src/com/android/quicksearchbox/util/SQLiteAsyncQuery.kt

/*
 * Copyright (C) 2022 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 com.android.quicksearchbox.util

import android.database.sqlite.SQLiteDatabase

/**
 * Abstract helper base class for asynchronous SQLite queries.
 *
 * @param <A> The type of the result of the query. </A>
 */
abstract class SQLiteAsyncQuery<A> {
  /**
   * Performs a query and computes some value from the result
   *
   * @param db A readable database.
   * @return The result of the query.
   */
  protected abstract fun performQuery(db: SQLiteDatabase?): A

  /** Runs the query against the database and passes the result to the consumer. */
  fun run(db: SQLiteDatabase?, consumer: Consumer<A>) {
    val result = performQuery(db)
    consumer.consume(result)
  }
}