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org.dizitart.no2.sync.SyncService Maven / Gradle / Ivy
/*
*
* Copyright 2017-2018 Nitrite author or authors.
*
* 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 org.dizitart.no2.sync;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.Setter;
import lombok.extern.slf4j.Slf4j;
import org.dizitart.no2.Document;
import org.dizitart.no2.NitriteCollection;
import org.dizitart.no2.event.EventBus;
import org.dizitart.no2.meta.Attributes;
import org.dizitart.no2.sync.data.ChangeFeed;
import org.dizitart.no2.sync.data.FeedOptions;
import java.util.List;
import static org.dizitart.no2.Constants.*;
import static org.dizitart.no2.FindOptions.limit;
import static org.dizitart.no2.filters.Filters.*;
import static org.dizitart.no2.util.Iterables.toList;
/**
* @author Anindya Chatterjee.
*/
@Slf4j
class SyncService {
@Getter @Setter(AccessLevel.NONE)
private SyncConfig syncConfig;
@Getter @Setter
private NitriteCollection changeLogRepository;
@Getter @Setter
private EventBus syncEventBus;
@Getter
private LocalCollection localCollection;
private String originator;
private SyncTemplate syncTemplate;
void pullChanges() {
if (syncTemplate.isOnline()) {
// pull all changes from remote to local, but local changes are
// not pushed to remote.
// create the last sync time of local, pull everything from remote
// from that time and update local.
try {
if (syncTemplate.trySyncLock(syncConfig.getSyncDelay(), originator)) {
notifyEvent(EventType.IN_PROGRESS);
Attributes attributes = localCollection.getAttributes();
attributes = attributes == null ? new Attributes(localCollection.getName()) : attributes;
long from = attributes.getLastSynced();
FeedOptions feedOptions = new FeedOptions();
feedOptions.setFromSequence(from);
ChangeFeed remoteChangeFeed = syncTemplate.changedSince(feedOptions);
localCollection.change(remoteChangeFeed);
attributes.setLastSynced(remoteChangeFeed.getSequenceNumber());
localCollection.setAttributes(attributes);
notifyEvent(EventType.COMPLETED);
}
} catch (Exception error) {
notifyErrorEvent(error, EventType.REPLICATION_ERROR);
} finally {
syncTemplate.releaseLock(originator);
}
}
}
void pushChanges() {
if (syncTemplate.isOnline()) {
// push all changes from local to remote, but remote changes
// are not downloaded to local.
try {
if (syncTemplate.trySyncLock(syncConfig.getSyncDelay(), originator)) {
notifyEvent(EventType.IN_PROGRESS);
Attributes attributes = localCollection.getAttributes();
attributes = attributes == null ? new Attributes(localCollection.getName()) : attributes;
long lastSequence = attributes.getLastSynced();
long newSequence = System.currentTimeMillis();
ChangeFeed changeFeed = localCollection.changedSince(lastSequence, newSequence);
changeFeed.setOriginator(originator);
changeFeed.setSequenceNumber(newSequence);
if (syncTemplate.change(changeFeed)) {
clearRemoveLogSince(newSequence);
}
attributes.setLastSynced(newSequence);
localCollection.setAttributes(attributes);
notifyEvent(EventType.COMPLETED);
}
} catch (Exception error) {
notifyErrorEvent(error, EventType.REPLICATION_ERROR);
} finally {
syncTemplate.releaseLock(originator);
}
}
}
void mergeChanges() {
if (syncTemplate.isOnline()) {
try {
if (syncTemplate.trySyncLock(syncConfig.getSyncDelay(), originator)) {
notifyEvent(EventType.IN_PROGRESS);
Attributes attributes = localCollection.getAttributes() == null
? new Attributes(localCollection.getName())
: localCollection.getAttributes();
long lastSequence = attributes.getLastSynced();
FeedOptions feedOptions = new FeedOptions();
feedOptions.setFromSequence(lastSequence);
ChangeFeed remoteChanges = syncTemplate.changedSince(feedOptions);
ChangeFeed localChanges = localCollection.changedSince(lastSequence,
remoteChanges.getSequenceNumber());
localChanges.setOriginator(originator);
if (mergeChanges(remoteChanges, localChanges)) {
clearRemoveLogSince(remoteChanges.getSequenceNumber());
}
attributes.setLastSynced(remoteChanges.getSequenceNumber());
localCollection.setAttributes(attributes);
notifyEvent(EventType.COMPLETED);
}
} catch (Exception error) {
notifyErrorEvent(error, EventType.REPLICATION_ERROR);
} finally {
syncTemplate.releaseLock(originator);
}
}
}
void resetLocalWithRemote(int offset, int size) {
if (syncTemplate.isOnline()) {
try {
notifyEvent(EventType.IN_PROGRESS);
localCollection.clear();
List documents = syncTemplate.fetch(offset, size);
for (Document document : documents) {
document.put(DOC_SOURCE, REPLICATOR);
}
localCollection.insert(documents.toArray(new Document[0]));
notifyEvent(EventType.COMPLETED);
} catch (Exception error) {
notifyErrorEvent(error, EventType.REPLICATION_ERROR);
}
}
}
void resetRemoteWithLocal(int offset, int size) {
if (syncTemplate.isOnline()) {
try {
if (syncTemplate.trySyncLock(syncConfig.getSyncDelay(), originator)) {
notifyEvent(EventType.IN_PROGRESS);
syncTemplate.clear();
NitriteCollection nitriteCollection = localCollection.getCollection();
Iterable documents = nitriteCollection.find(limit(offset, size));
ChangeFeed changeFeed = new ChangeFeed();
changeFeed.setModifiedDocuments(toList(documents));
changeFeed.setOriginator(originator);
syncTemplate.change(changeFeed);
notifyEvent(EventType.COMPLETED);
}
} catch (Exception error) {
notifyErrorEvent(error, EventType.REPLICATION_ERROR);
} finally {
syncTemplate.releaseLock(originator);
}
}
}
void setSyncConfig(SyncConfig syncConfig) {
this.syncConfig = syncConfig;
this.syncTemplate = syncConfig.getSyncTemplate();
}
void setLocalCollection(LocalCollection localCollection) {
this.localCollection = localCollection;
this.localCollection.setChangeLogRepository(changeLogRepository);
Attributes attributes = localCollection.getAttributes() == null
? new Attributes(localCollection.getName())
: localCollection.getAttributes();
localCollection.setAttributes(attributes);
this.originator = attributes.getUuid();
}
private void clearRemoveLogSince(long upto) {
changeLogRepository.remove(
and(
eq(COLLECTION, localCollection.getName()),
lte(DELETE_TIME, upto)
)
);
}
private boolean mergeChanges(ChangeFeed remoteChanges, ChangeFeed localChanges) {
boolean result = syncTemplate.change(localChanges);
localCollection.change(remoteChanges);
return result;
}
void notifyEvent(EventType eventType) {
SyncEventData eventData = new SyncEventData();
eventData.setEventType(eventType);
eventData.setCollectionName(localCollection.getName());
syncEventBus.post(eventData);
}
private void notifyErrorEvent(Throwable error, EventType eventType) {
log.error("Replication error", error);
SyncEventData eventData = new SyncEventData();
eventData.setEventType(eventType);
eventData.setCollectionName(localCollection.getName());
eventData.setError(error);
syncEventBus.post(eventData);
}
}
