cloud.strategies.CompositeRemoteConnectionStrategy.java Source code

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Here is the source code for cloud.strategies.CompositeRemoteConnectionStrategy.java

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/*
 * Copyright (c) 2014-2015 University of Ulm
 *
 * See the NOTICE file distributed with this work for additional information
 * regarding copyright ownership.  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 cloud.strategies;

import com.google.common.base.MoreObjects;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;

import de.uniulm.omi.cloudiator.sword.api.remote.RemoteConnection;
import de.uniulm.omi.cloudiator.sword.api.remote.RemoteException;

import java.util.Set;
import java.util.stream.Collectors;

import models.VirtualMachine;
import play.Logger;
import util.logging.Loggers;

/**
 * Created by daniel on 02.09.15.
 */
public class CompositeRemoteConnectionStrategy implements RemoteConnectionStrategy {

    private final static Logger.ALogger LOGGER = Loggers.of(Loggers.CLOUD_REMOTE);

    private final Set<RemoteConnectionStrategy> strategySet;

    private CompositeRemoteConnectionStrategy(Set<RemoteConnectionStrategy> strategySet) {
        if (strategySet.isEmpty()) {
            LOGGER.warn(String.format(
                    "%s is initializing with an empty strategy set. This is likely to cause errors.", this));
        }
        LOGGER.debug(String.format("%s is loading available strategy set. Contains %s strategies.", this,
                strategySet.size()));
        if (Logger.isTraceEnabled()) {
            strategySet.forEach(remoteConnectionStrategy -> Logger
                    .trace(String.format("%s is loading strategy %s", this, remoteConnectionStrategy)));
        }

        // wrap in immutable sorted set to ensure comparability.
        this.strategySet = ImmutableSet.copyOf(Sets.newTreeSet(strategySet));
    }

    @Override
    public RemoteConnection connect(VirtualMachine virtualMachine) throws RemoteException {

        Exception lastException = null;
        for (RemoteConnectionStrategy remoteConnectionStrategy : strategySet) {
            try {
                LOGGER.info(String.format("%s is using strategy %s to connect to virtual machine %s", this,
                        remoteConnectionStrategy, virtualMachine));
                return remoteConnectionStrategy.connect(virtualMachine);
            } catch (Exception e) {
                LOGGER.info(String.format("%s failed connecting to virtual machine %s using strategy %s", this,
                        virtualMachine, remoteConnectionStrategy), e);
                lastException = e;
            }
        }

        throw new RemoteException(
                "Tried all available remote connection strategies, but still could not connect to machine.",
                lastException);
    }

    @Override
    public int getPriority() {
        if (!strategySet.isEmpty()) {
            return strategySet.stream().findFirst().get().getPriority();
        }
        return Priority.MEDIUM;
    }

    public static class RemoteConnectionStrategiesFactory implements RemoteConnectionStrategyFactory {

        private final Set<RemoteConnectionStrategyFactory> remoteConnectionStrategyFactories;

        public RemoteConnectionStrategiesFactory(
                Set<RemoteConnectionStrategyFactory> remoteConnectionStrategyFactories) {
            this.remoteConnectionStrategyFactories = remoteConnectionStrategyFactories;
        }

        @Override
        public RemoteConnectionStrategy create() {
            Set<RemoteConnectionStrategy> strategies = remoteConnectionStrategyFactories.stream()
                    .map(RemoteConnectionStrategyFactory::create).collect(Collectors.toSet());
            return new CompositeRemoteConnectionStrategy(strategies);
        }
    }

    @Override
    public String toString() {
        return MoreObjects.toStringHelper(this).add("strategies", strategySet).toString();
    }
}