| # Gaudi Framework, version v21r6 |

Home |  | Generated: 11 Nov 2009

# IConverter Class Reference

`#include <GaudiKernel/IConverter.h>`

Inheritance diagram for IConverter:

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Collaboration diagram for IConverter:

[legend]

List of all members.

## Detailed Description

The data converters are responsible to translate data from one representation into another.

Concrete examples are e.g. converters creating transient objects representing parts of an event from the persistent (and disk based) representations. Converters will have to deal with the technology both representations are based on: in the upper example they have to know about the database internals as well as the structure of the transient representations. The converters know about the mechanism to retrieve persistent objects (ZEBRA, Objectivity, ) and only pass abstract instances of the converted objects, hence shielding the calling service from internals.

Data converters are meant to be light. This means there should not be all-in-one converters, which are able to convert the "world", but rather many converters. Each converter is then able to create a representation of a given type.

In order to function a converter must be able to

- Answer (when asked) which kind of representation the converter is able to create.
- Retrieve the source object from the source store.
- Create the requested representation using the information contained in the source object.
- Inform the registry entry of the created object that the object is now loaded.
- This registry entry is located in the data store which is supposed to manage the requested object.
- Register all leafs of the created object with the data store which is supposed to manage the requested object. Registering does not mean to create these representations, but rather to inform about the existence.

The interface should cover the entry points of concrete converter instances in order to serve conversion requests.

Author:
  Markus Frank

Version:
  1.0

Definition at line 58 of file IConverter.h.

## Public Types
enum | Status { INVALID_ADDRESS = IInterface::LAST_ERROR+1, INVALID_OBJECT, NO_MEMORY, BAD_STORAGE_TYPE, NO_SOURCE_OBJECT, ICONVERSIONSVC_LAST_ERROR }
| Status code. More...
## Public Member Functions
| DeclareInterfaceID (IConverter, 3, 0)
| InterfaceID.
virtual StatusCode | initialize ()=0
| Initialize the converter.
virtual StatusCode | finalize ()=0
| Terminate the converter.
virtual const CLID & | objType () const =0
| Retrieve the class type of objects the converter produces.
virtual long | repSvcType () const =0
| Retrieve the class type of the data store the converter uses.
virtual StatusCode | setDataProvider (IDataProviderSvc *pService)=0
| Set Data provider service.
virtual SmartIF < IDataProviderSvc > & | dataProvider () const =0
| Get Data provider service.
virtual StatusCode | setConversionSvc (IConversionSvc *pService)=0
| Set conversion service the converter is connected to.
virtual SmartIF< IConversionSvc > & | conversionSvc () const =0
| Get conversion service the converter is connected to.
virtual StatusCode | setAddressCreator (IAddressCreator *creator)=0
| Set address creator facility.
virtual SmartIF < IAddressCreator > & | addressCreator () const =0
| Get address creation interface needed to resolve links between objects.
virtual StatusCode | createObj (IOpaqueAddress *pAddress, DataObject *&refpObject)=0
| Create the transient representation of an object.
virtual StatusCode | fillObjRefs (IOpaqueAddress *pAddress, DataObject *pObject)=0
| Resolve the references of the created transient object.
virtual StatusCode | updateObj (IOpaqueAddress *pAddress, DataObject *refpObject)=0
| Update the transient object from the other representation.
virtual StatusCode | updateObjRefs (IOpaqueAddress *pAddress, DataObject *pObject)=0
| Update the references of an updated transient object.
virtual StatusCode | createRep (DataObject *pObject, IOpaqueAddress *&refpAddress)=0
| Convert the transient object to the requested representation.
virtual StatusCode | fillRepRefs (IOpaqueAddress *pAddress, DataObject *pObject)=0
| Resolve the references of the converted object.
virtual StatusCode | updateRep (IOpaqueAddress *pAddress, DataObject *pObject)=0
| Update the converted representation of a transient object.
virtual StatusCode | updateRepRefs (IOpaqueAddress *pAddress, DataObject *pObject)=0
| Update the references of an already converted object.

## Member Enumeration Documentation

enum IConverter::Status

Status code.

Enumerator:

  INVALID_ADDRESS | Invalid address information.
  INVALID_OBJECT | Object to be converted is invalid.
  NO_MEMORY | No more memory available.
  BAD_STORAGE_TYPE | Invalid storage type.
  NO_SOURCE_OBJECT | Error retrieving source data from source store.
  ICONVERSIONSVC_LAST_ERROR | Last entry.

Reimplemented from IInterface.

Reimplemented in IConversionSvc.

Definition at line 201 of file IConverter.h.

    00201               {
    00203     INVALID_ADDRESS = IInterface::LAST_ERROR+1,
    00205     INVALID_OBJECT,
    00207     NO_MEMORY,
    00209     BAD_STORAGE_TYPE,
    00211     NO_SOURCE_OBJECT,
    00213     ICONVERSIONSVC_LAST_ERROR
    00214   };

## Member Function Documentation

IConverter::DeclareInterfaceID | ( | IConverter | ,
|  | 3 | ,
|  | 0 |  |
| ) |  |  |

InterfaceID.

virtual StatusCode IConverter::initialize | ( |  | ) | `[pure virtual]`

Initialize the converter.

Returns:
  Status code indicating success or failure

Exceptions:

  | exception | (STL standard) in case of fatal errors

Implemented in Converter, PoolDbBaseCnv, and RootHistCnv::RNTupleCnv.

virtual StatusCode IConverter::finalize | ( |  | ) | `[pure virtual]`

Terminate the converter.

Returns:
  Status code indicating success or failure

Exceptions:

  | exception | (STL standard) in case of fatal errors

Implemented in Converter, PoolDbBaseCnv, and RootHistCnv::RNTupleCnv.

virtual const CLID& IConverter::objType | ( |  | ) | const`[pure virtual]`

Retrieve the class type of objects the converter produces.

Returns:
  Class type of the created object.

Implemented in Converter.

virtual long IConverter::repSvcType | ( |  | ) | const`[pure virtual]`

Retrieve the class type of the data store the converter uses.

Returns:
  Class type information about the source data store type the converter will use to retrieve the information.

Implemented in PoolDbBaseCnv, and RootHistCnv::RConverter.

virtual StatusCode IConverter::setDataProvider | ( | IDataProviderSvc * | pService | ) | `[pure virtual]`

Set Data provider service.

Returns:
  Status code indicating success or failure

Parameters:

  | pService | Pointer to data provider service

Implemented in Converter.

virtual SmartIF<IDataProviderSvc>& IConverter::dataProvider | ( |  | ) | const`[pure virtual]`

Get Data provider service.

Returns:
  Pointer to data provider service

Implemented in Converter.

virtual StatusCode IConverter::setConversionSvc | ( | IConversionSvc * | pService | ) | `[pure virtual]`

Set conversion service the converter is connected to.

Returns:
  Status code indicating success or failure

Parameters:

  | pService | Pointer to IConversionSvc interface

Implemented in Converter.

virtual SmartIF<IConversionSvc>& IConverter::conversionSvc | ( |  | ) | const`[pure virtual]`

Get conversion service the converter is connected to.

Returns:
  Pointer to IConversionSvc interface

Implemented in Converter.

virtual StatusCode IConverter::setAddressCreator | ( | IAddressCreator * | creator | ) | `[pure virtual]`

Set address creator facility.

Parameters:

  | creator | Reference to address creator interface

Returns:
  Status code indicating success or failure.

Implemented in Converter.

virtual SmartIF<IAddressCreator>& IConverter::addressCreator | ( |  | ) | const`[pure virtual]`

Get address creation interface needed to resolve links between objects.

Returns:
  Pointer to IAddressCreator interface

Implemented in Converter.

virtual StatusCode IConverter::createObj | ( | IOpaqueAddress * | pAddress,
|  | DataObject *& | refpObject |
| ) |  |  | `[pure virtual]`

Create the transient representation of an object.

The transient representation is created by loading the persistent object using the source information contained in the address.

Returns:
  Status code indicating success or failure

Parameters:

  | pAddress | Opaque address information to retrieve the requested object from the store in order to produce the transient object.
  | refpObject | Reference to location of pointer of the created object.

Implemented in Converter, PoolDbBaseCnv, PoolDbDatabaseCnv, PoolDbDirectoryCnv, PoolDbNTupleCnv, RootHistCnv::DirectoryCnv, RootHistCnv::RDirectoryCnv, RootHistCnv::RFileCnv, RootHistCnv::RHistogramCnv< T, S, Q >, and RootHistCnv::RNTupleCnv.

virtual StatusCode IConverter::fillObjRefs | ( | IOpaqueAddress * | pAddress,
|  | DataObject * | pObject |
| ) |  |  | `[pure virtual]`

Resolve the references of the created transient object.

After the object creation references of the objects pointing to objects outside its scope will have to be filled. The actual objects will not be loaded, but the recipe to load them will be present.

Returns:
  Status code indicating success or failure

Parameters:

  | pAddress | Opaque address information to retrieve the requested object from the store.
  | pObject | Pointer to location of the object

Implemented in Converter, PoolDbBaseCnv, PoolDbDirectoryCnv, PoolDbNTupleCnv, and RootHistCnv::RDirectoryCnv.

virtual StatusCode IConverter::updateObj | ( | IOpaqueAddress * | pAddress,
|  | DataObject * | refpObject |
| ) |  |  | `[pure virtual]`

Update the transient object from the other representation.

The transient representation will be updated by loading the persistent object using the source information contained in the address and then refill transient data.

Returns:
  Status code indicating success or failure

Parameters:

  | pAddress | Opaque address information to retrieve the requested object from the store.
  | pObject | Pointer to the object to be updated.

Implemented in Converter, PoolDbBaseCnv, PoolDbDirectoryCnv, PoolDbNTupleCnv, RootHistCnv::RHistogramCnv< T, S, Q >, and RootHistCnv::RNTupleCnv.

virtual StatusCode IConverter::updateObjRefs | ( | IOpaqueAddress * | pAddress,
|  | DataObject * | pObject |
| ) |  |  | `[pure virtual]`

Update the references of an updated transient object.

After the object was updated also the references of the objects pointing to objects outside its scope will have to be filled. The actual pointers to objects will only be filled if already present. Otherwise only the recipe to load them will be present.

Returns:
  Status code indicating success or failure

Parameters:

  | pAddress | Opaque address information to retrieve the requested object from the store.
  | pObject | Pointer to location of the object

Implemented in Converter, PoolDbBaseCnv, PoolDbDirectoryCnv, PoolDbKeyedContainerCnv, and PoolDbNTupleCnv.

virtual StatusCode IConverter::createRep | ( | DataObject * | pObject,
|  | IOpaqueAddress *& | refpAddress |
| ) |  |  | `[pure virtual]`

Convert the transient object to the requested representation.

e.g. conversion to persistent objects.

Returns:
  Status code indicating success or failure

Parameters:

  | pObject | Pointer to location of the object
  | refpAddress | Reference to location of pointer with the object address.

Implemented in Converter, PoolDbBaseCnv, PoolDbDirectoryCnv, PoolDbNTupleCnv, RootHistCnv::DirectoryCnv, RootHistCnv::RConverter, RootHistCnv::RDirectoryCnv, RootHistCnv::RFileCnv, and RootHistCnv::RNTupleCnv.

virtual StatusCode IConverter::fillRepRefs | ( | IOpaqueAddress * | pAddress,
|  | DataObject * | pObject |
| ) |  |  | `[pure virtual]`

Resolve the references of the converted object.

After the requested representation was created the references in this representation must be resolved.

Returns:
  Status code indicating success or failure

Parameters:

  | pObject | Pointer to location of the object

Implemented in Converter, PoolDbBaseCnv, and PoolDbNTupleCnv.

virtual StatusCode IConverter::updateRep | ( | IOpaqueAddress * | pAddress,
|  | DataObject * | pObject |
| ) |  |  | `[pure virtual]`

Update the converted representation of a transient object.

Returns:
  Status code indicating success or failure

Parameters:

  | pObject | Pointer to location of the object
  | refpAddress | Reference to location of pointer with the object address.

Implemented in Converter, PoolDbBaseCnv, PoolDbDirectoryCnv, PoolDbNTupleCnv, RootHistCnv::RDirectoryCnv, RootHistCnv::RFileCnv, and RootHistCnv::RNTupleCnv.

virtual StatusCode IConverter::updateRepRefs | ( | IOpaqueAddress * | pAddress,
|  | DataObject * | pObject |
| ) |  |  | `[pure virtual]`

Update the references of an already converted object.

The object must be retrieved before it can be updated.

Returns:
  Status code indicating success or failure

Parameters:

  | pAddress | Pointer to location of object address with the store.
  | pObject | Pointer to location of the object

Implemented in Converter, PoolDbBaseCnv, PoolDbDirectoryCnv, and PoolDbNTupleCnv.

The documentation for this class was generated from the following file:

- /afs/cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v21r6/GaudiKernel/GaudiKernel/IConverter.h