ProductRegistryHelper.cc

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#include "art/Framework/Core/ProductRegistryHelper.h"
// vim: set sw=2:

#include "art/Persistency/Provenance/MasterProductRegistry.h"
#include "canvas/Persistency/Provenance/BranchDescription.h"
#include "canvas/Persistency/Provenance/ModuleDescription.h"
#include "canvas/Persistency/Provenance/TypeLabel.h"
#include "canvas/Utilities/DebugMacros.h"
#include "canvas/Utilities/Exception.h"
#include "cetlib/container_algorithms.h"
#include "fhiclcpp/ParameterSet.h"
#include "fhiclcpp/ParameterSetRegistry.h"

#include <cassert>
#include <string>
#include <tuple>

namespace {

  // A user may wish to declare:
  //
  //   produces<Assns<A,B>>(instance_name);
  //   produces<Assns<B,A>>(instance_name);
  //
  // in their module constructor.  If the instance names are the same
  // for both produces declarations, then this is a logic error, since
  // Assns<A,B> and Assns<B,A> correspond to the same set of
  // associations.  This error can be detected by checking the
  // friendlyClassName, which resolves to the same string for
  // Assns<A,B> and Assns<B,A>.

  void
  check_for_duplicate_Assns(std::set<art::TypeLabel> const& typeLabels)
  {
    std::map<std::string, std::set<std::string>> instanceToFriendlyNames;
    for (auto const& tl : typeLabels) {
      auto const& productInstanceName = tl.productInstanceName();
      auto result = instanceToFriendlyNames[productInstanceName].emplace(
        tl.friendlyClassName());
      if (!result.second) {
        throw art::Exception(art::errors::LogicError,
                             "check_for_duplicate_Assns: ")
          << "An attempt has been made to call the equivalent of\n\n"
          << "   produces<" << tl.className() << ">(\"" << productInstanceName
          << "\")\n\n"
          << "which results in a prepared (\"friendly\") name of:\n\n"
          << "   " << *result.first << "\n\n"
          << "That friendly name has already been registered for this module.\n"
          << "Please check to make sure that produces<> has not already been\n"
          << "called for an Assns<> with reversed template arguments.  Such\n"
          << "behavior is not supported.  Contact artists@fnal.gov for "
             "guidance.\n";
      }
    }
  }
}

void
art::ProductRegistryHelper::registerProducts(
  MasterProductRegistry& mpr,
  ProductDescriptions& productsToRegister,
  ModuleDescription const& md)
{
  // First update the MPR with any extant products.
  if (productList_) {
    cet::transform_all(*productList_,
                       back_inserter(productsToRegister),
                       [](auto const& pr) { return pr.second; });
    mpr.updateFromModule(move(productList_));
  }

  // Now go through products that will be produced in the current process.
  check_for_duplicate_Assns(typeLabelList_[InEvent]);

  ProductDescriptions descriptions;
  for (std::size_t ibt{}; ibt != NumBranchTypes; ++ibt) {
    auto const bt = static_cast<BranchType>(ibt);
    for (auto const& val : typeLabelList_[bt]) {
      BranchDescription pd{bt, val, md};
      productsToRegister.push_back(pd);
      descriptions.push_back(std::move(pd));
    }
  }
  mpr.addProductsFromModule(move(descriptions));
}