[app] Add ContentProviderMigrator to migrate old repos to new DB

app/build.gradle

@@ -1,4 +1,5 @@
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
 apply plugin: 'checkstyle'
 apply plugin: 'pmd'
 

app/src/main/java/org/fdroid/fdroid/FDroidApp.java

@@ -57,6 +57,7 @@ import org.fdroid.database.Repository;
 import org.fdroid.fdroid.Preferences.ChangeListener;
 import org.fdroid.fdroid.Preferences.Theme;
 import org.fdroid.fdroid.data.App;
+import org.fdroid.fdroid.data.ContentProviderMigrator;
 import org.fdroid.fdroid.data.DBHelper;
 import org.fdroid.fdroid.installer.ApkFileProvider;
 import org.fdroid.fdroid.installer.InstallHistoryService;
@@ -414,6 +415,17 @@ public class FDroidApp extends Application implements androidx.work.Configuratio
         if (Preferences.get().isScanRemovableStorageEnabled()) {
             SDCardScannerService.scan(this);
         }
+
+        // Migrate repos from old content providers to new Room-based DB.
+        // Added end of 2022 for alphas, can be removed after sufficient time has passed.
+        Utils.runOffUiThread(() -> {
+            ContentProviderMigrator migrator = ContentProviderMigrator.INSTANCE;
+            if (migrator.needsMigration(this)) {
+                migrator.migrateOldRepos(this, db);
+                migrator.removeOldDb(this);
+                UpdateService.forceUpdateRepo(this);
+            }
+        });
     }
 
     /**

app/src/main/java/org/fdroid/fdroid/UpdateService.java

@@ -406,11 +406,7 @@ public class UpdateService extends JobIntentService {
                 }
             } else if ((manualUpdate || forcedUpdate) && fdroidPrefs.isOnDemandDownloadAllowed()) {
                 Utils.debugLog(TAG, "manually requested or forced update");
-                if (forcedUpdate) {
-                    DBHelper.resetRepos(this);
-                    // TODO check if we still need something like this:
-                    // InstalledAppProviderService.compareToPackageManager(this);
-                }
+                if (forcedUpdate) DBHelper.resetTransient(this);
             } else if (!fdroidPrefs.isBackgroundDownloadAllowed() && !fdroidPrefs.isOnDemandDownloadAllowed()) {
                 Utils.debugLog(TAG, "don't run update");
                 return;

app/src/main/java/org/fdroid/fdroid/data/ContentProviderMigrator.kt

@@ -0,0 +1,75 @@
+package org.fdroid.fdroid.data
+
+import android.content.Context
+import android.database.sqlite.SQLiteDatabase
+import android.database.sqlite.SQLiteOpenHelper
+import org.fdroid.database.FDroidDatabase
+import org.fdroid.database.InitialRepository
+
+object ContentProviderMigrator {
+
+    private const val OLD_DB_NAME = "fdroid"
+
+    fun needsMigration(context: Context): Boolean {
+        return context.databaseList().contains(OLD_DB_NAME)
+    }
+
+    fun migrateOldRepos(context: Context, db: FDroidDatabase) {
+        val repoDao = db.getRepositoryDao()
+        val repos = repoDao.getRepositories()
+        var weight = repos.last().weight
+        ContentProviderDbHelper(context).readableDatabase.use { oldDb ->
+            val projection = arrayOf("address", "pubkey", "inuse", "userMirrors", "disabledMirrors")
+            oldDb.query("fdroid_repo", projection, null, null, null, null, null).use { c ->
+                while (c.moveToNext()) {
+                    val address = c.getString(c.getColumnIndexOrThrow("address"))
+                    val certificate = c.getString(c.getColumnIndexOrThrow("pubkey"))
+                        ?.lowercase() ?: continue
+                    val enabled = c.getInt(c.getColumnIndexOrThrow("inuse")) == 1
+                    val userMirrors = c.getString(c.getColumnIndexOrThrow("userMirrors"))
+                        ?.split(',')
+                    val disabledMirrors = c.getString(c.getColumnIndexOrThrow("disabledMirrors"))
+                        ?.split(',')
+                    // find existing repos by address, because F-Droid archive re-uses certificate
+                    val repo = repos.find { it.address == address }
+                    if (repo == null) { // new repo to be added to new DB
+                        val newRepo = InitialRepository(
+                            name = "",
+                            address = address,
+                            description = "",
+                            certificate = certificate,
+                            version = 0,
+                            enabled = enabled,
+                            weight = ++weight,
+                        )
+                        repoDao.insert(newRepo)
+                    } else { // old repo that may need an update for the new DB
+                        if (repo.certificate != certificate) {
+                            continue // don't update with certificate does not match
+                        }
+                        if (repo.enabled != enabled) {
+                            repoDao.setRepositoryEnabled(repo.repoId, enabled)
+                        }
+                        if (!userMirrors.isNullOrEmpty()) {
+                            repoDao.updateUserMirrors(repo.repoId, userMirrors)
+                        }
+                        if (!disabledMirrors.isNullOrEmpty()) {
+                            repoDao.updateDisabledMirrors(repo.repoId, disabledMirrors)
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    fun removeOldDb(context: Context) {
+        context.deleteDatabase(OLD_DB_NAME)
+    }
+
+    private class ContentProviderDbHelper(
+        context: Context,
+    ) : SQLiteOpenHelper(context, OLD_DB_NAME, null, 85) {
+        override fun onCreate(db: SQLiteDatabase) {}
+        override fun onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {}
+    }
+}

app/src/main/java/org/fdroid/fdroid/data/DBHelper.java

@@ -81,6 +81,16 @@ public class DBHelper {
         }
     }
 
+    /**
+     * Removes all index data related to apps from the DB.
+     * Leaves repositories, their preferences as well as app preferences in place.
+     */
+    @AnyThread
+    public static void resetTransient(Context context) {
+        FDroidDatabase db = getDb(context);
+        Utils.runOffUiThread(() -> db.getAppDao().clearAll());
+    }
+
     @AnyThread
     public static void resetRepos(Context context) {
         FDroidDatabase db = getDb(context);