Incremental Install is a way of building & deploying an APK that tries to minimize the time it takes to make a change and see that change running on device. They work best with is_component_build=true
, and do not require a rooted device.
Add the gn arg:
incremental_install = true
This causes all apks to be built as incremental except for denylisted ones.
It is not enough to adb install
them. You must use the generated wrapper script:
out/Debug/bin/your_apk run out/Debug/bin/run_chrome_public_test_apk # Automatically sets --fast-local-dev
The basic idea is to sideload .dex and .so files to /data/local/tmp
rather than bundling them in the .apk. Then, when making a change, only the changed .dex / .so needs to be pushed to the device.
Faster Builds:
final_dex
step (where all .dex files are merged into one)Faster Installs:
adb install
for code-only changes.Slower Initial Runs:
DexOpt
needs to run on all .dex files. This step is normally done during adb install
, but is done on start-up for incremental apks.Caveats:
loadable_modules
are not sideloaded (they remain in the apk), so builds & installs that modify any of these are not as fast as those that modify only .java / .cc./data/local/tmp
, you need to use the wrapper scripts to uninstall them fully. E.g.:out/Default/bin/chrome_public_apk uninstall
AppComponentFactory.instantiateClassLoader()
is not supported.All incremental apks have the same classes.dex, which is built from:
//build/android/incremental_install:bootstrap_java
They also have a transformed AndroidManifest.xml
, which overrides the the main application class and any instrumentation classes so that they instead point to BootstrapApplication
. This is built by:
//build/android/incremental_install/generate_android_manifest.py
Wrapper scripts and install logic is contained in:
//build/android/incremental_install/create_install_script.py //build/android/incremental_install/installer.py
Finally, GN logic for incremental apks is sprinkled throughout.