Create SharedSessionRepository and remove bound service (#6844)

This removes all the bound service implementation, and starts the shared
sessions repository implementation. The shared repository is responsible
for sharing session data between processes in a simple way.

This does not detect cold starts yet. The `SharedSessionRepository`
class might be getting too much, we will consider splitting it up as
implementation goes further.

Author: mrober

firebase-sessions/src/androidTest/kotlin/com/google/firebase/sessions/FirebaseSessionsTests.kt

@@ -42,7 +42,6 @@ class FirebaseSessionsTests {
   @Test
   fun firebaseSessionsDependenciesDoInitialize() {
     assertThat(SessionFirelogPublisher.instance).isNotNull()
-    assertThat(SessionGenerator.instance).isNotNull()
     assertThat(SessionsSettings.instance).isNotNull()
   }
 

firebase-sessions/src/androidTest/kotlin/com/google/firebase/sessions/SessionLifecycleServiceBinderTest.kt

@@ -1,5 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright 2023 Google LLC -->
+<?xml version="1.0" encoding="utf-8"?><!-- Copyright 2023 Google LLC -->
 <!-- -->
 <!-- Licensed under the Apache License, Version 2.0 (the "License"); -->
 <!-- you may not use this file except in compliance with the License. -->
@@ -19,11 +18,8 @@
 
   <application>
     <service
-      android:name="com.google.firebase.sessions.SessionLifecycleService"
-      android:enabled="true"
-      android:exported="false" />
-    <service android:name="com.google.firebase.components.ComponentDiscoveryService"
-      android:exported="false">
+      android:exported="false"
+      android:name="com.google.firebase.components.ComponentDiscoveryService">
       <meta-data
         android:name="com.google.firebase.components:com.google.firebase.sessions.FirebaseSessionsRegistrar"
         android:value="com.google.firebase.components.ComponentRegistrar" />

firebase-sessions/src/main/AndroidManifest.xml

@@ -38,14 +38,14 @@ constructor(
   private val firebaseApp: FirebaseApp,
   private val settings: SessionsSettings,
   @Background backgroundDispatcher: CoroutineContext,
-  lifecycleServiceBinder: SessionLifecycleServiceBinder,
+  sessionsActivityLifecycleCallbacks: SessionsActivityLifecycleCallbacks,
 ) {
 
   init {
     Log.d(TAG, "Initializing Firebase Sessions SDK.")
     val appContext = firebaseApp.applicationContext.applicationContext
     if (appContext is Application) {
-      appContext.registerActivityLifecycleCallbacks(SessionsActivityLifecycleCallbacks)
+      appContext.registerActivityLifecycleCallbacks(sessionsActivityLifecycleCallbacks)
 
       CoroutineScope(backgroundDispatcher).launch {
         val subscribers = FirebaseSessionsDependencies.getRegisteredSubscribers()
@@ -56,16 +56,12 @@ constructor(
           if (!settings.sessionsEnabled) {
             Log.d(TAG, "Sessions SDK disabled. Not listening to lifecycle events.")
           } else {
-            val lifecycleClient = SessionLifecycleClient(backgroundDispatcher)
-            lifecycleClient.bindToService(lifecycleServiceBinder)
-            SessionsActivityLifecycleCallbacks.lifecycleClient = lifecycleClient
-
             firebaseApp.addLifecycleEventListener { _, _ ->
-              Log.w(
-                TAG,
-                "FirebaseApp instance deleted. Sessions library will stop collecting data.",
-              )
-              SessionsActivityLifecycleCallbacks.lifecycleClient = null
+              // Log.w(
+              //   TAG,
+              //   "FirebaseApp instance deleted. Sessions library will stop collecting data.",
+              // )
+              // TODO(mrober): Clean up on firebase app delete
             }
           }
         }

firebase-sessions/src/main/kotlin/com/google/firebase/sessions/FirebaseSessions.kt

@@ -66,7 +66,6 @@ import kotlinx.coroutines.CoroutineScope
 internal interface FirebaseSessionsComponent {
   val firebaseSessions: FirebaseSessions
 
-  val sessionDatastore: SessionDatastore
   val sessionFirelogPublisher: SessionFirelogPublisher
   val sessionGenerator: SessionGenerator
   val sessionsSettings: SessionsSettings
@@ -95,18 +94,10 @@ internal interface FirebaseSessionsComponent {
   interface MainModule {
     @Binds @Singleton fun eventGDTLoggerInterface(impl: EventGDTLogger): EventGDTLoggerInterface
 
-    @Binds @Singleton fun sessionDatastore(impl: SessionDatastoreImpl): SessionDatastore
-
     @Binds
     @Singleton
     fun sessionFirelogPublisher(impl: SessionFirelogPublisherImpl): SessionFirelogPublisher
 
-    @Binds
-    @Singleton
-    fun sessionLifecycleServiceBinder(
-      impl: SessionLifecycleServiceBinderImpl
-    ): SessionLifecycleServiceBinder
-
     @Binds
     @Singleton
     fun crashlyticsSettingsFetcher(impl: RemoteSettingsFetcher): CrashlyticsSettingsFetcher
@@ -123,6 +114,10 @@ internal interface FirebaseSessionsComponent {
 
     @Binds @Singleton fun settingsCache(impl: SettingsCacheImpl): SettingsCache
 
+    @Binds
+    @Singleton
+    fun sharedSessionRepository(impl: SharedSessionRepositoryImpl): SharedSessionRepository
+
     companion object {
       private const val TAG = "FirebaseSessions"
 
@@ -157,13 +152,14 @@ internal interface FirebaseSessionsComponent {
       fun sessionDataStore(
         appContext: Context,
         @Blocking blockingDispatcher: CoroutineContext,
+        sessionDataSerializer: SessionDataSerializer,
       ): DataStore<SessionData> =
         createDataStore(
-          serializer = SessionDataSerializer,
+          serializer = sessionDataSerializer,
           corruptionHandler =
             ReplaceFileCorruptionHandler { ex ->
               Log.w(TAG, "CorruptionException in session data DataStore", ex)
-              SessionDataSerializer.defaultValue
+              sessionDataSerializer.defaultValue
             },
           scope = CoroutineScope(blockingDispatcher),
           produceFile = { appContext.dataStoreFile("aqs/sessionDataStore.data") },

firebase-sessions/src/main/kotlin/com/google/firebase/sessions/FirebaseSessionsComponent.kt

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.firebase.sessions
+
+import androidx.datastore.core.CorruptionException
+import androidx.datastore.core.Serializer
+import java.io.InputStream
+import java.io.OutputStream
+import javax.inject.Inject
+import javax.inject.Singleton
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.Json
+
+/** Session data to be persisted. */
+@Serializable
+internal data class SessionData(val sessionDetails: SessionDetails, val backgroundTime: Time)
+
+/** DataStore json [Serializer] for [SessionData]. */
+@Singleton
+internal class SessionDataSerializer
+@Inject
+constructor(
+  private val sessionGenerator: SessionGenerator,
+  private val timeProvider: TimeProvider,
+) : Serializer<SessionData> {
+  override val defaultValue: SessionData
+    get() =
+      SessionData(
+        sessionDetails = sessionGenerator.generateNewSession(currentSession = null),
+        backgroundTime = timeProvider.currentTime(),
+      )
+
+  override suspend fun readFrom(input: InputStream): SessionData =
+    try {
+      Json.decodeFromString<SessionData>(input.readBytes().decodeToString())
+    } catch (ex: Exception) {
+      throw CorruptionException("Cannot parse session data", ex)
+    }
+
+  override suspend fun writeTo(t: SessionData, output: OutputStream) {
+    @Suppress("BlockingMethodInNonBlockingContext") // blockingDispatcher is safe for blocking calls
+    output.write(Json.encodeToString(SessionData.serializer(), t).encodeToByteArray())
+  }
+}