/*******************************************************************************
* Copyright (c) 2013, Equal Experts Ltd
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* The views and conclusions contained in the software and documentation
* are those of the authors and should not be interpreted as representing
* official policies, either expressed or implied, of the Tayra Project.
******************************************************************************/
package com.ee.tayra.domain;
import com.mongodb.Bytes;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import com.mongodb.QueryBuilder;
import com.mongodb.util.JSON;
import com.mongodb.util.JSONSerializers;
public class Oplog implements MongoCollection {
private final DBCollection oplog;
private static final String OPLOG_COLLECTIONNAME = "oplog.rs";
private static final String OPLOG_DB_NAME = "local";
public Oplog(final MongoClient mongo) {
DB local = mongo.getDB(OPLOG_DB_NAME);
boolean oplogExists = local.collectionExists(OPLOG_COLLECTIONNAME);
if (!oplogExists) {
throw new NotAReplicaSetNode("node is not a part of ReplicaSet");
}
oplog = local.getCollection(OPLOG_COLLECTIONNAME);
}
@Override
public final MongoCollectionIterator<String> find(final String
fromDocument, final boolean tailable) {
DBObject query = createQuery(fromDocument);
return new OplogIterator(oplog, query, tailable);
}
private DBObject createQuery(final String fromDocument) {
if (fromDocument == null || "".equals(fromDocument)) {
return null;
}
DBObject timestamp = (DBObject) JSON.parse(fromDocument);
return QueryBuilder
.start()
.put("ts")
.greaterThan(timestamp.get("ts"))
.get();
}
private static class OplogIterator implements
MongoCollectionIterator<String> {
private DBCursor cursor;
public OplogIterator(final DBCollection collection, final DBObject
query, final boolean tailable) {
cursor = collection.find(query);
if (tailable) {
cursor.addOption(Bytes.QUERYOPTION_TAILABLE);
cursor.addOption(Bytes.QUERYOPTION_AWAITDATA);
}
}
@Override
public boolean hasNext() {
if (cursor == null) {
throw new IteratorAlreadyClosed("Iterator Already Closed");
}
return cursor.hasNext();
}
@Override
public String next() {
if (cursor == null) {
throw new IteratorAlreadyClosed("Iterator Already Closed");
}
return JSONSerializers.getStrict().serialize(cursor.next());
}
@Override
public void remove() {
throw new UnsupportedOperationException(
"remove document on oplog is not supported"
);
}
@Override
public void close() {
cursor.close();
cursor = null;
}
}
}