html5ever VS bincode

Would you consider using some libraries in your project? There are lots of good ones in the Rust ecosystem, and many of them are not part of any existing browsers.

For example:

- https://github.com/servo/html5ever (HTML parsing - note: this is used in Servo)

- https://github.com/parcel-bundler/lightningcss (CSS parsing)

- https://github.com/DioxusLabs/taffy (web layout)

- https://github.com/pop-os/cosmic-text (text layout and rendering)

Obviously you should be free to work on whatever you like, but just as a benchmark on the scope of your project: I spent ~6 months implementing just the CSS Grid algorithm in Taffy last year. An entire browser from literal scratch is probably a 10 year project for one person.

So I'm doing some web scraping in Rust, and so I will need to parse HTML. [scraper](https://docs.rs/scraper/latest/scraper/) (which uses [html5ever](https://github.com/servo/html5ever)) is doing fine except that it's the bottleneck of my application.

So I need a faster parser. I've tried [tl](https://docs.rs/tl/latest/tl/) which would've been perfect except that it doesn't actually work on the HTML I have. When I try to `query_selector` the elements I need, it returns nothing.

[Kuchiki](https://docs.rs/kuchiki/latest/kuchiki/) is abandonded.

I couldn't figure out how to get [lol-html](https://github.com/cloudflare/lol-html) to work for me (it's designed for re-writing HTML, whatever that means). It doesn't seem to have an API to extract the inner text of an element.

[html5gum](https://github.com/untitaker/html5gum) seems to be just an HTML tokenizer, or otherwise just too low-level. I have not yet tried [quick-xml](https://github.com/tafia/quick-xml/) but judging from the README, it's pretty low-level too. I mean, if these are the only options left then I will try them. Otherwise, I would love to use a parser that's faster but as ergonomic as `scraper` or `tl`.

At this point, I would be happy with an Lxml bridge/port of some sort. I don't need to mutate HTML, just parse and read data from it.

See https://github.com/servo/html5ever/tree/master/rcdom for an example implementation to imitate.

Ermm... actually I meant something like this: playground, but then I realized it's basically (de)serialization, and I just found that we already have a crate for that: bincode.

One, figure out the bincode format (documented here: https://github.com/bincode-org/bincode/blob/trunk/docs/spec.md) and write your own parser. Maybe a one-off that specifically only handles this one data structure would be fairly straightforward.

Step 1: The Deserialize type requests data from the Deserializer with one of the deserialize_type methods. This gives it an opportunity to provide certain metadata about the type: structs provide a list of fields, enums provide a list of variants, tuples provide a length, etc. Some data formats (notably bincode) require this metadata to drive deserializing, as the wire format is not self-describing. Crucially, the Deserialize type also provides a visitor that is capable of receiving the requested data from the Deserializer.

Alternatively, give Bincode a try.

Like separate instructions? I was thinking if a instruction have unknown length I make sure I have some kind of header field that tells the data length of the instruction so receiver knows when next instruction starts. And I was planning on using Bincode with serde to serialize and dezerialize like structs and stuff.

Isn't this essentially bincode?

This is similar in practice to using abi_stable, and end-users will still receive compiled files, but your plugins will be sandboxed and a single build will work on all platforms. The downside is that it's a bit more work because WebAssembly's support for passing complex data types between the host and the WebAssembly code is in the preliminary stages, so you need to do something like using Serde to encode your data into something like Bincode or MessagePack (or JSON and friends) to hand it off between the host and the plugin.

What kind of access do you need to the data ? You should be able to make a safe api to the Vec class by iterating on in in chunks, and using a closure to translate data between u8 and other representations. ( f32, u32 has the fomr_ne_bytes() / to_ne_bytes() methods ) You could make a helper function that takes a format description ( i.e. "fffuucc" , and calculates the size of the chunk, and generates a closure for reading accessing the data, of the layout is completely dynamic. This closure could use an enum to wrap the different primitive types. ) Or if the layouts are known at compile time , you could use procedural macros to generate code for serializaion / deserialization inot the the [u8] , though https://crates.io/crates/bincode may already do that for you )

Apparently there's a lot of discussion going on about that (3 of the 4 open tickets on the bincode implementation are about it), for example this one.