org.apache.sysml.runtime.instructions.spark.functions.ReplicateBlockFunction.java Source code

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Here is the source code for org.apache.sysml.runtime.instructions.spark.functions.ReplicateBlockFunction.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.sysml.runtime.instructions.spark.functions;

import java.util.ArrayList;
import java.util.Iterator;

import org.apache.spark.api.java.function.PairFlatMapFunction;
import org.apache.sysml.runtime.matrix.data.MatrixBlock;
import org.apache.sysml.runtime.matrix.data.MatrixIndexes;

import scala.Tuple2;

public class ReplicateBlockFunction
        implements PairFlatMapFunction<Tuple2<MatrixIndexes, MatrixBlock>, MatrixIndexes, MatrixBlock> {
    private static final long serialVersionUID = -1184696764516975609L;

    private final long _len;
    private final long _blen;
    private final boolean _left;
    private final boolean _deep;

    public ReplicateBlockFunction(long len, long blen, boolean left) {
        //by default: shallow copy of blocks
        this(len, blen, left, false);
    }

    public ReplicateBlockFunction(long len, long blen, boolean left, boolean deep) {
        _len = len;
        _blen = blen;
        _left = left;
        _deep = deep;
    }

    @Override
    public Iterator<Tuple2<MatrixIndexes, MatrixBlock>> call(Tuple2<MatrixIndexes, MatrixBlock> arg0)
            throws Exception {
        ArrayList<Tuple2<MatrixIndexes, MatrixBlock>> ret = new ArrayList<>();
        MatrixIndexes ixIn = arg0._1();
        MatrixBlock blkIn = arg0._2();

        long numBlocks = (long) Math.ceil((double) _len / _blen);

        if (_left) //LHS MATRIX
        {
            //replicate wrt # column blocks in RHS
            long i = ixIn.getRowIndex();
            for (long j = 1; j <= numBlocks; j++) {
                MatrixIndexes tmpix = new MatrixIndexes(i, j);
                MatrixBlock tmpblk = _deep ? new MatrixBlock(blkIn) : blkIn;
                ret.add(new Tuple2<>(tmpix, tmpblk));
            }
        } else // RHS MATRIX
        {
            //replicate wrt # row blocks in LHS
            long j = ixIn.getColumnIndex();
            for (long i = 1; i <= numBlocks; i++) {
                MatrixIndexes tmpix = new MatrixIndexes(i, j);
                MatrixBlock tmpblk = _deep ? new MatrixBlock(blkIn) : blkIn;
                ret.add(new Tuple2<>(tmpix, tmpblk));
            }
        }

        //output list of new tuples
        return ret.iterator();
    }
}