Mercurial > hg > orthanc
view OrthancServer/Resources/ImplementationNotes/DatabasesClassHierarchy.txt @ 5815:42a7fbf13359 attach-custom-data
added missing file
author | Alain Mazy <am@orthanc.team> |
---|---|
date | Wed, 25 Sep 2024 16:36:43 +0200 |
parents | 28cc06e4859a |
children |
line wrap: on
line source
The main object to access the DB is the ServerIndex class that is accessible from the ServerContext. ServerIndex inherits from StatelessDatabaseOperations. StatelessDatabaseOperations owns an IDatabaseWrapper member (db). StatelessDatabaseOperations has 2 internal Transaction classes (ReadOnlyTransactions and ReadWriteTransactions) that implements the DB operations by calling the methods from IDatabaseWrapper:ITransaction. IDatabaseWrapper has 2 direct derived classes: - BaseDatabaseWrapper which simply provides a "not implemented" implementation of new methods to its derived classes: - OrthancPluginDatabase that is a legacy plugin interface - OrthancPluginDatabaseV3 that is a legacy plugin interface - SQLiteDatabaseWrapper that is used by the default SQLite DB in Orthanc - OrthancPluginDatabaseV4 that is the latest plugin interface and uses protobuf When you add a new method in the DB (e.g: UpdateAndGetStatistics with a new signature), you must: - define it as a member of StatelessDatabaseOperations - define it as a member of StatelessDatabaseOperations::ReadWriteTransactions or StatelessDatabaseOperations::ReadOnlyTransactions - define it as a member of IDatabaseWrapper:ITransaction - define it in OrthancDatabasePlugin.proto (new request + new response + new message) - define it in OrthancPluginDatabaseV4 - define a NotImplemented default implementation in BaseDatabaseWrapper - optionally define it in SQLiteDatabaseWrapper if it can be implemented in SQLite - very likely define it as a DbCapabilities in IDatabaseWrapper::DbCapabilities (e.g: Has/SetUpdateAndGetStatistics()) such that the Orthanc core knows if it can use it or not. Then, in the orthanc-databases repo, you should: - define it as a virtual member of IDatabaseBackend - define it as a member of IndexBackend - add a handler for the new protobuf message in DatabaseBackendAdapterV4