fv package — File Vault Service
The file vault service (wt.fv package) is responsible
for the definition and execution of rules that define the vaulting algorithm
for content items. This allows the content service to store content items
locally in external files instead of ORACLE BLOBs in a centralized Oracle
database resulting in speed up of upload and download process.
Design Overview
File Vault Model
File folder is an equivalent of a directory on the
disk drive. Folders are logically grouped to form vaults. Each folder has a
sequence number that defines the order in which the folders within the vault
will be used for storing content items. When a folder overflows, the vault
manager makes it read-only and begins using the next available folder in the
sequence. All the folders must be mounted to all the method server hosts in
order to provide access to content items stored in them. Mappings between
Folders and Vaults are maintained both ways so that given a vault, the
contained folder can be fetched. Similarly, given a folder, the containing
vault can be fetched. Depending on the domain a content holder belongs to, a
class and life cycle state content item is stored in one of the vaults or in
the ORACLE BLOB.
Following is the class diagram for vaulting rules:
External Interface
There is no external API for customer use.
Event Processing
The service emits OVERFLOW events with the FvFolder
object as a target on folder overflow and the FvVault object as a target on
vault overflow. An event is emitted from within a transaction. Vetoing an event
or throwing an exception has no effect on the operation that caused the event
to be emitted.