org.apache.mahout.cf.taste.hadoop.item.VectorAndPrefsWritable.java Source code

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Here is the source code for org.apache.mahout.cf.taste.hadoop.item.VectorAndPrefsWritable.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.mahout.cf.taste.hadoop.item;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.List;

import com.google.common.collect.Lists;
import org.apache.hadoop.io.Writable;
import org.apache.mahout.math.Varint;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.VectorWritable;

public final class VectorAndPrefsWritable implements Writable {

    private Vector vector;
    private List<Long> userIDs;
    private List<Float> values;

    public VectorAndPrefsWritable() {
    }

    public VectorAndPrefsWritable(Vector vector, List<Long> userIDs, List<Float> values) {
        set(vector, userIDs, values);
    }

    public void set(Vector vector, List<Long> userIDs, List<Float> values) {
        this.vector = vector;
        this.userIDs = userIDs;
        this.values = values;
    }

    public Vector getVector() {
        return vector;
    }

    public List<Long> getUserIDs() {
        return userIDs;
    }

    public List<Float> getValues() {
        return values;
    }

    @Override
    public void write(DataOutput out) throws IOException {
        VectorWritable vw = new VectorWritable(vector);
        vw.setWritesLaxPrecision(true);
        vw.write(out);
        Varint.writeUnsignedVarInt(userIDs.size(), out);
        for (int i = 0; i < userIDs.size(); i++) {
            Varint.writeSignedVarLong(userIDs.get(i), out);
            out.writeFloat(values.get(i));
        }
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        VectorWritable writable = new VectorWritable();
        writable.readFields(in);
        vector = writable.get();
        int size = Varint.readUnsignedVarInt(in);
        userIDs = Lists.newArrayListWithCapacity(size);
        values = Lists.newArrayListWithCapacity(size);
        for (int i = 0; i < size; i++) {
            userIDs.add(Varint.readSignedVarLong(in));
            values.add(in.readFloat());
        }
    }

    @Override
    public String toString() {
        return vector + "\t" + userIDs + '\t' + values;
    }
}