[GIRAPH-137] De-duplicate pagerank implementation in PageRankBenchmark

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.0.0
• Labels: newbie
• Assignee: Harsh J
• Reporter: Jakob Homan
• Created: 31/Jan/12 21:25
• Updated: 03/Feb/12 20:06
• Resolved: 03/Feb/12 19:50

Description

Currently in PageRankBenchmark we have the code for pagerank duplicated in each of the implementations of Vertex:

    public static class PageRankHashMapVertex extends HashMapVertex<
            LongWritable, DoubleWritable, DoubleWritable, DoubleWritable> {
        @Override
        public void compute(Iterator<DoubleWritable> msgIterator) {
            if (getSuperstep() >= 1) {
                double sum = 0;
                while (msgIterator.hasNext()) {
                    sum += msgIterator.next().get();
                }
                DoubleWritable vertexValue =
                    new DoubleWritable((0.15f / getNumVertices()) + 0.85f *
                                       sum);
                setVertexValue(vertexValue);
            }

            if (getSuperstep() < getConf().getInt(SUPERSTEP_COUNT, -1)) {
                long edges = getNumOutEdges();
                sendMsgToAllEdges(
                    new DoubleWritable(getVertexValue().get() / edges));
            } else {
                voteToHalt();
            }
        }
    }

    public static class PageRankEdgeListVertex extends EdgeListVertex<
            LongWritable, DoubleWritable, DoubleWritable, DoubleWritable> {
        @Override
        public void compute(Iterator<DoubleWritable> msgIterator) {
            if (getSuperstep() >= 1) {
                double sum = 0;
                while (msgIterator.hasNext()) {
                    sum += msgIterator.next().get();
                }
                DoubleWritable vertexValue =
                    new DoubleWritable((0.15f / getNumVertices()) + 0.85f *
                                       sum);
                setVertexValue(vertexValue);
            }

            if (getSuperstep() < getConf().getInt(SUPERSTEP_COUNT, -1)) {
                long edges = getNumOutEdges();
                sendMsgToAllEdges(
                        new DoubleWritable(getVertexValue().get() / edges));
            } else {
                voteToHalt();
            }
        }
    }

This code can be consolidated into private class and the two implementations just extend that.