FairEmail/app/src/main/java/androidx/room/Room.kt

117 lines
4.2 KiB
Kotlin

/*
* Copyright (C) 2016 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.room
import android.content.Context
import androidx.annotation.RestrictTo
/**
* Utility functions for Room.
*/
object Room {
internal const val LOG_TAG = "ROOM"
/**
* The master table where room keeps its metadata information.
*/
const val MASTER_TABLE_NAME = RoomMasterTable.TABLE_NAME
private const val CURSOR_CONV_SUFFIX = "_CursorConverter"
@Suppress("UNCHECKED_CAST")
@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
@JvmStatic
fun <T, C> getGeneratedImplementation(
klass: Class<C>,
suffix: String
): T {
val fullPackage = klass.getPackage()!!.name
val name: String = klass.canonicalName!!
val postPackageName =
if (fullPackage.isEmpty()) name else name.substring(fullPackage.length + 1)
val implName = postPackageName.replace('.', '_') + suffix
return try {
val fullClassName = if (fullPackage.isEmpty()) {
implName
} else {
"$fullPackage.$implName"
}
val aClass = Class.forName(
fullClassName, true, klass.classLoader
) as Class<T>
aClass.getDeclaredConstructor().newInstance()
} catch (e: ClassNotFoundException) {
throw RuntimeException(
"Cannot find implementation for ${klass.canonicalName}. $implName does not " +
"exist"
)
} catch (e: IllegalAccessException) {
throw RuntimeException(
"Cannot access the constructor ${klass.canonicalName}"
)
} catch (e: InstantiationException) {
throw RuntimeException(
"Failed to create an instance of ${klass.canonicalName}"
)
}
}
/**
* Creates a RoomDatabase.Builder for an in memory database. Information stored in an in memory
* database disappears when the process is killed.
* Once a database is built, you should keep a reference to it and re-use it.
*
* @param context The context for the database. This is usually the Application context.
* @param klass The abstract class which is annotated with [Database] and extends
* [RoomDatabase].
* @param T The type of the database class.
* @return A `RoomDatabaseBuilder<T>` which you can use to create the database.
*/
@JvmStatic
fun <T : RoomDatabase> inMemoryDatabaseBuilder(
context: Context,
klass: Class<T>
): RoomDatabase.Builder<T> {
return RoomDatabase.Builder(context, klass, null)
}
/**
* Creates a RoomDatabase.Builder for a persistent database. Once a database is built, you
* should keep a reference to it and re-use it.
*
* @param context The context for the database. This is usually the Application context.
* @param klass The abstract class which is annotated with [Database] and extends
* [RoomDatabase].
* @param name The name of the database file.
* @param T The type of the database class.
* @return A `RoomDatabaseBuilder<T>` which you can use to create the database.
*/
@JvmStatic
fun <T : RoomDatabase> databaseBuilder(
context: Context,
klass: Class<T>,
name: String?
): RoomDatabase.Builder<T> {
require(!name.isNullOrBlank()) {
"Cannot build a database with null or empty name." +
" If you are trying to create an in memory database, use Room" +
".inMemoryDatabaseBuilder"
}
return RoomDatabase.Builder(context, klass, name)
}
}