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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.giraph.aggregators.matrix.sparse;
20  
21  import org.apache.giraph.aggregators.AggregatorUsage;
22  import org.apache.giraph.aggregators.matrix.MatrixSumAggregator;
23  import org.apache.giraph.master.MasterAggregatorUsage;
24  import org.apache.giraph.worker.WorkerAggregatorUsage;
25  
26  /**
27   * The double matrix aggregator is used to register and aggregate double
28   * matrices.
29   */
30  public class DoubleSparseMatrixSumAggregator extends MatrixSumAggregator {
31    /** sparse vector with single entry */
32    private DoubleSparseVector singletonVector = new DoubleSparseVector();
33  
34    /**
35     * Create a new matrix aggregator with the given prefix name for the vector
36     * aggregators.
37     *
38     * @param name the prefix for the row vector aggregators
39     */
40    public DoubleSparseMatrixSumAggregator(String name) {
41      super(name);
42    }
43  
44    /**
45     * Register the double vector aggregators, one for each row of the matrix.
46     *
47     * @param numRows the number of rows
48     * @param master the master to register the aggregators
49     */
50    public void register(int numRows, MasterAggregatorUsage master)
51      throws InstantiationException, IllegalAccessException {
52      for (int i = 0; i < numRows; ++i) {
53        master.registerAggregator(getRowAggregatorName(i),
54            DoubleSparseVectorSumAggregator.class);
55      }
56    }
57  
58    /**
59     * Add the given value to the entry specified.
60     *
61     * @param i the row
62     * @param j the column
63     * @param v the value
64     * @param worker the worker to aggregate
65     */
66    public void aggregate(int i, int j, double v, WorkerAggregatorUsage worker) {
67      singletonVector.clear();
68      singletonVector.set(j, v);
69      worker.aggregate(getRowAggregatorName(i), singletonVector);
70    }
71  
72    /**
73     * Set the values of the matrix to the master specified. This is typically
74     * used in the master, to build an external DoubleMatrix and only set it at
75     * the end.
76     *
77     * @param matrix the matrix to set the values
78     * @param master the master
79     */
80    public void setMatrix(DoubleSparseMatrix matrix,
81        MasterAggregatorUsage master) {
82      int numRows = matrix.getNumRows();
83      for (int i = 0; i < numRows; ++i) {
84        master.setAggregatedValue(getRowAggregatorName(i), matrix.getRow(i));
85      }
86    }
87  
88    /**
89     * Read the aggregated values of the matrix.
90     *
91     * @param numRows the number of rows
92     * @param aggUser the master or worker
93     * @return the double matrix
94     */
95    public DoubleSparseMatrix getMatrix(int numRows, AggregatorUsage aggUser) {
96      DoubleSparseMatrix matrix = new DoubleSparseMatrix(numRows);
97      for (int i = 0; i < numRows; ++i) {
98        DoubleSparseVector vec = aggUser.getAggregatedValue(
99            getRowAggregatorName(i));
100       matrix.setRow(i, vec);
101     }
102     return matrix;
103   }
104 }