Hello, TL;DR: is it OK in elixir to pass large (MBytes) binary strings through function parameters ? If not, what would be a clean way to transfer this binary to the end user in a Plug HTTP response ? Context: My program reads binary data from storage using a NIF, in a format that Elixir does not …

[image] jschaeff: is it OK in elixir to pass large (MBytes) binary strings through function parameters ? It is [image] jschaeff: What are the impacts of passing large data through function parameters ? None

Large binaries (> 64 byte or so) are passed by reference. Small binaries by value. Only exception, the small binarie is a substring of a large binarie, in that case a fat pointer is passed, hindering the original binary from garbage collection as long as the substring is “alive”, thats why many sli…

[image] NobbZ: Large binaries (> 64 byte or so) are passed by reference. Small binaries by value. All binaries are passed by reference into a function call. You are taking about sending binaries between processes

You are right, in function calls both are passed by reference, my bad. Sending across processes is where it differs. Though the question is literally about “function parameters” (emph mine): [image] jschaeff: TL;DR: is it OK in elixir to pass large (MBytes) binary strings through function para…

[image] jschaeff: TL;DR: is it OK in elixir to pass large (MBytes) binary strings through function parameters ? [image] NobbZ: Large binaries (> 64 byte or so) are passed by reference. Small binaries by value. … The only “expensive” action is to send them over a network. … Binaries ar…

Thanks for all the answers, short and detailed ones. Indeed, my NIF function is a short-living one, I think I’m safe here. Again, this forum is great thanks to you all nice folks. Have a nice day !

Passing binary data through functions

Questions & Help Questions

Asd May 12, 2026, 1:14pm 2

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