org.apache.reef.io.network.util.Utils.java Source code

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Here is the source code for org.apache.reef.io.network.util.Utils.java

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/*
 * 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.reef.io.network.util;

import com.google.protobuf.ByteString;
import org.apache.commons.lang.StringUtils;
import org.apache.reef.io.network.proto.ReefNetworkGroupCommProtos;
import org.apache.reef.wake.ComparableIdentifier;
import org.apache.reef.wake.Identifier;
import org.apache.reef.wake.IdentifierFactory;

import java.net.Inet4Address;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

/**
 * Utility class for REEF IO network module.
 */
public final class Utils {

    private static final String DELIMITER = "-";

    /**
     * Parse a string of multiple IDs.
     *
     * @param ids A string containing multiple IDs
     * @param factory An Identifier factory
     * @param <T> A type
     * @return A list of identifier
     */
    public static <T extends Identifier> List<T> parseList(final String ids, final IdentifierFactory factory) {
        final List<T> result = new ArrayList<>();
        for (final String token : ids.split(DELIMITER)) {
            result.add((T) factory.getNewInstance(token.trim()));
        }
        return result;
    }

    public static String listToString(final List<ComparableIdentifier> ids) {
        return StringUtils.join(ids, DELIMITER);
    }

    public static List<Integer> createUniformCounts(final int elemSize, final int childSize) {
        final int remainder = elemSize % childSize;
        final int quotient = elemSize / childSize;
        final ArrayList<Integer> result = new ArrayList<>(childSize);
        result.addAll(Collections.nCopies(remainder, quotient + 1));
        result.addAll(Collections.nCopies(childSize - remainder, quotient));
        return Collections.unmodifiableList(result);
    }

    private static class AddressComparator implements Comparator<Inet4Address> {
        @Override
        public int compare(final Inet4Address aa, final Inet4Address ba) {
            final byte[] a = aa.getAddress();
            final byte[] b = ba.getAddress();
            // local subnet comes after all else.
            if (a[0] == 127 && b[0] != 127) {
                return 1;
            }
            if (a[0] != 127 && b[0] == 127) {
                return -1;
            }
            for (int i = 0; i < 4; i++) {
                if (a[i] < b[i]) {
                    return -1;
                }
                if (a[i] > b[i]) {
                    return 1;
                }
            }
            return 0;
        }
    }

    public static ReefNetworkGroupCommProtos.GroupCommMessage bldGCM(
            final ReefNetworkGroupCommProtos.GroupCommMessage.Type msgType, final Identifier from,
            final Identifier to, final byte[]... elements) {

        final ReefNetworkGroupCommProtos.GroupCommMessage.Builder gcmBuilder = ReefNetworkGroupCommProtos.GroupCommMessage
                .newBuilder().setType(msgType).setSrcid(from.toString()).setDestid(to.toString());

        final ReefNetworkGroupCommProtos.GroupMessageBody.Builder bodyBuilder = ReefNetworkGroupCommProtos.GroupMessageBody
                .newBuilder();

        for (final byte[] element : elements) {
            bodyBuilder.setData(ByteString.copyFrom(element));
            gcmBuilder.addMsgs(bodyBuilder.build());
        }

        return gcmBuilder.build();
    }

    /**
     * Empty private constructor to prohibit instantiation of utility class.
     */
    private Utils() {
    }
}