/*
 * 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.
 */

/*
 * Copyright 2015 ScyllaDB
 *
 * Modified by ScyllaDB
 */

package org.apache.cassandra.streaming;

import java.io.Serializable;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Collection;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import javax.json.JsonArray;
import javax.json.JsonObject;

import com.google.common.base.Predicate;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;

/**
 * Stream session info.
 */
public final class SessionInfo implements Serializable
{
    public final InetAddress peer;
    public final int sessionIndex;
    public final InetAddress connecting;
    /** Immutable collection of receiving summaries */
    public final Collection<StreamSummary> receivingSummaries;
    /** Immutable collection of sending summaries*/
    public final Collection<StreamSummary> sendingSummaries;
    /** Current session state */
    public final StreamSession.State state;

    private final Map<String, ProgressInfo> receivingFiles;
    private final Map<String, ProgressInfo> sendingFiles;

    static InetAddress address(String val) {
        try {
            return InetAddress.getByName(val);
        } catch (UnknownHostException e) {
        }
        return null;
    }


    public SessionInfo(InetAddress peer,
                       int sessionIndex,
                       InetAddress connecting,
                       Collection<StreamSummary> receivingSummaries,
                       Collection<StreamSummary> sendingSummaries,
                       StreamSession.State state) {
        this.peer = peer;
        this.sessionIndex = sessionIndex;
        this.connecting = connecting;
        this.receivingSummaries = ImmutableSet.copyOf(receivingSummaries);
        this.sendingSummaries = ImmutableSet.copyOf(sendingSummaries);
        this.receivingFiles = new ConcurrentHashMap<>();
        this.sendingFiles = new ConcurrentHashMap<>();
        this.state = state;
    }

    public SessionInfo(String peer,
            int sessionIndex,
            String connecting,
            Collection<StreamSummary> receivingSummaries,
            Collection<StreamSummary> sendingSummaries,
            String state) {
        this(address(peer), sessionIndex, address(connecting), receivingSummaries, sendingSummaries,
                StreamSession.State.valueOf(state));
    }

    public static SessionInfo fromJsonObject(JsonObject obj) {
        return new SessionInfo(obj.getString("peer"), obj.getInt("sessionIndex"),
                obj.getString("connecting"),
                StreamSummary.fromJsonArr(obj.getJsonArray("receivingSummaries")),
                StreamSummary.fromJsonArr(obj.getJsonArray("sendingSummaries")),
                obj.getString("state"));
    }

    public static Set<SessionInfo> fromJsonArr(JsonArray arr) {
        Set<SessionInfo> res = new HashSet<SessionInfo>();
        if (arr != null) {
            for (int i = 0; i < arr.size(); i++) {
                res.add(fromJsonObject(arr.getJsonObject(i)));
            }
        }
        return res;
    }

    public boolean isFailed()
    {
        return state == StreamSession.State.FAILED;
    }

    /**
     * Update progress of receiving/sending file.
     *
     * @param newProgress new progress info
     */
    public void updateProgress(ProgressInfo newProgress)
    {
        assert peer.equals(newProgress.peer);

        Map<String, ProgressInfo> currentFiles = newProgress.direction == ProgressInfo.Direction.IN
                                                    ? receivingFiles : sendingFiles;
        currentFiles.put(newProgress.fileName, newProgress);
    }

    public Collection<ProgressInfo> getReceivingFiles()
    {
        return receivingFiles.values();
    }

    public Collection<ProgressInfo> getSendingFiles()
    {
        return sendingFiles.values();
    }

    /**
     * @return total number of files already received.
     */
    public long getTotalFilesReceived()
    {
        return getTotalFilesCompleted(receivingFiles.values());
    }

    /**
     * @return total number of files already sent.
     */
    public long getTotalFilesSent()
    {
        return getTotalFilesCompleted(sendingFiles.values());
    }

    /**
     * @return total size(in bytes) already received.
     */
    public long getTotalSizeReceived()
    {
        return getTotalSizeInProgress(receivingFiles.values());
    }

    /**
     * @return total size(in bytes) already sent.
     */
    public long getTotalSizeSent()
    {
        return getTotalSizeInProgress(sendingFiles.values());
    }

    /**
     * @return total number of files to receive in the session
     */
    public long getTotalFilesToReceive()
    {
        return getTotalFiles(receivingSummaries);
    }

    /**
     * @return total number of files to send in the session
     */
    public long getTotalFilesToSend()
    {
        return getTotalFiles(sendingSummaries);
    }

    /**
     * @return total size(in bytes) to receive in the session
     */
    public long getTotalSizeToReceive()
    {
        return getTotalSizes(receivingSummaries);
    }

    /**
     * @return total size(in bytes) to send in the session
     */
    public long getTotalSizeToSend()
    {
        return getTotalSizes(sendingSummaries);
    }

    private long getTotalSizeInProgress(Collection<ProgressInfo> files)
    {
        long total = 0;
        for (ProgressInfo file : files)
            total += file.currentBytes;
        return total;
    }

    private long getTotalFiles(Collection<StreamSummary> summaries)
    {
        long total = 0;
        for (StreamSummary summary : summaries)
            total += summary.files;
        return total;
    }

    private long getTotalSizes(Collection<StreamSummary> summaries)
    {
        long total = 0;
        for (StreamSummary summary : summaries)
            total += summary.totalSize;
        return total;
    }

    private long getTotalFilesCompleted(Collection<ProgressInfo> files)
    {
        Iterable<ProgressInfo> completed = Iterables.filter(files, new Predicate<ProgressInfo>()
        {
            public boolean apply(ProgressInfo input)
            {
                return input.isCompleted();
            }
        });
        return Iterables.size(completed);
    }
}

@@ -2612,36 +2612,16 @@
 aries = 
-ImmutableSet.copyOf(
 receivin
@@ -2622,33 +2622,32 @@
 ceivingSummaries
-)
 ;%0A        this.s
@@ -2668,28 +2668,8 @@
 s = 
-ImmutableSet.copyOf(
 send
@@ -2676,25 +2676,24 @@
 ingSummaries
-)
 ;%0A        th
@@ -3361,25 +3361,26 @@
 Int(%22session
-I
+_i
 ndex%22),%0A    
@@ -3481,33 +3481,34 @@
 Array(%22receiving
-S
+_s
 ummaries%22)),%0A   
@@ -3567,25 +3567,26 @@
 ray(%22sending
-S
+_s
 ummaries%22)),
@@ -6666,32 +6666,97 @@
 ummaries)%0A    %7B%0A
+        if (summaries == null) %7B%0A            return 0;%0A        %7D%0A
         long tot

allow null and modified API