com.continuuity.weave.internal.appmaster.RunnableContainerRequest.java Source code

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Here is the source code for com.continuuity.weave.internal.appmaster.RunnableContainerRequest.java

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/*
 * Copyright 2012-2013 Continuuity,Inc.
 *
 * Licensed 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 com.continuuity.weave.internal.appmaster;

import com.continuuity.weave.api.RuntimeSpecification;
import com.continuuity.weave.api.WeaveSpecification;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterators;
import com.google.common.collect.Maps;
import com.google.common.collect.Multimap;
import org.apache.hadoop.yarn.api.records.Resource;

import java.util.Collection;
import java.util.Iterator;
import java.util.Map;

/**
 * Data structure for holding set of runnable specifications based on resource capability.
 */
final class RunnableContainerRequest {
    private final WeaveSpecification.Order.Type orderType;
    private final Iterator<Map.Entry<Resource, Collection<RuntimeSpecification>>> requests;

    RunnableContainerRequest(WeaveSpecification.Order.Type orderType,
            Multimap<Resource, RuntimeSpecification> requests) {
        this.orderType = orderType;
        this.requests = requests.asMap().entrySet().iterator();
    }

    WeaveSpecification.Order.Type getOrderType() {
        return orderType;
    }

    /**
     * Remove a resource request and return it.
     * @return The {@link Resource} and {@link Collection} of {@link RuntimeSpecification} or
     *         {@code null} if there is no more request.
     */
    Map.Entry<Resource, ? extends Collection<RuntimeSpecification>> takeRequest() {
        Map.Entry<Resource, Collection<RuntimeSpecification>> next = Iterators.getNext(requests, null);
        return next == null ? null : Maps.immutableEntry(next.getKey(), ImmutableList.copyOf(next.getValue()));
    }
}