EN API: Only use a single writable database instance

Should fix some issues with older Android versions, #1115

play-services-core/src/main/kotlin/org/microg/gms/ui/ExposureNotificationsAppPreferencesFragment.kt

@@ -47,14 +47,14 @@ class ExposureNotificationsAppPreferencesFragment : PreferenceFragmentCompat() {
 
     fun updateContent() {
         packageName?.let { packageName ->
-            val database = ExposureDatabase(requireContext())
+            ExposureDatabase.with(requireContext()) { database ->
                 var str = getString(R.string.pref_exposure_app_checks_summary, database.countMethodCalls(packageName, "provideDiagnosisKeys"))
                 val lastCheckTime = database.lastMethodCall(packageName, "provideDiagnosisKeys")
                 if (lastCheckTime != null && lastCheckTime != 0L) {
                     str += "\n" + getString(R.string.pref_exposure_app_last_check_summary, DateUtils.getRelativeDateTimeString(context, lastCheckTime, DateUtils.MINUTE_IN_MILLIS, DateUtils.WEEK_IN_MILLIS, DateUtils.FORMAT_SHOW_TIME))
                 }
                 checks.summary = str
-            database.close()
+            }
         }
     }
 }

play-services-core/src/main/kotlin/org/microg/gms/ui/ExposureNotificationsPreferencesFragment.kt

@@ -25,16 +25,10 @@ class ExposureNotificationsPreferencesFragment : PreferenceFragmentCompat() {
     private lateinit var exposureAppsNone: Preference
     private lateinit var collectedRpis: Preference
     private lateinit var advertisingId: Preference
-    private lateinit var database: ExposureDatabase
     private val handler = Handler()
     private val updateStatusRunnable = Runnable { updateStatus() }
     private val updateContentRunnable = Runnable { updateContent() }
 
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-        database = ExposureDatabase(requireContext())
-    }
-
     override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
         addPreferencesFromResource(R.xml.preferences_exposure_notifications)
     }
@@ -53,13 +47,14 @@ class ExposureNotificationsPreferencesFragment : PreferenceFragmentCompat() {
 
     override fun onResume() {
         super.onResume()
+
         updateStatus()
         updateContent()
     }
 
     override fun onPause() {
         super.onPause()
-        database.close()
+
         handler.removeCallbacks(updateStatusRunnable)
         handler.removeCallbacks(updateContentRunnable)
     }
@@ -78,6 +73,7 @@ class ExposureNotificationsPreferencesFragment : PreferenceFragmentCompat() {
             handler.postDelayed(updateContentRunnable, UPDATE_CONTENT_INTERVAL)
             val context = requireContext()
             val (apps, lastHourKeys, currentId) = withContext(Dispatchers.IO) {
+                ExposureDatabase.with(context) { database ->
                     val apps = database.appList.map { packageName ->
                         context.packageManager.getApplicationInfoIfExists(packageName)
                     }.filterNotNull().mapIndexed { idx, applicationInfo ->
@@ -96,9 +92,9 @@ class ExposureNotificationsPreferencesFragment : PreferenceFragmentCompat() {
                     }
                     val lastHourKeys = database.hourRpiCount
                     val currentId = database.currentRpiId
-                database.close()
                     Triple(apps, lastHourKeys, currentId)
                 }
+            }
             collectedRpis.summary = getString(R.string.pref_exposure_collected_rpis_summary, lastHourKeys)
             advertisingId.summary = currentId.toString()
             exposureApps.removeAll()

play-services-core/src/main/kotlin/org/microg/gms/ui/ExposureNotificationsRpisFragment.kt

@@ -22,12 +22,6 @@ import kotlin.math.roundToInt
 class ExposureNotificationsRpisFragment : PreferenceFragmentCompat() {
     private lateinit var histogramCategory: PreferenceCategory
     private lateinit var histogram: BarChartPreference
-    private lateinit var database: ExposureDatabase
-
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-        database = ExposureDatabase(requireContext())
-    }
 
     override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
         addPreferencesFromResource(R.xml.preferences_exposure_notifications_rpis)
@@ -43,14 +37,10 @@ class ExposureNotificationsRpisFragment : PreferenceFragmentCompat() {
         updateChart()
     }
 
-    override fun onPause() {
-        super.onPause()
-        database.close()
-    }
-
     fun updateChart() {
         lifecycleScope.launchWhenResumed {
             val (totalRpiCount, rpiHistogram) = withContext(Dispatchers.IO) {
+                ExposureDatabase.with(requireContext()) { database ->
                     val map = linkedMapOf<String, Float>()
                     val lowestDate = Math.round((Date().time / 24 / 60 / 60 / 1000 - 13).toDouble()) * 24 * 60 * 60 * 1000
                     for (i in 0..13) {
@@ -63,9 +53,9 @@ class ExposureNotificationsRpisFragment : PreferenceFragmentCompat() {
                         map[date.toString()] = entry.value.toFloat()
                     }
                     val totalRpiCount = database.totalRpiCount
-                database.close()
                     totalRpiCount to map
                 }
+            }
             histogramCategory.title = getString(R.string.prefcat_exposure_rpis_histogram_title, totalRpiCount)
             histogram.labelsFormatter = { it.roundToInt().toString() }
             histogram.scale = Scale(0f, rpiHistogram.values.max() ?: 0f)

play-services-core/src/main/kotlin/org/microg/gms/ui/Utils.kt

@@ -13,7 +13,7 @@ fun PackageManager.getApplicationInfoIfExists(packageName: String?, flags: Int =
     try {
         getApplicationInfo(it, flags)
     } catch (e: Exception) {
-        Log.w(TAG, "Package does not exist", e)
+        Log.w(TAG, "Package $packageName not installed.")
         null
     }
 }

play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/AdvertiserService.kt

@@ -40,7 +40,7 @@ class AdvertiserService : LifecycleService() {
 
     override fun onCreate() {
         super.onCreate()
-        database = ExposureDatabase(this)
+        database = ExposureDatabase.ref(this)
     }
 
     override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
@@ -56,7 +56,7 @@ class AdvertiserService : LifecycleService() {
     override fun onDestroy() {
         super.onDestroy()
         stopAdvertising()
-        database.close()
+        database.unref()
     }
 
     fun startAdvertising() {

play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureDatabase.kt

@@ -24,22 +24,8 @@ import java.util.concurrent.TimeUnit
 import java.util.concurrent.atomic.AtomicInteger
 import kotlin.math.roundToInt
 
-class ExposureDatabase(context: Context) : SQLiteOpenHelper(context, DB_NAME, null, DB_VERSION) {
+class ExposureDatabase private constructor(context: Context) : SQLiteOpenHelper(context, DB_NAME, null, DB_VERSION) {
-    private val refCount = AtomicInteger(0)
+    private var refCount = 0
-
-    fun ref(): ExposureDatabase {
-        refCount.incrementAndGet()
-        return this
-    }
-
-    fun unref() {
-        val nu = refCount.decrementAndGet()
-        if (nu == 0) {
-            close()
-        } else if (nu < 0) {
-            throw RuntimeException("ref/unref mismatch")
-        }
-    }
 
     override fun onCreate(db: SQLiteDatabase) {
         onUpgrade(db, 0, DB_VERSION)
@@ -447,6 +433,35 @@ class ExposureDatabase(context: Context) : SQLiteOpenHelper(context, DB_NAME, nu
 
     fun generateCurrentPayload(metadata: ByteArray) = currentTemporaryExposureKey.generatePayload(currentIntervalNumber.toInt(), metadata)
 
+    override fun getWritableDatabase(): SQLiteDatabase {
+        if (this != instance) {
+            throw IllegalStateException("Tried to open writable database from secondary instance")
+        }
+        val db = super.getWritableDatabase()
+        db.enableWriteAheadLogging()
+        return db
+    }
+
+    override fun close() {
+        synchronized(Companion) {
+            super.close()
+            instance = null
+        }
+    }
+
+    fun ref(): ExposureDatabase = synchronized(Companion) {
+        refCount++
+        return this
+    }
+
+    fun unref() = synchronized(Companion) {
+        refCount--
+        if (refCount == 0) {
+            close()
+        } else if (refCount < 0) {
+            throw IllegalStateException("ref/unref mismatch")
+        }
+    }
 
     companion object {
         private const val DB_NAME = "exposure.db"
@@ -457,6 +472,23 @@ class ExposureDatabase(context: Context) : SQLiteOpenHelper(context, DB_NAME, nu
         private const val TABLE_TEK_CHECK = "tek_check"
         private const val TABLE_DIAGNOSIS = "diagnosis"
         private const val TABLE_CONFIGURATIONS = "configurations"
+
+        private var instance: ExposureDatabase? = null
+        fun ref(context: Context): ExposureDatabase = synchronized(this) {
+            if (instance == null) {
+                instance = ExposureDatabase(context.applicationContext)
+            }
+            instance!!.ref()
+        }
+
+        fun <T> with(context: Context, call: (ExposureDatabase) -> T): T {
+            val it = ref(context)
+            try {
+                return call(it)
+            } finally {
+                it.unref()
+            }
+        }
     }
 }
 

play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureNotificationService.kt

@@ -18,21 +18,6 @@ import org.microg.gms.common.GmsService
 import org.microg.gms.common.PackageUtils
 
 class ExposureNotificationService : BaseService(TAG, GmsService.NEARBY_EXPOSURE) {
-    lateinit var database: ExposureDatabase
-
-    override fun onDestroy() {
-        super.onDestroy()
-        database.unref()
-    }
-
-    override fun onCreate() {
-        super.onCreate()
-        if (!this::database.isInitialized) {
-            database = ExposureDatabase(this)
-        }
-        database.ref()
-    }
-
     override fun handleServiceRequest(callback: IGmsCallbacks, request: GetServiceRequest, service: GmsService) {
         PackageUtils.getAndCheckCallingPackage(this, request.packageName)
 
@@ -53,7 +38,7 @@ class ExposureNotificationService : BaseService(TAG, GmsService.NEARBY_EXPOSURE)
         }
 
         Log.d(TAG, "handleServiceRequest: " + request.packageName)
-        callback.onPostInitCompleteWithConnectionInfo(SUCCESS, ExposureNotificationServiceImpl(this, request.packageName, database), ConnectionInfo().apply {
+        callback.onPostInitCompleteWithConnectionInfo(SUCCESS, ExposureNotificationServiceImpl(this, request.packageName), ConnectionInfo().apply {
             features = arrayOf(Feature("nearby_exposure_notification", 2))
         })
     }

play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureNotificationServiceImpl.kt

@@ -26,7 +26,7 @@ import org.microg.gms.nearby.exposurenotification.proto.TemporaryExposureKeyProt
 import java.util.*
 import java.util.zip.ZipInputStream
 
-class ExposureNotificationServiceImpl(private val context: Context, private val packageName: String, private val database: ExposureDatabase) : INearbyExposureNotificationService.Stub() {
+class ExposureNotificationServiceImpl(private val context: Context, private val packageName: String) : INearbyExposureNotificationService.Stub() {
     private fun confirm(action: String, callback: (resultCode: Int, resultData: Bundle?) -> Unit) {
         val intent = Intent(ACTION_CONFIRM)
         intent.`package` = context.packageName
@@ -59,9 +59,11 @@ class ExposureNotificationServiceImpl(private val context: Context, private val
             if (resultCode == SUCCESS) {
                 ExposurePreferences(context).scannerEnabled = true
             }
+            ExposureDatabase.with(context) { database ->
                 database.noteAppAction(packageName, "start", JSONObject().apply {
                     put("result", resultCode)
                 }.toString())
+            }
             try {
                 params.callback.onResult(Status(if (resultCode == SUCCESS) SUCCESS else FAILED_REJECTED_OPT_IN, resultData?.getString("message")))
             } catch (e: Exception) {
@@ -75,9 +77,11 @@ class ExposureNotificationServiceImpl(private val context: Context, private val
             if (resultCode == SUCCESS) {
                 ExposurePreferences(context).scannerEnabled = false
             }
+            ExposureDatabase.with(context) { database ->
                 database.noteAppAction(packageName, "stop", JSONObject().apply {
                     put("result", resultCode)
                 }.toString())
+            }
             try {
                 params.callback.onResult(Status.SUCCESS)
             } catch (e: Exception) {
@@ -94,7 +98,7 @@ class ExposureNotificationServiceImpl(private val context: Context, private val
         }
     }
 
-    override fun getTemporaryExposureKeyHistory(params: GetTemporaryExposureKeyHistoryParams) {
+    override fun getTemporaryExposureKeyHistory(params: GetTemporaryExposureKeyHistoryParams): Unit = ExposureDatabase.with(context) { database ->
         confirm(CONFIRM_ACTION_START) { resultCode, resultData ->
             val (status, response) = if (resultCode == SUCCESS) {
                 SUCCESS to database.allKeys
@@ -122,7 +126,7 @@ class ExposureNotificationServiceImpl(private val context: Context, private val
             .setTransmissionRiskLevel(transmission_risk_level ?: 0)
             .build()
 
-    private fun storeDiagnosisKeyExport(token: String, export: TemporaryExposureKeyExport): Int {
+    private fun storeDiagnosisKeyExport(token: String, export: TemporaryExposureKeyExport): Int = ExposureDatabase.with(context) { database ->
         Log.d(TAG, "Importing keys from file ${export.start_timestamp?.let { Date(it * 1000) }} to ${export.end_timestamp?.let { Date(it * 1000) }}")
         for (key in export.keys) {
             database.storeDiagnosisKey(packageName, token, key.toKey())
@@ -130,13 +134,12 @@ class ExposureNotificationServiceImpl(private val context: Context, private val
         for (key in export.revised_keys) {
             database.updateDiagnosisKey(packageName, token, key.toKey())
         }
-        return export.keys.size + export.revised_keys.size
+        export.keys.size + export.revised_keys.size
     }
 
     override fun provideDiagnosisKeys(params: ProvideDiagnosisKeysParams) {
-        database.ref()
         Thread(Runnable {
-            try {
+            ExposureDatabase.with(context) { database ->
                 if (params.configuration != null) {
                     database.storeConfiguration(packageName, params.token, params.configuration)
                 }
@@ -205,13 +208,11 @@ class ExposureNotificationServiceImpl(private val context: Context, private val
                 } catch (e: Exception) {
                     Log.w(TAG, "Callback failed", e)
                 }
-            } finally {
-                database.unref()
             }
         }).start()
     }
 
-    override fun getExposureSummary(params: GetExposureSummaryParams) {
+    override fun getExposureSummary(params: GetExposureSummaryParams): Unit = ExposureDatabase.with(context) { database ->
         val configuration = database.loadConfiguration(packageName, params.token)
         if (configuration == null) {
             try {
@@ -219,7 +220,7 @@ class ExposureNotificationServiceImpl(private val context: Context, private val
             } catch (e: Exception) {
                 Log.w(TAG, "Callback failed", e)
             }
-            return
+            return@with
         }
         val exposures = database.findAllMeasuredExposures(packageName, params.token)
         val response = ExposureSummary.ExposureSummaryBuilder()
@@ -251,7 +252,7 @@ class ExposureNotificationServiceImpl(private val context: Context, private val
         }
     }
 
-    override fun getExposureInformation(params: GetExposureInformationParams) {
+    override fun getExposureInformation(params: GetExposureInformationParams): Unit = ExposureDatabase.with(context) { database ->
         // TODO: Notify user?
         val configuration = database.loadConfiguration(packageName, params.token)
         if (configuration == null) {
@@ -260,7 +261,7 @@ class ExposureNotificationServiceImpl(private val context: Context, private val
             } catch (e: Exception) {
                 Log.w(TAG, "Callback failed", e)
             }
-            return
+            return@with
         }
         val response = database.findAllMeasuredExposures(packageName, params.token).map {
             it.toExposureInformation(configuration)

play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ScannerService.kt

@@ -15,12 +15,12 @@ import android.os.IBinder
 @TargetApi(21)
 class ScannerService : Service() {
     private var started = false
-    private lateinit var db: ExposureDatabase
+    private lateinit var database: ExposureDatabase
     private val callback = object : ScanCallback() {
         override fun onScanResult(callbackType: Int, result: ScanResult?) {
             val data = result?.scanRecord?.serviceData?.get(SERVICE_UUID) ?: return
             if (data.size < 16) return // Ignore invalid advertisements
-            db.noteAdvertisement(data.sliceArray(0..15), data.drop(16).toByteArray(), result.rssi)
+            database.noteAdvertisement(data.sliceArray(0..15), data.drop(16).toByteArray(), result.rssi)
         }
     }
     private val scanner: BluetoothLeScanner
@@ -36,9 +36,15 @@ class ScannerService : Service() {
         return START_STICKY
     }
 
+    override fun onCreate() {
+        super.onCreate()
+        database = ExposureDatabase.ref(this)
+    }
+
     override fun onDestroy() {
         super.onDestroy()
         stopScan()
+        database.unref()
     }
 
     override fun onBind(intent: Intent?): IBinder? {
@@ -48,7 +54,6 @@ class ScannerService : Service() {
     @Synchronized
     private fun startScan() {
         if (started) return
-        db = ExposureDatabase(this)
         scanner.startScan(
                 listOf(ScanFilter.Builder().setServiceUuid(SERVICE_UUID).setServiceData(SERVICE_UUID, byteArrayOf(0), byteArrayOf(0)).build()),
                 ScanSettings.Builder().build(),
@@ -61,7 +66,6 @@ class ScannerService : Service() {
     private fun stopScan() {
         if (!started) return
         scanner.stopScan(callback)
-        db.close()
         started = false
     }
 }