OperatingImageBypassJavaHeap Save Abandoned

OperatingImageBypassJavaHeap

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Stop maintaining announcement:

In devices above Android 8.0, bitmaps will store in native heap. In the future, devices will keep upgrading to newly above 8.0 so that this repo will be useless. This is why I stopped maintenance. I'm very sorry about that.

It is fact that Android's jvm Dalvik/ART accords to JVM standard. So that Android JVM has set xmx in its configuration. Here I don't want to describe more infomation about what xmx is. You can look into docs or websites for learning it. It limits size of java heap in one application. So that as you operrate large bitmap, device may throw OOM.

Although, size of physical memory, such as RAM, has been increasing for the decade, but the limitation of java heap still exist. Furthermore, the camera is improve though, so the images that we need operate keep incresing though. Another way, even though some brand or company who produce phones has modified xmx of their Android phones, the limitation is still not enough for large images.

On the other hand, the native heap has no limitation. It is able to allocate reach physical size. So, operating images in native heap can avoid OOM. In this repo I bypass Bitmap. In case it bypass bitmap, it will bypass java heap.

To sum up, native heap is a free space I can use and the repo works in. All operations of image be in native heap that will compeletely avoid OOM.

The evidence for that the native heap doesn't have limitation.

I have tried to allocate numerous memory in native heap and don't execute free. The allocated memory is exceed 1G that didm't occur OOM.

Below a picture, I run adb shell dumpsys meminfo PACKAGENAME to printed that memory information.

the repo progress

• rotate jpeg

• compress jpeg

• resize jpeg

• compress png (2018.04.10)

  • provide other algrithm about compression, may introduce optipng which has been used in most services or applications.

• rotate png

• resize png

build tips

before you run on device, you need put a test.jpg on external storage.

After you run:

    test.jpg ----------compress/rotate---------> test2.jpg

Thanks

base on::bither-android-lib

github:libjpeg-turbo

source.android.com/...../dalvik_vm_properties

sourceforge:libjpeg