1. AliRoot Classes for access to Calibration and Alignment objects Magali Gruwé CERN PH/AIP ALICE Offline Meeting February 17 th 2005 To be presented to detector representatives during Alignment and Calibration Workshop (February 23 rd )

2. 2 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 Layout  Wish list  Functionalities  Usage  AliRoot classes  AliRunData  AliMetaData  AliRunDataStorage  AliRunDataFile  AliRunDataAlien  In practice (what does a user have to do?)  In the macros  In the reconstruction code

3. 3 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 Wish list/Functionalities  Simple user interface  Identification of data by strings  Automatically get the right object that is valid for the current run  Same interface for different types of data sources (Simple file, AliEn, something else?…)

4. 4 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 Example of usage  Detector person would like to retrieve some parameter of its sub-detector:  In a macro, specify where the data is stored (local file?, AliEn?)  In the macro, specify metadata:  Which data to get (specified by a string)?  Specific version of the data?  Other characteristics?  The required data is retrieved:  Valid for current run  Closest to specified version or most recent version  Possibility to store the retrieved data into a local file for later usage

5. 5 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 Layout  Wish list  Functionalities  Usage  AliRoot classes  AliRunData  AliMetaData  AliRunDataStorage  AliRunDataFile  AliRunDataAlien  In practice (what does a user have to do?)  In the macros  In the reconstruction code

6. 6 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 Schema AliRunDataAlien AliRunDataFile AliRunDataCombination AliRunDataStorageAliRunData AliRunLoader AliDETReconstructor GetRunObject(“string”) Get(“string”,run number) AliMetaData TObject* AliRunDataAliMetaData AliRunDataAliMetaData

7. 7 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 AliRoot Classes (I)  AliRunData:  Contains an object of the database and knows about its validity range  Constructor:  AliRunData::AliRunData(TObject* object, const AliMetaData& metaData)  Contains:  The run dependent data:  Calibration, alignment, geometry, field map,… data  Entirely defined by detector people:  Data such as gains, histograms, pedestals…  The metadata (AliMetaData):  Describes the “validity” of the data  See later…

8. 8 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 AliRoot Classes (II)  AliMetaData:  Metadata of the run dependent data:  Describes the “validity” of the data  Name (any regular expression)  Range of runs for which it is valid  Cycle (Reconstruction pass, etc…)  What else?…  Metadata is attached to AliRunData objects

9. 9 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 AliRoot Classes (III)  AliRunDataStorage:  Provides a simple interface to all run dependent data objects  Virtual interface to the database  Only one AliRunDataStorage instance at a time  Could be an  AliRunDataFile (for a local file)  AliRunDataAlien (for an AliEn file)  What else?…  Probably need for an AliRunDataCombination?  The user does not have to care about the details of where and how the data are stored: this is encapsulated in the implementation of the AliRunDataStorage subclasses:  The user can easily switch between different sources of data (local file for testing, or master database)

10. 10 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 AliRoot Classes (IV)  AliRunDataStorage:  Methods:  void Select(const AliMetaData& metaData)  Specify one or adds a metadata selection criterion  const TObject* Get(const char* name, Int_t runNumber)  Gets an object from the database according to specified selection criteria  Bool_t Put(const TObject* object, const AliMetaData& metaData)  Puts a given object into the database, together with associated metadata  Bool_t RecordToFile(const char* fileName)  Prepares for recording into a local file the entries (AliRunData objects) retrieved from the database

11. 11 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 AliRoot Classes (V)  AliRunDataFile:  Access class for a database in a (local) file  Methods:  GetEntry(AliMetaData& metaData, Int_t runNumber)  Gets an object from the database  PutEntry(AliRunData* entry)  Puts an object into the database  File is specified by a name (including path). Data objects with appropriate metadata are looked for in all cycles of the specified filename, till found.

12. 12 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 AliRoot Classes (VI)  AliRunDataAlien:  Access class for a database in an AliEn file  No implementation yet  Note that in this case, the AliEn file catalogue needs metadata knowledge: metadata is associated to files (as well as to objects). There is some redundancy.

13. 13 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 AliRoot Classes (VII)  Obviously still to be done:  Implementation of AliRunDataAlien  Continue implementation of AliRunDataStorage (Put method)  More thinking about AliMetaData  We probably also need:  An AliRunDataCombination  To deal with cases where some calibration data comes from a local file and the rest comes from AliEn, for example  Yet another AliRunDataStorage type  To deal with the case where we want to load all data stored in a given file, regardless of metadata (whether metadata are present or not)

14. 14 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 Layout  Wish list  Functionalities  Usage  AliRoot classes  AliRunData  AliMetaData  AliRunDataStorage  AliRunDataFile  AliRunDataAlien  In practice (what does a user have to do?)  In the macros  In the reconstruction code

15. 15 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 In a User Macro  Create an instance of the desired database access class:  AliRunDataFile, AliRunDataAlien, … is created  And configured (location, file name, …)  Perform the metadata selection by using the Select method of the AliRunDataStorage class.  May be called several times to specify several selection criteria  If no selection criterion is given, then the (matching) object with the highest version number is returned  The selection criteria are specified via meta data objects

16. 16 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 Selection of Data Objects  Example:  // Select version 2 for all TPC objects  AliMetaData metaData(^TPC/*”);  metaData.SetVersion(2);  AliRunDataStorage::Instance()->Select(metaData);  // But version 3 for TPC/Calibration/Param  metaData.SetName(“TPC/Calibration/Param”);  metaData.SetVersion(3);  AliRunDataStorage::Instance()->Select(metaData);

17. 17 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 In the reconstruction code  Access the data per run via the run loader  runLoader->GetRunObject(“TPC/Calibration/Param”)  The runLoader knows the run number  Other meta data selections were done in users macros  The getRunObject is used in the reconstruction (simulation/analysis) code without any metadata selection (except for the name)  The metadata selection is not done in the compiled code, but rather in the users macros

18. 18 Magali Gruwé CERN PH/AIP ALICE Offline Meeting, February 17 th, 2005 Comments  The name of the metadata can be any regular expression  The data itself is identified via a string which can contain a path  The matching of the name to (alien files), directories, catalogues,… is subject to the implementation: the user should not have to care about it  There is redundancy:  Metadata associated to data objects  Metadata associated to files