IOPool/Input/src/RootPromptReadDelayedReader.h - master - githubmirror/cmssw

IOPool/Input/src/RootPromptReadDelayedReader.h
84 строки3 KB
Chris Jones
Improvements based on review feedback
19 май 2025, 21:52
19 май 2025, 21:527618354
#ifndef IOPool_Input_RootPromptReadDelayedReader_h
#define IOPool_Input_RootPromptReadDelayedReader_h

/*----------------------------------------------------------------------

RootPromptReadDelayedReader.h // used by ROOT input sources

----------------------------------------------------------------------*/

#include "DataFormats/Provenance/interface/BranchID.h"
#include "FWCore/Utilities/interface/InputType.h"
#include "FWCore/Utilities/interface/propagate_const.h"
#include "FWCore/Utilities/interface/thread_safety_macros.h"
#include "RootTree.h"
#include "RootDelayedReaderBase.h"

#include <map>
#include <memory>
#include <string>
#include <exception>

class TClass;
namespace edm {
  class InputFile;
  class RootTree;
  class SharedResourcesAcquirer;
  class Exception;

  //------------------------------------------------------------
  // Class RootPromptReadDelayedReader: pretends to support file reading.
  //

  class RootPromptReadDelayedReader : public RootDelayedReaderBase {
  public:
    typedef roottree::BranchInfo BranchInfo;
    typedef roottree::BranchMap BranchMap;
    typedef roottree::EntryNumber EntryNumber;
    RootPromptReadDelayedReader(RootTree const& tree,
                                std::shared_ptr<InputFile> filePtr,
                                InputType inputType,
                                unsigned int iNIndexes);

    ~RootPromptReadDelayedReader() override;

    RootPromptReadDelayedReader(RootPromptReadDelayedReader const&) = delete;
    RootPromptReadDelayedReader& operator=(RootPromptReadDelayedReader const&) = delete;
    RootPromptReadDelayedReader(RootPromptReadDelayedReader&&) = delete;
    RootPromptReadDelayedReader& operator=(RootPromptReadDelayedReader&&) = delete;

    struct Cache {
      std::unique_ptr<edm::WrapperBase> wrapperBase_;
      edm::WrapperBase* wrapperBasePtr_ = nullptr;  // TBranch::SetAddress() needs a long live pointer to reference.
    };

    void readAllProductsNow(EDProductGetter const* ep) override;

  private:
    std::shared_ptr<WrapperBase> getProduct_(BranchID const& k, EDProductGetter const* ep) override;
    void mergeReaders_(DelayedReader* other) override { nextReader_ = other; }
    void reset_() override { nextReader_ = nullptr; }
    std::pair<SharedResourcesAcquirer*, std::recursive_mutex*> sharedResources_() const override;

    BranchMap const& branches() const { return tree_.branches(); }
    BranchInfo const* getBranchInfo(unsigned int k) const { return branches().find(k); }
    std::vector<std::unordered_map<unsigned int, Cache>> cacheMaps_;
    // NOTE: filePtr_ appears to be unused, but is needed to prevent
    // the file containing the branch from being reclaimed.
    RootTree const& tree_;
    edm::propagate_const<std::shared_ptr<InputFile>> filePtr_;
    edm::propagate_const<DelayedReader*> nextReader_;
    // We do not use propagate_const because the acquirer is itself mutable.
    std::unique_ptr<SharedResourcesAcquirer> resourceAcquirer_;
    std::shared_ptr<std::recursive_mutex> mutex_;
    InputType inputType_;

    //If a fatal exception happens we need to make a copy so we can
    // rethrow that exception on other threads. This avoids TTree
    // non-exception safety problems on later calls to TTree.
    //All uses of the ROOT file are serialized
    CMS_SA_ALLOW mutable std::exception_ptr lastException_;
  };  // class RootPromptReadDelayedReader
  //------------------------------------------------------------
}  // namespace edm
#endif