org.apache.giraph.hive.common.HiveParsing.java Source code

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Here is the source code for org.apache.giraph.hive.common.HiveParsing.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.giraph.hive.common;

import org.apache.giraph.edge.Edge;
import org.apache.giraph.edge.EdgeFactory;
import org.apache.hadoop.io.DoubleWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;

import com.facebook.hiveio.record.HiveReadableRecord;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;

import java.util.List;
import java.util.Map;

/**
 * Helpers for parsing with Hive.
 */
public class HiveParsing {
    /** Don't construct */
    private HiveParsing() {
    }

    /**
     * Parse a byte from a Hive record
     * @param record Hive record to parse
     * @param columnIndex offset of column in row
     * @return byte
     */
    public static byte parseByte(HiveReadableRecord record, int columnIndex) {
        return record.getByte(columnIndex);
    }

    /**
     * Parse a int from a Hive record
     * @param record Hive record to parse
     * @param columnIndex offset of column in row
     * @return int
     */
    public static int parseInt(HiveReadableRecord record, int columnIndex) {
        return record.getInt(columnIndex);
    }

    /**
     * Parse a Integer ID from a Hive record
     * @param record Hive record to parse
     * @param columnIndex offset of column in row
     * @param reusableId Reusable vertex id object
     * @return IntWritable ID
     */
    public static IntWritable parseIntID(HiveReadableRecord record, int columnIndex, IntWritable reusableId) {
        reusableId.set(parseInt(record, columnIndex));
        return reusableId;
    }

    /**
     * Parse a Long ID from a Hive record
     * @param record Hive record to parse
     * @param columnIndex offset of column in row
     * @param reusableId Reusable vertex id object
     * @return LongWritable ID
     */
    public static LongWritable parseLongID(HiveReadableRecord record, int columnIndex, LongWritable reusableId) {
        reusableId.set(record.getLong(columnIndex));
        return reusableId;
    }

    /**
     * Parse a weight from a Hive record
     * @param record Hive record to parse
     * @param columnIndex offset of column in row
     * @param reusableDoubleWritable Reusable DoubleWritable object
     *
     * @return DoubleWritable weight
     */
    public static DoubleWritable parseDoubleWritable(HiveReadableRecord record, int columnIndex,
            DoubleWritable reusableDoubleWritable) {
        reusableDoubleWritable.set(record.getDouble(columnIndex));
        return reusableDoubleWritable;
    }

    /**
     * Parse edges as mappings of integer => double (id to weight)
     * @param record Hive record to parse
     * @param columnIndex offset of column in row
     * @return edges
     */
    @SuppressWarnings("unchecked")
    public static Iterable<Edge<IntWritable, DoubleWritable>> parseIntDoubleEdges(HiveReadableRecord record,
            int columnIndex) {
        Object edgesObj = record.get(columnIndex);
        if (edgesObj == null) {
            return ImmutableList.of();
        }
        Map<Long, Double> readEdges = (Map<Long, Double>) edgesObj;
        List<Edge<IntWritable, DoubleWritable>> edges = Lists.newArrayListWithCapacity(readEdges.size());
        for (Map.Entry<Long, Double> entry : readEdges.entrySet()) {
            edges.add(EdgeFactory.create(new IntWritable(entry.getKey().intValue()),
                    new DoubleWritable(entry.getValue())));
        }
        return edges;
    }

    /**
     * Parse edges from a list
     * @param record hive record
     * @param index column index
     * @return iterable of edges
     */
    public static Iterable<Edge<IntWritable, NullWritable>> parseIntNullEdges(HiveReadableRecord record,
            int index) {
        List<Long> ids = (List<Long>) record.get(index);
        if (ids == null) {
            return ImmutableList.of();
        }
        ImmutableList.Builder<Edge<IntWritable, NullWritable>> builder = ImmutableList.builder();
        for (long id : ids) {
            builder.add(EdgeFactory.create(new IntWritable((int) id)));
        }
        return builder.build();
    }

    /**
     * Parse edges as mappings of long => double (id to weight)
     * @param record Hive record to parse
     * @param columnIndex offset of column in row
     * @return edges
     */
    @SuppressWarnings("unchecked")
    public static Iterable<Edge<LongWritable, DoubleWritable>> parseLongDoubleEdges(HiveReadableRecord record,
            int columnIndex) {
        Object edgesObj = record.get(columnIndex);
        if (edgesObj == null) {
            return ImmutableList.of();
        }
        Map<Long, Double> readEdges = (Map<Long, Double>) edgesObj;
        List<Edge<LongWritable, DoubleWritable>> edges = Lists.newArrayListWithCapacity(readEdges.size());
        for (Map.Entry<Long, Double> entry : readEdges.entrySet()) {
            edges.add(EdgeFactory.create(new LongWritable(entry.getKey()), new DoubleWritable(entry.getValue())));
        }
        return edges;
    }
}