Interface for const operations on an auxiliary store. More...
#include <IConstAuxStore.h>
Public Member Functions | |
| virtual | ~IConstAuxStore () |
| Destructor. | |
| virtual const void * | getData (SG::auxid_t auxid) const =0 |
| Return the data vector for one aux data item. | |
| virtual void * | getDecoration (auxid_t auxid, size_t size, size_t capacity)=0 |
| Return the data vector for one aux data decoration item. | |
| virtual const SG::auxid_set_t & | getAuxIDs () const =0 |
| Return a set of identifiers for existing data items in this store. | |
| virtual void | lock ()=0 |
| Lock the container. | |
| virtual void | clearDecorations ()=0 |
| Clear all decorations. | |
| virtual size_t | size () const =0 |
| Return the number of elements in the store. | |
Interface for const operations on an auxiliary store.
A DataVector may have auxiliary data associated with it. These data are kept in separate AuxStore objects; this defines the interface for const operations on such a store.
An AuxStore may store a number of different aux data items; these are identified by an integer of type auxid_t. Each item is stored as a vector with one entry per entry in the containing DataVector.
This interface provides methods for getting a const pointer to an existing vector of aux data items and for getting the set of existing aux data items.
In addition, sometimes we want to add additional auxiliary data to an existing, const container; this is called `decorating' it. For example, we retrieve a const container from StoreGate, run some algorithm on it, and attach additional data to the object that can be accessed by downstream algorithms or written to a file. To support this, we add the getDecoration operation, as well as lock and clearDecorations. When the object is first being filled, it is unlocked. It gets locked when StoreGateSvc::setConst is called on it. From then on, we can only create decorations. Calling clearDecorations will restore the state back to where it was when lock was called. (Be sure that the container's cache also gets cleared.)
getDecoration then works as follows:
| virtual void SG::IConstAuxStore::clearDecorations | ( | ) | [pure virtual] |
Clear all decorations.
Erase all decorations from the store, restoring the state to when lock was called. Be sure to clear the cache of the referencing container!
Implemented in SG::AuxStoreInternal, xAOD::AuxContainerBase, xAOD::AuxInfoBase, xAOD::ShallowAuxContainer, xAOD::TAuxStore, and xAOD::ByteStreamAuxContainer_v1.
| virtual const SG::auxid_set_t& SG::IConstAuxStore::getAuxIDs | ( | ) | const [pure virtual] |
Return a set of identifiers for existing data items in this store.
This should include identifiers for all items, const and non-const.
Implemented in SG::AuxStoreInternal, xAOD::AuxContainerBase, xAOD::AuxInfoBase, xAOD::ShallowAuxContainer, xAOD::TAuxStore, and xAOD::ByteStreamAuxContainer_v1.
| virtual const void* SG::IConstAuxStore::getData | ( | SG::auxid_t | auxid | ) | const [pure virtual] |
Return the data vector for one aux data item.
| auxid | The identifier of the desired aux data item. |
Each aux data item is stored as a vector, with one entry per entry in the owning container. This returns a pointer to the start of the vector.
This should return 0 if the item doesn't exist.
Implemented in SG::AuxStoreInternal.
| virtual void* SG::IConstAuxStore::getDecoration | ( | auxid_t | auxid, | |
| size_t | size, | |||
| size_t | capacity | |||
| ) | [pure virtual] |
Return the data vector for one aux data decoration item.
| auxid | The identifier of the desired aux data item. | |
| size | The current size of the container (in case the data item does not already exist). | |
| capacity | The current capacity of the container (in case the data item does not already exist). |
Each aux data item is stored as a vector, with one entry per entry in the owning container. This returns a pointer to the start of the vector.
If the data item does not exist, it then it will be created and initialized with default values. If the container is locked, then the new item will be marked as a decoration. size and capacity give the size for the new aux data item vector.
If the data item already exists, then we return it if either the container is not locked or the item is marked as a decoration. Otherwise we throw an exception.
Implemented in SG::AuxStoreInternal.
| virtual void SG::IConstAuxStore::lock | ( | ) | [pure virtual] |
Lock the container.
After this, only decorations can be changed/modified. If the container is already locked, this is a no-op.
Implemented in SG::AuxStoreInternal, xAOD::AuxContainerBase, xAOD::AuxInfoBase, xAOD::ShallowAuxContainer, xAOD::TAuxStore, and xAOD::ByteStreamAuxContainer_v1.
| virtual size_t SG::IConstAuxStore::size | ( | ) | const [pure virtual] |
Return the number of elements in the store.
May return 0 for a store with no aux data.
Implemented in SG::AuxStoreInternal, xAOD::AuxContainerBase, xAOD::AuxInfoBase, xAOD::ShallowAuxContainer, xAOD::TAuxStore, and xAOD::ByteStreamAuxContainer_v1.
1.6.1
