Chimera Cache Configuration
Chimera can cache documents on the local filesystem to improve
performance under many circumstances.
The file that describes the cache configuration is called the
cacheinfo file. The cache can actually be divided into separate,
individually configured caches. Each cache is described by
a line in the cacheinfo file. Blank lines or lines beginning with
'#' are ignored.
Each cache entry is made up of the following white space (excluding
carriage returns and line feeds) delimited fields:
directory domain size TTL clean
Directory
The directory field is the name of the directory where the cache files
are stored. More than one cache can share the same directory. If
the directory does not exist then the cache entry is ignored.
Domain
The domain field is an Internet domain name. This is used to
determine which documents are put in the cache. An asterick (*) means
that all domains are stored in that cache. The domain is matched
to the domain of the source of the document starting at the end
of the name (huh?). For example,
cs.unlv.edu
and
cleanhead.cs.unlv.edu
match. This is done because the author was too lazy to include the code
to do real regular expressions. Also, it doesn't make sense to match
it any other way.
Size
The size field is used to specify the maximum size of the cache in bytes.
TTL
The TTL field is used to specify the time-to-live value for the documents
in the cache. Documents are reloaded from the original source if they
were written to the cache longer than TTL seconds ago. A manual
reload resets the TTL.
Clean
The clean field is used to specify whether or not chimera should remove
all of the cache files before it exits.
Example cacheinfo File
#
# directory domain size ttl clean
#
/sd1/john/cache1 unlv.edu 500000 14400 1
/sd1/john/cache2 * 10000000 0 0
Default Cache
There is a default cache in case a cache info file is not available.
The X resources cacheTTL, cacheDir, cacheSize, and cacheClean
determine are used to specify the characteristics of the default
cache. By default they are
/tmp * 4000000 14400 1