gobblin.source.workunit.ExtractFactory.java Source code

Introduction

Here is the source code for gobblin.source.workunit.ExtractFactory.java

Source

/*
 * 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.source.workunit;

import java.util.Locale;
import java.util.Set;

import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

import com.google.common.base.Strings;
import com.google.common.collect.Sets;

import gobblin.source.workunit.Extract.TableType;

public class ExtractFactory {
    private final Set<Extract> createdInstances;
    private final DateTimeFormatter dtf;

    public ExtractFactory(String dateTimeFormat) {
        this.createdInstances = Sets.newHashSet();
        this.dtf = DateTimeFormat.forPattern(dateTimeFormat).withLocale(Locale.US).withZone(DateTimeZone.UTC);
    }

    /**
     * Returns a unique {@link Extract} instance.
     * Any two calls of this method from the same {@link ExtractFactory} instance guarantees to
     * return {@link Extract}s with different IDs.
     *
     * @param type {@link TableType}
     * @param namespace dot separated namespace path
     * @param table table name
     * @return a unique {@link Extract} instance
     */
    public synchronized Extract getUniqueExtract(TableType type, String namespace, String table) {
        Extract newExtract = new Extract(type, namespace, table);
        while (this.createdInstances.contains(newExtract)) {
            if (Strings.isNullOrEmpty(newExtract.getExtractId())) {
                newExtract.setExtractId(this.dtf.print(new DateTime()));
            } else {
                DateTime extractDateTime = this.dtf.parseDateTime(newExtract.getExtractId());
                newExtract.setExtractId(this.dtf.print(extractDateTime.plusSeconds(1)));
            }
        }
        this.createdInstances.add(newExtract);
        return newExtract;
    }
}