Maksim Volkau dadhi

People

I was curious about the results reported here, which reports that Scala's mutable maps are slower than Java's: http://www.infoq.com/news/2011/11/yammer-scala

In my tests, Scala's OpenHashMap equals or beats java's HashMap:

Insertion 100k elements (String keys) time in ms:

	using System;

	namespace PureIO {
	/*
	C# does not have proper sum types. They must be emulated.

	This data type is one of 4 possible values:
	- WriteOut, being a pair of a string and A
	- WriteErr, being a pair of a string and A
	- readLine, being a function from string to A

	@ECHO OFF
	SETLOCAL
	SET VERSION=%1
	SET NUGET=buildsupport\nuget.exe

	FOR %%G IN (packaging\nuget\*.nuspec) DO (
	%NUGET% pack %%G -Version %VERSION% -Symbols -o artifacts
	)

	// http://clojure.com/blog/2012/05/08/reducers-a-library-and-model-for-collection-processing.html
	// original by Nick Palladinos: http://fssnip.net/ip

	#r "FSharp.PowerPack.Parallel.Seq.dll"

	module Reducer =
	open System
	open System.Text
	open System.Collections.Generic
	open System.Linq

	using System;
	using System.Collections;
	using System.Collections.Generic;

	/*
	A basic lens library for the purpose of demonstration.
	Implements a lens as the costate comonad coalgebra.

	This library is not complete.
	A more complete lens library would take from

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD