Apps are too big (in size)

[mid-kid]

Every separate kivy app installed has an identical copy of the libraries. That makes every kivy app be about 20MB in size when only including the kivy library and it's dependencies. That's very big considering the actual content of the app.

There are several options to solve this problem I can think of:

• Go the necessitas/sl4a way and have an app for the libraries only. Users will be annoyed.
• Have every app include a piece of code to download precompiled libs (+ deps) to a .kivy folder in the sdcard. The sdcard needs to be available and have enough space.
• Use tinypy (though I doubt the compatibility + the project is pretty much moribund)
• Instead of extracting the python libraries from a zip, I think the python interpreter can load the zip directly. This will help a bit for size, but not for (startup) performance.
• I think nuitka can include all the necessary scripts into a single binary, then you just need several .so files (libpython, sdl, etc) and in my crappy theory, that should work. I don't know if this will reduce the size much, but at least you get performance, so that's a plus, I guess.
• Any ideas?

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[brousch]

We rehash this problem every few months. As you've discovered, there is no
ideal solution.
On Feb 1, 2014 5:59 PM, "mid-kid" notifications@github.com wrote:

Every separate kivy app installed has an identical copy of the libraries.
That makes every kivy app be about 20MB in size when only including the
kivy library and it's dependencies. That's very big considering the actual
content of the app.

There are several options to solve this problem I can think of:

• Go the necessitas way and have an app for the libraries only. Users
  will be annoyed.
• Have every app include a piece of code to download precompiled libs
  (+ deps) to a .kivy folder in the sdcard. The sdcard needs to be available.
• Use tinypy (though I doubt the compatibility + the project is pretty
  much morubund)
• Instead of extracting the python libraries from a zip, I think the
  python interpreter can load the zip directly. This will help a bit for
  size, but not for (startup) performance.
• I think nuitka can include all the necessary scripts into a single
  binary, then you just need several .so files (libpython, sdl, etc) and in
  my crappy theory, that should work. I don't know if this will reduce the
  size much, but at least you get performance, so that's a plus, I guess.
• Any ideas?

Reply to this email directly or view it on GitHubhttps://github.com//issues/202
.

[akshayaurora]

Every kivy app is not 20MB, look at the showcase. It's 6MB, you need to trim your app. Kivy itself comes under 5-6 mb as evident by the showcase.

[tito]

• Avoiding extraction of the application, and use the files directly from the apk. But native libraries expect a C path to be used with fopen() (ffmpeg / libpng / libjpeg / etc.). I made an experiment to redirect all of them to the android asset_ native API, it worked. No more unpack on the first start, and all the start are almost the same. If we store the pyo/data in the zip with compression, everytime you'll want to read it, it will be much slower. If we save them in the APK without compression, the starttime is identical as the current method, the APK is bigger, but it takes less space it total on the disk (APK + unpack in /sdcard (or /data in private mode)).
• Compiling Python to C using nuikta or Cython generate bigger files = .pyo is smaller than a .so. If the goal is to reduce the size of the app, that's wrong :)
• A strip tool. This would be for Python, not just for Kivy: C have "strip" that can remove all the unused functions / methods, because during the link of your application (ie, on iOS), it build a list of all the symbol used, and knows the one who are not used at all, and strip them. We don't have a such tool for Python. With a similar approach + exclude / inclusion symbol file, we could generate a directory with only the files / symbol used by the app.
• A better usage of strip in C. Currently, only the debugging symbol are stripped. We might be able to strip some part of the Python interpreter that we don't use at all.
• Reduce the bootstrap (python -v -m 'import kivy.uix.widget'), see all the modules imported, and check if reordering / avoiding to use some modules might help. This will end to reduce the size of the app, and be faster at boot.

And more, but all the things we currently explored have much more drawbacks than usability. The current state is a mix. It can always be improved, but must not be complex to use as well.

[tito]

And yes, a minimal APK size is ~5MB. 20MB is already big. And most of the time, it's due to the data in your application, not Kivy.

[brousch]

It is 20MB after extraction. If you ;look in Settings->Apps you can dee
this size. Showcase is about 35MB.
On Feb 1, 2014 6:18 PM, "Mathieu Virbel" notifications@github.com wrote:

And yes, a minimal APK size is ~5MB. 20MB is already big. And most of the
time, it's due to the data in your application, not Kivy.

Reply to this email directly or view it on GitHubhttps://github.com//issues/202#issuecomment-33886483
.

[mid-kid]

I see I missed a point there:
I was pretty much talking about the size in the internal memory after extraction and moved to SD, as shown by the android system package manager in the downloaded apps tab, which may be a bit problematic on devices low on internal memory.
The app I got the numbers with is a self-compiled launcher with only kivy (master branch) + deps.

Please note that the package manager has calculated the size wrong since as far as I can remember. Just try to move an app to/from the SD and look at the total.

Sorry for the confusion.

[adamski]

This is my main concern before delving into learning Kivy for mobile app development... I'm currently using JUCE and C++ but would rather be using Python for main part of the app.. however, app size and battery drain are concerns that I've seen raised about Kivy mobile apps.

[tshirtman]

I do think 6-7Megs are acceptable sizes for an app these days, and a lot more if you have data, you rarely ever see less than one meg apps anymore, imho. For battery drain, i never witnessed anything about kivy that would cause that, i do have a few unity apps that makes my phone burn my hand and empty my battery pretty quick (nexus 4), nothing of that kind happened with any kivy app that i tested.

[mid-kid]

@tshirtman

It may not be much of a problem on some newer phones with more storage, but if you can make it a bit smaller, and in the process support more phones, why not?
It can clearly be optimized.
And yes, <1m apps are rare, but I'm not talking about that. There's a big difference between that, and 20M (which makes it to the top 10 biggest apps on my phone).

P.S. I'm not talking about performance.

[brousch]

"Why not?" If we could do it without a bunch of extra work we would. This
has not been solved, so it has not been done.
On Jul 20, 2014 7:34 AM, "mid-kid" notifications@github.com wrote:

@tshirtman https://github.com/tshirtman

It may not be much of a problem on some newer phones with more storage,
but if you can make it a bit smaller, and in the process support more
phones, why not?
It can clearly be optimized.
And yes, <1m apps are rare, but I'm not talking about that. There's a big
difference between that, and 20M (which makes it to the top 10 biggest apps
on my phone).

P.S. I'm not talking about performance.

—
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#202 (comment)
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[mid-kid]

Please note the "if you can" ;)

[adamski]

I'm seeing two sizes stated here - ±20mb and 6-7mb - is the smaller size the compressed installer one would download from the app store? For my needs (musical tuning app), comparable apps are around 500kb on the app store.. so in this case, Kivy is not for me, but I am considering it for building API consuming mobile apps at the company I work for, as in this case size should not be such an issue.

[brousch]

6MB is the smallest size for the APK. Once installed, it will be reported
as about 20MB in Android App Settings.
On Jul 20, 2014 10:22 AM, "Adam Wilson" notifications@github.com wrote:

I'm seeing two sizes stated here - ±20mb and 6-7mb - is the smaller size
the compressed installer one would download from the app store? For my
needs (musical tuning app), comparable apps are around 500kb on the app
store.. so in this case, Kivy is not for me, but I am considering it for
building API consuming mobile apps at the company I work for, as in this
case size should not be such an issue.

—
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#202 (comment)
.

[mid-kid]

A kivy APK is 6MB, once it is run for the first time, libraries are extracted, which ends up as 20MB (Compressed data + estracted data). I can confirm that the android app manager is not the only who reports so, diskusage does too.

[akshayaurora]

@mid-kid. This is a known limitation. Kivy might not be suited for every
purpose out there. there have been some attempts at removing some more
default modules of python that are usually not needed like distuils etc.

Expecting the kivy apk to be around 500KB though might not be feasible, yet!

We need a good selection mechanism they while packaging figures out all the
libs needed and only includes those files that are actually being used.

On Sun, Jul 20, 2014 at 8:38 PM, mid-kid notifications@github.com wrote:

A kivy APK is 6MB, once it is run for the first time, libraries are
extracted, which ends up as 20MB (Compressed data + estracted data). I can
confirm that the android app manager is not the only who reports so,
diskusage does too.

—
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#202 (comment)
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