Switch to FileMetadata to use statx instead of stat on Linux and Apple platforms by swankjesse · Pull Request #1772 · square/okio

swankjesse · 2026-02-05T21:53:39Z

MohammedKHC · 2026-02-06T10:16:47Z

This is good!
But also I think that we may use statx call on Linux.
It's only downside is that we need to use custom cinterop. and check if it's available at runtime..

Please refer to this code
https://github.com/MohammadKHC/mokio/blob/main/mokio/src/linuxMain/kotlin/metadata/FileMetadata.linux.kt#L40
and
https://github.com/MohammadKHC/mokio/blob/main/mokio/src/nativeInterop/linux/statx.def

And if we couldn't use statx then we should really let the creation time be mtime.. as in some cases (ex, modifying the file permissions) will make ctime newer than mtime!

MohammedKHC · 2026-02-06T10:34:54Z

+ *   createdAt: 2026-01-01T01:01:01Z
+ *   lastModifiedAt: 2026-02-02T02:02:02Z
+ *
+ * It would be nicer to do this in the test itself with exec(), but we don't yet have a handy


What if okio provided an api to set file attributes?
Maybe something like this
https://github.com/MohammadKHC/mokio/blob/main/mokio/src/commonMain/kotlin/metadata/FileAttribute.kt

Although iam sure that you can even do better than it.
Iam really bad at writing documentation for things. I usually just leave the code as is..

I don’t believe that it’s an API many people want?

Some background here, where I argue that files are less frequently UI and therefore setting metadata is not as useful as it once was.

There is definitely a use for it, but it’s difficult to do well. For example, I don’t believe cloud file systems do a particularly good job of preserving metadata!

I read your article, and I mostly agree with it.

It’s not just cloud file systems that don’t preserve file metadata—Git doesn’t either. Aside from whether a file is executable, Git ignores file metadata entirely.

https://softwareengineering.stackexchange.com/questions/350403/why-doesnt-git-set-the-file-time
https://superuser.com/a/1422661

That said, I think that we do need to support at least one piece of metadata: whether a file is executable.
This is very common on Unix systems.

Setting file creation or last-modified times only really makes sense for things like restoring family photo dates in the gallery 😄

And other attributes don’t seem necessary unless you’re building something very specialized.

However they are kinda nice to have in a filesystem API!

Yeah, they are nice to have in a FileSystem API. I certainly prefer metadata over access control!

swankjesse · 2026-02-06T15:59:05Z

@MohammadKHC your mokio project is rad!

I hope you don’t mind I’d like to copy your Process class (and the code that supports it) into okio-testing-support. I want to do processes in our tests! I would like to later promote that code into the main production artifact, but I want to start small by running it in our tests. There’s a lot of little design decisions in these things and I don’t yet have an intuition on how it should work. Forking processes is forbidden on iOS!

MohammedKHC · 2026-02-06T18:03:59Z

@swankjesse

I absolutely don’t mind — and I’m glad you liked Mokio.

I actually built it hoping some parts might eventually be useful for Okio, so feel free to copy the Process class and any supporting code.

There may be some imperfect design decisions, but it works for my use case.

Mokio doesn’t support iOS for the same reason you mentioned: forking processes isn’t supported there. I considered a custom source set or stubs, but I decided it wasn’t worth the extra complexity for my use case.

Happy to see where this goes if it’s promoted later.

Thanks!

swankjesse · 2026-02-08T16:21:22Z

 @OptIn(UnsafeNumber::class)
 internal val timespec.epochMillis: Long
-  get() = tv_sec * 1000L + tv_sec / 1_000_000L
+  get() = tv_sec * 1000L + tv_nsec / 1_000_000L


Longstanding severe bug!

I assume we got away with it cause it's usually zero? Otherwise we wouldn't have passed our tests.

swankjesse · 2026-02-09T04:32:47Z

+          isDirectory = stat.st_mode.toInt() and S_IFMT == S_IFDIR,
+          symlinkTarget = symlinkTarget(stat.st_mode.toInt(), path),
+          size = stat.st_size,
+          createdAtMillis = stat.st_mtim.epochMillis,


behavior change from st_ctim

JakeWharton · 2026-02-10T18:38:59Z

  }

+fun fromIso8601String(iso8601String: String): Instant =
+  Instant.fromEpochMilliseconds(Instant.parse(iso8601String).toEpochMilliseconds())


Why the round trip through millis after parsing?

It's probably to ignore some nanosecond precision..
Although I am not sure if it's intentional or not..

Edit: after checking the assertInRange code I think that this is redundant.
Sorry for replying before checking the code 😶‍🌫️

Yep. Just a bug. Fixed!

(introduced by deleting our commonMain Instant for Wasm)

MohammedKHC · 2026-02-10T19:18:28Z

+/**
+ * Returns true if the host file system probably exposes metadata like file creation time.
+ *
+ * The file system that GitHub actions gives us doesn't do anything when we `touch` a file.
+ */
+val fileSystemHasGoodMetadata: Boolean
+  get() = getEnv("GITHUB_WORKSPACE") == null
+


After reviewing the code again, I don’t think this is a GitHub issue.

GNU touch itself does not modify the creation time (and on Linux there’s no way to do that anyway).

Relevant code:
https://github.com/coreutils/coreutils/blob/3d35e82b9b0460769c1966b1ef8acc0b5e5c8348/src/touch.c#L138-L160
https://github.com/coreutils/coreutils/blob/3d35e82b9b0460769c1966b1ef8acc0b5e5c8348/src/touch.c#L218

I’m not sure about macOS and Windows, though.

Ahh, it’s a Linux issue, not a GitHub issue. That makes sense.

I was able to do validate our code worked successfully running Linux in Docker on my Mac, but that would have relied on my Mac’s touch command.

#1755

Also fallback if STATX_BTIME isn't set

square/okio#1772

MohammedKHC reviewed Feb 6, 2026

View reviewed changes

swankjesse commented Feb 8, 2026

View reviewed changes

swankjesse changed the title ~~Switch to FileMetadata to use st_birthtimespec on Apple platforms~~ Switch to FileMetadata to use statx instead of stat on Linux and Apple platforms Feb 8, 2026

MohammedKHC reviewed Feb 8, 2026

View reviewed changes

Comment thread okio/src/linuxMain/kotlin/okio/LinuxPosixVariant.kt Outdated

MohammedKHC reviewed Feb 8, 2026

View reviewed changes

Comment thread okio/src/linuxMain/headers/okio_statx.h Outdated

MohammedKHC reviewed Feb 8, 2026

View reviewed changes

Comment thread okio/src/linuxMain/kotlin/okio/LinuxPosixVariant.kt Outdated

MohammedKHC reviewed Feb 8, 2026

View reviewed changes

Comment thread okio/src/linuxMain/headers/okio_statx.h

swankjesse force-pushed the jwilson.0205.birthtime branch from 43630e5 to ddd7c3f Compare February 9, 2026 04:31

swankjesse commented Feb 9, 2026

View reviewed changes

MohammedKHC approved these changes Feb 9, 2026

View reviewed changes

swankjesse marked this pull request as ready for review February 9, 2026 12:38

swankjesse requested a review from JakeWharton February 9, 2026 23:57

JakeWharton approved these changes Feb 10, 2026

View reviewed changes

MohammedKHC reviewed Feb 10, 2026

View reviewed changes

swankjesse added 7 commits March 11, 2026 16:48

Switch to FileMetadata to use st_birthtimespec on Apple platforms

6711591

#1755

Use statx instead of stat on Linux

1c127a6

Fixup calling statx

1f17edb

Missing file

da43968

Hardcode __NR_statx for Linux X64

61352ce

More platforms

4dfc740

Fallback if statx isn't available

069930f

Also fallback if STATX_BTIME isn't set

swankjesse force-pushed the jwilson.0205.birthtime branch from ddd7c3f to 069930f Compare March 11, 2026 20:54

swankjesse merged commit 65c0c26 into master Mar 11, 2026
26 of 27 checks passed

swankjesse deleted the jwilson.0205.birthtime branch March 11, 2026 21:44

This was referenced Mar 12, 2026

FileMetadata with last modification information #463 Kotlin/kotlinx-io#488

Open

FileMetadata.createdAtMillis does not return the file creationTime on unix. #1755

Closed

MohammedKHC added a commit to MohammedKHC/mokio that referenced this pull request Mar 14, 2026

Use statx provided by okio 3.17.0

c4d0ea2

square/okio#1772

Conversation

swankjesse commented Feb 5, 2026

Uh oh!

MohammedKHC commented Feb 6, 2026

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

swankjesse commented Feb 6, 2026

Uh oh!

MohammedKHC commented Feb 6, 2026

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

MohammedKHC Feb 10, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

MohammedKHC Feb 10, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

MohammedKHC Feb 10, 2026 •

edited

Loading

MohammedKHC Feb 10, 2026 •

edited

Loading