[Question] Native java port

[bmarwell]

Hi!

I'm very interested in this project, although I (personally) have no use case right now. But I really like the idea of this concept and that existing standards (like HTTP GET range requests) are being used.

I was wondering if it is possible to create a java-only port. From what I see in the spec, I'd say: Yes, this should be possible.

The only thing which may be a bit tricky is the zstd part. As for now, there is no native java implementation (only a jni binding).
Hint: If you were going to add more compression algorithms (brotli, lz4 and lz5/lizard might be good candidates): There are at least JNI-bindings for brotli and lz4 available. lz4 is also available in plain java.

So, I'm still looking for use cases and hope that a java port would be feasible. If you do have any suggestions and/or ideas, I'd love to hear them!

[jdieter]

Sorry it's taken me so long to respond. I've been on holiday and then just started a new job.

My thoughts on a pure java port are:

• Brilliant! I'd love to see one
• Any compression algorithms added to the Java port would also need to be added to the C library (the format is extensible to add new compression algorithms)

[bmarwell]

Hi,

no worries. I do not have any use cases at the moment and would likely not start before there is one. My best idea so far was: F-Droid. Haven't used it lately, but downloading repository metadata was always slow.

So I might just start with the no-compression, as soon as there is a use case.

[bmarwell]

Here you go (WIP): https://github.com/bmhm/zchunk-java

[jdieter]

Nice work! If you wanted to move it into the zchunk org here on github, I'd be happy to do that, even this early on.

[bmarwell]

Sure, let me just change the package names first. io.github.zchunk?

I'd love to see some more people interested in this, I might not be able to support it as much as I wanted to..

[jdieter]

Ok, I've added you as a member. Can you please verify that you have commit access? I'll be available for the next 3-4 hours, as it's Sunday evening here.

[bmarwell]

Hi, I tried to transfer it, but I get this error: You don’t have the permission to create repositories on zchunk.

I though there would be a message like "waiting for approval", but there is no such message.

// Edit: Is there a slack for zchunk already? :)

[jdieter]

Have you accepted the invitation to the zchunk org?

[bmarwell]

Thanks for the hint… it's now "ours" ;-) https://github.com/zchunk/zchunk-java

[jdieter]

Excellent! Glad to have you onboard. You should have the ability to add new collaborators to zchunk-java, change their permissions, etc. Let me know if you run into any problems.

[bmarwell]

Sure, thanks!
Feel free to update the readme or the wiki as needed. I wrote a page for the compressed int spec.

[bmarwell]

I think before we close this issue, we should head over to the guys from https://github.com/f-droid and ask them if they are interested.
And also ask them if such a library needs special treatment for android.

[jdieter]

I think f-droid (and android in general) is about apps. Unless a library is available as part of the Android API, I think it will need to be bundled with whatever apps use it.

[bmarwell]

I do not want to make it available on F-Droid. I want the F-Droid app to use zchunk to download the repository metadata.

[jdieter]

I'm sorry, I should have realized that that's what you meant. I suspect that they'll want a proof-of-concept before moving forward with it, but it sure wouldn't hurt to talk to them.