HistoryDatabase.java

/* Room database for connection history storage */
 
package com.freerdp.freerdpcore.data;
 
import android.content.Context;
 
import androidx.annotation.NonNull;
import androidx.room.Database;
import androidx.room.Room;
import androidx.room.RoomDatabase;
import androidx.room.migration.Migration;
import androidx.sqlite.db.SupportSQLiteDatabase;
 
@Database(entities = { HistoryEntity.class }, version = 2, exportSchema = false)
public abstract class HistoryDatabase extends RoomDatabase
{
  private static final String DB_NAME = "history.db";
 
  private static volatile HistoryDatabase instance;
 
  public abstract HistoryDao historyDao();
 
  public static HistoryDatabase getInstance(Context context)
  {
    if (instance == null)
    {
      synchronized (HistoryDatabase.class)
      {
        if (instance == null)
        {
          instance = Room.databaseBuilder(context.getApplicationContext(),
                                          HistoryDatabase.class, DB_NAME)
                         .addMigrations(MIGRATION_1_2)
                         .fallbackToDestructiveMigration()
                         .build();
        }
      }
    }
    return instance;
  }
 
  // v1: item TEXT PRIMARY KEY, timestamp INTEGER (both nullable — old SQLiteOpenHelper schema)
  // v2: item TEXT NOT NULL PRIMARY KEY, timestamp INTEGER NOT NULL (Room schema)
  private static final Migration MIGRATION_1_2 = new Migration(1, 2) {
    @Override public void migrate(@NonNull SupportSQLiteDatabase db)
    {
      db.execSQL("CREATE TABLE IF NOT EXISTS `quick_connect_history_new` ("
                 + "`item` TEXT NOT NULL, "
                 + "`timestamp` INTEGER NOT NULL DEFAULT 0, "
                 + "PRIMARY KEY(`item`))");
      db.execSQL("INSERT INTO `quick_connect_history_new` (item, timestamp) "
                 + "SELECT item, IFNULL(timestamp, 0) FROM `quick_connect_history`");
      db.execSQL("DROP TABLE `quick_connect_history`");
      db.execSQL("ALTER TABLE `quick_connect_history_new` RENAME TO `quick_connect_history`");
    }
  };
}