Apr. 8, 2002Calibration Database Browser Workshop1 Database Access Using D0OM H. Greenlee Calibration Database Browser Workshop Apr. 8, 2002

Calibration Database Browser Workshop2 D0OM Components D0OM Object Model. Preprocessor and dictionary system. I/O Interface. –Non-database: d0Stream. Open/close/read/write. –Database: d0StreamDB. Query. Calibration Data Model. –Superset of D0OM object model. I/O back ends. –DSPACK/EVPACK. –Direct Oracle (d0omORACLE). C++ to database mapping dictionary. –Client-Server Oracle (d0omCORBA). C++ to database mapping dictionary.

Apr. 8, 2002Calibration Database Browser Workshop3 D0OM I/O Classes

Apr. 8, 2002Calibration Database Browser Workshop4 Calibration Architectures Calibration Manager d0omORACLE Oracle Database D0OM Dictionary Mapping Dictionary Calibration Manager Low Level Server Mapping Dictionary D0OM Client D0OM Dictionary High Level D0OM Server Direct Database Connection Database Client-Server Architecture Calibration Data Model Calibration Data Model Oracle Database

Apr. 8, 2002Calibration Database Browser Workshop5 Client Server Architecture Client and server use corba protocol to communicate. Client written in C++ (e.g part of d0reco). –Uses orbacus corba implementation. –Dynamic corba (no compiled in knowledge of database schema). Only type any (no dynany). Server written entirely in python. –Uses omniorb corba implementation. –Consists of high level part (schema independent) and low level part (schema- specific generated idl and python). –Schema specific part generated using fnal product db_server_gen (script dbgen.py).

Apr. 8, 2002Calibration Database Browser Workshop6 D0OM Object Model Atomic types. Strings. Arrays. Bare pointers. STL collections. D0OM base class: d0_Object. D0OM smart pointer: d0_Ref. User-defined classes.

Apr. 8, 2002Calibration Database Browser Workshop7 Calibration Data Model Database base class: d0_DBObject. Query Classes. –d0_Query and d0_Query_Base. Database Pointers. –d0_DynRef. –d0_RefTo. Database Collections –d0_Query_Collection. –d0_RefBy. Database key class. –Abstract class d0_DBKey. –Concrete classes d0_DBKey_1, d0_DBKey_2, etc.

Apr. 8, 2002Calibration Database Browser Workshop8 Database Base Class Class d0_DBObject contains database key. –Template parameter class K must fulfill d0_DBKey interface requirement. Attribute name fields of key are filled automatically from dictionary when d0_DBObject is constructed.

Apr. 8, 2002Calibration Database Browser Workshop9 Database Pointer Classes The database pointer classes inherit D0OM smart pointer interface (d0_Ref ). The database pointer classes support true deferred I/O: –They can be initialized to point to an object in a database without doing any I/O. (This was not true for dspack d0_Ref.) d0_DynRef represents a relationship based on a general query object, which can be specified at run-time. –Can not be stored in database. d0_RefTo represents a static one-to- one relationship based on key class K. –Key is automatically converted to query. –Points to d0_DBObject or d0_RefTo<>/d0_RefBy<> (symmetric relationship). –Can be stored in database.

Apr. 8, 2002Calibration Database Browser Workshop10 Smart Pointer Class Diagram

Apr. 8, 2002Calibration Database Browser Workshop11 Database Collections The database collection classes have interfaces similar to an STL collection. The database collection classes also support true deferred I/O. d0_Query_Collection represents a run- time collection based on a general query (plural version of d0_DynRef ). d0_RefBy represents a static one-to- many relationship based on key K (plural version of d0_RefTo ).

Apr. 8, 2002Calibration Database Browser Workshop12 Query Classes Query classes d0_Query and d0_Query_Base act as front end to query method d0StreamDB::query. d0_Query returns collection of d0_Ref ’s when executed. d0_Query_Base returns a collection of d0_Ref_Any’s when executed.

Apr. 8, 2002Calibration Database Browser Workshop13 Database Key Classes Abstract class d0_DBKey and subclasses. Unlike ordinary persistent data, database keys know the names of their database columns. –Keys can easily be turned into query objects. –Keys can be constructed by hand, or extracted from database base objects.

Apr. 8, 2002Calibration Database Browser Workshop14 Public Indirect Pointers New public indirect pointer class d0om_Query_Indptr is not specific to any D0OM I/O mechanism (but requires d0StreamDB::query to be implemented by back end).

Apr. 8, 2002Calibration Database Browser Workshop15 C++ to Database Mapping Goals: –Full support for D0OM object model, including polymorphism (e.g. for writing event data). –Flexible C++ to database mapping (e.g. for reading a human designed database).

Apr. 8, 2002Calibration Database Browser Workshop16 Database Representation of C++ Objects. Ordinary (non-database) persistent objects (derived from d0_Object). Database persistent objects (derived from d0_DBObject. Object id. & reference count columns are optional.

Apr. 8, 2002Calibration Database Browser Workshop17 Database Representation (cont.) Ordinary pointers and d0_Ref ’s. Dynamic type column and type table are optional. Not use in D0.

Apr. 8, 2002Calibration Database Browser Workshop18 Database Representation (cont.) Database smart pointer d0_RefTo. Dynamic pointers are not polymorphic. Object id and reference count columns not used in D0.

Apr. 8, 2002Calibration Database Browser Workshop19 Database Representation (cont.) STL Collection. Not used in D0.

Apr. 8, 2002Calibration Database Browser Workshop20 Database Representation (cont.) Database collection d0_RefBy. Object id and reference count not used in D0.

Apr. 8, 2002Calibration Database Browser Workshop21 External Database Dictionary D0omORACLE and d0omCORBA use an external python mapping dictionary. The following elements of C++ to database mapping can be controlled. –Class name  Table name. –Data member name  Column name. –Server-based foreign key relationships. –Metadata table and column names (not currently used). External dictionary is input to db_server_gen. I believe that it is possible to generate database dictionary automatically (i.e. from oracle designer), but I don’t know how.

Apr. 8, 2002Calibration Database Browser Workshop22 Generating server files using db_server_gen Need database dictionary files. –GENLIST.py (contains list of table modules) –MASTER.py (list of directories) –One python file for each database table. –Python modules must be on $PYTHONPATH. Run script dbgen.py to generate low level server files: % setup db_server_gen % dbgen.py –d0om Files generated: –Base layer idl files (one per table). –Python server files. –C++ header and implementation files.

Apr. 8, 2002Calibration Database Browser Workshop23 Programming Using d0omORACLE/d0omCORBA Use stream factory to open stream. d0StreamFactory* factory = d0StreamFactory::locateStreamFactory(); d0StreamDB* stream = factory->make_d0StreamDB(name, “”, ios::in); –Specific stream type is “ORACLE,” “CORBA,” or “” (empty string). –For d0omORACLE, specify stream name as database connect string (password optional). –For d0omCORBA, specify stream name as corba name of server (as registered with name server).

Apr. 8, 2002Calibration Database Browser Workshop24 Programming Using d0omORACLE/d0omCORBA Linking. –Force load LoadORACLE.o or LoadCORBA.o. –Link with D0 libraries –ld0omORACLE or -ld0omCORBA. –For product libraries use srt_d0 makefile fragments arch_spec_oracle.mk or arch_spec_corba_common.mk and arch_spec_orbacus.mk (automatic with ctbuild).

Apr. 8, 2002Calibration Database Browser Workshop25 Running d0omCORBA programs Start the server. –Add dictionary files (GENLIST.py, etc.) and generated python files to $PYTHONPATH. –Setup products omniOrb, dcoracle, and sam_util (or sam). –Specify database user name/password using env variables DB_SERVER_USERNAME and DB_SERER_PASSWORD. –Start server: % DbListener.py –n= -t=d0om –c=ServantFactory –m= Running the client. –Setup fnal product sam_util or sam (makes corba naming service available). –Run client program. Client can run on different node than server. Password is not required for client.

Apr. 8, 2002Calibration Database Browser Workshop26 Documentation D0omCORBA and d0omORACLE –d0omCORBA/doc/database_access.ps –d0omCORBA/doc/database_dictionary.ps. Calibration data model. –d0stream/doc/calibration_classes.ps. D0om generally. –d0om/d0c/d0om_user_guide.ps.