Sync database optimizations

* enable WAL as early as possible
* don't close database in SyncAdapter but only in SyncService
* version bump to 1.0.4

app/build.gradle

@@ -17,8 +17,8 @@ android {
         minSdkVersion 14
         targetSdkVersion 22
 
-        versionCode 93
-        versionName "1.0.3"
+        versionCode 94
+        versionName "1.0.4"
 
         buildConfigField "long", "buildTime", System.currentTimeMillis() + "L"
     }

app/src/main/java/at/bitfire/davdroid/model/ServiceDB.java

@@ -72,15 +72,21 @@ public class ServiceDB {
 
         public OpenHelper(Context context) {
             super(context, DATABASE_NAME, null, DATABASE_VERSION);
+
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
+                setWriteAheadLoggingEnabled(true);
         }
 
         @Override
         public void onOpen(SQLiteDatabase db) {
-            db.enableWriteAheadLogging();
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
                 db.setForeignKeyConstraintsEnabled(true);
-            else
+            else {
+                if (!db.enableWriteAheadLogging())
+                    App.log.warning("Couldn't enable write-ahead logging");
+
                 db.execSQL("PRAGMA foreign_keys=ON;");
+            }
         }
 
         @Override

app/src/main/java/at/bitfire/davdroid/syncadapter/CalendarsSyncAdapterService.java

@@ -8,18 +8,14 @@
 package at.bitfire.davdroid.syncadapter;
 
 import android.accounts.Account;
-import android.app.Service;
-import android.content.AbstractThreadedSyncAdapter;
 import android.content.ContentProviderClient;
 import android.content.ContentValues;
 import android.content.Context;
-import android.content.Intent;
 import android.content.SyncResult;
 import android.database.Cursor;
 import android.database.DatabaseUtils;
 import android.database.sqlite.SQLiteDatabase;
 import android.os.Bundle;
-import android.os.IBinder;
 import android.provider.CalendarContract;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
@@ -32,7 +28,6 @@ import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.InvalidAccountException;
 import at.bitfire.davdroid.model.CollectionInfo;
 import at.bitfire.davdroid.model.ServiceDB.Collections;
-import at.bitfire.davdroid.model.ServiceDB.OpenHelper;
 import at.bitfire.davdroid.model.ServiceDB.Services;
 import at.bitfire.davdroid.resource.LocalCalendar;
 import at.bitfire.ical4android.CalendarStorageException;
@@ -43,14 +38,14 @@ public class CalendarsSyncAdapterService extends SyncAdapterService {
     @Override
     public void onCreate() {
         super.onCreate();
-        syncAdapter = new SyncAdapter(this, dbHelper);
+        syncAdapter = new SyncAdapter(this, dbHelper.getReadableDatabase());
     }
 
 
 	private static class SyncAdapter extends SyncAdapterService.SyncAdapter {
 
-        public SyncAdapter(Context context, OpenHelper dbHelper) {
-            super(context, dbHelper);
+        public SyncAdapter(Context context, SQLiteDatabase db) {
+            super(context, db);
         }
 
         @Override

app/src/main/java/at/bitfire/davdroid/syncadapter/ContactsSyncAdapterService.java

@@ -8,31 +8,24 @@
 package at.bitfire.davdroid.syncadapter;
 
 import android.accounts.Account;
-import android.app.Service;
-import android.content.AbstractThreadedSyncAdapter;
 import android.content.ContentProviderClient;
 import android.content.ContentValues;
 import android.content.Context;
-import android.content.Intent;
 import android.content.SyncResult;
 import android.database.Cursor;
 import android.database.DatabaseUtils;
 import android.database.sqlite.SQLiteDatabase;
 import android.os.Bundle;
-import android.os.IBinder;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
-import java.util.List;
 import java.util.logging.Level;
 
-import at.bitfire.davdroid.AccountSettings;
 import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.InvalidAccountException;
 import at.bitfire.davdroid.model.CollectionInfo;
 import at.bitfire.davdroid.model.ServiceDB;
 import at.bitfire.davdroid.model.ServiceDB.Collections;
-import at.bitfire.davdroid.model.ServiceDB.OpenHelper;
 import lombok.Cleanup;
 
 public class ContactsSyncAdapterService extends SyncAdapterService {
@@ -40,14 +33,14 @@ public class ContactsSyncAdapterService extends SyncAdapterService {
 	@Override
 	public void onCreate() {
         super.onCreate();
-        syncAdapter = new ContactsSyncAdapter(this, dbHelper);
+        syncAdapter = new ContactsSyncAdapter(this, dbHelper.getReadableDatabase());
 	}
 
 
 	private static class ContactsSyncAdapter extends SyncAdapter {
 
-        public ContactsSyncAdapter(Context context, OpenHelper dbHelper) {
-            super(context, dbHelper);
+        public ContactsSyncAdapter(Context context, SQLiteDatabase db) {
+            super(context, db);
         }
 
         @Override

app/src/main/java/at/bitfire/davdroid/syncadapter/SyncAdapterService.java

@@ -50,11 +50,12 @@ public abstract class SyncAdapterService extends Service {
 
 
     public static abstract class SyncAdapter extends AbstractThreadedSyncAdapter {
-        protected final SQLiteDatabase db;
 
-        public SyncAdapter(Context context, ServiceDB.OpenHelper dbHelper) {
+        protected final SQLiteDatabase db;      // will be closed in SyncAdapterService::onDestroy(), don't close manually!
+
+        public SyncAdapter(Context context, SQLiteDatabase db) {
             super(context, false);
-            db = dbHelper.getReadableDatabase();
+            this.db = db;
         }
 
         @Override

app/src/main/java/at/bitfire/davdroid/syncadapter/TasksSyncAdapterService.java

@@ -8,18 +8,14 @@
 package at.bitfire.davdroid.syncadapter;
 
 import android.accounts.Account;
-import android.app.Service;
-import android.content.AbstractThreadedSyncAdapter;
 import android.content.ContentProviderClient;
 import android.content.ContentValues;
 import android.content.Context;
-import android.content.Intent;
 import android.content.SyncResult;
 import android.database.Cursor;
 import android.database.DatabaseUtils;
 import android.database.sqlite.SQLiteDatabase;
 import android.os.Bundle;
-import android.os.IBinder;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
@@ -31,7 +27,6 @@ import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.InvalidAccountException;
 import at.bitfire.davdroid.model.CollectionInfo;
 import at.bitfire.davdroid.model.ServiceDB.Collections;
-import at.bitfire.davdroid.model.ServiceDB.OpenHelper;
 import at.bitfire.davdroid.model.ServiceDB.Services;
 import at.bitfire.davdroid.resource.LocalTaskList;
 import at.bitfire.ical4android.CalendarStorageException;
@@ -43,14 +38,14 @@ public class TasksSyncAdapterService extends SyncAdapterService {
 	@Override
 	public void onCreate() {
         super.onCreate();
-        syncAdapter = new SyncAdapter(this, dbHelper);
+        syncAdapter = new SyncAdapter(this, dbHelper.getReadableDatabase());
 	}
 
 
 	private static class SyncAdapter extends SyncAdapterService.SyncAdapter {
 
-        public SyncAdapter(Context context, OpenHelper dbHelper) {
-            super(context, dbHelper);
+        public SyncAdapter(Context context, SQLiteDatabase db) {
+            super(context, db);
         }
 
         @Override
@@ -73,8 +68,6 @@ public class TasksSyncAdapterService extends SyncAdapterService {
                 App.log.log(Level.SEVERE, "Couldn't enumerate local task lists", e);
             } catch (InvalidAccountException e) {
                 App.log.log(Level.SEVERE, "Couldn't get account settings", e);
-            } finally {
-                db.close();
             }
 
             App.log.info("Task sync complete");