zcash-android-wallet-sdk/docs/testing/manual_testing/Switch cache to store blocks on disk.md

About

This manual test case provides information on how to manually test the implemented action of switching our mechanism of persisting CompactBlocks cache from in database storage to on disk storage.

The benefit of this approach is that the storing blocks on-disk does not require storing of blobs into
the sqlite database, which can cause poor performance as the database grows large. Instead, we store them on disk and insert only a limited portion of a block information (metadata) into the database.

Observed result of this manual test should be:

• there should be no Cache database in the older (/databases/) or the newer (/no_backup/co.electricoin.zcash/) legacy locations
• files containing protobuf-encoded CompactBlocks stored in /no_backup/co.electricoin.zcash/blocks/ location

Prerequisites

• Install Android Studio
• Install an emulator to Android Studio
• Install a git client
• Clone the Zcash Android SDK repository

Prepare steps

1. Create some existing persistent wallet state using a version prior to the introduction of the disk-based cache. To do this, check out commit zcash/zcash-android-wallet-sdk#910 (currently commit a67d287e5cc90fe3a774b02174dca1b32331058c).
2. Update dependencies lock (if needed) and sync Gradle files
3. Select one of the Mainnet build variants from Build Variant window
4. Build and run the demo-app on selected emulator
5. Once the app is open, select e.g. Alyssa P. Hacker secret phrase and then let the SDK create the Cache database files with auto-start syncing on the home screen
6. Wait a moment to be sure that the sync mechanism has already been initialized and started to fill in the Cache database with CompactBlocks entries.
7. Open Device File Explorer in Android Studio, select the same emulator device from the top drop-down menu
8. Go to /data/data/cash.z.ecc.android.sdk.demoapp.mainnet/no_backup/co.electricoin.zcash/
9. Verify there are cache.sqlite3 and possibly some rollback files too (suffixed with journal or wal). The file names can vary, depending on the current build variant.

Check steps

1. Install the newer version of the SDK and its demo-app to the same device to check the switch to the new type of the CompactBlocks cache storing
   1. Switch to the latest commit on the Main branch in your git client
   2. Update dependencies lock (if needed) and sync Gradle files
   3. Run the demo-app on the same emulator device as previously
2. Once the app is opened go through the same steps as previously to let the SDK apply the new cache storing mechanisms
3. Open the Device File Explorer in the Android Studio again
4. Go to /data/data/cash.z.ecc.android.sdk.demoapp.mainnet/no_backup/co.electricoin.zcash/
   1. Verify there is a new zcash_sdk_[network_name]_fs_cache directory in place
   2. Verify it contains a blockmeta.sqlite block metadata database file
   3. Also verify that this directory contains a blocks directory with new block cache files in it
   4. Verify there is no cache.sqlite3 database file, and check that no rollback files (suffixed with journal or wal) are present. The file names can vary, depending on the current build variant.
5. Inspect older legacy database folder /data/data/cash.z.ecc.android.sdk.demoapp.mainnet/databases/, which also should not contain cache.sqlite3 or rollback files.