BayernMessenger/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/RealmLiveEntityObserver.kt

75 lines
2.5 KiB
Kotlin

/*
* Copyright 2019 New Vector Ltd
*
* 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 im.vector.matrix.android.internal.database
import com.zhuinden.monarchy.Monarchy
import im.vector.matrix.android.internal.util.createBackgroundHandler
import io.realm.OrderedCollectionChangeSet
import io.realm.OrderedRealmCollectionChangeListener
import io.realm.Realm
import io.realm.RealmConfiguration
import io.realm.RealmObject
import io.realm.RealmResults
import java.util.concurrent.atomic.AtomicBoolean
import java.util.concurrent.atomic.AtomicReference
internal interface LiveEntityObserver {
fun start()
fun dispose()
fun isStarted(): Boolean
}
internal abstract class RealmLiveEntityObserver<T : RealmObject>(protected val realmConfiguration: RealmConfiguration)
: LiveEntityObserver, OrderedRealmCollectionChangeListener<RealmResults<T>> {
private companion object {
val BACKGROUND_HANDLER = createBackgroundHandler("LIVE_ENTITY_BACKGROUND")
}
protected abstract val query: Monarchy.Query<T>
private val isStarted = AtomicBoolean(false)
private val backgroundRealm = AtomicReference<Realm>()
private lateinit var results: AtomicReference<RealmResults<T>>
override fun start() {
if (isStarted.compareAndSet(false, true)) {
BACKGROUND_HANDLER.post {
val realm = Realm.getInstance(realmConfiguration)
backgroundRealm.set(realm)
val queryResults = query.createQuery(realm).findAll()
queryResults.addChangeListener(this)
results = AtomicReference(queryResults)
}
}
}
override fun dispose() {
if (isStarted.compareAndSet(true, false)) {
BACKGROUND_HANDLER.post {
results.getAndSet(null).removeAllChangeListeners()
backgroundRealm.getAndSet(null).also {
it.close()
}
}
}
}
override fun isStarted(): Boolean {
return isStarted.get()
}
}