Store the user avatar thumbnail in the session database

Add a `userAvatarData` column to the session database, containing the base64 encoded
thumbnail of the user avatar. It will allow rendering the avatar of an account without
having to use its Matrix client, for instance on the signed out screen, or for other
accounts when the homeservers are not federated.

The thumbnail is downloaded when the user profile is retrieved or updated, and only if
the avatar URL has changed. The profile is now also persisted when received from the
own profile subscription.

Part of #5571

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

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

@@ -84,12 +84,13 @@ class DatabaseSessionStore(
                     lastUsageIndex = result.lastUsageIndex,
                     userDisplayName = result.userDisplayName,
                     userAvatarUrl = result.userAvatarUrl,
+                    userAvatarData = result.userAvatarData,
                 ).toDbModel()
             )
         }
     }
 
-    override suspend fun updateUserProfile(sessionId: String, displayName: String?, avatarUrl: String?) {
+    override suspend fun updateUserProfile(sessionId: String, displayName: String?, avatarUrl: String?, avatarData: String?) {
         sessionDataMutex.withLock {
             val result = database.sessionDataQueries.selectByUserId(sessionId)
                 .executeAsOneOrNull()
@@ -102,6 +103,7 @@ class DatabaseSessionStore(
                 result.copy(
                     userDisplayName = displayName,
                     userAvatarUrl = avatarUrl,
+                    userAvatarData = avatarData,
                 ).toDbModel()
             )
         }

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

@@ -31,6 +31,7 @@ internal fun SessionData.toDbModel(): DbSessionData {
         lastUsageIndex = lastUsageIndex,
         userDisplayName = userDisplayName,
         userAvatarUrl = userAvatarUrl,
+        userAvatarData = userAvatarData,
     )
 }
 
@@ -52,5 +53,6 @@ internal fun DbSessionData.toApiModel(): SessionData {
         lastUsageIndex = lastUsageIndex,
         userDisplayName = userDisplayName,
         userAvatarUrl = userAvatarUrl,
+        userAvatarData = userAvatarData,
     )
 }

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

@@ -36,7 +36,10 @@ CREATE TABLE SessionData (
     -- user display name
     userDisplayName TEXT,
     -- user avatar url
-    userAvatarUrl TEXT
+    userAvatarUrl TEXT,
+    -- added in version 13
+    -- user avatar thumbnail data, base64 encoded
+    userAvatarData TEXT
 );
 
 

libraries/session-storage/impl/src/main/sqldelight/migrations/12.sqm

@@ -0,0 +1,4 @@
+-- Migrate DB from version 12
+-- Add the thumbnail of the user avatar, base64 encoded, so that the avatar can be rendered without a Matrix client.
+
+ALTER TABLE SessionData ADD COLUMN userAvatarData TEXT;

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

@@ -134,17 +134,18 @@ class DatabaseSessionStoreTest {
 
     @Test
     fun `updateUserProfile does nothing if the session is not found`() = runTest {
-        databaseSessionStore.updateUserProfile(aSessionData.userId, "userDisplayName", "userAvatarUrl")
+        databaseSessionStore.updateUserProfile(aSessionData.userId, "userDisplayName", "userAvatarUrl", "userAvatarData")
         assertThat(database.sessionDataQueries.selectByUserId(aSessionData.userId).executeAsOneOrNull()).isNull()
     }
 
     @Test
     fun `updateUserProfile update the data`() = runTest {
         database.sessionDataQueries.insertSessionData(aSessionData)
-        databaseSessionStore.updateUserProfile(aSessionData.userId, "userDisplayName", "userAvatarUrl")
+        databaseSessionStore.updateUserProfile(aSessionData.userId, "userDisplayName", "userAvatarUrl", "userAvatarData")
         val updatedSession = database.sessionDataQueries.selectByUserId(aSessionData.userId).executeAsOne()
         assertThat(updatedSession.userDisplayName).isEqualTo("userDisplayName")
         assertThat(updatedSession.userAvatarUrl).isEqualTo("userAvatarUrl")
+        assertThat(updatedSession.userAvatarData).isEqualTo("userAvatarData")
     }
 
     @Test
@@ -231,6 +232,7 @@ class DatabaseSessionStoreTest {
             lastUsageIndex = 0,
             userDisplayName = "userDisplayName",
             userAvatarUrl = "userAvatarUrl",
+            userAvatarData = "userAvatarData",
         )
         val secondSessionData = SessionData(
             userId = "userId",
@@ -249,6 +251,7 @@ class DatabaseSessionStoreTest {
             lastUsageIndex = 1,
             userDisplayName = "userDisplayNameAltered",
             userAvatarUrl = "userAvatarUrlAltered",
+            userAvatarData = "userAvatarDataAltered",
         )
         assertThat(firstSessionData.userId).isEqualTo(secondSessionData.userId)
         assertThat(firstSessionData.loginTimestamp).isNotEqualTo(secondSessionData.loginTimestamp)
@@ -273,6 +276,7 @@ class DatabaseSessionStoreTest {
         assertThat(alteredSession.lastUsageIndex).isEqualTo(firstSessionData.lastUsageIndex)
         assertThat(alteredSession.userDisplayName).isEqualTo(firstSessionData.userDisplayName)
         assertThat(alteredSession.userAvatarUrl).isEqualTo(firstSessionData.userAvatarUrl)
+        assertThat(alteredSession.userAvatarData).isEqualTo(firstSessionData.userAvatarData)
     }
 
     @Test
@@ -294,6 +298,7 @@ class DatabaseSessionStoreTest {
             lastUsageIndex = 0,
             userDisplayName = "userDisplayName",
             userAvatarUrl = "userAvatarUrl",
+            userAvatarData = "userAvatarData",
         )
         val secondSessionData = SessionData(
             userId = "userIdUnknown",
@@ -312,6 +317,7 @@ class DatabaseSessionStoreTest {
             lastUsageIndex = 1,
             userDisplayName = "userDisplayNameAltered",
             userAvatarUrl = "userAvatarUrlAltered",
+            userAvatarData = "userAvatarDataAltered",
         )
         assertThat(firstSessionData.userId).isNotEqualTo(secondSessionData.userId)
 

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

@@ -30,4 +30,5 @@ internal fun aDbSessionData(
     lastUsageIndex = 0,
     userDisplayName = null,
     userAvatarUrl = null,
+    userAvatarData = null,
 )