lexbor VS flamegraph

Project is deprecated in favour of the same developer's lexbor project[0].

[0]: https://github.com/lexbor/lexbor

It supports both CSS selectors and XPath like Nokogiri, but with separate engines - parsing and CSS engine by Lexbor, XPath engine by libxml2. (Nokogiri internally converts CSS selectors to XPath syntax, and uses XPath engine for all searches).

An HTML parser, probably the simplest relatively modern example I could find is 1MB https://github.com/lexbor/lexbor (haven't used it, but might look more into it now that I know it exists.)

Lazyweb link: https://github.com/rushter/selectolax

although I don't follow the need to have what appears to be two completely separate HTML parsing C libraries as dependencies; seeing this in the readme for Modest gives me the shivers because lxml has _seen some shit_

> Modest is a fast HTML renderer implemented as a pure C99 library with no outside dependencies.

although its other dep seems much more cognizant about the HTML5 standard, for whatever that's worth: https://github.com/lexbor/lexbor#lexbor

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> It looks like the author of the article just googled some libraries for each language and didn't research the topic

Heh, oh, new to the Internet, are you? :-D

Lexbor is here: https://github.com/lexbor/lexbor

Well, regarding HTML5, what I've found was libxml (does not support tag-soup HTML5), https://github.com/lexbor/lexbor, for which I was unable to find good documentation ( see https://lexbor.com/docs/lexbor/#dom), Apache Xerces (appears to not support tag-soup HTML5 as well), and Gumbo, which does not appear to be active and to support selectors and XPath (although there are libraries that add that).

I think we've all (mostly?) tried it. It really is the Wild West of the web when you're trying to parse other people's HTML, though.

I've played around with this parser which is extremely quick. https://github.com/lexbor/lexbor

I’m glad to have the opportunity to contribute to an open-source project that is used by thousands of people. Hopefully, we will speed up Nokogiri (or XML parser it uses) to match the performance of html5ever or lexbor at some point in the future. 800 ms to extract data from HTML is still too much.

You can install cargo-flamegraph with cargo install flamegraph. There are some underlying requirements to be able to use cargo-flamegraph; you will want to take a look at the repo here to make sure you have the right dependencies.

I tried to diagnose the issue with flamegraph, but unfortunately the flamegraph didn't show anything beyond the next call for some reason

having some tools to identify slowness origins (flamegraph is one... but not sure it's the way to go)

I'm currently implementing a solution for the first part of the day 16. It work but it is really slow... I'd like to : - understand why - having some tools to identify slowness origins (flamegraph is one... but not sure it's the way to go) - eventually have some clue/solution/idea - have general feedback on what in my "coding style" is not appropriate for rust (I come from java/kotlin/ts even if I've already coded a bit in c/c++) : for example I love iterator & sequence but i feel they are not really suited to overuse in rust (mostly because of async & result).

Use a profiler. Flamegraph is a good way to visualise profiler output. This lets you identify which functions are taking up a large amount of time - and hence helps you identify where to focus your optimisation efforts.

You tried trying to see what takes the most time under load via flames? https://github.com/flamegraph-rs/flamegraph

Well, in cases like that the answer is straight forward, use a profiler like https://github.com/flamegraph-rs/flamegraph

I don't see any obvious problems with your algorithm. I've had luck using cargo-flamegraph to identify the slow parts of my code. That's going to show you which parts to focus on improving the performance of!

From the readme of cargo flamegraph: