DataStoreFactory.kt
/*
* Copyright 2020 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.datastore
import android.content.Context
import androidx.datastore.core.DataMigration
import androidx.datastore.core.DataStore
import androidx.datastore.core.DataStoreFactory
import androidx.datastore.core.handlers.ReplaceFileCorruptionHandler
import androidx.datastore.core.Serializer
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.SupervisorJob
import java.io.File
/**
* Create an instance of SingleProcessDataStore. Never create more than one instance of
* DataStore for a given file; doing so can break all DataStore functionality. You should
* consider managing your DataStore instance as a singleton. Note: this function is *not*
* comparable to [Context.getSharedPreferences]; this function creates and returns a
* new instance of DataStore each time it is called.
*
* @param fileName the filename relative to Context.filesDir that DataStore acts on. The File is
* obtained by calling File(context.filesDir, fileName). No two instances of DataStore should
* act on the same file at the same time.
* @param corruptionHandler The corruptionHandler is invoked if DataStore encounters a
* [androidx.datastore.CorruptionException] when attempting to read data. CorruptionExceptions are
* thrown by
* serializers when data can not be de-serialized.
* @param migrations are run before any access to data can occur. Each producer and migration
* may be run more than once whether or not it already succeeded (potentially because another
* migration failed or a write to disk failed.)
* @param scope The scope in which IO operations and transform functions will execute.
*
* @return a new DataStore instance with the provided configuration
*/
public fun <T> Context.createDataStore(
fileName: String,
serializer: Serializer<T>,
corruptionHandler: ReplaceFileCorruptionHandler<T>? = null,
migrations: List<DataMigration<T>> = listOf(),
scope: CoroutineScope = CoroutineScope(Dispatchers.IO + SupervisorJob())
): DataStore<T> =
DataStoreFactory.create(
serializer = serializer,
corruptionHandler = corruptionHandler,
migrations = migrations,
scope = scope
) { File(this.filesDir, "datastore/$fileName") }