alt Hacker NewsThe comedy option would be to use the new multi-memory feature to juggle a bunch of 32bit memories instead of a 64bit one, at the cost of your sanity.
Replies
Somewhat related. At some point around 15 years ago I needed to work with large images in Java, and at least at the time the language used 32-bit integers for array sizes and indices. My image data was about 30 gigs in size, and despite having enough RAM and running a 64-bit OS and JVM I couldn't fit image data into s ingle array.
This multi-memory setup reminds me of my array juggling I had to do back then. While intellectually challenging it was not fun at all.
It looks like memories have to be declared up front, and the memcpy instruction takes the memories to copy between as numeric literals. So I guess you can't use it to allocate dynamic buffers. But maybe you could decide memory 0 = heap and memory 1 = pixel data or something like that?
Honestly you could allocate a new memory for every page :-)
The problem with multi-memory (and why it hasn't seen much usage, despite having been supported in many runtimes for years) is that basically no language supports distinct memory spaces. You have to rewrite everything to use WASM intrinsics to work on a specific memory.