org.apache.jackrabbit.oak.plugins.document.mongo.replica.GetRootRevisionsCallable Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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
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* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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* See the License for the specific language governing permissions and
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package org.apache.jackrabbit.oak.plugins.document.mongo.replica;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import org.apache.jackrabbit.oak.plugins.document.Document;
import org.apache.jackrabbit.oak.plugins.document.Revision;
import org.apache.jackrabbit.oak.plugins.document.RevisionVector;
import org.apache.jackrabbit.oak.stats.Clock;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.mongodb.BasicDBObject;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
public class GetRootRevisionsCallable implements Callable> {
private static final Logger LOG = LoggerFactory.getLogger(GetRootRevisionsCallable.class);
private final String hostName;
private final NodeCollectionProvider nodeCollections;
private final Clock clock;
public GetRootRevisionsCallable(Clock clock, String hostName, NodeCollectionProvider nodeCollections) {
this.hostName = hostName;
this.nodeCollections = nodeCollections;
this.clock = clock;
}
@Override
public Timestamped call() throws Exception {
List revisions = new ArrayList();
DBCollection collection = nodeCollections.get(hostName);
long start = clock.getTime();
DBObject root = collection.findOne(new BasicDBObject(Document.ID, "0:/"));
long end = clock.getTime();
long mid = (start + end) / 2;
if (root == null) {
LOG.warn("Can't get the root document on {}", hostName);
return null;
}
DBObject lastRev = (DBObject) root.get("_lastRev");
for (String clusterId : lastRev.keySet()) {
String rev = (String) lastRev.get(clusterId);
revisions.add(Revision.fromString(rev));
}
LOG.debug("Got /_lastRev from {}: {}", hostName, lastRev);
return new Timestamped(new RevisionVector(revisions), mid);
}
}