fix cache cleanup deleting more statuses than it should (#2348)

* fix cache cleanup deleting more statuses than it should

* reset LOAD_AT_ONCE

* improve tests

* move cache clean code back to ViewModel

app/src/main/java/com/keylesspalace/tusky/appstore/CacheUpdater.kt

@@ -6,12 +6,11 @@ import com.keylesspalace.tusky.db.AppDatabase
 import io.reactivex.rxjava3.core.Single
 import io.reactivex.rxjava3.disposables.Disposable
 import io.reactivex.rxjava3.schedulers.Schedulers
-import java.util.concurrent.TimeUnit
 import javax.inject.Inject
 
 class CacheUpdater @Inject constructor(
     eventHub: EventHub,
-    accountManager: AccountManager,
+    private val accountManager: AccountManager,
     private val appDatabase: AppDatabase,
     gson: Gson
 ) {
@@ -21,11 +20,6 @@ class CacheUpdater @Inject constructor(
     init {
         val timelineDao = appDatabase.timelineDao()
 
-        Schedulers.io().scheduleDirect {
-            val olderThan = System.currentTimeMillis() - CLEANUP_INTERVAL
-            appDatabase.timelineDao().cleanup(olderThan)
-        }
-
         disposable = eventHub.events.subscribe { event ->
             val accountId = accountManager.activeAccount?.id ?: return@subscribe
             when (event) {
@@ -61,8 +55,4 @@ class CacheUpdater @Inject constructor(
             .subscribeOn(Schedulers.io())
             .subscribe()
     }
-
-    companion object {
-        val CLEANUP_INTERVAL = TimeUnit.DAYS.toMillis(14)
-    }
 }

app/src/main/java/com/keylesspalace/tusky/components/timeline/viewmodel/CachedTimelineViewModel.kt

@@ -43,11 +43,14 @@ import com.keylesspalace.tusky.network.TimelineCases
 import com.keylesspalace.tusky.util.dec
 import com.keylesspalace.tusky.util.inc
 import com.keylesspalace.tusky.viewdata.StatusViewData
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.rx3.await
 import retrofit2.HttpException
 import javax.inject.Inject
+import kotlin.time.DurationUnit
+import kotlin.time.toDuration
 
 /**
  * TimelineViewModel that caches all statuses in a local database
@@ -81,6 +84,16 @@ class CachedTimelineViewModel @Inject constructor(
         }
         .cachedIn(viewModelScope)
 
+    init {
+        viewModelScope.launch {
+            delay(5.toDuration(DurationUnit.SECONDS)) // delay so the db is not locked during initial ui refresh
+            accountManager.activeAccount?.id?.let { accountId ->
+                db.timelineDao().cleanup(accountId, MAX_STATUSES_IN_CACHE)
+                db.timelineDao().cleanupAccounts(accountId)
+            }
+        }
+    }
+
     override fun updatePoll(newPoll: Poll, status: StatusViewData.Concrete) {
         // handled by CacheUpdater
     }
@@ -207,4 +220,8 @@ class CachedTimelineViewModel @Inject constructor(
             }
         }
     }
+
+    companion object {
+        private const val MAX_STATUSES_IN_CACHE = 1000
+    }
 }

app/src/main/java/com/keylesspalace/tusky/components/timeline/viewmodel/TimelineViewModel.kt

@@ -43,7 +43,6 @@ import com.keylesspalace.tusky.settings.PrefKeys
 import com.keylesspalace.tusky.viewdata.StatusViewData
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.rx3.asFlow
 import kotlinx.coroutines.rx3.await

app/src/main/java/com/keylesspalace/tusky/db/TimelineDao.kt

@@ -98,8 +98,29 @@ AND serverId = :statusId"""
     )
     abstract fun delete(accountId: Long, statusId: String)
 
-    @Query("""DELETE FROM TimelineStatusEntity WHERE createdAt < :olderThan""")
-    abstract fun cleanup(olderThan: Long)
+    /**
+     * Cleans the TimelineStatusEntity table from old status entries.
+     * @param accountId id of the account for which to clean statuses
+     * @param limit how many statuses to keep
+     */
+    @Query(
+        """DELETE FROM TimelineStatusEntity WHERE timelineUserId = :accountId AND serverId NOT IN
+        (SELECT serverId FROM TimelineStatusEntity WHERE timelineUserId = :accountId ORDER BY LENGTH(serverId) DESC, serverId DESC LIMIT :limit)
+    """
+    )
+    abstract suspend fun cleanup(accountId: Long, limit: Int)
+
+    /**
+     * Cleans the TimelineAccountEntity table from accounts that are no longer referenced in the TimelineStatusEntity table
+     * @param accountId id of the user account for which to clean timeline accounts
+     */
+    @Query(
+        """DELETE FROM TimelineAccountEntity WHERE timelineUserId = :accountId AND serverId NOT IN
+        (SELECT authorServerId FROM TimelineStatusEntity WHERE timelineUserId = :accountId) 
+        AND serverId NOT IN 
+        (SELECT reblogAccountId FROM TimelineStatusEntity WHERE timelineUserId = :accountId AND reblogAccountId IS NOT NULL)"""
+    )
+    abstract suspend fun cleanupAccounts(accountId: Long)
 
     @Query(
         """UPDATE TimelineStatusEntity SET poll = :poll

app/src/test/java/com/keylesspalace/tusky/db/TimelineDaoTest.kt

@@ -5,7 +5,6 @@ import androidx.room.Room
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.platform.app.InstrumentationRegistry
 import com.google.gson.Gson
-import com.keylesspalace.tusky.appstore.CacheUpdater
 import com.keylesspalace.tusky.components.timeline.Placeholder
 import com.keylesspalace.tusky.components.timeline.toEntity
 import com.keylesspalace.tusky.entity.Status
@@ -66,28 +65,25 @@ class TimelineDaoTest {
 
     @Test
     fun cleanup() = runBlocking {
-        val now = System.currentTimeMillis()
-        val oldDate = now - CacheUpdater.CLEANUP_INTERVAL - 20_000
-        val oldThisAccount = makeStatus(
-            statusId = 5,
-            createdAt = oldDate
-        )
-        val oldAnotherAccount = makeStatus(
-            statusId = 10,
-            createdAt = oldDate,
-            accountId = 2
-        )
-        val recentThisAccount = makeStatus(
-            statusId = 30,
-            createdAt = System.currentTimeMillis()
+
+        val statusesBeforeCleanup = listOf(
+            makeStatus(statusId = 100),
+            makeStatus(statusId = 10, authorServerId = "3"),
+            makeStatus(statusId = 8, reblog = true, authorServerId = "10"),
+            makeStatus(statusId = 5),
+            makeStatus(statusId = 3, authorServerId = "4"),
+            makeStatus(statusId = 2, accountId = 2, authorServerId = "5"),
+            makeStatus(statusId = 1, authorServerId = "5")
         )
-        val recentAnotherAccount = makeStatus(
-            statusId = 60,
-            createdAt = System.currentTimeMillis(),
-            accountId = 2
+
+        val statusesAfterCleanup = listOf(
+            makeStatus(statusId = 100),
+            makeStatus(statusId = 10, authorServerId = "3"),
+            makeStatus(statusId = 8, reblog = true, authorServerId = "10"),
+            makeStatus(statusId = 2, accountId = 2, authorServerId = "5"),
         )
 
-        for ((status, author, reblogAuthor) in listOf(oldThisAccount, oldAnotherAccount, recentThisAccount, recentAnotherAccount)) {
+        for ((status, author, reblogAuthor) in statusesBeforeCleanup) {
             timelineDao.insertAccount(author)
             reblogAuthor?.let {
                 timelineDao.insertAccount(it)
@@ -95,15 +91,34 @@ class TimelineDaoTest {
             timelineDao.insertStatus(status)
         }
 
-        timelineDao.cleanup(now - CacheUpdater.CLEANUP_INTERVAL)
+        timelineDao.cleanup(accountId = 1, limit = 3)
+        timelineDao.cleanupAccounts(accountId = 1)
 
         val loadParams: PagingSource.LoadParams<Int> = PagingSource.LoadParams.Refresh(null, 100, false)
 
-        val loadedStatusAccount1 = (timelineDao.getStatusesForAccount(1).load(loadParams) as PagingSource.LoadResult.Page).data
-        val loadedStatusAccount2 = (timelineDao.getStatusesForAccount(2).load(loadParams) as PagingSource.LoadResult.Page).data
+        val loadedStatuses = (timelineDao.getStatusesForAccount(1).load(loadParams) as PagingSource.LoadResult.Page).data
+
+        assertStatuses(statusesAfterCleanup, loadedStatuses)
+
+        val loadedAccounts: MutableList<Pair<Long, String>> = mutableListOf()
+        val accountCursor = db.query("SELECT timelineUserId, serverId FROM TimelineAccountEntity", null)
+        accountCursor.moveToFirst()
+        while (!accountCursor.isAfterLast) {
+            val accountId: Long = accountCursor.getLong(accountCursor.getColumnIndex("timelineUserId"))
+            val serverId: String = accountCursor.getString(accountCursor.getColumnIndex("serverId"))
+            loadedAccounts.add(accountId to serverId)
+            accountCursor.moveToNext()
+        }
 
-        assertStatuses(listOf(recentThisAccount), loadedStatusAccount1)
-        assertStatuses(listOf(recentAnotherAccount), loadedStatusAccount2)
+        val expectedAccounts = listOf(
+            1L to "3",
+            1L to "10",
+            1L to "R10",
+            1L to "20",
+            2L to "5"
+        )
+
+        assertEquals(expectedAccounts, loadedAccounts)
     }
 
     @Test
@@ -115,8 +130,6 @@ class TimelineDaoTest {
             makeStatus(statusId = 1)
         )
 
-        timelineDao.deleteRange(1, oldStatuses.last().first.serverId, oldStatuses.first().first.serverId)
-
         for ((status, author, reblogAuthor) in oldStatuses) {
             timelineDao.insertAccount(author)
             reblogAuthor?.let {
@@ -152,6 +165,42 @@ class TimelineDaoTest {
         assertStatuses(newStatuses, loadedStatuses)
     }
 
+    @Test
+    fun deleteRange() = runBlocking {
+        val statuses = listOf(
+            makeStatus(statusId = 100),
+            makeStatus(statusId = 15),
+            makeStatus(statusId = 14),
+            makeStatus(statusId = 13),
+            makeStatus(statusId = 12),
+            makeStatus(statusId = 11),
+            makeStatus(statusId = 9)
+        )
+
+        for ((status, author, reblogAuthor) in statuses) {
+            timelineDao.insertAccount(author)
+            reblogAuthor?.let {
+                timelineDao.insertAccount(it)
+            }
+            timelineDao.insertStatus(status)
+        }
+
+        timelineDao.deleteRange(1, "12", "14")
+
+        val pagingSource = timelineDao.getStatusesForAccount(1)
+        val loadResult = pagingSource.load(PagingSource.LoadParams.Refresh(null, 100, false))
+        val loadedStatuses = (loadResult as PagingSource.LoadResult.Page).data
+
+        val remainingStatuses = listOf(
+            makeStatus(statusId = 100),
+            makeStatus(statusId = 15),
+            makeStatus(statusId = 11),
+            makeStatus(statusId = 9)
+        )
+
+        assertStatuses(remainingStatuses, loadedStatuses)
+    }
+
     @Test
     fun deleteAllForInstance() = runBlocking {