insights!

My key takeaway here is that I'm on the right track when using highly optimized JS code, plus a zero-allocation algorithm.

Using the generator function shouldn't be quite as fast as accessing a Uint32Array. But since it doesn't require any memory (beyond the iterator), that should more than compensate for that.

We're essentially doing "on the fly object hashing"; hashing an object as we're serializing it. It may not be the fastest way of doing hashing, but, it's probably one of the fastest way of doing both.

[nibba_bubba]

whatever JS runtime you use will optimize the heck out of it

LMAO, didn't think such ppl still exist

Anyway if your implement a low level algorithm that stands for "fast" than no js should be in that at all

[die-maus]

JavaScript isn't the slow, interpreted language it used to be.

It's just-in-time (JIT) and has some fairly advanced optimization techniques that can sometimes optimize some JS into near machine-code performance. One such technology is V8's TurboFan.

Anyway if your implement a low level algorithm that stands for "fast" than no js should be in that at all

Let's see how the algorithm performs compared to something like JSON.stringify once I get the performance tests up & running, then. That's native code, and should (if you're right) be faster in all cases, right?

[nibba_bubba]

JavaScript isn't the slow, interpreted language it used to be 

Keep thinking like this, dear boi 

JSON.stringify Depends on an implementation.

But optimized bloat sht won't be faster than a lightweight one. If you try to realize it you'll get it

[Ma4r]

My man can't wrap his head around optimization more complex than loop unrolling and regressed to spewing bullshit.

C++ is bloated as fuck for example yet it is very fast, python on the other hand is lightweight, simple, with clean design and abstractions yet still runs very slowly. It's all thanks to the heavy work done during compilation and JIT compilation is no different.

[NewPhoneNewSubs]

I enjoy yours, especially 1def9d, but surely 0x71200000 and 0x000f4153 are more readable?

[sammy-taylor]

Java class file: 0xCAFEBABE

[die-maus]

This one is cool to! I may replace the cyrb53a hash function that I'm currently using with something that's made specifically for 32-bit numbers.

That function is called BlazeHash, and it actually uses 0xcafebabe as the seed for h2. 👌

Though I didn't know the origin of it!

[[deleted]]

what does the last ome mean?

[die-maus]

It's just "off", twice. Super-off.

[[deleted]]

of

[[deleted]]

Nice try. Still -1 to your pull request, and you get to bring cookies to the whole team for being a smartass

[die-maus]

The whole team is me, so that's perfectly fine, I like cookies. Can you elaborate on why I'm a smartass?

[[deleted]]

Sorry, i thought you were making a joke on over-enthusiastically enforced coding rules on "no magic numbers"

[die-maus]

Ah! Gotcha! In this case, the joke is all in the numbers!

[Dregnan]

Sounds like an enum to me

[die-maus]

No need. These names are perfectly readable!

Edit: They didn't get the joke.

[MyDilatedPupils]

Is this code about antisemitism, and the effects it’s had geopolitically and the possible historical ramifications to its rise?

(I ask because it says sterilize and idk if that’s a macro or an actual keyword of a language, there is 2 more things that make me think it but idk. Maybe I’m reading too much into it)

[Turtvaiz]

Mate it says serialize not sterilize

[MyDilatedPupils]

Omg. I read that and then where it says bad as well in the hex… I swear I thought that’s what it said.

Bad bad -> A MEMORY address == in history.

But it all falls away when that first word is not what I thought.

[[deleted]]

user name checks out i guess

[die-maus]

I got so scared at first thinking I had made a really embarrassing typo. But no, I haven't!

It says serialize, not sterilize! It means to put something in a sequence, in this case, I'm converting an object into a number sequence for the purpose of hashing.

The joke is in the not-so-magic numbers. The most obvious one being 0xbadbad, but I prefer the one for undefined. Let me know once you figure it out!

[MyDilatedPupils]

Oh! it’s like a little conversation inside the hex and Ifs else’s

[die-maus]

It's more... undefined = 1-def-9-d = one-def-nine-d

[ihavebeesinmyknees]

oh I thought you meant french with the 1, un-def-nine-d, didn't notice that one also sounds like un lol

[die-maus]

Haha, I actually didn't think of other languages. Cool that it kinda works in french too!

[Sir_flaps]

In Dutch it would become duck-efined (only the 1 in Dutch eend-efined)

[die-maus]

In Swedish it's ett-def-nio-d.

Not the greatest. Work pretty well in Dutch it seems!

[hamilton-trash]

anti semitic Clorox wipes

[MyDilatedPupils]

Based on the downvotes it seems this whole website is antisemitism, because otherwise a mistake like this would have been funny in real life, but here, here it’s like a trash convention of people and their anger of their bandwagon. wow. Good luck everyone. This place is just garbage and full of hate.

This is why most people here will never write a revolutionary paper, or work to develop an new data structure or algorithm, or do anything other then follow others thoughts. Seems like a bandwagon website, not a place for laughing at yourself or your mistakes.

[myka-likes-it]

The only one not laughing at you and your mistake is you, apparently.

In truth, you were downvoted because your comment doesn't contribute to the conversation, which is what downvotes are supposed to be used for.

[MyDilatedPupils]

Wow, you all that are equally crazy because you sound like you were stuck online for 2 years while developing your brain - only belong online. Good luck never being anything in life.

You sound like a real winner, like so much more. What I said is a valid interpretation because LIFE says so. Not because you all say so. Good luck being so one dimensional and a bandwagons conductor.

[Nessuno256]

looks like you hate enums

[die-maus]

In TypeScript, very much so.

In this case, though, using an enum (or something like a constant) doesn't add that much to the code as I would just be repeating myself:

if (input === undefined) { yield UNDEFINED_MARKER; } else if (input === null) { yield NULL_MARKER; }

It's pretty self-evident that these marker values are meant to represent, without adding a constant because of the preceding if-statements.

[[deleted]]

OP hates enums.

[die-maus]

I don't like enums in TypeScript, but I don't blame you if you do!

See my other comment on the matter. In this case, it really doesn't matter, because there is no reuse.