AthToolSupport/AsgDataHandles/AsgDataHandles/WriteDecorHandle.icc

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/*
 * Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration.
 */
/**
 * @file AsgDataHandles/WriteDecorHandle.icc
 * @author Nils Krumnack <Nils.Erik.Krumnack@cern.h>
 * @author scott snyder <snyder@bnl.gov> (for original version)
 * @brief Handle class for adding a decoration to an object.
 */
 
 
// #include "CxxUtils/checker_macros.h"
 
 
namespace SG {
 
 
/**
 * @brief Constructor from a WriteDecorHandleKey.
 * @param key The key object holding the clid/key/store/attr.
 *
 * This will raise an exception if the StoreGate key is blank,
 * or if the event store cannot be found.
 */
template <class T, class D>
WriteDecorHandle<T, D>::WriteDecorHandle (const WriteDecorHandleKey<T>& key)
  : Base (key.contHandleKey(), nullptr),
    m_decorKey (key.key()),
    m_acc (SG::decorKeyFromKey (key.key()))
    // m_madeAlias (false)
{
}
 
 
/**
 * @brief Constructor from a ReadDecorHandleKey and an explicit event context.
 * @param key The key object holding the clid/key.
 * @param ctx The event context.
 *
 * This will raise an exception if the StoreGate key is blank,
 * or if the event store cannot be found.
 *
 * If the default event store has been requested, then the thread-specific
 * store from the event context will be used.
 */
template <class T, class D>
WriteDecorHandle<T, D>::WriteDecorHandle (const WriteDecorHandleKey<T>& key,
                                          const EventContext& ctx)
  : Base (key.contHandleKey(), &ctx),
    m_decorKey (key.key()),
    m_acc (SG::decorKeyFromKey (key.key()))
    // m_madeAlias (false)
{
}
 
 
// /**
//  * @brief Copy constructor.
//  */
// template <class T, class D>
// WriteDecorHandle<T, D>::WriteDecorHandle (const WriteDecorHandle& rhs)
//   : Base (rhs),
//     m_decorKey (rhs.m_decorKey),
//     m_acc (rhs.m_acc),
//     m_madeAlias (rhs.m_madeAlias)
// {
// }
 
 
// /**
//  * @brief Move constructor.
//  */
// template <class T, class D>
// WriteDecorHandle<T, D>::WriteDecorHandle (WriteDecorHandle&& rhs)
//   : Base (std::move (rhs)),
//     m_decorKey (std::move (rhs.m_decorKey)),
//     m_acc (std::move (rhs.m_acc)),
//     m_madeAlias (rhs.m_madeAlias)
// {
//   rhs.m_madeAlias = false;
// }
 
 
// /**
//  * @brief Destructor.  This will lock the decoration.
//  */
// template <class T, class D>
// WriteDecorHandle<T, D>::~WriteDecorHandle()
// {
//   // Lock the decoration.  But don't do anything if we haven't touched it.
//   if (m_madeAlias) {
//     const IConstAuxStore* store = this->vectorData()->getConstStore();
//     if (store) {
//       IConstAuxStore* store_nc ATLAS_THREAD_SAFE = const_cast<IConstAuxStore*> (store);
//       store_nc->lockDecoration (auxid());
//     }
//   }
// }
 
 
// /**
//  * @brief Assignment operator.
//  */
// template <class T, class D>
// WriteDecorHandle<T, D>& WriteDecorHandle<T, D>::operator= (const WriteDecorHandle& rhs)
// {
//   if (this != &rhs) {
//     *static_cast<Base*>(this) = rhs;
//     m_acc = rhs.m_acc;
//     m_decorKey = rhs.m_decorKey;
//     m_madeAlias = rhs.m_madeAlias;
//   }
//   return *this;
// }
 
 
// /**
//  * @brief Move operator.
//  */
// template <class T, class D>
// WriteDecorHandle<T, D>& WriteDecorHandle<T, D>::operator= (WriteDecorHandle&& rhs)
// {
//   if (this != &rhs) {
//     *static_cast<Base*>(this) = std::move (rhs);
//     m_acc = std::move (rhs.m_acc);
//     m_decorKey = std::move (rhs.m_decorKey);
//     m_madeAlias = rhs.m_madeAlias;
//     rhs.m_madeAlias = false;
//   }
//   return *this;
// }
 
 
/**
 * @brief Is the referenced container present in SG?
 *
 * Note that this tests for the presence of the _container_,
 * not for the decoration.
 *
 * Const method; the handle does not change as a result of this.
 */
template <class T, class D>
bool WriteDecorHandle<T, D>::isPresent() const
{
  return Base::isPresent();
}
 
 
// /**
//  * @brief Explicitly set the event store.
//  * @param store The new event store.
//  *
//  * This implicitly does a reset().
//  *
//  * We need to override this so that the setting gets made on the container
//  * handle as well.
//  */
// template <class T, class D>
// StatusCode WriteDecorHandle<T, D>::setProxyDict (IProxyDict* store)
// {
//   m_madeAlias = false;
//   return Base::setProxyDict (store);
// }
 
 
/**
 * @brief Fetch the variable for one element, as a reference.
 * @param e The element for which to fetch the variable.
 */
template <class T, class D>
typename WriteDecorHandle<T, D>::reference_type
WriteDecorHandle<T, D>::operator() (const AuxElement& e)
{
  this->cptr();
  return m_acc (e);
}
 
 
// /**
//  * @brief Fetch the variable for one element, as a reference.
//  * @param index The index of the desired element.
//  *
//  * This looks up the variable in the object referenced by this handle.
//  * For a standalone object, pass an index of 0.
//  */
// template <class T, class D>
// typename WriteDecorHandle<T, D>::reference_type
// WriteDecorHandle<T, D>::operator() (size_t i)
// {
//   this->cptr();
//   return m_acc (*this->vectorData(), i);
// }
 
 
// /**
//  * @brief Get a pointer to the start of the auxiliary data array,
//  *        for the referenced object.
//  */
// template <class T, class D>
// typename WriteDecorHandle<T, D>::container_pointer_type
// WriteDecorHandle<T, D>::getDecorationArray()
// {
//   return reinterpret_cast<container_pointer_type>
//     (this->vectorData()->getDecorationArray (m_acc.auxid()));
// }
 
 
/**
 * @brief Test to see if this variable exists in the store,
 *        for the referenced object.
 *        Specialization for the case of a standalone object
 *        (@c T derives from @c SG::AuxElement).
 */
template <class T, class D>
inline
bool WriteDecorHandle<T, D>::isAvailable (std::true_type)
{
  const T* ptr = this->ptr();
  if (ptr) {
    const SG::AuxVectorData* obj = ptr->container();
    if (obj) {
      return obj->isAvailable (m_acc.auxid());
    }
  }
 
  return false;
}
 
 
/**
 * @brief Test to see if this variable exists in the store,
 *        for the referenced object.
 *        Specialization for the case of a container
 *        (@c T does not derive from @c SG::AuxElement).
 */
template <class T, class D>
inline
bool WriteDecorHandle<T, D>::isAvailable (std::false_type)
{
  const T* ptr = this->ptr();
  if (ptr) {
    return ptr->isAvailable (m_acc.auxid());
  }
 
  return false;
}
 
 
/**
 * @brief Test to see if this variable exists in the store,
 *        for the referenced object.
 */
template <class T, class D>
inline
bool WriteDecorHandle<T, D>::isAvailable()
{
  // if (!this->m_ptr) {
  //   ReadHandle<T>::typeless_dataPointer_impl (true);
  // }
  // We can't just use vectorData() because that will create the decoration
  // as a side effect.
  return isAvailable (typename std::is_base_of<SG::AuxElement, T>::type());
}
 
 
// /**
//  * @brief Return the aux id for this variable.
//  */
// template <class T, class D>
// SG::auxid_t WriteDecorHandle<T, D>::auxid() const
// {
//   return m_acc.auxid();
// }
 
 
// /**
//  * @brief Return the mode (read/write/update) for this handle.
//  */
// template <class T, class D>
// inline
// Gaudi::DataHandle::Mode WriteDecorHandle<T, D>::mode() const
// {
//   return Gaudi::DataHandle::Writer;
// }
 
 
/**
 * @brief Return the name of the decoration alias (CONT.DECOR).
 */
template <class T, class D>
inline
std::string WriteDecorHandle<T, D>::decorKey() const
{
  return m_decorKey;
}
 
 
// /**
//  * @brief Retrieve an object from StoreGate.
//  * @param quiet If true, suppress failure messages.
//  *
//  * Extended for decoration handles: when we first retrieve the object,
//  * we make an alias for the decoration and also create the decoration itself.
//  */
// template <class T, class D>
// void* WriteDecorHandle<T, D>::typeless_dataPointer_impl (bool quiet)
// {
//   if (this->m_ptr && this->m_madeAlias)
//     return this->m_ptr;
//   if (!this->m_ptr) {
//     ReadHandle<T>::typeless_dataPointer_impl (quiet);
//   }
//   if (!this->m_ptr) {
//     return nullptr;
//   }
//   if (this->alias (WriteHandleKey<T> (this->m_decorKey)).isFailure())
//     return nullptr;
//   // Important to call the base class method above before calling vectorData;
//   // otherwise, we'll get an infinite recursion.
//   // Also don't call getDecorationArray if the container is empty.
//   if (this->m_ptr && this->vectorData()->size_v() > 0) {
//     m_acc.getDecorationArray (*this->vectorData());
//   }
//   this->m_madeAlias = true;
//   return this->m_ptr;
// }
 
 
// /** 
//  * @brief Return the referenced object as a @c SG::AuxVectorData.
//  *        Specialization for the case of a standalone object
//  *        (@c T derives from @c SG::AuxElement).
//  */
// template <class T, class D>
// const SG::AuxVectorData* WriteDecorHandle<T, D>::vectorData (std::true_type)
// {
//   return (*this)->container();
// }
 
 
// /** 
//  * @brief Return the referenced object as a @c SG::AuxVectorData.
//  *        Specialization for the case of a container
//  *        (@c T does not derive from @c SG::AuxElement).
//  */
// template <class T, class D>
// const SG::AuxVectorData* WriteDecorHandle<T, D>::vectorData (std::false_type)
// {
//   return this->cptr();
// }
 
 
// /** 
//  * @brief Return the referenced object as a @c SG::AuxVectorData.
//  *
//  * If @c T is a container object, then this should be the object itself.
//  * But if it is a standalone object, deriving from @c SG::AuxElement,
//  * then we need to call container() on the object.
//  */
// template <class T, class D>
// const SG::AuxVectorData* WriteDecorHandle<T, D>::vectorData()
// {
//   return vectorData (typename std::is_base_of<SG::AuxElement, T>::type());
// }
 
 
/**
 * @brief Return a @c WriteDecorHandle referencing @c key.
 * @param key The key object holding the clid/key/store.
 *
 * This will raise an exception if the StoreGate key is blank,
 * or if the event store cannot be found.
 *
 * The type of the decoration must be included as an explicit template parameter:
 *
 *@code
 *   auto handle = SG::makeHandle<float> (key);
 @endcode
 *
 * Note that @c D comes first in the argument list.  It's given explicitly,
 * while @c T is inferred from @c key.
 */
template <class D, class T>
WriteDecorHandle<T, D> makeHandle (const WriteDecorHandleKey<T>& key)
{
  return WriteDecorHandle<T, D> (key);
}
 
 
/**
 * @brief Return a @c WriteDecorHandle referencing @c key for an explicit context.
 * @param key The key object holding the clid/key/store.
 * @param ctx The event context.
 *
 * This will raise an exception if the StoreGate key is blank,
 * or if the event store cannot be found.
 *
 * If the default event store has been requested, then the thread-specific
 * store from the event context will be used.
 *
 * The type of the decoration must be included as an explicit template parameter:
 *
 *@code
 *   auto handle = SG::makeHandle<float> (key, ctx);
 @endcode
 *
 * Note that @c D comes first in the argument list.  It's given explicitly,
 * while @c T is inferred from @c key.
 */
template <class D, class T>
WriteDecorHandle<T, D> makeHandle (const WriteDecorHandleKey<T>& key,
                                   const EventContext& ctx)
{
  return WriteDecorHandle<T, D> (key, ctx);
}
 
 
// /**
//  * @brief These two signatures are to catch cases where the explicit
//  *        template argument is omitted from the @c makeHandle call
//  *        and give an error tailored to that.  Otherwise, the @c makeHandle
//  *        call for @c ReadHandle would match, potentially giving a much
//  *        more confusing error.
//  */
// template <class T>
// void makeHandle (const WriteDecorHandleKey<T>& /*key*/)
// {
//   // If you see an error from here, you've forgotten the explicit template
//   // argument to @c makeHandle giving the decoration type.
//   // See the examples of @c makeHandle above.
//   return T::makeHandleForDecorationsRequiresExplicitTemplateArgument();
// }
// template <class T>
// void makeHandle (const WriteDecorHandleKey<T>& /*key*/,
//                  const EventContext& /*ctx*/)
// {
//   // If you see an error from here, you've forgotten the explicit template
//   // argument to @c makeHandle giving the decoration type.
//   // See the examples of @c makeHandle above.
//   return T::makeHandleForDecorationsRequiresExplicitTemplateArgument();
// }
 
 
} // namespace SG