Timeline : try to get a better PagedList/Epoxy integration. Still need to be refined.

app/build.gradle

@@ -56,6 +56,8 @@ dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     implementation 'com.android.support:appcompat-v7:28.0.0'
     implementation 'com.android.support.constraint:constraint-layout:1.1.3'
+    // Paging
+    implementation "android.arch.paging:runtime:1.0.1"
 
     implementation 'com.jakewharton.threetenabp:threetenabp:1.1.1'
     implementation 'com.jakewharton.timber:timber:4.7.1'
@@ -66,7 +68,6 @@ dependencies {
 
     implementation("com.airbnb.android:epoxy:$epoxy_version")
     kapt "com.airbnb.android:epoxy-processor:$epoxy_version"
-    implementation "com.airbnb.android:epoxy-paging:$epoxy_version"
     implementation 'com.airbnb.android:mvrx:0.6.0'
 
     // FP

app/src/main/java/im/vector/riotredesign/features/home/room/detail/RoomDetailFragment.kt

@@ -73,9 +73,8 @@ class RoomDetailFragment : RiotFragment(), TimelineEventController.Callback {
         val layoutManager = LinearLayoutManager(context, LinearLayoutManager.VERTICAL, true)
         scrollOnNewMessageCallback = ScrollOnNewMessageCallback(layoutManager)
         recyclerView.layoutManager = layoutManager
-        //timelineEventController.addModelBuildListener { it.dispatchTo(scrollOnNewMessageCallback) }
         recyclerView.setHasFixedSize(true)
-        recyclerView.setItemViewCacheSize(20)
+        //timelineEventController.addModelBuildListener { it.dispatchTo(scrollOnNewMessageCallback) }
         recyclerView.setController(timelineEventController)
         timelineEventController.callback = this
     }

app/src/main/java/im/vector/riotredesign/features/home/room/detail/timeline/MessageItem.kt

@@ -8,7 +8,7 @@ import im.vector.riotredesign.R
 import im.vector.riotredesign.core.epoxy.KotlinModel
 import im.vector.riotredesign.features.home.AvatarRenderer
 
-data class MessageItem(
+class MessageItem(
         val message: CharSequence? = null,
         val time: CharSequence? = null,
         val avatarUrl: String?,

app/src/main/java/im/vector/riotredesign/features/home/room/detail/timeline/TextItem.kt

@@ -4,7 +4,7 @@ import android.widget.TextView
 import im.vector.riotredesign.R
 import im.vector.riotredesign.core.epoxy.KotlinModel
 
-data class TextItem(
+class TextItem(
         val text: CharSequence? = null
 ) : KotlinModel(R.layout.item_event_text) {
 

app/src/main/java/im/vector/riotredesign/features/home/room/detail/timeline/TimelineEventController.kt

@@ -1,73 +1,46 @@
 package im.vector.riotredesign.features.home.room.detail.timeline
 
-import android.arch.paging.PagedList
 import com.airbnb.epoxy.EpoxyAsyncUtil
-import com.airbnb.epoxy.EpoxyController
+import com.airbnb.epoxy.EpoxyModel
 import im.vector.matrix.android.api.session.events.model.EnrichedEvent
 import im.vector.matrix.android.api.session.events.model.EventType
 import im.vector.matrix.android.api.session.room.timeline.TimelineData
 import im.vector.riotredesign.core.extensions.localDateTime
 import im.vector.riotredesign.features.home.LoadingItemModel_
+import im.vector.riotredesign.features.home.room.detail.timeline.paging.PagedListEpoxyController
 
 class TimelineEventController(private val roomId: String,
                               private val messageItemFactory: MessageItemFactory,
                               private val textItemFactory: TextItemFactory,
                               private val dateFormatter: TimelineDateFormatter
-) : EpoxyController(
+) : PagedListEpoxyController<EnrichedEvent>(
         EpoxyAsyncUtil.getAsyncBackgroundHandler(),
         EpoxyAsyncUtil.getAsyncBackgroundHandler()
 ) {
-
     init {
         setFilterDuplicates(true)
     }
 
-    private val pagedListCallback = object : PagedList.Callback() {
+    private var isLoadingForward: Boolean = false
-        override fun onChanged(position: Int, count: Int) {
+    private var isLoadingBackward: Boolean = false
-            buildSnapshotList()
-        }
 
-        override fun onInserted(position: Int, count: Int) {
-            buildSnapshotList()
-        }
-
-        override fun onRemoved(position: Int, count: Int) {
-            buildSnapshotList()
-        }
-    }
-
-    private var snapshotList: List<EnrichedEvent> = emptyList()
-    private var timelineData: TimelineData? = null
     var callback: Callback? = null
 
     fun update(timelineData: TimelineData?) {
-        timelineData?.events?.removeWeakCallback(pagedListCallback)
+        isLoadingForward = timelineData?.isLoadingForward ?: false
-        this.timelineData = timelineData
+        isLoadingBackward = timelineData?.isLoadingBackward ?: false
-        timelineData?.events?.addWeakCallback(null, pagedListCallback)
+        submitList(timelineData?.events)
-        buildSnapshotList()
+        requestModelBuild()
     }
 
-    override fun buildModels() {
-        buildModelsWith(
-                snapshotList,
-                timelineData?.isLoadingForward ?: false,
-                timelineData?.isLoadingBackward ?: false
-        )
-    }
 
-    private fun buildModelsWith(events: List<EnrichedEvent?>,
+    override fun buildItemModels(currentPosition: Int, items: List<EnrichedEvent?>): List<EpoxyModel<*>> {
-                                isLoadingForward: Boolean,
+        if (items.isNullOrEmpty()) {
-                                isLoadingBackward: Boolean) {
+            return emptyList()
-        if (events.isEmpty()) {
-            return
         }
-        LoadingItemModel_()
+        val epoxyModels = ArrayList<EpoxyModel<*>>()
-                .id(roomId + "forward_loading_item")
+        val event = items[currentPosition] ?: return emptyList()
-                .addIf(isLoadingForward, this)
+        val nextEvent = if (currentPosition + 1 < items.size) items[currentPosition + 1] else null
-
-        for (index in 0 until events.size) {
-            val event = events[index] ?: continue
-            val nextEvent = if (index + 1 < events.size) events[index + 1] else null
 
         val date = event.root.localDateTime()
         val nextDate = nextEvent?.root?.localDateTime()
@@ -77,30 +50,31 @@ class TimelineEventController(private val roomId: String,
             EventType.MESSAGE -> messageItemFactory.create(event, nextEvent, addDaySeparator, date, callback)
             else -> textItemFactory.create(event)
         }
-
+        item?.also {
-            item
+            it.id(event.localId)
-                    ?.onBind {
+            epoxyModels.add(it)
-                        timelineData?.events?.loadAround(index)
         }
-                    ?.id(event.localId)
-                    ?.addTo(this)
 
         if (addDaySeparator) {
             val formattedDay = dateFormatter.formatMessageDay(date)
-                DaySeparatorItem(formattedDay).id(roomId + formattedDay).addTo(this)
+            val daySeparatorItem = DaySeparatorItem(formattedDay).id(roomId + formattedDay)
+            epoxyModels.add(daySeparatorItem)
         }
+        return epoxyModels
     }
 
+    override fun addModels(models: List<EpoxyModel<*>>) {
+        LoadingItemModel_()
+                .id(roomId + "forward_loading_item")
+                .addIf(isLoadingForward, this)
+
+        super.add(models)
+
         LoadingItemModel_()
                 .id(roomId + "backward_loading_item")
                 .addIf(isLoadingBackward, this)
-
     }
 
-    private fun buildSnapshotList() {
-        snapshotList = timelineData?.events?.snapshot() ?: emptyList()
-        requestModelBuild()
-    }
 
     interface Callback {
         fun onUrlClicked(url: String)

app/src/main/java/im/vector/riotredesign/features/home/room/detail/timeline/paging/PagedListEpoxyController.kt

@@ -0,0 +1,125 @@
+/*
+ * Copyright 2018 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 im.vector.riotredesign.features.home.room.detail.timeline.paging
+
+import android.arch.paging.PagedList
+import android.os.Handler
+import android.support.v7.util.DiffUtil
+import com.airbnb.epoxy.EpoxyController
+import com.airbnb.epoxy.EpoxyModel
+import com.airbnb.epoxy.EpoxyViewHolder
+
+/**
+ * An [EpoxyController] that can work with a [PagedList].
+ *
+ * Internally, it caches the model for each item in the [PagedList]. You should override
+ * [buildItemModel] method to build the model for the given item. Since [PagedList] might include
+ * `null` items if placeholders are enabled, this method needs to handle `null` values in the list.
+ *
+ * By default, the model for each item is added  to the model list. To change this behavior (to
+ * filter items or inject extra items), you can override [addModels] function and manually add built
+ * models.
+ *
+ * @param T The type of the items in the [PagedList].
+ */
+abstract class PagedListEpoxyController<T>(
+        /**
+         * The handler to use for building models. By default this uses the main thread, but you can use
+         * [EpoxyAsyncUtil.getAsyncBackgroundHandler] to do model building in the background.
+         *
+         * The notify thread of your PagedList (from setNotifyExecutor in the PagedList Builder) must be
+         * the same as this thread. Otherwise Epoxy will crash.
+         */
+        modelBuildingHandler: Handler = EpoxyController.defaultModelBuildingHandler,
+        /**
+         * The handler to use when calculating the diff between built model lists.
+         * By default this uses the main thread, but you can use
+         * [EpoxyAsyncUtil.getAsyncBackgroundHandler] to do diffing in the background.
+         */
+        diffingHandler: Handler = EpoxyController.defaultDiffingHandler,
+        /**
+         * [PagedListEpoxyController] uses an [DiffUtil.ItemCallback] to detect changes between
+         * [PagedList]s. By default, it relies on simple object equality but you can provide a custom
+         * one if you don't use all fields in the object in your models.
+         */
+        itemDiffCallback: DiffUtil.ItemCallback<T> = DEFAULT_ITEM_DIFF_CALLBACK as DiffUtil.ItemCallback<T>
+) : EpoxyController(modelBuildingHandler, diffingHandler) {
+    // this is where we keep the already built models
+    protected val modelCache = PagedListModelCache(
+            modelBuilder = { pos, item ->
+                buildItemModels(pos, item)
+            },
+            rebuildCallback = {
+                requestModelBuild()
+            },
+            itemDiffCallback = itemDiffCallback,
+            modelBuildingHandler = modelBuildingHandler
+    )
+
+    final override fun buildModels() {
+        addModels(modelCache.getModels())
+    }
+
+    override fun onModelBound(
+            holder: EpoxyViewHolder,
+            boundModel: EpoxyModel<*>,
+            position: Int,
+            previouslyBoundModel: EpoxyModel<*>?
+    ) {
+        modelCache.loadAround(boundModel)
+    }
+
+    /**
+     * This function adds all built models to the adapter. You can override this method to add extra
+     * items into the model list or remove some.
+     */
+    open fun addModels(models: List<EpoxyModel<*>>) {
+        super.add(models)
+    }
+
+    /**
+     * Builds the model for a given item. This must return a single model for each item. If you want
+     * to inject headers etc, you can override [addModels] function.
+     *
+     * If the `item` is `null`, you should provide the placeholder. If your [PagedList] is configured
+     * without placeholders, you don't need to handle the `null` case.
+     */
+    abstract fun buildItemModels(currentPosition: Int, items: List<T?>): List<EpoxyModel<*>>
+
+    /**
+     * Submit a new paged list.
+     *
+     * A diff will be calculated between this list and the previous list so you may still get calls
+     * to [buildItemModel] with items from the previous list.
+     */
+    fun submitList(newList: PagedList<T>?) {
+        modelCache.submitList(newList)
+    }
+
+    companion object {
+        /**
+         * [PagedListEpoxyController] calculates a diff on top of the PagedList to check which
+         * models are invalidated.
+         * This is the default [DiffUtil.ItemCallback] which uses object equality.
+         */
+        val DEFAULT_ITEM_DIFF_CALLBACK = object : DiffUtil.ItemCallback<Any>() {
+            override fun areItemsTheSame(oldItem: Any, newItem: Any) = oldItem == newItem
+
+            override fun areContentsTheSame(oldItem: Any, newItem: Any) = oldItem == newItem
+        }
+    }
+}

app/src/main/java/im/vector/riotredesign/features/home/room/detail/timeline/paging/PagedListModelCache.kt

@@ -0,0 +1,171 @@
+/*
+ * Copyright 2018 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 im.vector.riotredesign.features.home.room.detail.timeline.paging
+
+import android.annotation.SuppressLint
+import android.arch.paging.AsyncPagedListDiffer
+import android.arch.paging.PagedList
+import android.os.Handler
+import android.support.v7.recyclerview.extensions.AsyncDifferConfig
+import android.support.v7.util.DiffUtil
+import android.support.v7.util.ListUpdateCallback
+import android.util.Log
+import com.airbnb.epoxy.EpoxyController
+import com.airbnb.epoxy.EpoxyModel
+import java.util.concurrent.Executor
+import java.util.concurrent.atomic.AtomicBoolean
+
+/**
+ * A PagedList stream wrapper that caches models built for each item. It tracks changes in paged lists and caches
+ * models for each item when they are invalidated to avoid rebuilding models for the whole list when PagedList is
+ * updated.
+ */
+class PagedListModelCache<T>(
+        private val modelBuilder: (itemIndex: Int, items: List<T>) -> List<EpoxyModel<*>>,
+        private val rebuildCallback: () -> Unit,
+        private val itemDiffCallback: DiffUtil.ItemCallback<T>,
+        private val diffExecutor: Executor? = null,
+        private val modelBuildingHandler: Handler
+) {
+
+
+    // Int is the index of the pagedList item
+    // We have to be able to find the pagedlist position coming from an epoxy model to trigger
+    // LoadAround with accuracy
+    private val modelCache = linkedMapOf<EpoxyModel<*>, Int>()
+    private var isCacheStale = AtomicBoolean(true)
+
+    /**
+     * Tracks the last accessed position so that we can report it back to the paged list when models are built.
+     */
+    private var lastPosition: Int? = null
+
+    /**
+     * Observer for the PagedList changes that invalidates the model cache when data is updated.
+     */
+    private val updateCallback = object : ListUpdateCallback {
+        override fun onChanged(position: Int, count: Int, payload: Any?) {
+            invalidate()
+            rebuildCallback()
+        }
+
+        override fun onMoved(fromPosition: Int, toPosition: Int) {
+            invalidate()
+            rebuildCallback()
+        }
+
+        override fun onInserted(position: Int, count: Int) {
+            invalidate()
+            rebuildCallback()
+        }
+
+        override fun onRemoved(position: Int, count: Int) {
+            invalidate()
+            rebuildCallback()
+        }
+    }
+
+    private val asyncDiffer = @SuppressLint("RestrictedApi")
+    object : AsyncPagedListDiffer<T>(
+            updateCallback,
+            AsyncDifferConfig.Builder<T>(
+                    itemDiffCallback
+            ).also { builder ->
+                if (diffExecutor != null) {
+                    builder.setBackgroundThreadExecutor(diffExecutor)
+                }
+                // we have to reply on this private API, otherwise, paged list might be changed when models are being built,
+                // potentially creating concurrent modification problems.
+                builder.setMainThreadExecutor { runnable: Runnable ->
+                    modelBuildingHandler.post(runnable)
+                }
+            }.build()
+    ) {
+        init {
+            if (modelBuildingHandler != EpoxyController.defaultModelBuildingHandler) {
+                try {
+                    // looks like AsyncPagedListDiffer in 1.x ignores the config.
+                    // Reflection to the rescue.
+                    val mainThreadExecutorField =
+                            AsyncPagedListDiffer::class.java.getDeclaredField("mMainThreadExecutor")
+                    mainThreadExecutorField.isAccessible = true
+                    mainThreadExecutorField.set(this, Executor {
+                        modelBuildingHandler.post(it)
+                    })
+                } catch (t: Throwable) {
+                    val msg = "Failed to hijack update handler in AsyncPagedListDiffer." +
+                            "You can only build models on the main thread"
+                    Log.e("PagedListModelCache", msg, t)
+                    throw IllegalStateException(msg, t)
+                }
+            }
+        }
+    }
+
+    fun submitList(pagedList: PagedList<T>?) {
+        asyncDiffer.submitList(pagedList)
+    }
+
+    fun getModels(): List<EpoxyModel<*>> {
+        if (isCacheStale.compareAndSet(true, false)) {
+            asyncDiffer.currentList?.forEachIndexed { position, _ ->
+                buildModel(position)
+            }
+        }
+        lastPosition?.let {
+            triggerLoadAround(it)
+        }
+        return modelCache.keys.toList()
+    }
+
+    fun loadAround(model: EpoxyModel<*>) {
+        modelCache[model]?.let { itemPosition ->
+            triggerLoadAround(itemPosition)
+            lastPosition = itemPosition
+        }
+    }
+
+    // PRIVATE METHODS *****************************************************************************
+
+    private fun invalidate() {
+        modelCache.clear()
+        isCacheStale.set(true)
+    }
+
+    private fun cacheModelsAtPosition(itemPosition: Int, epoxyModels: Set<EpoxyModel<*>>) {
+        epoxyModels.forEach {
+            modelCache[it] = itemPosition
+        }
+    }
+
+    private fun buildModel(pos: Int) {
+        if (pos >= asyncDiffer.currentList?.size ?: 0) {
+            return
+        }
+        modelBuilder(pos, asyncDiffer.currentList as List<T>).also {
+            cacheModelsAtPosition(pos, it.toSet())
+        }
+    }
+
+    private fun triggerLoadAround(position: Int) {
+        asyncDiffer.currentList?.let {
+            if (it.size > 0) {
+                it.loadAround(Math.min(position, it.size - 1))
+            }
+        }
+    }
+}

app/src/main/res/layout/item_event_message.xml

@@ -28,7 +28,7 @@
         android:ellipsize="end"
         android:maxLines="1"
         android:paddingBottom="8dp"
-        android:textSize="15sp"
+        android:textSize="16sp"
         app:layout_constraintBottom_toTopOf="@+id/toolbarSubtitleView"
         app:layout_constraintEnd_toStartOf="@+id/messageTimeView"
         app:layout_constraintHorizontal_bias="0.0"
@@ -55,7 +55,7 @@
         android:layout_marginStart="64dp"
         android:layout_marginBottom="8dp"
         android:textColor="@color/dark_grey"
-        android:textSize="14sp"
+        android:textSize="16sp"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/query/ChunkEntityQueries.kt

@@ -37,6 +37,10 @@ internal fun ChunkEntity.Companion.findAllIncludingEvents(realm: Realm, eventIds
             .findAll()
 }
 
+internal fun ChunkEntity.Companion.findIncludingEvent(realm: Realm, eventId: String): ChunkEntity? {
+    return findAllIncludingEvents(realm, listOf(eventId)).firstOrNull()
+}
+
 internal fun ChunkEntity.Companion.create(realm: Realm, prevToken: String?, nextToken: String?): ChunkEntity {
     return realm.createObject<ChunkEntity>().apply {
         this.prevToken = prevToken

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/members/RoomMemberExtractor.kt

@@ -15,7 +15,12 @@ import io.realm.RealmQuery
 internal class RoomMemberExtractor(private val monarchy: Monarchy,
                                    private val roomId: String) {
 
+    private val cached = HashMap<String, RoomMember?>()
+
     fun extractFrom(event: EventEntity): RoomMember? {
+        if (cached.containsKey(event.eventId)) {
+            return cached[event.eventId]
+        }
         val sender = event.sender ?: return null
         // If the event is unlinked we want to fetch unlinked state events
         val unlinked = event.isUnlinked
@@ -27,7 +32,9 @@ internal class RoomMemberExtractor(private val monarchy: Monarchy,
         } else {
             baseQuery(monarchy, roomId, sender, unlinked).last(since = event.stateIndex)?.content
         }
-        return ContentMapper.map(content).toModel()
+        val roomMember: RoomMember? = ContentMapper.map(content).toModel()
+        cached[event.eventId] = roomMember
+        return roomMember
     }
 
     private fun baseQuery(monarchy: Monarchy,

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/timeline/DefaultPaginationTask.kt

@@ -7,7 +7,7 @@ import im.vector.matrix.android.internal.task.Task
 import im.vector.matrix.android.internal.util.FilterUtil
 
 
-internal interface PaginationTask : Task<PaginationTask.Params, TokenChunkEvent> {
+internal interface PaginationTask : Task<PaginationTask.Params, Boolean> {
 
     data class Params(
             val roomId: String,
@@ -22,14 +22,13 @@ internal class DefaultPaginationTask(private val roomAPI: RoomAPI,
                                      private val tokenChunkEventPersistor: TokenChunkEventPersistor
 ) : PaginationTask {
 
-    override fun execute(params: PaginationTask.Params): Try<TokenChunkEvent> {
+    override fun execute(params: PaginationTask.Params): Try<Boolean> {
         val filter = FilterUtil.createRoomEventFilter(true)?.toJSONString()
         return executeRequest<PaginationResponse> {
             apiCall = roomAPI.getRoomMessagesFrom(params.roomId, params.from, params.direction.value, params.limit, filter)
         }.flatMap { chunk ->
             tokenChunkEventPersistor
                     .insertInDb(chunk, params.roomId, params.direction)
-                    .map { chunk }
         }
     }
 

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/timeline/DefaultTimelineService.kt

@@ -22,7 +22,8 @@ import im.vector.matrix.android.internal.util.tryTransactionAsync
 import io.realm.Realm
 import io.realm.RealmQuery
 
-private const val PAGE_SIZE = 30
+private const val PAGE_SIZE = 50
+private const val PREFETCH_DISTANCE = 20
 
 internal class DefaultTimelineService(private val roomId: String,
                                       private val monarchy: Monarchy,
@@ -51,6 +52,7 @@ internal class DefaultTimelineService(private val roomId: String,
         val pagedListConfig = PagedList.Config.Builder()
                 .setEnablePlaceholders(false)
                 .setPageSize(PAGE_SIZE)
+                .setPrefetchDistance(PREFETCH_DISTANCE)
                 .build()
 
         val livePagedListBuilder = LivePagedListBuilder(domainSourceFactory, pagedListConfig).setBoundaryCallback(boundaryCallback)

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/timeline/TimelineBoundaryCallback.kt

@@ -6,11 +6,11 @@ import com.zhuinden.monarchy.Monarchy
 import im.vector.matrix.android.api.MatrixCallback
 import im.vector.matrix.android.api.session.events.model.EnrichedEvent
 import im.vector.matrix.android.internal.database.model.ChunkEntity
-import im.vector.matrix.android.internal.database.query.findAllIncludingEvents
+import im.vector.matrix.android.internal.database.query.findIncludingEvent
 import im.vector.matrix.android.internal.task.TaskExecutor
 import im.vector.matrix.android.internal.task.configureWith
 import im.vector.matrix.android.internal.util.PagingRequestHelper
-import java.util.*
+import timber.log.Timber
 
 internal class TimelineBoundaryCallback(private val roomId: String,
                                         private val taskExecutor: TaskExecutor,
@@ -43,6 +43,7 @@ internal class TimelineBoundaryCallback(private val roomId: String,
     }
 
     override fun onItemAtEndLoaded(itemAtEnd: EnrichedEvent) {
+        Timber.v("On item at end loaded")
         val token = itemAtEnd.root.eventId?.let { getToken(it, PaginationDirection.BACKWARDS) }
                 ?: return
 
@@ -52,6 +53,7 @@ internal class TimelineBoundaryCallback(private val roomId: String,
     }
 
     override fun onItemAtFrontLoaded(itemAtFront: EnrichedEvent) {
+        Timber.v("On item at front loaded")
         val token = itemAtFront.root.eventId?.let { getToken(it, PaginationDirection.FORWARDS) }
                 ?: return
 
@@ -63,7 +65,7 @@ internal class TimelineBoundaryCallback(private val roomId: String,
     private fun getToken(eventId: String, direction: PaginationDirection): String? {
         var token: String? = null
         monarchy.doWithRealm { realm ->
-            val chunkEntity = ChunkEntity.findAllIncludingEvents(realm, Collections.singletonList(eventId)).firstOrNull()
+            val chunkEntity = ChunkEntity.findIncludingEvent(realm, eventId)
             token = if (direction == PaginationDirection.FORWARDS) chunkEntity?.nextToken else chunkEntity?.prevToken
         }
         return token
@@ -80,8 +82,8 @@ internal class TimelineBoundaryCallback(private val roomId: String,
 
         paginationTask.configureWith(params)
                 .enableRetry()
-                .dispatchTo(object : MatrixCallback<TokenChunkEvent> {
+                .dispatchTo(object : MatrixCallback<Boolean> {
-                    override fun onSuccess(data: TokenChunkEvent) {
+                    override fun onSuccess(data: Boolean) {
                         requestCallback.recordSuccess()
                     }
 

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/timeline/TokenChunkEventPersistor.kt

@@ -2,12 +2,7 @@ package im.vector.matrix.android.internal.session.room.timeline
 
 import arrow.core.Try
 import com.zhuinden.monarchy.Monarchy
-import im.vector.matrix.android.internal.database.helper.addAll
+import im.vector.matrix.android.internal.database.helper.*
-import im.vector.matrix.android.internal.database.helper.addOrUpdate
-import im.vector.matrix.android.internal.database.helper.addStateEvents
-import im.vector.matrix.android.internal.database.helper.deleteOnCascade
-import im.vector.matrix.android.internal.database.helper.isUnlinked
-import im.vector.matrix.android.internal.database.helper.merge
 import im.vector.matrix.android.internal.database.model.ChunkEntity
 import im.vector.matrix.android.internal.database.model.RoomEntity
 import im.vector.matrix.android.internal.database.query.create
@@ -21,8 +16,11 @@ internal class TokenChunkEventPersistor(private val monarchy: Monarchy) {
 
     fun insertInDb(receivedChunk: TokenChunkEvent,
                    roomId: String,
-                   direction: PaginationDirection): Try<Unit> {
+                   direction: PaginationDirection): Try<Boolean> {
 
+        if (receivedChunk.events.isEmpty() && receivedChunk.stateEvents.isEmpty()) {
+            return Try.just(false)
+        }
         return monarchy
                 .tryTransactionSync { realm ->
                     val roomEntity = RoomEntity.where(realm, roomId).findFirst()
@@ -71,6 +69,7 @@ internal class TokenChunkEventPersistor(private val monarchy: Monarchy) {
                     roomEntity.addOrUpdate(currentChunk)
                     roomEntity.addStateEvents(receivedChunk.stateEvents, isUnlinked = currentChunk.isUnlinked())
                 }
+                .map { true }
     }
 
     private fun handleMerge(roomEntity: RoomEntity,