/*
* 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.session.room.timeline
import arrow.core.Try
import com.zhuinden.monarchy.Monarchy
import im.vector.matrix.android.internal.database.helper.*
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
import im.vector.matrix.android.internal.database.query.find
import im.vector.matrix.android.internal.database.query.findAllIncludingEvents
import im.vector.matrix.android.internal.database.query.where
import im.vector.matrix.android.internal.session.user.UserEntityFactory
import im.vector.matrix.android.internal.util.tryTransactionSync
import io.realm.kotlin.createObject
import timber.log.Timber
import javax.inject.Inject
/**
* Insert Chunk in DB, and eventually merge with existing chunk event
*/
internal class TokenChunkEventPersistor @Inject constructor(private val monarchy: Monarchy) {
/**
*
* ========================================================================================================
* | Backward case |
* ========================================================================================================
*
* *--------------------------* *--------------------------*
* | startToken1 | | startToken1 |
* *--------------------------* *--------------------------*
* | | | |
* | | | |
* | receivedChunk backward | | |
* | Events | | |
* | | | |
* | | | |
* | | | |
* *--------------------------* *--------------------------* | |
* | startToken0 | | endToken1 | => | Merged chunk |
* *--------------------------* *--------------------------* | Events |
* | | | |
* | | | |
* | Current Chunk | | |
* | Events | | |
* | | | |
* | | | |
* | | | |
* *--------------------------* *--------------------------*
* | endToken0 | | endToken0 |
* *--------------------------* *--------------------------*
*
*
* ========================================================================================================
* | Forward case |
* ========================================================================================================
*
* *--------------------------* *--------------------------*
* | startToken0 | | startToken0 |
* *--------------------------* *--------------------------*
* | | | |
* | | | |
* | Current Chunk | | |
* | Events | | |
* | | | |
* | | | |
* | | | |
* *--------------------------* *--------------------------* | |
* | endToken0 | | startToken1 | => | Merged chunk |
* *--------------------------* *--------------------------* | Events |
* | | | |
* | | | |
* | receivedChunk forward | | |
* | Events | | |
* | | | |
* | | | |
* | | | |
* *--------------------------* *--------------------------*
* | endToken1 | | endToken1 |
* *--------------------------* *--------------------------*
*
* ========================================================================================================
*
*/
enum class Result {
SHOULD_FETCH_MORE,
SUCCESS
}
fun insertInDb(receivedChunk: TokenChunkEvent,
roomId: String,
direction: PaginationDirection): Try {
return monarchy
.tryTransactionSync { realm ->
Timber.v("Start persisting ${receivedChunk.events.size} events in $roomId towards $direction")
val roomEntity = RoomEntity.where(realm, roomId).findFirst()
?: realm.createObject(roomId)
val nextToken: String?
val prevToken: String?
if (direction == PaginationDirection.FORWARDS) {
nextToken = receivedChunk.end
prevToken = receivedChunk.start
} else {
nextToken = receivedChunk.start
prevToken = receivedChunk.end
}
if (ChunkEntity.find(realm, roomId, nextToken = nextToken) != null || ChunkEntity.find(realm, roomId, prevToken = prevToken) != null) {
Timber.v("Already inserted - SKIP")
return@tryTransactionSync
}
val prevChunk = ChunkEntity.find(realm, roomId, nextToken = prevToken)
val nextChunk = ChunkEntity.find(realm, roomId, prevToken = nextToken)
// The current chunk is the one we will keep all along the merge processChanges.
// We try to look for a chunk next to the token,
// otherwise we create a whole new one
var currentChunk = if (direction == PaginationDirection.FORWARDS) {
prevChunk?.apply { this.nextToken = nextToken }
} else {
nextChunk?.apply { this.prevToken = prevToken }
}
?: ChunkEntity.create(realm, prevToken, nextToken)
if (receivedChunk.events.isEmpty() && receivedChunk.end == receivedChunk.start) {
Timber.v("Reach end of $roomId")
currentChunk.isLastBackward = true
} else {
Timber.v("Add ${receivedChunk.events.size} events in chunk(${currentChunk.nextToken} | ${currentChunk.prevToken}")
val eventIds = ArrayList(receivedChunk.events.size)
for (event in receivedChunk.events) {
event.eventId?.also { eventIds.add(it) }
currentChunk.add(roomId, event, direction, isUnlinked = currentChunk.isUnlinked())
UserEntityFactory.createOrNull(event)?.also {
realm.insertOrUpdate(it)
}
}
// Then we merge chunks if needed
if (currentChunk != prevChunk && prevChunk != null) {
currentChunk = handleMerge(roomEntity, direction, currentChunk, prevChunk)
} else if (currentChunk != nextChunk && nextChunk != null) {
currentChunk = handleMerge(roomEntity, direction, currentChunk, nextChunk)
} else {
val newEventIds = receivedChunk.events.mapNotNull { it.eventId }
ChunkEntity
.findAllIncludingEvents(realm, newEventIds)
.filter { it != currentChunk }
.forEach { overlapped ->
currentChunk = handleMerge(roomEntity, direction, currentChunk, overlapped)
}
}
roomEntity.addOrUpdate(currentChunk)
for (stateEvent in receivedChunk.stateEvents) {
roomEntity.addStateEvent(stateEvent, isUnlinked = currentChunk.isUnlinked())
UserEntityFactory.createOrNull(stateEvent)?.also {
realm.insertOrUpdate(it)
}
}
currentChunk.updateSenderDataFor(eventIds)
}
}
.map {
if (receivedChunk.events.isEmpty() && receivedChunk.stateEvents.isEmpty() && receivedChunk.start != receivedChunk.end) {
Result.SHOULD_FETCH_MORE
} else {
Result.SUCCESS
}
}
}
private fun handleMerge(roomEntity: RoomEntity,
direction: PaginationDirection,
currentChunk: ChunkEntity,
otherChunk: ChunkEntity): ChunkEntity {
// We always merge the bottom chunk into top chunk, so we are always merging backwards
Timber.v("Merge ${currentChunk.prevToken} | ${currentChunk.nextToken} with ${otherChunk.prevToken} | ${otherChunk.nextToken}")
return if (direction == PaginationDirection.BACKWARDS) {
currentChunk.merge(roomEntity.roomId, otherChunk, PaginationDirection.BACKWARDS)
roomEntity.deleteOnCascade(otherChunk)
currentChunk
} else {
otherChunk.merge(roomEntity.roomId, currentChunk, PaginationDirection.BACKWARDS)
roomEntity.deleteOnCascade(currentChunk)
otherChunk
}
}
}