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.IX Title "HTML::Mason::Cache::BaseCache 3pm"
.TH HTML::Mason::Cache::BaseCache 3pm 2024-03-05 "perl v5.38.2" "User Contributed Perl Documentation"
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.nh
.SH NAME
HTML::Mason::Cache::BaseCache \- Base cache object
.SH DESCRIPTION
.IX Header "DESCRIPTION"
This is the base module for all cache implementations used in Mason.
It provides a few additional methods on top of \f(CW\*(C`Cache::BaseCache\*(C'\fR in
Dewitt Clinton's \f(CW\*(C`Cache::Cache\*(C'\fR package.
.PP
An object of this class is returned from \f(CW$m\fR\->cache.
.SH METHODS
.IX Header "METHODS"
.IP "clear ()" 4
.IX Item "clear ()"
Remove all values in the cache.
.IP "get (key, [%params])" 4
.IX Item "get (key, [%params])"
Returns the value associated with \fIkey\fR or undef if it is
non-existent or expired. This is extended with the following optional
name/value parameters:
.RS 4
.IP "busy_lock => duration" 4
.IX Item "busy_lock => duration"
If the value has expired, set its expiration time to the current time plus
\&\fIduration\fR (instead of removing it from the cache) before returning undef.
This is used to prevent multiple processes from recomputing the same
expensive value simultaneously. The \fIduration\fR may be of any form acceptable
to set.
.IP "expire_if => sub" 4
.IX Item "expire_if => sub"
If the value exists and has not expired, call \fIsub\fR with the cache
object as a single parameter. If \fIsub\fR returns a true value, expire
the value.
.RE
.RS 4
.RE
.IP "get_object (key)" 4
.IX Item "get_object (key)"
Returns the underlying \f(CW\*(C`Cache::Object\*(C'\fR object associated with \fIkey\fR.
The most useful methods on this object are
.Sp
.Vb 3
\&    $co\->get_created_at();    # when was object stored in cache
\&    $co\->get_accessed_at();   # when was object last accessed
\&    $co\->get_expires_at();    # when does object expire
.Ve
.IP "expire (key)" 4
.IX Item "expire (key)"
Expires the value associated with \fIkey\fR, if it exists. Differs from
remove only in that
the cache object is left around, e.g. for retrieval by
get_object.
.IP "remove (key)" 4
.IX Item "remove (key)"
Removes the cache object associated with \fIkey\fR, if it exists.
.IP "set (key, data, [duration])" 4
.IX Item "set (key, data, [duration])"
Associates \fIdata\fR with \fIkey\fR in the cache. \fIduration\fR
indicates the time until the value should be erased.  If
\&\fIduration\fR is unspecified, the value will never expire
by time.
.Sp
\&\fR\f(CI$expires_in\fR\fI\fR may be a simple number of seconds, or a string of the
form "[number] [unit]", e.g., "10 minutes".  The valid units are s,
second, seconds, sec, m, minute, minutes, min, h, hour, hours, d, day,
days, w, week, weeks, M, month, months, y, year, and years.