perf(detect-libc): faster musl check by looking for ldd file

[H4ad]

Closes #18

Now, we use by default the comparison of check if ldd file exists.

Performance

Before:

[family] Time Spent 30.49158699810505ms
[isNonGlibcLinux] Time Spent 29.517467997968197ms
[versionSync] Time Spent 26.344385005533695ms

npm run bench:calls

Now:

[family] Time Spent 0.15008499845862389ms
[isNonGlibcLinux] Time Spent 0.1661360003054142ms
[versionSync] Time Spent 0.184239000082016ms

npm run bench:calls

[H4ad]

@lovell I don't know if perf is appropriated to describe this change since it could be a breaking change, so let me know if you want me to change to other message.

[lovell]

Hi, thanks for the PR, I've left a few thoughts and questions inline.

[lovell]

Could we use this same approach for a potential versionFromFilesystem()? For example, the /usr/bin/ldd file on some glibc-based Linux will contain the string literal "GLIBC X.Y".

[H4ad]

In theory, we can:

This is the content of /usr/bin/ldd

We just need to build a faster parser to extract this information.

Do you want to include the change on version in this PR too?

[H4ad]

@lovell How did you test linux musl? I'm trying to understand what is the output of cat /usr/bin/ldd on musl

[lovell]

Although we can probably determine the family from the /usr/bin/ldd file on musl-based Linux, we are unlikely to be able to determine the version.

$ docker run -it --rm alpine:3.18 cat /usr/bin/ldd
#!/bin/sh
exec /lib/ld-musl-x86_64.so.1 --list "$@"

[H4ad]

Hey @lovell, any updates?

[lovell]

Looks great, thank you. Is there anything else you wanted to add, or is this good for release?

[H4ad]

It's good for a release!

[lovell]

v2.0.2 now available, tudo bom, obrigado!

[styfle]

This .toLowerCase() is redundant since MUSL on line 57 is already lowercase.

[H4ad]

I did this just to make sure the text is always lowercase and a change to musl won't affect this constant.
But better than removing .toLowerCase could be just putting the string literal, since they are different information even though it is the same string.

[styfle]

Yeah, might be best to inline those strings in the getFamilyFromLddContent() function since each is only used once, no need for a variable

[lovell]

PRs welcome 😅

[styfle]

I created #20