cargo-bloat VS resvg

And, importantly, Rust has good tooling for finding out where bloat, if any, comes from, cargo-bloat

You can run cargo bloat --time --release -j 1 (github) to see what dependency takes the most time and try to replace it. It would probably be some proc-macro monstrosity.

I think you will be interested in cargo-bloat

Try to use this tool to get some insight. https://github.com/RazrFalcon/cargo-bloat

I've seen resvg as a potential pick, but it feels huge and seems to be importing skia, which itself is a whole rendering engine. Furthermore, I have no idea if I can pass my own 2D buffer to resvg and let it draw to it.

For example, when converting vector SVG images to raster PNG images with resvg, most of the time is spent compressing the PNG image. This is a lot of wasted work if we just want to read the image instead of transferring it over the network! The fast compression mode eliminates all this wasted work, resulting in huge performance and efficiency gains.

Just as a point of reference, I have a ~75KLOC project (includes dependencies) called resvg which takes just 4s in the debug mode and 8s in the release mode to build on M1 Pro.

resvg is very fast, although the performance depends on the exact SVG you feed it - sometimes faster than librsvg, sometimes slower (although librsvg is also written in Rust now, it does use unsafe while resvg doesn't)

So I am absolutely clueless about Rust and just installed it an hour ago to use this tool called "usvg" https://github.com/RazrFalcon/resvg/tree/master/usvg

So, all you gotta do is rewrite the parsers. Funny you mention librsvg because there is a library called resvg that has a thumbnailer implementation for Windows Explorer. https://github.com/RazrFalcon/resvg