JANA/Topology/JFoldArrow.h

0001 // Copyright 2023, Jefferson Science Associates, LLC.
0002 // Subject to the terms in the LICENSE file found in the top-level directory.
0003
0004 #pragma once
0005
0006 #include <JANA/JEventFolder.h>
0007 #include <JANA/Topology/JArrow.h>
0008
0009 class JFoldArrow : public JArrow {
0010 public:
0011     enum PortIndex {CHILD_IN=0, CHILD_OUT=1, PARENT_OUT=2};
0012
0013 private:
0014     JEventFolder* m_folder = nullptr;
0015
0016     JEventLevel m_parent_level;
0017     JEventLevel m_child_level;
0018
0019 public:
0020     JFoldArrow(
0021         std::string name,
0022         JEventLevel parent_level,
0023         JEventLevel child_level)
0024
0025       : m_parent_level(parent_level),
0026         m_child_level(child_level)
0027     {
0028         set_name(name);
0029         create_ports(1, 2);
0030         m_next_input_port = CHILD_IN;
0031     }
0032
0033     void set_folder(JEventFolder* folder) {
0034         m_folder = folder;
0035     }
0036
0037     void initialize() final {
0038         if (m_folder != nullptr) {
0039             m_folder->DoInit();
0040             LOG_INFO(m_logger) << "Initialized JEventFolder '" << m_folder->GetTypeName() << "'" << LOG_END;
0041         }
0042         else {
0043             LOG_INFO(m_logger) << "Initialized JEventFolder (trivial)" << LOG_END;
0044         }
0045     }
0046
0047     void finalize() final {
0048         if (m_folder != nullptr) {
0049             m_folder->DoFinish();
0050             LOG_INFO(m_logger) << "Finalized JEventFolder '" << m_folder->GetTypeName() << "'" << LOG_END;
0051         }
0052         else {
0053             LOG_INFO(m_logger) << "Finalized JEventFolder (trivial)" << LOG_END;
0054         }
0055     }
0056
0057     void fire(JEvent* event, OutputData& outputs, size_t& output_count, JArrow::FireResult& status) final {
0058
0059         assert(m_next_input_port == CHILD_IN);
0060
0061         // Check that child is at the correct event level
0062         if (event->GetLevel() != m_child_level) {
0063             throw JException("JFoldArrow received a child with the wrong event level");
0064         }
0065
0066         if (m_folder != nullptr) {
0067             auto parent = const_cast<JEvent*>(&event->GetParent(m_parent_level));
0068             m_folder->DoFold(*event, *parent);
0069         }
0070
0071         status = JArrow::FireResult::KeepGoing;
0072         outputs[0] = {event, CHILD_OUT};
0073         output_count = 1;
0074
0075         auto* released_parent = event->ReleaseParent(m_parent_level);
0076         if (released_parent != nullptr) {
0077             // JEvent::ReleaseParent() returns nullptr if there are remaining references
0078             // to the parent event. If non-null, we are completely done with the parent
0079             // and are free to return it to the pool. In the future we could have the pool
0080             // itself handle the logic for releasing parents, in which case we could avoid
0081             // trivial JEventFolders.
0082
0083             outputs[1] = {released_parent, PARENT_OUT};
0084             output_count = 2;
0085         }
0086     }
0087
0088 };
0089
0090