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A fork of the Apache Cassandra Project ready to embed Elasticsearch.
/*
* 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
*
* 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.apache.cassandra.service.pager;
import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.db.*;
import org.apache.cassandra.db.filter.*;
import org.apache.cassandra.db.partitions.*;
import org.apache.cassandra.exceptions.RequestExecutionException;
import org.apache.cassandra.exceptions.RequestValidationException;
import org.apache.cassandra.service.ClientState;
import org.apache.cassandra.transport.Server;
/**
* Static utility methods for paging.
*/
public class QueryPagers
{
private QueryPagers() {};
/**
* Convenience method that count (live) cells/rows for a given slice of a row, but page underneath.
*/
public static int countPaged(CFMetaData metadata,
DecoratedKey key,
ColumnFilter columnFilter,
ClusteringIndexFilter filter,
DataLimits limits,
ConsistencyLevel consistencyLevel,
ClientState state,
final int pageSize,
int nowInSec,
boolean isForThrift) throws RequestValidationException, RequestExecutionException
{
SinglePartitionReadCommand command = SinglePartitionReadCommand.create(isForThrift, metadata, nowInSec, columnFilter, RowFilter.NONE, limits, key, filter);
final SinglePartitionPager pager = new SinglePartitionPager(command, null, Server.CURRENT_VERSION);
int count = 0;
while (!pager.isExhausted())
{
try (PartitionIterator iter = pager.fetchPage(pageSize, consistencyLevel, state))
{
DataLimits.Counter counter = limits.newCounter(nowInSec, true);
PartitionIterators.consume(counter.applyTo(iter));
count += counter.counted();
}
}
return count;
}
}