import org.apache.cassandra.streaming.StreamResultFuture; //导入依赖的package包/类
public StreamResultFuture fetchAsync()
{
    for (Map.Entry<String, Map.Entry<InetAddress, Collection<Range<Token>>>> entry : toFetch.entries())
    {
        String keyspace = entry.getKey();
        InetAddress source = entry.getValue().getKey();
        InetAddress preferred = SystemKeyspace.getPreferredIP(source);
        Collection<Range<Token>> ranges = entry.getValue().getValue();
        /* Send messages to respective folks to stream data over to me */
        if (logger.isDebugEnabled())
            logger.debug("{}ing from {} ranges {}", description, source, StringUtils.join(ranges, ", "));
        streamPlan.requestRanges(source, preferred, keyspace, ranges);
    }

    return streamPlan.execute();
}
 

import org.apache.cassandra.streaming.StreamResultFuture; //导入依赖的package包/类
public StreamResultFuture fetchAsync()
{
    for (Map.Entry<String, Map.Entry<InetAddress, Collection<Range<Token>>>> entry : toFetch.entries())
    {
        String keyspace = entry.getKey();
        InetAddress source = entry.getValue().getKey();
        InetAddress preferred = SystemKeyspace.getPreferredIP(source);
        Collection<Range<Token>> ranges = entry.getValue().getValue();

        // filter out already streamed ranges
        Set<Range<Token>> availableRanges = stateStore.getAvailableRanges(keyspace, StorageService.instance.getTokenMetadata().partitioner);
        if (ranges.removeAll(availableRanges))
        {
            logger.info("Some ranges of {} are already available. Skipping streaming those ranges.", availableRanges);
        }

        if (logger.isTraceEnabled())
            logger.trace("{}ing from {} ranges {}", description, source, StringUtils.join(ranges, ", "));
        /* Send messages to respective folks to stream data over to me */
        streamPlan.requestRanges(source, preferred, keyspace, ranges);
    }

    return streamPlan.execute();
}
 

import org.apache.cassandra.streaming.StreamResultFuture; //导入依赖的package包/类
@Override
public void run()
{
    try
    {
        // streaming connections are per-session and have a fixed version.  we can't do anything with a wrong-version stream connection, so drop it.
        if (version != StreamMessage.CURRENT_VERSION)
            throw new IOException(String.format("Received stream using protocol version %d (my version %d). Terminating connection", version, MessagingService.current_version));

        DataInput input = new DataInputStream(socket.getInputStream());
        StreamInitMessage init = StreamInitMessage.serializer.deserialize(input, version);

        // The initiator makes two connections, one for incoming and one for outgoing.
        // The receiving side distinguish two connections by looking at StreamInitMessage#isForOutgoing.
        // Note: we cannot use the same socket for incoming and outgoing streams because we want to
        // parallelize said streams and the socket is blocking, so we might deadlock.
        StreamResultFuture.initReceivingSide(init.sessionIndex, init.planId, init.description, init.from, socket, init.isForOutgoing, version);
    }
    catch (IOException e)
    {
        logger.debug("IOException reading from socket; closing", e);
        try
        {
            socket.close();
        }
        catch (IOException e2)
        {
            logger.debug("error closing socket", e2);
        }
    }
}
 

import org.apache.cassandra.streaming.StreamResultFuture; //导入依赖的package包/类
public StreamResultFuture fetchAsync()
{
    for (Map.Entry<String, Map.Entry<InetAddress, Collection<Range<Token>>>> entry : toFetch.entries())
    {
        String keyspace = entry.getKey();
        InetAddress source = entry.getValue().getKey();
        Collection<Range<Token>> ranges = entry.getValue().getValue();
        /* Send messages to respective folks to stream data over to me */
        if (logger.isDebugEnabled())
            logger.debug("{}ing from {} ranges {}", description, source, StringUtils.join(ranges, ", "));
        streamPlan.requestRanges(source, keyspace, ranges);
    }

    return streamPlan.execute();
}
 

import org.apache.cassandra.streaming.StreamResultFuture; //导入依赖的package包/类
@Override
public void run()
{
    try
    {
        // streaming connections are per-session and have a fixed version.  we can't do anything with a wrong-version stream connection, so drop it.
        if (version != StreamMessage.CURRENT_VERSION)
            throw new IOException(String.format("Received stream using protocol version %d (my version %d). Terminating connection", version, MessagingService.current_version));

        DataInput input = new DataInputStream(socket.getInputStream());
        StreamInitMessage init = StreamInitMessage.serializer.deserialize(input, version);

        // The initiator makes two connections, one for incoming and one for outgoing.
        // The receiving side distinguish two connections by looking at StreamInitMessage#isForOutgoing.
        // Note: we cannot use the same socket for incoming and outgoing streams because we want to
        // parallelize said streams and the socket is blocking, so we might deadlock.
        StreamResultFuture.initReceivingSide(init.planId, init.description, init.from, socket, init.isForOutgoing, version);
    }
    catch (IOException e)
    {
        logger.debug("IOException reading from socket; closing", e);
        try
        {
            socket.close();
        }
        catch (IOException e2)
        {
            logger.debug("error closing socket", e2);
        }
    }
}
 

import org.apache.cassandra.streaming.StreamResultFuture; //导入依赖的package包/类
@Override
@SuppressWarnings("resource") // Not closing constructed DataInputPlus's as the stream needs to remain open.
public void run()
{
    try
    {
        // streaming connections are per-session and have a fixed version.
        // we can't do anything with a wrong-version stream connection, so drop it.
        if (version != StreamMessage.CURRENT_VERSION)
            throw new IOException(String.format("Received stream using protocol version %d (my version %d). Terminating connection", version, StreamMessage.CURRENT_VERSION));

        DataInputPlus input = new DataInputStreamPlus(socket.getInputStream());
        StreamInitMessage init = StreamInitMessage.serializer.deserialize(input, version);

        //Set SO_TIMEOUT on follower side
        if (!init.isForOutgoing)
            socket.setSoTimeout(DatabaseDescriptor.getStreamingSocketTimeout());

        // The initiator makes two connections, one for incoming and one for outgoing.
        // The receiving side distinguish two connections by looking at StreamInitMessage#isForOutgoing.
        // Note: we cannot use the same socket for incoming and outgoing streams because we want to
        // parallelize said streams and the socket is blocking, so we might deadlock.
        StreamResultFuture.initReceivingSide(init.sessionIndex, init.planId, init.description, init.from, this, init.isForOutgoing, version, init.keepSSTableLevel, init.isIncremental);
    }
    catch (IOException e)
    {
        logger.error(String.format("IOException while reading from socket from %s, closing: %s",
                                   socket.getRemoteSocketAddress(), e));
        close();
    }
}