SettingsNode.java

package org.apache.cassandra.stress.settings;

import java.io.*;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;

public class SettingsNode implements Serializable
{

    public final List<String> nodes;

    public SettingsNode(Options options)
    {
        if (options.file.setByUser())
        {
            try
            {
                String node;
                List<String> tmpNodes = new ArrayList<String>();
                BufferedReader in = new BufferedReader(new InputStreamReader(new FileInputStream(options.file.value())));
                try
                {
                    while ((node = in.readLine()) != null)
                    {
                        if (node.length() > 0)
                            tmpNodes.add(node);
                    }
                    nodes = Arrays.asList(tmpNodes.toArray(new String[tmpNodes.size()]));
                }
                finally
                {
                    in.close();
                }
            }
            catch(IOException ioe)
            {
                throw new RuntimeException(ioe);
            }

        }
        else
            nodes = Arrays.asList(options.list.value().split(","));
    }

    public String randomNode()
    {
        int index = (int) (Math.random() * nodes.size());
        if (index >= nodes.size())
            index = nodes.size() - 1;
        return nodes.get(index);
    }

    // Option Declarations

    public static final class Options extends GroupedOptions
    {
        final OptionSimple file = new OptionSimple("file=", ".*", null, "Node file (one per line)", false);
        final OptionSimple list = new OptionSimple("", "[^=,]+(,[^=,]+)*", "localhost", "comma delimited list of hosts", false);

        @Override
        public List<? extends Option> options()
        {
            return Arrays.asList(file, list);
        }
    }

    // CLI Utility Methods

    public static SettingsNode get(Map<String, String[]> clArgs)
    {
        String[] params = clArgs.remove("-node");
        if (params == null)
            return new SettingsNode(new Options());

        GroupedOptions options = GroupedOptions.select(params, new Options());
        if (options == null)
        {
            printHelp();
            System.out.println("Invalid -node options provided, see output for valid options");
            System.exit(1);
        }
        return new SettingsNode((Options) options);
    }

    public static void printHelp()
    {
        GroupedOptions.printOptions(System.out, "-node", new Options());
    }

    public static Runnable helpPrinter()
    {
        return new Runnable()
        {
            @Override
            public void run()
            {
                printHelp();
            }
        };
    }
}