cassandra-trunk/src/java/org/apache/cassandra/dht/StreamStateStore.java
/*
 * 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.dht;

import java.util.Set;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.Streams;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.cassandra.db.SystemKeyspace;
import org.apache.cassandra.streaming.StreamEvent;
import org.apache.cassandra.streaming.StreamEventHandler;
import org.apache.cassandra.streaming.StreamRequest;
import org.apache.cassandra.streaming.StreamState;

/**
 * Store and update available ranges (data already received) to system keyspace.
 */
public class StreamStateStore implements StreamEventHandler
{
    private static final Logger logger = LoggerFactory.getLogger(StreamStateStore.class);

    public SystemKeyspace.AvailableRanges getAvailableRanges(String keyspace, IPartitioner partitioner)
    {
        return SystemKeyspace.getAvailableRanges(keyspace, partitioner);
    }

    /**
     * Check if given token's data is available in this node. This doesn't handle transientness in a useful way
     * so it's only used by a legacy test
     *
     * @param keyspace keyspace name
     * @param token token to check
     * @return true if given token in the keyspace is already streamed and ready to be served.
     */
    @VisibleForTesting
    public boolean isDataAvailable(String keyspace, Token token)
    {
        SystemKeyspace.AvailableRanges availableRanges = getAvailableRanges(keyspace, token.getPartitioner());

        return Streams.concat(availableRanges.full.stream(),
                              availableRanges.trans.stream())
                      .anyMatch(range -> range.contains(token));
    }

    /**
     * When StreamSession completes, make all keyspaces/ranges in session available to be served.
     *
     * @param event Stream event.
     */
    @Override
    public void handleStreamEvent(StreamEvent event)
    {
        if (event.eventType == StreamEvent.Type.STREAM_COMPLETE)
        {
            StreamEvent.SessionCompleteEvent se = (StreamEvent.SessionCompleteEvent) event;
            if (se.success)
            {
                Set<String> keyspaces = se.transferredRangesPerKeyspace.keySet();
                for (String keyspace : keyspaces)
                {
                    SystemKeyspace.updateTransferredRanges(se.streamOperation, se.peer, keyspace, se.transferredRangesPerKeyspace.get(keyspace));
                }
                for (StreamRequest request : se.requests)
                {
                    SystemKeyspace.updateAvailableRanges(request.keyspace, request.full.ranges(), request.transientReplicas.ranges());
                }
            }
        }
    }

    @Override
    public void onSuccess(StreamState streamState) {}

    @Override
    public void onFailure(Throwable throwable) {}
}
