root/trunk/midgard/core/midgard/README.quota

Copyright (C) 2003 David Schmitter, Dataflow Solutions GmbH <schmitt@dataflow.ch>

Quotas
******

Overview
--------
With Midgard Quotas, you can define per-sitegroup restrictions on 
a) the number of records for each table 
b) the maximum content size in each table, where you can define which fields count as content
c) the maximum size for attachments.
d) the maximum content size for all objects of a sitegroup.
If you try to create / update a record, and the quota for the table is reached, error MGD_ERR_QUOTA ("Quota reached") is triggered.
The same happens if you open an attachment and the maximum attachment size is reached.

Installation
------------
./configure --with-quota
Create the quota table using quota.sql in /data 

Configuration
-------------
New apache configuration directive:
MidgardCheckQuota (On|Off) default: Off

Class + function reference
--------------------------

New object 
class Quota {
        var $id;
        var $sitegroup; // sitegroup 
        var $tablename; // table or special name 'blobsdata' for filesystem blobs or special name 'wholesg' for all objects of the SG
        var $spacefields; // the fields that count as content for this table
        var $number; // max number of records
        var $space; // max length of content fields or max disk space for filesystem blobs (both in KB)
        var $eff_number; // effective number of objects for which this quota is defined
        var $eff_space; // effective size of objects for which this quota is defined
}       

New functions:
mgd_list_quotas();
mgd_get_quota([int id]);
mgd_get_quota_by_tablename(string tablename);
mgd_get_quota_info_by_tablename(string tablename, [int sitegroup]);
mgd_create_quota(int sitegroup, string tablename, string spacefields, int number, int space);
mgd_update_quota(int id, int sitegroup, string tablename, string spacefields, int number, int space);
mgd_delete_quota(int id);

Example
-------
/* as $midgard->root: */

/* The total size of all content fields of table page_i may not exceed 1000 KB for sitegroup $sg */
mgd_create_quota($sg, 'page_i', 'content', 0, 1000); 

/* The total size of all value fields of table pageelement_i may not exceed 1000 KB for sitegroup $sg */
mgd_create_quota($sg, 'pageelement_i', 'content', 0, 1000);

/* The total size of all content & abstract fields of table article_i may not exceed 1000 KB for sitegroup $sg */
mgd_create_quota($sg, 'article_i', 'content,abstract', 0, 1000);

/* The total size of all value fields of table element_i may not exceed 1000 KB for sitegroup $sg */
mgd_create_quota($sg, 'element_i', 'value', 0, 1000);

/* The total size of all code fields of table element_i may not exceed 1000 KB for sitegroup $sg */
mgd_create_quota($sg, 'snippet_i', 'code', 0, 1000);

/* The total size of all extra & pgpkey fields of table person may not exceed 1000 KB for sitegroup $sg */
mgd_create_quota($sg, 'person', 'extra,pgpkey', 0, 1000);

/* The total size of all attachments may not exceed 10000 KB for sitegroup $sg */
mgd_create_quota($sg, 'blobsdata', '', 0, 10000);

/* The total size of all table fields and blobs data defined above may not exceed 10000 KB for sitegroup $sg */
mgd_create_quota($sg, 'wholesg', '', 0, 12000);

/* The total number of articles may not exceed 1000 for sitegroup $sg */
mgd_create_quota($sg, 'article', '', 1000, 0);

/* ... */
/* as normal user: */

$qinfo = mgd_get_quota_info_by_tablename('blobsdata');
$qinfosg = mgd_get_quota_info_by_tablename('wholesg');

/* Test if file $filename could be written into an attachment according to quota rules */
if ($qinfo->eff_space + (filesize($filename) / 1024) >= $qinfo->space or $qinfosg->eff_space + (filesize($filename) / 1024) >= $qinfosg->space) {       
        echo "File too big";
}