/**
* Runs all the migrations in the configuration which version key is not already present in the
* database. The migration will get run in the same order they are in the list.
*
* @param configuration Configuration with the database and all the migrations.
*/
public static void migrate(Configuration configuration) {
Migrate4Droid.configuration = configuration;
ensureMigrationDao();
List<Migration> migrations = configuration.getMigrations();
List<String> actual = migrationDao.getAllMigrations();
for (Migration m : migrations) if (!actual.contains(m.getMigration())) runMigration(m);
}
/**
* Register in the database all of the migrations in the <code>config</code> parameter as run.
*
* @param config Configuration with the migrations that need to be marked as run.
*/
public static void markAsMigrated(Configuration config) {
configuration = config;
ensureMigrationDao();
List<String> actual = migrationDao.getAllMigrations();
for (Migration m : config.getMigrations())
if (!actual.contains(m.getMigration())) markAsMigrated(m);
}
/**
* Moves the database to the <code>migration</code> specified, using the migrations in the <code>
* configuration</code>, iterating them and checking:
*
* <ul>
* <li>If the migration's key is smaller than or equal to the desired <code>migration</code>'s
* key parameterized and it's not present in the database, the migration will get upgraded.
* That is, its method {@link Migration#up()} will be called. The order will be the same as
* the migrations are in the <code>configuration</code>.
* <li>If the migration's key is greater than the desired <code>migration</code>'s key
* parameterized and it IS present in the database, the migration will get downgraded. That
* is, its method {@link Migration#down()} will be called. The order will be the opposite
* the migrations are in the <code>configuration</code>.
* </ul>
*
* @param configuration Configuration with the database and all the migrations that have to be
* considered during the migration.
* @param migration String key of the migration the database is desired to be.
*/
public static void migrate(Configuration configuration, String migration) {
Migrate4Droid.configuration = configuration;
ensureMigrationDao();
List<Migration> migrations = configuration.getMigrations();
List<Migration> downs = new ArrayList<Migration>();
List<String> actual = migrationDao.getAllMigrations();
for (Migration m : migrations) {
String mig = m.getMigration();
if (mig.compareTo(migration) <= 0 && !actual.contains(mig)) runMigration(m);
else if (mig.compareTo(migration) > 0 && actual.contains(mig)) downs.add(0, m);
}
for (Migration m : downs) runMigration(m, false);
}
/**
* Executes the migration in the database. If <code>up</code> is set to <code>true</code>, then
* the method {@link Migration#up()} will be called. Otherwise, the method {@link
* Migration#down()} will get called.
*
* @param m The migration to run.
* @param up If <code>true</code>, it will upgrade. Otherwise, it will downgrade.
*/
private static void runMigration(Migration m, boolean up) {
SQLiteDatabase db = configuration.getDatabase();
db.beginTransaction();
try {
if (up) {
m.up();
markAsMigrated(m);
} else {
m.down();
migrationDao.delete(m.getMigration());
}
db.setTransactionSuccessful();
} catch (Exception e) {
Logger.e("Exception when migrating " + m.getClass().getName(), e);
} finally {
db.endTransaction();
}
}
/**
* If {@link Migrate4Droid#migrationDao} is <code>null</code>, instantiates it. Otherwise, just
* updates the database in the Dao using the actual in the {@link Migrate4Droid#configuration}
* object.
*/
private static void ensureMigrationDao() {
if (migrationDao == null) migrationDao = new DbMigrationDao(configuration.getDatabase());
else migrationDao.setDatabase(configuration.getDatabase());
}
protected static void markAsMigrated(Migration m) {
DbMigration mig = new DbMigration();
mig.setMigration(m.getMigration());
migrationDao.save(mig);
}
