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<HTML>
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<meta name="GENERATOR" content="Microsoft Internet Assistant for PowerPoint 97">
<TITLE>Example - Simple Cache</TITLE>
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<BODY >
<H1>Example - Simple Cache</H1>
<P><UL>
<LI><H2>nsv and ns_mutex can implement a simple cache:</H2>
</UL></P>
<P><UL>
proc cache.get {key} {
</UL><UL>
set lock [nsv_get cache lock]
</UL><UL>
ns_mutex lock $lock
</UL><UL>
if ![nsv_exists cache value,$key] {
</UL><UL>
nsv_set cache $key [ fetch data for $key ]
</UL><UL>
}
</UL><UL>
set value [nsv_get cache $key]
</UL><UL>
ns_mutex unlock $lock
</UL><UL>
return $value
</UL><UL>
}</UL></P>
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