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From: Benjamin Manes <ben.manes@gmail.com>
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Subject: Re: Non-blocking DataRowStore - need help to test
Date: Thu, 23 Feb 2012 13:05:05 -0800
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Hi,
I'm the author of CLHM, brought to you by a friendly Google alert. :)

If Cayenne is currently using Guava, then there won't be a dependency =
increase. I helped rearchitect MapMaker and design its replacement, =
CacheBuilder, which are based on CLHM's algorithms. This is a more =
feature-rich implementation with the support of a team at Google =
(whereas CLHM is my weekend project). We also fixed my mistake of only =
weighing by value, since I hadn't realized how popular memory-based =
weighing would be (I was trying to avoid unbounded collections as =
values).

Technically CLHM provides more concurrency than CacheBuilder by not =
relying on segment locks and later using a lock-free ring buffer. These =
will be an advantage when it is backed by JDK8's new CHM (see =
ConcurrentHashMapV8) or Cliff Click's NBHM. A JSR-166 implementation =
will be a marriage of CHMv8, CLHM, and CacheBuilder.

CLHM is back-ported to JDK5 on every release, so you'll find the JDK5 =
source under /tags. I do development on /trunk assuming JDK6.

Feel free to file issues against CLHM (or Guava) if you'd like =
enhancements to either. Both are used in large production environments.

Cheers,
Ben=

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