DatabaseProvider.java

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package androidx.media3.database;

import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import androidx.media3.common.util.UnstableApi;

/**
 * Provides {@link SQLiteDatabase} instances to media library components, which may read and write
 * tables prefixed with {@link #TABLE_PREFIX}.
 */
@UnstableApi
public interface DatabaseProvider {

  /** Prefix for tables that can be read and written by media library components. */
  String TABLE_PREFIX = "ExoPlayer";

  /**
   * Creates and/or opens a database that will be used for reading and writing.
   *
   * <p>Once opened successfully, the database is cached, so you can call this method every time you
   * need to write to the database. Errors such as bad permissions or a full disk may cause this
   * method to fail, but future attempts may succeed if the problem is fixed.
   *
   * @throws SQLiteException If the database cannot be opened for writing.
   * @return A read/write database object.
   */
  SQLiteDatabase getWritableDatabase();

  /**
   * Creates and/or opens a database. This will be the same object returned by {@link
   * #getWritableDatabase()} unless some problem, such as a full disk, requires the database to be
   * opened read-only. In that case, a read-only database object will be returned. If the problem is
   * fixed, a future call to {@link #getWritableDatabase()} may succeed, in which case the read-only
   * database object will be closed and the read/write object will be returned in the future.
   *
   * <p>Once opened successfully, the database is cached, so you can call this method every time you
   * need to read from the database.
   *
   * @throws SQLiteException If the database cannot be opened.
   * @return A database object valid until {@link #getWritableDatabase()} is called.
   */
  SQLiteDatabase getReadableDatabase();
}