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Library code for Realm Kotlin. This artifact is not supposed to be consumed directly, but through 'io.realm.kotlin:gradle-plugin:0.4.1' instead.
/*
* Copyright 2020 Realm Inc.
*
* 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 io.realm
import io.realm.internal.Mediator
import io.realm.internal.RealmObjectInternal
import io.realm.internal.RealmReference
import io.realm.internal.link
import io.realm.interop.Link
import io.realm.interop.NativePointer
import io.realm.interop.RealmInterop
import kotlinx.coroutines.flow.Flow
import kotlin.reflect.KClass
// FIXME API-QUERY Final query design is tracked in https://github.com/realm/realm-kotlin/issues/84
// - Lazy API makes it harded to debug
// - Postponing execution to actually accessing the elements also prevents query parser errors to
// be raised. Maybe we can get an option to prevalidate queries in the C-API?
/**
* A _Realm Result_ holds the results of querying the Realm.
*
* @see Realm.objects
* @see MutableRealm.objects
*/
class RealmResults : AbstractList, Queryable {
private val mode: Mode
private val realm: RealmReference
private val clazz: KClass
private val schema: Mediator
internal val result: NativePointer
private enum class Mode {
// FIXME Needed to make working with @LinkingObjects easier.
EMPTY, // RealmResults that is always empty.
RESULTS // RealmResults wrapping a Realm Core Results.
}
// Wrap existing native Results class
private constructor(realm: RealmReference, results: NativePointer, clazz: KClass, schema: Mediator) {
this.mode = Mode.RESULTS
this.realm = realm
this.result = results
this.clazz = clazz
this.schema = schema
}
internal companion object {
internal fun fromQuery(realm: RealmReference, query: NativePointer, clazz: KClass, schema: Mediator): RealmResults {
// realm_query_find_all doesn't fully evaluate until you interact with it.
return RealmResults(realm, RealmInterop.realm_query_find_all(query), clazz, schema)
}
internal fun fromResults(realm: RealmReference, results: NativePointer, clazz: KClass, schema: Mediator): RealmResults {
return RealmResults(realm, results, clazz, schema)
}
}
/**
* The current version of the data in this Realm.
*/
public fun version(): VersionId {
return realm.owner.version
}
override val size: Int
get() = RealmInterop.realm_results_count(result).toInt()
override fun get(index: Int): T {
val link: Link = RealmInterop.realm_results_get(result, index.toLong())
val model = schema.createInstanceOf(clazz) as RealmObjectInternal
model.link(realm, schema, clazz, link)
@Suppress("UNCHECKED_CAST")
return model as T
}
/**
* Perform a query on the objects of this result using the Realm Query Language.
*
* See [these docs](https://docs.mongodb.com/realm-sdks/java/latest/io/realm/RealmQuery.html#rawPredicate-java.lang.String-java.lang.Object...-)
* for a description of the equivalent realm-java API and
* [these docs](https://docs.mongodb.com/realm-sdks/js/latest/tutorial-query-language.html)
* for a more detailed description of the actual Realm Query Language.
*
* Ex.:
* `'color = "tan" AND name BEGINSWITH "B" SORT(name DESC) LIMIT(5)`
*
* @param query The query string to use for filtering and sort.
* @param args The query parameters.
* @return new result according to the query and query arguments.
*/
@Suppress("SpreadOperator")
override fun query(query: String, vararg args: Any): RealmResults {
return fromQuery(
realm,
RealmInterop.realm_query_parse(result, clazz.simpleName!!, query, *args),
clazz,
schema,
)
}
/**
* FIXME Hidden until we can add proper support
*
* Observe changes to a Realm result.
*
* Follows the pattern of [Realm.addChangeListener]
*/
internal fun addChangeListener(callback: Callback>): Cancellable {
realm.checkClosed()
return realm.owner.registerResultsChangeListener(this, callback)
}
/**
* Observe changes to the RealmResult. If there is any change to objects represented by the query
* backing the RealmResult, the flow will emit the updated RealmResult. The flow will continue
* running indefinitely until canceled.
*
* The change calculations will on on the thread represented by [RealmConfiguration.notificationDispatcher].
*
* @return a flow representing changes to the RealmResults.
*/
fun observe(): Flow> {
realm.checkClosed()
return realm.owner.registerResultsObserver(this)
}
/**
* Delete all objects from this result from the realm.
*/
fun delete() {
// TODO OPTIMIZE Are there more efficient ways to do this? realm_query_delete_all is not
// available in C-API yet, but should probably await final query design
// https://github.com/realm/realm-kotlin/issues/84
RealmInterop.realm_results_delete_all(result)
}
/**
* Returns a frozen copy of this query result. If it is already frozen, the same instance
* is returned.
*/
internal fun freeze(realm: RealmReference): RealmResults {
val frozenDbPointer = realm.dbPointer
val frozenResults = RealmInterop.realm_results_freeze(result, frozenDbPointer)
return fromResults(realm, frozenResults, clazz, schema)
}
/**
* Thaw the frozen query result, turning it back into a live, thread-confined RealmResults.
*/
internal fun thaw(realm: RealmReference): RealmResults {
val liveDbPointer = realm.dbPointer
val liveResultPtr = RealmInterop.realm_results_thaw(result, liveDbPointer)
return fromResults(realm, liveResultPtr, clazz, schema)
}
}