Merge branch 'fix-506--rename-temp-table' into 'master'

Speed up "Saving Application Details" part of repo update

Fixes 506.

This does the thing mentioned in 506 (renaming temp table, rather than copying data). In the process, I also identified that the temp tables were missing key indexes which slowed the process down. This fix took the update time from ~100 seconds to ~60 seconds on my Nexus 4.

Below are a couple of log cats from before and after the change (this logging is not part of this MR, it was just for diagnosing the problem).

*Before change:*

```
            AppProvider  D  Calculating whether apps are compatible, based on whether any of their apks are compatible
                         D  Update compatible flags took 20244ms
                         D  Calculating suggested versions for all apps which specify an upstream version code.
                         D  Update suggested from upstream took 17808ms
                         D  Calculating suggested versions for all apps which don't specify an upstream version code.
                         D  Update suggested from latest took 129ms
            AppProvider  D  Update icon URLs took 7879ms
          UpdateService  I  Updating repo(s) complete, took 104 seconds to complete.
```

*After change:*

```
            AppProvider  D  Calculating whether apps are compatible, based on whether any of their apks are compatible
                         D  Update compatible flags took 1047ms
                         D  Calculating suggested versions for all apps which specify an upstream version code.
                         D  Update suggested from upstream took 601ms
                         D  Calculating suggested versions for all apps which don't specify an upstream version code.
                         D  Update suggested from latest took 136ms
                         D  Update icon URLs took 887ms
          UpdateService  I  Updating repo(s) complete, took 63 seconds to complete.
```



See merge request !179

F-Droid/src/org/fdroid/fdroid/UpdateService.java

@@ -391,7 +391,6 @@ public class UpdateService extends IntentService implements ProgressListener {
             if (!changes) {
                 Utils.debugLog(TAG, "Not checking app details or compatibility, because all repos were up to date.");
             } else {
-                sendStatus(this, STATUS_INFO, getString(R.string.status_checking_compatibility));
                 notifyContentProviders();
 
                 if (prefs.getBoolean(Preferences.PREF_UPD_NOTIFY, true)) {

F-Droid/src/org/fdroid/fdroid/data/RepoPersister.java

@@ -62,9 +62,13 @@ public class RepoPersister {
     @NonNull
     private final Map<String, List<Apk>> apksToSave = new HashMap<>();
 
+    @NonNull
+    private final CompatibilityChecker checker;
+
     public RepoPersister(@NonNull Context context, @NonNull Repo repo) {
         this.repo = repo;
         this.context = context;
+        checker = new CompatibilityChecker(context);
     }
 
     public void saveToDb(App app, List<Apk> packages) throws RepoUpdater.UpdateException {
@@ -78,8 +82,7 @@ public class RepoPersister {
 
     public void commit(ContentValues repoDetailsToSave) throws RepoUpdater.UpdateException {
         flushBufferToDb();
-        TempAppProvider.Helper.commit(context);
+        TempAppProvider.Helper.commitAppsAndApks(context);
-        TempApkProvider.Helper.commit(context);
         RepoProvider.Helper.update(context, repo, repoDetailsToSave);
     }
 
@@ -282,7 +285,6 @@ public class RepoPersister {
      * in order to see if, and why an apk is not compatible.
      */
     private void calcApkCompatibilityFlags(List<Apk> apks) {
-        final CompatibilityChecker checker = new CompatibilityChecker(context);
         for (final Apk apk : apks) {
             final List<String> reasons = checker.getIncompatibleReasons(apk);
             if (reasons.size() > 0) {

F-Droid/src/org/fdroid/fdroid/data/TempApkProvider.java

@@ -17,26 +17,23 @@ public class TempApkProvider extends ApkProvider {
 
     private static final String PROVIDER_NAME = "TempApkProvider";
 
-    static final String TABLE_TEMP_APK = "temp_fdroid_apk";
+    static final String TABLE_TEMP_APK = "temp_" + DBHelper.TABLE_APK;
 
     private static final String PATH_INIT = "init";
-    private static final String PATH_COMMIT = "commit";
 
     private static final int CODE_INIT = 10000;
-    private static final int CODE_COMMIT = CODE_INIT + 1;
 
     private static final UriMatcher matcher = new UriMatcher(-1);
 
     static {
         matcher.addURI(getAuthority(), PATH_INIT, CODE_INIT);
-        matcher.addURI(getAuthority(), PATH_COMMIT, CODE_COMMIT);
         matcher.addURI(getAuthority(), PATH_APK + "/#/*", CODE_SINGLE);
         matcher.addURI(getAuthority(), PATH_REPO_APK + "/#/*", CODE_REPO_APK);
     }
 
     @Override
     protected String getTableName() {
-        return "temp_" + super.getTableName();
+        return TABLE_TEMP_APK;
     }
 
     public static String getAuthority() {
@@ -76,15 +73,6 @@ public class TempApkProvider extends ApkProvider {
             context.getContentResolver().insert(uri, new ContentValues());
         }
 
-        /**
-         * Saves data from the temp table to the apk table, by removing _EVERYTHING_ from the real
-         * apk table and inserting all of the records from here. The temporary table is then removed.
-         */
-        public static void commit(Context context) {
-            Uri uri = Uri.withAppendedPath(getContentUri(), PATH_COMMIT);
-            context.getContentResolver().insert(uri, new ContentValues());
-        }
-
     }
 
     @Override
@@ -93,9 +81,6 @@ public class TempApkProvider extends ApkProvider {
             case CODE_INIT:
                 initTable();
                 return null;
-            case CODE_COMMIT:
-                commitTable();
-                return null;
             default:
                 return super.insert(uri, values);
         }
@@ -138,12 +123,9 @@ public class TempApkProvider extends ApkProvider {
     private void initTable() {
         write().execSQL("DROP TABLE IF EXISTS " + getTableName());
         write().execSQL("CREATE TABLE " + getTableName() + " AS SELECT * FROM " + DBHelper.TABLE_APK);
+        write().execSQL("CREATE INDEX IF NOT EXISTS apk_vercode on " + getTableName() + " (vercode);");
+        write().execSQL("CREATE INDEX IF NOT EXISTS apk_id on " + getTableName() + " (id);");
+        write().execSQL("CREATE INDEX IF NOT EXISTS apk_compatible ON " + getTableName() + " (compatible);");
     }
 
-    private void commitTable() {
-        Log.i(TAG, "Deleting all apks from " + DBHelper.TABLE_APK + " so they can be copied from " + getTableName());
-        write().execSQL("DELETE FROM " + DBHelper.TABLE_APK);
-        write().execSQL("INSERT INTO " + DBHelper.TABLE_APK + " SELECT * FROM " + getTableName());
-        getContext().getContentResolver().notifyChange(ApkProvider.getContentUri(), null);
-    }
 }

F-Droid/src/org/fdroid/fdroid/data/TempAppProvider.java

@@ -3,9 +3,12 @@ package org.fdroid.fdroid.data;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.UriMatcher;
+import android.database.sqlite.SQLiteDatabase;
 import android.net.Uri;
 import android.util.Log;
 
+import org.fdroid.fdroid.Utils;
+
 /**
  * This class does all of its operations in a temporary sqlite table.
  */
@@ -15,7 +18,7 @@ public class TempAppProvider extends AppProvider {
 
     private static final String PROVIDER_NAME = "TempAppProvider";
 
-    private static final String TABLE_TEMP_APP = "temp_fdroid_app";
+    private static final String TABLE_TEMP_APP = "temp_" + DBHelper.TABLE_APP;
 
     private static final String PATH_INIT = "init";
     private static final String PATH_COMMIT = "commit";
@@ -63,11 +66,10 @@ public class TempAppProvider extends AppProvider {
          * Saves data from the temp table to the apk table, by removing _EVERYTHING_ from the real
          * apk table and inserting all of the records from here. The temporary table is then removed.
          */
-        public static void commit(Context context) {
+        public static void commitAppsAndApks(Context context) {
             Uri uri = Uri.withAppendedPath(getContentUri(), PATH_COMMIT);
             context.getContentResolver().insert(uri, new ContentValues());
         }
-
     }
 
     @Override
@@ -112,12 +114,31 @@ public class TempAppProvider extends AppProvider {
     private void initTable() {
         write().execSQL("DROP TABLE IF EXISTS " + getTableName());
         write().execSQL("CREATE TABLE " + getTableName() + " AS SELECT * FROM " + DBHelper.TABLE_APP);
+        write().execSQL("CREATE INDEX IF NOT EXISTS app_id ON " + getTableName() + " (id);");
+        write().execSQL("CREATE INDEX IF NOT EXISTS app_upstreamVercode ON " + getTableName() + " (upstreamVercode);");
+        write().execSQL("CREATE INDEX IF NOT EXISTS app_compatible ON " + getTableName() + " (compatible);");
     }
 
     private void commitTable() {
-        Log.i(TAG, "Deleting all apks from " + DBHelper.TABLE_APP + " so they can be copied from " + getTableName());
+        final SQLiteDatabase db = write();
-        write().execSQL("DELETE FROM " + DBHelper.TABLE_APP);
+        try {
-        write().execSQL("INSERT INTO " + DBHelper.TABLE_APP + " SELECT * FROM " + getTableName());
+            db.beginTransaction();
-        getContext().getContentResolver().notifyChange(AppProvider.getContentUri(), null);
+
+            Log.i(TAG, "Renaming " + TABLE_TEMP_APP + " to " + DBHelper.TABLE_APP);
+            db.execSQL("DROP TABLE " + DBHelper.TABLE_APP);
+            db.execSQL("ALTER TABLE " + TABLE_TEMP_APP + " RENAME TO " + DBHelper.TABLE_APP);
+
+            Log.i(TAG, "Renaming " + TempApkProvider.TABLE_TEMP_APK + " to " + DBHelper.TABLE_APK);
+            db.execSQL("DROP TABLE " + DBHelper.TABLE_APK);
+            db.execSQL("ALTER TABLE " + TempApkProvider.TABLE_TEMP_APK + " RENAME TO " + DBHelper.TABLE_APK);
+
+            Utils.debugLog(TAG, "Successfully renamed both tables, will commit transaction");
+            db.setTransactionSuccessful();
+
+            getContext().getContentResolver().notifyChange(AppProvider.getContentUri(), null);
+            getContext().getContentResolver().notifyChange(ApkProvider.getContentUri(), null);
+        } finally {
+            db.endTransaction();
+        }
     }
 }