gobblin.data.management.policy.SelectBetweenTimeBasedPolicy.java Source code

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Here is the source code for gobblin.data.management.policy.SelectBetweenTimeBasedPolicy.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 gobblin.data.management.policy;

import java.util.Collection;
import java.util.List;

import lombok.ToString;

import org.joda.time.DateTime;
import org.joda.time.Period;
import org.joda.time.format.PeriodFormatter;
import org.joda.time.format.PeriodFormatterBuilder;

import com.google.common.base.Optional;
import com.google.common.base.Predicate;
import com.google.common.collect.Collections2;
import com.google.common.collect.Lists;
import com.typesafe.config.Config;

import gobblin.annotation.Alias;
import gobblin.data.management.version.FileSystemDatasetVersion;
import gobblin.data.management.version.TimestampedDatasetVersion;

/**
 * Policy used to select versions in a time range. It selects {@link TimestampedDatasetVersion}s that are not older than
 * <code>maxLookBackPeriod</code> and not newer than <code>minLookBackPeriod</code>.
 * <ul>
 * <li> If minLookbackTime is absent, the current time is used as min lookback
 * <li> If maxLookbackTime is absent, an infinite time is used for max lookback
 * </ul>
 *
 */
@Alias("SelectBetweenTimeBasedPolicy")
@ToString
public class SelectBetweenTimeBasedPolicy implements VersionSelectionPolicy<TimestampedDatasetVersion> {

    protected final Optional<Period> minLookBackPeriod;
    protected final Optional<Period> maxLookBackPeriod;

    /**
     * Optional max lookback time. Versions older than this will not be selected
     */
    public static final String TIME_BASED_SELECTION_MAX_LOOK_BACK_TIME_KEY = "selection.timeBased.maxLookbackTime";

    /**
     * Optional min lookback time. Versions newer than this will not be selected
     */
    public static final String TIME_BASED_SELECTION_MIN_LOOK_BACK_TIME_KEY = "selection.timeBased.minLookbackTime";

    public SelectBetweenTimeBasedPolicy(Config conf) {

        this(conf.hasPath(TIME_BASED_SELECTION_MIN_LOOK_BACK_TIME_KEY)
                ? Optional.of(getLookBackPeriod(conf.getString(TIME_BASED_SELECTION_MIN_LOOK_BACK_TIME_KEY)))
                : Optional.<Period>absent(),
                conf.hasPath(TIME_BASED_SELECTION_MAX_LOOK_BACK_TIME_KEY)
                        ? Optional
                                .of(getLookBackPeriod(conf.getString(TIME_BASED_SELECTION_MAX_LOOK_BACK_TIME_KEY)))
                        : Optional.<Period>absent());

    }

    public SelectBetweenTimeBasedPolicy(Optional<Period> minLookBackPeriod, Optional<Period> maxLookBackPeriod) {

        this.minLookBackPeriod = minLookBackPeriod;
        this.maxLookBackPeriod = maxLookBackPeriod;
    }

    @Override
    public Class<? extends FileSystemDatasetVersion> versionClass() {
        return TimestampedDatasetVersion.class;
    }

    @Override
    public Collection<TimestampedDatasetVersion> listSelectedVersions(List<TimestampedDatasetVersion> allVersions) {
        return Lists.newArrayList(Collections2.filter(allVersions, getSelectionPredicate()));
    }

    private Predicate<TimestampedDatasetVersion> getSelectionPredicate() {
        return new Predicate<TimestampedDatasetVersion>() {
            @Override
            public boolean apply(TimestampedDatasetVersion version) {
                return version.getDateTime()
                        .plus(SelectBetweenTimeBasedPolicy.this.maxLookBackPeriod
                                .or(new Period(DateTime.now().getMillis())))
                        .isAfterNow()
                        && version.getDateTime()
                                .plus(SelectBetweenTimeBasedPolicy.this.minLookBackPeriod.or(new Period(0)))
                                .isBeforeNow();
            }
        };
    }

    protected static Period getLookBackPeriod(String lookbackTime) {
        PeriodFormatter periodFormatter = new PeriodFormatterBuilder().appendYears().appendSuffix("y")
                .appendMonths().appendSuffix("M").appendDays().appendSuffix("d").appendHours().appendSuffix("h")
                .appendMinutes().appendSuffix("m").toFormatter();
        return periodFormatter.parsePeriod(lookbackTime);
    }
}