Session database: add count query.

libraries/session-storage/api/src/main/kotlin/io/element/android/libraries/sessionstorage/api/SessionStore.kt

@@ -50,6 +50,11 @@ interface SessionStore {
      */
     suspend fun getAllSessions(): List<SessionData>
 
+    /**
+     * Get the number of sessions.
+     */
+    suspend fun numberOfSessions(): Int
+
     /**
      * Get the latest session, or null if no session exists.
      */

libraries/session-storage/impl/src/main/kotlin/io/element/android/libraries/sessionstorage/impl/DatabaseSessionStore.kt

@@ -161,6 +161,15 @@ class DatabaseSessionStore(
         }
     }
 
+    override suspend fun numberOfSessions(): Int {
+        return sessionDataMutex.withLock {
+            database.sessionDataQueries.count()
+                .executeAsOneOrNull()
+                ?.toInt()
+                ?: 0
+        }
+    }
+
     override fun sessionsFlow(): Flow<List<SessionData>> {
         return database.sessionDataQueries.selectAll()
             .asFlow()

libraries/session-storage/impl/src/main/sqldelight/io/element/android/libraries/matrix/session/SessionData.sq

@@ -47,6 +47,9 @@ SELECT * FROM SessionData ORDER BY lastUsageIndex DESC LIMIT 1;
 selectAll:
 SELECT * FROM SessionData ORDER BY lastUsageIndex DESC;
 
+count:
+SELECT count(*) FROM SessionData;
+
 selectByUserId:
 SELECT * FROM SessionData WHERE userId = ?;
 

libraries/session-storage/impl/src/test/kotlin/io/element/android/libraries/sessionstorage/impl/DatabaseSessionStoreTest.kt

@@ -52,6 +52,7 @@ class DatabaseSessionStoreTest {
 
         assertThat(database.sessionDataQueries.selectLatest().executeAsOneOrNull()).isEqualTo(aSessionData)
         assertThat(database.sessionDataQueries.selectAll().executeAsList().size).isEqualTo(1)
+        assertThat(database.sessionDataQueries.count().executeAsOneOrNull()).isEqualTo(1)
     }
 
     @Test
@@ -109,6 +110,7 @@ class DatabaseSessionStoreTest {
 
         assertThat(foundSession).isEqualTo(aSessionData)
         assertThat(database.sessionDataQueries.selectAll().executeAsList().size).isEqualTo(2)
+        assertThat(database.sessionDataQueries.count().executeAsOneOrNull()).isEqualTo(2)
     }
 
     @Test
@@ -196,12 +198,16 @@ class DatabaseSessionStoreTest {
                 position = 1,
                 lastUsageIndex = 1,
             )
+            assertThat(database.sessionDataQueries.count().executeAsOneOrNull()).isEqualTo(1)
             databaseSessionStore.addSession(secondSessionData.toApiModel())
             assertThat(awaitItem().size).isEqualTo(2)
+            assertThat(database.sessionDataQueries.count().executeAsOneOrNull()).isEqualTo(2)
             databaseSessionStore.removeSession(aSessionData.userId)
             assertThat(awaitItem().size).isEqualTo(1)
+            assertThat(database.sessionDataQueries.count().executeAsOneOrNull()).isEqualTo(1)
             databaseSessionStore.removeSession(secondSessionData.userId)
             assertThat(awaitItem()).isEmpty()
+            assertThat(database.sessionDataQueries.count().executeAsOneOrNull()).isEqualTo(0)
         }
     }
 

libraries/session-storage/test/src/main/kotlin/io/element/android/libraries/sessionstorage/test/InMemorySessionStore.kt

@@ -67,6 +67,10 @@ class InMemorySessionStore(
         return sessionDataListFlow.value
     }
 
+    override suspend fun numberOfSessions(): Int {
+        return sessionDataListFlow.value.size
+    }
+
     override suspend fun getLatestSession(): SessionData? {
         return sessionDataListFlow.value.firstOrNull()
     }