- While doing cross-compiling of Forgejo (with CGO enabled) it was noticed that besides compiling sqlite3, github.com/DataDog/zstd (a CGO wrapper around the reference zstd library) took a long time to compile. Upon investigating why this library was included in the first place I concluded that this library is not even used and compiling this package is a waste of time and CPU cycles.
- https://github.com/sassoftware/go-rpmutils is the library that uses the CGO zstd library, and would use it the pure Go variant (https://github.com/klauspost/compress/zstd) if CGO is enabled (which is the default). It uses zstd to uncompress the payload of a RPM packages. This is a operation that Forgejo does not use in the slightest, hence being unused code.
- It is not possible to force compiling the pure Go variant if CGO is enabled. Therefore forking and removing this code is the only option to avoid compiling the zstd C library. The changes made to the fork can be seen here: 2660c86d57...v1.0.0
- Via [actiongraph](https://github.com/icio/actiongraph) you can precisely see where the Go compiler is spending time, on a beefy machine the compilation takes of the zstd C library takes ~40s. For reference compiling the sqlite3 C library takes ~50s.
- The forgejo binary (build via `make backend`) reduced its size by 835776 bytes (0.8 MiB).
TL;DR forked library to remove unused code to avoid Go spending a considerable amount of time compiling the reference zstd library that in the end is never used.
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## Release notes
<!--URL:https://codeberg.org/forgejo/forgejo-->
- Features
- [PR](https://codeberg.org/forgejo/forgejo/pulls/7953): <!--number 7953 --><!--line 0 --><!--description cmVwbGFjZSBnby1ycG11dGlscyBsaWJyYXJ5IHdpdGggb3VyIG93bg==-->replace go-rpmutils library with our own<!--description-->
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Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7953
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Gusted <postmaster@gusted.xyz>
Co-committed-by: Gusted <postmaster@gusted.xyz>
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