PackageManagerService snapshot: statistics
Bug: 177425470
Collect periodic snapshot statistics. The statistics are:
1. Number of snapshots built
2. Number of times a snapshot was reused
3. Number of "big" snapshot build times
4. Number of "quick" snapshot rebuilds
4. Maximum time spent building a single snapshot
5. Cumulative time spent building snapshots
All statistics are reset after being logged.
Collect event snapshot statistics. The statistics are:
1. The time taken for a big snapshot build
At most 5 events are logged in any periodic poll interval.
The periodic log interval is 10 minutes. This will be lengthened
after we have some dogfood exprience.
A long snapshot build time is currently defined as anything over 5ms.
A quick snapshot rebuild is one that happens within 100ms of the
previous snapshot.
This change is designed to monitor the health of the snapshot feature.
A future improvement will allow statistics to be dumped on demand and
to report statistics via WestWorld.
Also:
1. A places that still used the word "cache" are changed to use the
word "snapshot".
2. The unused DEBUG_CACHE flag is removed
Test: atest
* FrameworksServicesTests:UserSystemPackageInstallerTest
* FrameworksServicesTests:PackageManagerSettingsTests
* FrameworksServicesTests:PackageManagerServiceTest
* FrameworksServicesTests:AppsFilterTest
* FrameworksServicesTests:PackageInstallerSessionTest
* FrameworksServicesTests:ScanTests
Change-Id: Id964f7d9fc16cf49e064044643b3c65862183a7d
2 files changed