NAME

       Alzabo::Runtime::UniqueRowCache - Implements a row cache for Alzabo

SYNOPSIS

         use Alzabo::Runtime::UniqueRowCache;

         Alzabo::Runtime::UniqueRowCache->clear();

DESCRIPTION

       This is a very simple caching mechanism for "Alzabo::Runtime::Row" objects that tries to ensure that for
       there is never more than one row object in memory for a given database row.

       To use it, simply load it.

       It can be foiled through the use of "Storable" or other "deep magic" cloning code, like in the "Clone"
       module.

       The cache is a simple hash kept in memory.  If you use this module, you are responsible for clearing the
       cache as needed.  The only time it is cleared automatically is when a table update or delete is
       performed, in which case all cached rows for that table are cleared.

       In a persistent environment like mod_perl, you should clear the cache on a regular basis in order to
       prevent the cache from getting out of sync with the database.  A good way to do this is to clear it at
       the start of every request.

METHODS

       All methods provided are class methods.

       •   clear

           This clears the entire cache

       •   clear_table( $table_object )

           Given a table object, this method clears all the cached rows from that table.

       •   row_in_cache( $table_name, $row_id )

           Given a table name and a row id, as returned by the "Alzabo::Runtime::Row->id_as_string" method, this
           method returns the matching row from the cache, if it exists.  Otherwise it returns undef.

       •   delete_from_cache( $table_name, $row_id )

           Given a table name and a row id, as returned by the "Alzabo::Runtime::Row->id_as_string" method, this
           method returns the matching row from the cache.

       •   write_to_cache( $row_object )

           Given a row object, this method stores it in the cache.

AVOIDING THE CACHE

       If you want to not cache a row, then you can pass the "no_cache" parameter to any table or schema method
       that creates a new row object or a cursor, such as "Alzabo::Runtime::Table->insert()",
       "Alzabo::Runtime::Table->rows_where()".

AUTHOR

       Dave Rolsky, <autarch@urth.org>