[xwiki-devs] [proposal] Add an xwiki-store module with a UUID user defined type.

Hi all, In order to allow XWikiAttachment to reference data in multiple places, we need XWikiAttachment to know the location of it's content. XWikiAttachmentContent uses an id which is identical to the XWikiAttachment id meaning XWikiAttachmentContent has no id of it's own, only a foreign key which points to the content. To remedy this I propose the addition of a UUID hibernate UserType. This type will store a UUID as a 16 byte VARBINARY entry (little endian encoding) in order to minimize the size and database load. Note: I discovered that a UUID type was added in a later version of hibernate so when we upgrade we can decide whether to begin using their implementation. I would like to add the UUID type as the first class in a new module xwiki-store (in a submodule called xwiki-store-hibernate). I think the best approach is to add new database code to xwiki-store slowly until eventually the storage drivers in the core are no longer used thus "moving a mountain one shovel full at a time". The UUID implementation: http://svn.xwiki.org/svnroot/xwiki/contrib/sandbox/xwiki-store/xwiki-store-… How it works: Add this to the xwiki.hbm.xml where you want to add a UUID: <property name="contentUUID" type="org.xwiki.store.hibernate.types.UUIDToBinaryType"> <column name="contentuuid" /> </property> (type can be mapped to a shorter name such as "UUID") Add this to the bean class: public UUID getContentUUID() public void setContentUUID(final UUID contentUUID) Hibernate takes care of the rest. WDYT? Caleb