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Date: Fri, 28 Dec 2007 11:55:08 +0200
From: Diomidis Spinellis <dds@FreeBSD.org>
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To: Garrett Cooper <youshi10@u.washington.edu>
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Cc: hackers@FreeBSD.org
Subject: Re: BSD license compatible hash algorithm?
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Garrett Cooper wrote:
> On Dec 27, 2007, at 4:30 PM, Garrett Cooper wrote:
> 
>> Hi all,
>>     Just wondering if anyone knew of a good BSD license compatible 
>> key-based hash placement / retrieval algorithm that was available 
>> anywhere.
>>     I'm looking for a reliable way to lookup objects to see if a given 
>> action would be performed in my revised pkg_install(1), to thus 
>> efficiently pre-plan out the installation dependencies and fully 
>> utilize multiprocessing capabilities of contemporary machines / 
>> eliminate duplicate dependency install requirements.
>>     I know I can use tree structures or hash(3), but I want to avoid 
>> trees (inefficient with large data sets of course) and I was looking 
>> for a non-BDB based solution (for right now, with this given structure 
>> as I don't want to write everything to disk).

You can pass NULL as a file name to dbopen, and thereby not store the 
results permanently in a file.  BDB will still use a temporary file 
internally, but this will be invisible to your users.

Diomidis Spinellis - http://www.spinellis.gr