Exploring whether changes to snappy-java have resulted in worse compression in newer versions

build.sbt

name := "Snappy Benchmark"

version := "1.0"

scalaVersion := "2.10.4"

libraryDependencies += "org.xerial.snappy" % "snappy-java" % sys.env.getOrElse("SNAPPY_VERSION", "1.1.1.6")

SnappyBenchmark.scala

import java.io._

import org.xerial.snappy.SnappyOutputStream


object Main {
  def main(args: Array[String]) {
    val blockSize = sys.env.getOrElse("BLOCK_SIZE", "32768").toInt
    val resetFrequency = sys.env.getOrElse("RESET_FREQUENCY", "100").toInt
    val byteArrayOutputstream = new ByteArrayOutputStream()
    val snappyOutputStream = new SnappyOutputStream(byteArrayOutputstream, blockSize)
    val objectOutputStream = new ObjectOutputStream(snappyOutputStream)
    val objects = 1 to 1000
    var counter = 0
    objects.foreach { obj =>
      objectOutputStream.write(obj)
      counter += 1
      if (counter >= resetFrequency) {
        objectOutputStream.reset()
        counter = 0
      }
    }
    objectOutputStream.close()
    println("SIZE=" + byteArrayOutputstream.toByteArray.size)
  }
}

test.sh

#!/usr/bin/env bash

SNAPPY_VERSIONS=(
    1.1.1.6
    1.1.1.5
    1.1.1.4
    1.1.1.3
    1.1.1.2
    1.1.1.1
    1.1.1
    1.1.1-M4
    1.1.1-M3
    1.1.1-M2
    1.1.1-M1
    1.1.0.1
    1.1.0
    1.1.0-M4
    1.1.0-M3
    1.1.0-M2
    1.1.0-M1
    1.0.5.4
    1.0.5.3
    1.0.5.2
    1.0.5.1
    1.0.5
    1.0.5-M4
    1.0.5-M3
    1.0.5-M2
    1.0.5-M1
    1.0.4.1
    1.0.4
    1.0.3.3
    1.0.3.2
    1.0.3.1
    1.0.3
)

RESET_FREQUENCIES=( "100" )

for SNAPPY_VERSION in ${SNAPPY_VERSIONS[@]}
do
    for RESET_FREQUENCY in ${RESET_FREQUENCIES[@]}
    do
        export SNAPPY_VERSION
        size=$(sbt run | grep 'SIZE' | cut -d'=' -f2)
        echo "$SNAPPY_VERSION    $size"
    done
done