data::objectdriver::driver::cache::apache(3pm) [debian man page]
Data::ObjectDriver::Driver::Cache::Apache(3pm) User Contributed Perl Documentation Data::ObjectDriver::Driver::Cache::Apache(3pm) NAME
Data::ObjectDriver::Driver::Cache::Apache - object driver for caching objects in Apache's request space SYNOPSIS
package MyObject; use base qw( Data::ObjectDriver::BaseObject ); __PACKAGE__->install_properties({ ... driver => Data::ObjectDriver::Driver::Cache::Apache->new( fallback => Data::ObjectDriver::Driver::Cache::Memcached->new( cache => Cache::Memcached->new({ servers => @MEMCACHED_SERVERS }), fallback => Data::ObjectDriver::Driver::DBI->new( @$DBI_INFO ), ), ), ... }); 1; DESCRIPTION
Data::ObjectDriver::Driver::Cache::Apache provides automatic caching of retrieved objects in the per-request memory space of your Apache mod_perl processes, when used in conjunction with your actual object driver. It can be used to provide even faster results over memcached when requesting objects that have already been requested during the same request by some other part of your application, at the cost of the memory necessary to store the objects. If your models can be used in an Apache mod_perl application as well as another context such as a command line shell, consider replacing the Apache layer of your caching with a "Data::ObjectDriver::Driver::Cache::RAM" layer when Apache is not available. See Data::ObjectDriver::Driver::Cache::Apache. USAGE
o Data::ObjectDriver::Driver::Cache::Apache->new(%params) Required members of %params are: o "fallback" The "Data::ObjectDriver" object driver from which to request objects that are not found in the Apache process cache. DIAGNOSTICS
The Apache driver provides integration with the "Data::ObjectDriver" debug and profiling systems. As these systems are designed around SQL queries, synthetic queries are logged to represent caching operations. The operations generated by this driver are: o "APACHECACHE_GET ?" Retrieve an object. The argument is the cache key for the requested object. o "APACHECACHE_ADD ?,?" Add an object to the cache. The arguments are the cache key for the object and the flattened representation of the object to cache. o "APACHECACHE_SET ?,?" Put an object in the cache. The arguments are the cache key for the object and the flattened representation of the object to cache. o "APACHECACHE_DELETE ?" Remove an object from the cache. The argument is the cache key for the object to invalidate. SEE ALSO
Apache, Apache2::RequestUtil LICENSE
Data::ObjectDriver is free software; you may redistribute it and/or modify it under the same terms as Perl itself. AUTHOR &; COPYRIGHT Except where otherwise noted, Data::ObjectDriver is Copyright 2005-2006 Six Apart, cpan@sixapart.com. All rights reserved. perl v5.12.4 2011-08-29 Data::ObjectDriver::Driver::Cache::Apache(3pm)
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Data::ObjectDriver::ResultSet(3pm) User Contributed Perl Documentation Data::ObjectDriver::ResultSet(3pm) NAME
Data::ObjectDriver::ResultSet - Manage a DB query SYNOPSIS
# Get a resultset object for Object::Widget, which inherits from # Data::ObjectDriver::BaseObject my $result = Object::Widget->result($terms, $args); $result->add_term({color => 'blue'}); $result->add_limit(10); $result->add_offset(100); while (not $result->is_empty) { my $widget = $result->next; # Do stuff with $widget } DESCRIPTION
This object is returned by the 'result' method found in the Data::ObjectDriver::BaseObject class. This object manages a query and the resulting data. It allows additional search terms and arguments to be added and will not submit the query until a method that returns data is called. By passing this object around code in multiple places can alter the query easily until the data is needed. Once a method returning data is called (next, count, etc) the query is submitted to the database and the returned data is managed by the ResultSet object like an iterator. METHODS
$result_set = $class->result($terms, $args) This method is actually defined in Data::ObjectDriver::BaseObject but it is the way a new ResultSet object is created. Arguments: $terms - A hashref. Same format as the first argument to Data::ObjectDriver::DBI::search $args - A hashref. Same format as the second argument to Data::ObjectDriver::DBI::search Return value: This method returns a Data::ObjectDriver::ResultSet object $new_result = Data::ObjectDriver::ResultSet->iterator(@data) Create a new result set object that takes existing data and operates only as an iterator, without any of the query managment. Arguments: $data - An array ref of data elements Return value: A Data::ObjectDriver::ResultSet object add_constraint Apply a constraint to the result. The format of the two arguments is the same as for Data::ObjectDriver::DBI::search Arguments: $terms - A hashref of object fields and values constraining them. Same as first parameter to result method. $args - A hashref of values that affect the returned data, such as limit and sort by. Same as first parameter to result method. ; Return value : Returns 1 if successful and 0 otherwise ; Notes : Do we fail if called after we've retrieved the result set? Ignore it? Requery? ; Example $res->add_constraint({object_id => $id}, {limit => 100}) add_term Apply a single search term to the result. Equivalent to: $res->add_constraint($terms) Arguments: $terms - A hashref of object fields and values constraining them ; Return value : Returns 1 if successful and 0 otherwise ; Notes : Same question as for add_constraint ; Example $res->add_term({object_id => $id}) clear_term Clear a single search term from the result. Arguments: @terms - An array of term names to clear ; Return value : Returns 1 if successful and 0 otherwise ; Notes : none ; Example $res->clear_term(qw(limit offset)) add_limit Apply a limit to the result. Equivalent to: $res->add_constraint({}, {limit => $limit}) Arguments: $limit - A scalar numeric value giving the limit of the number of objects returned ; Return value : Returns 1 if successful and 0 otherwise ; Notes : ; Example $res->add_limit(100) clear_limit Clear any limit value in the result. Arguments: none ; Return value : Returns 1 if successful and 0 otherwise ; Notes : None ; Example $res->clear_limit add_offset Add an offset for the results returned. Result set must also have a limit set at some point. Arguments: $offset - A scalar numeric value giving the offset for the first object returned ; Return value : Returns 1 if successful and 0 otherwise ; Notes : none ; Example $res->add_offset(5_000) clear_offset Clear any offset value in the result. Arguments: none ; Return value : Returns 1 if successful and 0 otherwise ; Notes : ; Example $res->clear_offset add_order Add a sort order for the results returned. Arguments: [0] = $order = - A scalar string value giving the sort order for the results, one of ascend or descend ; Return value : Returns 1 if successful and 0 otherwise ; Notes : >none'' ; Example $res->add_order('ascend') clear_order Clear any offset value in the result. Arguments: none ; Return value : Returns 1 if successful and 0 otherwise ; Notes : none ; Example $res->clear_order index Return the current index into the result set. Arguments: none ; Return value : An integer giving the zero based index of the current element in the result set. ; Notes : none ; Example $idx = $res->index; next Retrieve the next item in the resultset Arguments: none ; Return value : The next object or undef if past the end of the result set ; Notes : Calling this method will force a DB query. All subsequent calls to curr will return this object ; Example $obj = $res->next; peek_next Retrieve the next item in the resultset WITHOUT advancing the cursor. Arguments: none ; Return value : The next object or undef if past the end of the result set ; Notes : Calling this method will force a DB query. All subsequent calls to curr will return this object ; Example while ($bottle = $res->next){ if ($bottle->type eq 'Bud Light' && $res->peek_next->type eq 'Chimay'){ $bottle->pass; #don't spoil my palate }else{ $bottle->drink; } } prev Retrieve the previous item in the result set Arguments: none ; Return value : The previous object or undef if before the beginning of the result set ; Notes : All subsequent calls to curr will return this object ; Example $obj = $res->prev; curr Retrieve the current item in the result set. This item is set by calls to next and prev Arguments: none ; Return value : The current object or undef if past the boundaries of the result set ; Notes : none ; Example $obj = $res->curr slice Return a slice of the result set. This is logically equivalent to setting a limit and offset and then retrieving all the objects via -next>. If you call slice and then call next, you will get undef and additionally is_empty will be true. Arguments: $from - Scalar integer giving the start of the slice range $to - Scalar integer giving the end of the slice range ; Return value : An array of objects ; Notes : Objects are index from 0 just like perl arrays. ; Example my @objs = $res->slice(0, 20) count Get the count of the items in the result set. Arguments: none ; Return value : A scalar count of the number of items in the result set ; Notes : This will cause a count() query on the database if the result set hasn't been retrieved yet. If the result set has been retrieved it will just return the number of objects stored in the result set object. ; Example $num = $res->count is_finished Returns whether we've arrived at the end of the result set Arguments: none ; Return value : Returns 1 if we are finished iterating though the result set and 0 otherwise ; Notes : none ; Example while (not $res->is_finished) { my $obj = $res->next; # Stuff ... } dod_debug Set this and you'll see $Data::ObjectDriver::DEBUG output when I go to get the results. rewind Move back to the start of the iterator for this instance of results of a query. first Returns the first object in the result set. Arguments: none ; Return value : The first object in the result set ; Notes : Resets the current cursor so that calls to curr return this value. ; Example $obj = $res->first last Returns the last object in the result set. Arguments: none ; Return value : The last object in the result set ; Notes : Resets the current cursor so that calls to curr return this value. ; Example $obj = $res->last is_last Returns 1 if the cursor is on the last row of the result set, 0 if it is not. Arguments: none ; Return value : Returns 1 if the cursor is on the last row of the result set, 0 if it is not. ; Example if ( $res->is_last ) { ## do some stuff } perl v5.12.4 2011-08-29 Data::ObjectDriver::ResultSet(3pm)