Arecibo LZF

gistfile1.java

/*
 * Copyright 2010-2012 Ning, Inc.
 *
 * Ning 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 com.ning.arecibo.util.timeline;

import com.ning.compress.lzf.LZFEncoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.Random;

public class LZFCompressor
{
    private static final Logger log = LoggerFactory.getLogger(LZFCompressor.class);

    public static void main(final String[] args) throws IOException
    {
        final int hostId = 123;
        final int sampleKindId = 456;
        final int timelineTimesId = 789;
        final TimelineChunkAccumulator accumulator = new TimelineChunkAccumulator(hostId, sampleKindId);
        final Random randomGenerator = new Random();

        // 1 day timeline with 2 samples per minute
        for (int i = 0; i < 2880; i++) {
            // sin test with 10% noise: Original payload: 25920 bytes, compressed payload: 16781 bytes (64.74%)
            final Double value = Math.sin(i * 1.0 / 4 * Math.PI) * (100 - randomGenerator.nextInt(10)) / 100;
            // constant test: Original payload: 253 bytes, compressed payload: 26 bytes (10.3%)
            //final Double value = 10.0;
            // constant test with 10% noise: Original payload: 23868 bytes, compressed payload: 9859 byes (41.4%)
            //final Double value = 10.0 * (100 - randomGenerator.nextInt(10))/100;
            accumulator.addSample(new ScalarSample<Double>(SampleOpcode.DOUBLE, value));
        }

        final TimelineChunk chunk = accumulator.extractTimelineChunkAndReset(timelineTimesId);
        final byte[] bytes = chunk.getSamples();
        final byte[] compressedBytes = LZFEncoder.encode(bytes);

        log.info("Original payload: {} bytes, compressed payload: {} bytes ({}%)",
            new Object[]{bytes.length, compressedBytes.length, 100.0 * compressedBytes.length / bytes.length});
    }
}