Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!news.albasani.net!.POSTED!not-for-mail From: Jan Burse Newsgroups: comp.lang.java.programmer Subject: Re: java8 up to 6x slower than java7 Date: Sun, 16 Feb 2014 14:43:06 +0100 Organization: albasani.net Lines: 20 Message-ID: References: <29a51a94-8f9a-41b1-980f-e8c13e2d11a2@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: news.albasani.net MnB6G2KMSgTyCETJpfSxEDOxUikc3ojPGGrFvBz5jv9BS9MpSxGoJTaedUZoDU4tOC1k0qMW/i2W8aqC7eGoZw== NNTP-Posting-Date: Sun, 16 Feb 2014 13:43:06 +0000 (UTC) Injection-Info: news.albasani.net; logging-data="lWtRQhlGPrFldfStRWVOj7TBGnuinT9czaa53GghtgwTMkFl6uUG1J9V8Fet7yJ65iyoPmW3Nt4HdpOjOfdQDLa7qaaBhLyTwsJpFQXivEJNt/Js6hmKLZ4yv3NrJwa4"; mail-complaints-to="abuse@albasani.net" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0 SeaMonkey/2.24 In-Reply-To: Cancel-Lock: sha1:RtM3QbPBjKvI/YYFCgYYMrkLM44= Xref: csiph.com comp.lang.java.programmer:27526 Jan Burse schrieb: > For the slower use cases I am planing using my custom > HashMap. The custom HashMap has some further advantages > besides sparing the iterator, I also don't do mod > counting. Last but not least, one feature I am constantly missing from HashMap, is that it should grow back in size. HashMap is only growing and growing, and never automatically shrinks. > One trick to develop a custom HashMap is to use the > JDK source code, and create a stripped down variant. > Not sure whether copyright allows this really. So I > didn't mention that here. The shrinking I didn't find in the JDK source code, so this is genuine implementation. I use a lower watermark which is 1/4 and I am shrinking to 1/2. Works pretty well so far.