Generators/GeneratorObjects/GeneratorObjects/HepMcParticleLink.h

@@ -70,8 +70,8 @@ enum EBC_EVCOLL : unsigned char {
  * As a special case, a GenEvent number of 0 is interpreted as the first
  * GenEvent in the collection.
  *
- * The particle within the GenEvent is represented by a barcode.
- * A barcode of 0 implies a null link.
+ * The particle within the GenEvent is represented by a unique ID.
+ * A unique ID of 0 implies a null link.
  *
  * In order to dereference a link, we need to reference a particular
  * event store.  By default, the current store (as defined by
@@ -90,6 +90,11 @@ public:
     IS_POSITION = 1,
   };
 
+  enum UniqueIDFlag {
+    IS_ID = 0,
+    IS_BARCODE = 1,
+  };
+
 
   /**
    * @brief Persistent representation of a link.
@@ -98,18 +103,19 @@ public:
   class ExtendedBarCode {
   public:
     /// All 1's.  Used to represent an undefined index/position.
-    constexpr static index_type UNDEFINED = ~static_cast<index_type>(0);
+    constexpr static index_type UNDEFINED = ~static_cast<index_type>(0); // TODO Move to MagicNumbers.h?
+    constexpr static barcode_type UNDEFINEDBC = ~static_cast<barcode_type>(0); // TODO Move to MagicNumbers.h?
 
 
     /** 
-     * @brief Default constructor.  Makes a null link (barcode 0).
+     * @brief Default constructor.  Makes a null link (unique ID 0).
      */
     ExtendedBarCode();
 
 
     /** 
      * @brief Constructor.
-     * @param barcode Barcode of target particle.
+     * @param uid Unique ID of target particle.
      * @param eventIndex Identifies the target GenEvent in a McEventCollection,
      *        as either the event number if @c isIndexEventPosition is IS_EVENTNUM,
      *        or the position in the container
@@ -118,15 +124,16 @@ public:
      * @param evtColl Identifies which McEventCollection to use.
      * @param isIndexEventPosition: See @c eventIndex.
      */
-    ExtendedBarCode (barcode_type barcode,
+    ExtendedBarCode (barcode_type uid,
                      index_type eventIndex,
                      EBC_EVCOLL evtColl=EBC_MAINEVCOLL,
-                     PositionFlag isIndexEventPosition = IS_EVENTNUM);
+                     PositionFlag isIndexEventPosition = IS_EVENTNUM,
+                     UniqueIDFlag isUniqueIDBarcode = IS_ID);
 
                     
     /** 
      * @brief Constructor.
-     * @param barcode Barcode of target particle.
+     * @param uid Unique ID of target particle.
      * @param eventIndex Identifies the target GenEvent in a McEventCollection,
      *        as either the event number if @c isIndexEventPosition is IS_EVENTNUM,
      *        or the position in the container
@@ -136,10 +143,11 @@ public:
      *        as a character ('a'..'d').
      * @param isIndexEventPosition: See @c eventIndex.
      */
-    ExtendedBarCode (barcode_type barcode,
+    ExtendedBarCode (barcode_type uid,
                      index_type eventIndex,
                      char evtColl,
-                     PositionFlag isIndexEventPosition = IS_EVENTNUM);
+                     PositionFlag isIndexEventPosition = IS_EVENTNUM,
+                     UniqueIDFlag isUniqueIDBarcode = IS_ID);
 
 
     /**
@@ -165,10 +173,21 @@ public:
     ExtendedBarCode& operator= (ExtendedBarCode&& rhs) noexcept;
 
     /**
-     * @brief Barcode of target variable (0 for a null link).
+     * @brief Unique ID of target variable (0 for a null link).
      */
-    barcode_type barcode() const;
+    barcode_type uid() const;
 
+    /**
+     * @brief Return the GenParticle id/barcode.
+     * @param id[out] GenParticle::id, or @c UNDEFINED.
+     * @param barcode[out] barcode (deprecated), or @c UNDEFINED.
+     *
+     * The GenParticle within the GenEvent is identified either by
+     * the GenParticle::id or the barcode.
+     * This method will return this by setting either @c id or @c barcode;
+     * the other one is set to @c UNDEFINED.
+     */
+    void uniqueID(barcode_type& id, barcode_type& barcode) const;
 
     /**
      * @brief Return the event index/position.
@@ -183,6 +202,12 @@ public:
     void eventIndex (index_type& index, index_type& position) const;
 
 
+    /**
+       * @brief return true if neither barcode nor id are valid
+     */
+    bool linkIsNull() const;
+
+
     /**
      * @brief Return which collection we're targeting, as an enum.
      */
@@ -255,6 +280,22 @@ public:
                       const HepMcParticleLink& rhs);
 
 
+    /**
+     * @brief Compare the unique ID part of two links.
+     * @param lhs First link to compare.
+     * @param rhs Second link to compare.
+     * @returns -1, 0, or 1, depending on the result of the comparison.
+     *
+     * The unique ID part of the link can be represented as either
+     * a barcode or the id.
+     * If necessary, the links will be normalized so that they
+     * both refer to an id.
+     */
+    static
+    int compareUniqueID (const HepMcParticleLink& lhs,
+                      const HepMcParticleLink& rhs);
+
+
     /**
      * @brief Dump in textual format to a stream.
      */
@@ -282,10 +323,27 @@ public:
     void makeIndex (index_type index, index_type position) const;
 
 
+    /**
+     * @brief Change m_BC from barcode to ID.
+     * @param ID GenParticle::id value to set.
+     * @param barcode existing barcode value.
+     *
+     * If the link is currently referencing a GenParticle with @c barcode,
+     * update it so that it instead references the GenParticle
+     * with id value @c ID.
+     *
+     * This may be called concurrently, as long as all such concurrent
+     * calls have the same arguments.
+     */
+    void makeID (barcode_type ID, barcode_type barcode) const;
+
+
   private:
     /// Flag marking that an index refers to an event position.
     constexpr static index_type POSITION_MASK = UNDEFINED ^ (UNDEFINED>>1);
 
+    /// Flag marking that an unique ID refers to a barcode.
+    constexpr static barcode_type BARCODE_MASK = UNDEFINED ^ (UNDEFINED>>1);
 
     /**
      * @brief Initialize the event index part of the link.
@@ -293,11 +351,20 @@ public:
      * @param positionFlag If IS_POSITION, @c idx represents a position
      *        in the collection; otherwise, it represents an event number.
      */
-    void setIndex (index_type idx, PositionFlag isPosition);
+    void setIndex (index_type idx, PositionFlag positionFlag);
+
+
+    /**
+     * @brief Initialize the unique identifier part of the link.
+     * @param uid The id or barcode.
+     * @param barcodeFlag If IS_BARCODE, @c uid represents a GenParticle barcode (deprecated);
+     *        otherwise, it represents a GenParticle::id().
+     */
+    void setUniqueID (barcode_type uid, UniqueIDFlag barcodeFlag);
 
 
-    /// Barcode of the target particle.  0 means a null link.
-    barcode_type m_BC;
+    /// Unique ID of the target particle.  0 means a null link.
+    mutable std::atomic<barcode_type> m_BC;
 
     /// Identifies the target GenEvent within the event collection.
     /// If the high bit is set, then this (with the high bit clear)
@@ -326,7 +393,7 @@ public:
 
   /**
    * @brief Constructor.
-   * @param barCode Barcode of the target particle.  0 means a null link.
+   * @param uid Unique ID of the target particle.  0 means a null link.
    * @param eventIndex Identifies the target GenEvent in a McEventCollection,
    *        as either the event number if @c isIndexEventPosition is IS_EVENTNUM,
    *        or the position in the container
@@ -336,16 +403,17 @@ public:
    * @param positionFlag: See @c eventIndex.
    * @param sg Optional specification of a specific store to reference.
    */
-  HepMcParticleLink (barcode_type barCode,
+  HepMcParticleLink (barcode_type uid,
                      uint32_t eventIndex = 0,
                      EBC_EVCOLL evColl = EBC_MAINEVCOLL,
                      PositionFlag positionFlag = IS_EVENTNUM,
+                     UniqueIDFlag uniqueIDFlag = IS_ID,
                      IProxyDict* sg = SG::CurrentEventStore::store());
 
 
   /**
    * @brief Constructor.
-   * @param barCode Barcode of the target particle.  0 means a null link.
+   * @param uid Unique ID of the target particle.  0 means a null link.
    * @param eventIndex Identifies the target GenEvent in a McEventCollection,
    *        as either the event number if @c isIndexEventPosition is IS_EVENTNUM,
    *        or the position in the container
@@ -355,16 +423,17 @@ public:
    * @param positionFlag: See @c eventIndex.
    * @param ctx Context of the store to reference.
    */
-  HepMcParticleLink (barcode_type barCode,
+  HepMcParticleLink (barcode_type uid,
                      uint32_t eventIndex,
                      EBC_EVCOLL evColl,
                      PositionFlag positionFlag,
+                     UniqueIDFlag uniqueIDFlag,
                      const EventContext& ctx);
 
 
  /**
    * @brief Constructor.
-   * @param barCode Barcode of the target particle.  0 means a null link.
+   * @param uid Unique ID of the target particle.  0 means a null link.
    * @param eventIndex Identifies the target GenEvent in a McEventCollection,
    *        as either the event number if @c isIndexEventPosition is IS_EVENTNUM,
    *        or the position in the container
@@ -374,10 +443,11 @@ public:
    * @param positionFlag: See @c eventIndex.
    * @param sg Optional specification of a specific store to reference.
    */
-  HepMcParticleLink (barcode_type barCode,
+  HepMcParticleLink (barcode_type uid,
                      uint32_t eventIndex,
                      const std::string& evCollName,
                      PositionFlag positionFlag = IS_EVENTNUM,
+                     UniqueIDFlag uniqueIDFlag = IS_ID,
                      IProxyDict* sg = SG::CurrentEventStore::store());
 
 
@@ -547,6 +617,12 @@ public:
   int barcode() const;
 
 
+  /**
+   * @brief Return the id of the target particle.  0 for a null link.
+   */
+  int id() const;
+
+
   /**
    * @brief Return the event number of the referenced GenEvent.
    *        0 means the first GenEvent in the collection.

Generators/GeneratorObjects/GeneratorObjects/HepMcParticleLink.icc

@@ -24,7 +24,7 @@ HepMcParticleLink::ExtendedBarCode::ExtendedBarCode()
 
 /** 
  * @brief Constructor.
- * @param barcode Barcode of target particle.
+ * @param uid Unique ID of target particle.
  * @param eventIndex Identifies the target GenEvent in a McEventCollection,
  *        as either the event number if @c isIndexEventPosition is IS_EVENTNUM,
  *        or the position in the container
@@ -35,20 +35,21 @@ HepMcParticleLink::ExtendedBarCode::ExtendedBarCode()
  */
 inline
 HepMcParticleLink::ExtendedBarCode::ExtendedBarCode
-  (barcode_type barcode,
+  (barcode_type uid,
    index_type eventIndex,
    EBC_EVCOLL evtColl /*=EBC_MAINEVCOLL*/,
-   PositionFlag isIndexEventPosition /*=IS_EVENTNUM*/)
-    : m_BC(barcode),
-      m_evtColl (evtColl)
+   PositionFlag isIndexEventPosition /*=IS_EVENTNUM*/,
+   UniqueIDFlag isUniqueIDBarcode /*= IS_ID*/)
+    : m_evtColl (evtColl)
 {
   setIndex (eventIndex, isIndexEventPosition);
+  setUniqueID (uid, isUniqueIDBarcode);
 }
 
 
 /** 
  * @brief Constructor.
- * @param barcode Barcode of target particle.
+ * @param uid Unique ID of target particle.
  * @param eventIndex Identifies the target GenEvent in a McEventCollection,
  *        as either the event number if @c isIndexEventPosition is IS_EVENTNUM,
  *        or the position in the container
@@ -60,14 +61,16 @@ HepMcParticleLink::ExtendedBarCode::ExtendedBarCode
  */
 inline
 HepMcParticleLink::ExtendedBarCode::ExtendedBarCode
-  (barcode_type barcode,
+  (barcode_type uid,
    index_type eventIndex,
    char evtColl,
-   PositionFlag isIndexEventPosition /*=IS_EVENTNUM*/)
-    : ExtendedBarCode (barcode,
+   PositionFlag isIndexEventPosition /*=IS_EVENTNUM*/,
+   UniqueIDFlag isUniqueIDBarcode /*= IS_ID*/)
+    : ExtendedBarCode (uid,
                        eventIndex,
                        eventCollectionFromChar (evtColl),
-                       isIndexEventPosition)
+                       isIndexEventPosition,
+                       isUniqueIDBarcode)
 {
 }
 
@@ -77,7 +80,7 @@ HepMcParticleLink::ExtendedBarCode::ExtendedBarCode
  */
 inline
 HepMcParticleLink::ExtendedBarCode::ExtendedBarCode (const ExtendedBarCode& rhs)
-  : m_BC (rhs.m_BC),
+  : m_BC (static_cast<barcode_type> (rhs.m_BC)),
     m_evtIndex (static_cast<index_type> (rhs.m_evtIndex)),
     m_evtColl (rhs.m_evtColl)
 {
@@ -89,7 +92,7 @@ HepMcParticleLink::ExtendedBarCode::ExtendedBarCode (const ExtendedBarCode& rhs)
  */
 inline
 HepMcParticleLink::ExtendedBarCode::ExtendedBarCode (ExtendedBarCode&& rhs) noexcept
-  : m_BC (std::exchange(rhs.m_BC,0)),
+  : m_BC (rhs.m_BC.load()), // no move constructor for atomics
     m_evtIndex (rhs.m_evtIndex.load()), // no move constructor for atomics
     m_evtColl (std::exchange(rhs.m_evtColl,EBC_MAINEVCOLL))
 {
@@ -103,7 +106,7 @@ HepMcParticleLink::ExtendedBarCode&
 HepMcParticleLink::ExtendedBarCode::operator= (const ExtendedBarCode& rhs)
 {
   if (this != &rhs) {
-    m_BC = rhs.m_BC;
+    m_BC = static_cast<barcode_type> (rhs.m_BC);
     m_evtIndex = static_cast<index_type> (rhs.m_evtIndex);
     m_evtColl=rhs.m_evtColl;
   }
@@ -118,19 +121,20 @@ HepMcParticleLink::ExtendedBarCode&
 HepMcParticleLink::ExtendedBarCode::operator= (ExtendedBarCode&& rhs) noexcept
 {
   if (this != &rhs) {
-    m_BC = std::exchange(rhs.m_BC, 0);
+    m_BC = static_cast<barcode_type> (rhs.m_BC.load());
     m_evtIndex = static_cast<index_type>(rhs.m_evtIndex.load());
     m_evtColl = std::exchange(rhs.m_evtColl, EBC_MAINEVCOLL);
   }
   return *this;
 }
 
+
 /**
- * @brief Barcode of target variable (0 for a null link).
+ * @brief Unique ID of target variable (0 for a null link).
  */
 inline
 HepMcParticleLink::barcode_type
-HepMcParticleLink::ExtendedBarCode::barcode() const
+HepMcParticleLink::ExtendedBarCode::uid() const
 {
   return m_BC;
 }
@@ -162,6 +166,32 @@ void HepMcParticleLink::ExtendedBarCode::eventIndex (index_type& index,
 }
 
 
+/**
+ * @brief Return the GenParticle id/barcode.
+ * @param id[out] GenParticle::id, or @c UNDEFINEDBC.
+ * @param barcode[out] barcode (deprecated), or @c UNDEFINEDBC.
+ *
+ * The GenParticle within the GenEvent is identified either by
+ * the GenParticle::id or the barcode.
+ * This method will return this by setting either @c id or @c barcode;
+ * the other one is set to @c UNDEFINEDBC.
+ */
+inline
+void HepMcParticleLink::ExtendedBarCode::uniqueID (barcode_type& id,
+                                                     barcode_type& barcode) const
+{
+  barcode_type uid = m_BC;
+  if (uid & BARCODE_MASK) {
+    id = UNDEFINEDBC;
+    barcode = uid & ~BARCODE_MASK;
+  }
+  else {
+    id = uid;
+    barcode = UNDEFINEDBC;
+  }
+}
+
+
 /**
  * @brief Return which collection we're targeting, as an enum.
  */
@@ -279,6 +309,76 @@ HepMcParticleLink::ExtendedBarCode::compareIndex (const HepMcParticleLink& lhs,
 }
 
 
+
+/**
+ * @brief Compare the unique ID part of two links.
+ * @param lhs First link to compare.
+ * @param rhs Second link to compare.
+ * @returns -1, 0, or 1, depending on the result of the comparison.
+ *
+ * The unique ID part of the link can be represented as either
+ * a barcode or the id.
+ * If necessary, the links will be normalized so that they
+ * both refer to an id.
+ */
+inline
+int
+HepMcParticleLink::ExtendedBarCode::compareUniqueID (const HepMcParticleLink& lhs,
+                                                  const HepMcParticleLink& rhs)
+{
+  // Get the stored indices.  The high bit will be set of they
+  // represent a position.  Do a quick test for equality.
+  barcode_type uid1 = lhs.m_extBarcode.m_BC;
+  barcode_type uid2 = rhs.m_extBarcode.m_BC;
+  if (uid1 == uid2) return 0;
+
+  // Normalize the values so that they both refer to event number;
+  // this happens as a side-effect of calling cptr().
+  if (uid1 & BARCODE_MASK) {
+    lhs.cptr();
+    uid1 = lhs.m_extBarcode.m_BC;
+  }
+  if (uid2 & BARCODE_MASK) {
+    rhs.cptr();
+    uid2 = rhs.m_extBarcode.m_BC;
+  }
+
+  // Compare.
+  if (uid1 == uid2) {
+    return 0;
+  }
+  else if (uid1 < uid2) {
+    return -1;
+  }
+  else {
+    return 1;
+  }
+}
+
+
+/**
+ * @brief Change m_BC from barcode to ID.
+ * @param ID GenParticle::id value to set.
+ * @param barcode existing barcode value.
+ *
+ * If the link is currently referencing a GenParticle with @c barcode,
+ * update it so that it instead references the GenParticle
+ * with id value @c ID.
+ *
+ * This may be called concurrently, as long as all such concurrent
+ * calls have the same arguments.
+ */
+inline
+void HepMcParticleLink::ExtendedBarCode::makeID (barcode_type ID,
+                                                 barcode_type barcode) const
+{
+  assert ((ID & BARCODE_MASK) == 0);
+  barcode_type old = barcode | BARCODE_MASK;
+  m_BC.compare_exchange_strong (old, ID);
+  assert (old == (barcode|BARCODE_MASK) || old == ID);
+}
+
+
 /**
  * @brief Change index from position to number.
  * @param index Event number to set.
@@ -302,6 +402,25 @@ void HepMcParticleLink::ExtendedBarCode::makeIndex (index_type index,
 }
 
 
+   /**
+     * @brief Initialize the unique identifier part of the link.
+     * @param uid The id or barcode.
+     * @param barcodeFlag If IS_BARCODE, @c uid represents a GenParticle barcode (deprecated);
+     *        otherwise, it represents a GenParticle::id().
+     */
+inline
+void
+HepMcParticleLink::ExtendedBarCode::setUniqueID (barcode_type uid,
+                                              UniqueIDFlag barcodeFlag)
+{
+  assert ((uid & BARCODE_MASK) == 0);
+  if (barcodeFlag == IS_BARCODE) {
+    uid |= BARCODE_MASK;
+  }
+  m_BC = uid;
+}
+
+
 /**
  * @brief Initialize the event index part of the link.
  * @param idx The index or position.
@@ -320,6 +439,16 @@ HepMcParticleLink::ExtendedBarCode::setIndex (index_type idx,
   m_evtIndex = idx;
 }
 
+inline bool HepMcParticleLink::ExtendedBarCode::linkIsNull() const
+{
+  barcode_type particle_id, particle_barcode;
+  uniqueID (particle_id, particle_barcode);
+  return (
+          (particle_id == 0 && particle_barcode == ExtendedBarCode::UNDEFINEDBC) ||
+          (particle_id  == ExtendedBarCode::UNDEFINEDBC && particle_barcode == 0)
+          );
+}
+
 
 //**************************************************************************
 // HepMcParticleLink
@@ -350,7 +479,7 @@ HepMcParticleLink::HepMcParticleLink (const EventContext& ctx)
                        
 /**
  * @brief Constructor.
- * @param barCode Barcode of the target particle.  0 means a null link.
+ * @param uid Unique ID of the target particle.  0 means a null link.
  * @param eventIndex Identifies the target GenEvent in a McEventCollection,
  *        as either the event number if @c isIndexEventPosition is IS_EVENTNUM,
  *        or the position in the container
@@ -361,20 +490,21 @@ HepMcParticleLink::HepMcParticleLink (const EventContext& ctx)
  * @param sg Optional specification of a specific store to reference.
  */
 inline
-HepMcParticleLink::HepMcParticleLink (barcode_type barCode,
+HepMcParticleLink::HepMcParticleLink (barcode_type uid,
                                       uint32_t eventIndex /*= 0*/,
                                       EBC_EVCOLL evColl /*= EBC_MAINEVCOLL*/,
                                       PositionFlag positionFlag /*= IS_EVENTNUM*/,
+                                      UniqueIDFlag uniqueIDFlag /*=IS_ID*/,
                                       IProxyDict* sg /*= SG::CurrentEventStore::store()*/)
   : m_store (sg),
-    m_extBarcode (barCode, eventIndex, evColl, positionFlag)
+    m_extBarcode (uid, eventIndex, evColl, positionFlag, uniqueIDFlag)
 {
 }
 
                       
 /**
  * @brief Constructor.
- * @param barCode Barcode of the target particle.  0 means a null link.
+ * @param uid Unique ID of the target particle.  0 means a null link.
  * @param eventIndex Identifies the target GenEvent in a McEventCollection,
  *        as either the event number if @c isIndexEventPosition is IS_EVENTNUM,
  *        or the position in the container
@@ -385,21 +515,22 @@ HepMcParticleLink::HepMcParticleLink (barcode_type barCode,
  * @param sg Optional specification of a specific store to reference.
  */
 inline
-HepMcParticleLink::HepMcParticleLink (barcode_type barCode,
+HepMcParticleLink::HepMcParticleLink (barcode_type uid,
                                       uint32_t eventIndex /*= 0*/,
                                       const std::string& evCollName,
                                       PositionFlag positionFlag /*= IS_EVENTNUM*/,
+                                      UniqueIDFlag uniqueIDFlag /*=IS_ID*/,
                                       IProxyDict* sg /*= SG::CurrentEventStore::store()*/)
-  : HepMcParticleLink (barCode, eventIndex,
+  : HepMcParticleLink (uid, eventIndex,
                        find_enumFromKey (evCollName),
-                       positionFlag, sg)
+                       positionFlag, uniqueIDFlag, sg)
 {
 }
 
 
 /**
  * @brief Constructor.
- * @param barCode Barcode of the target particle.  0 means a null link.
+ * @param uid Unique ID of the target particle.  0 means a null link.
  * @param eventIndex Identifies the target GenEvent in a McEventCollection,
  *        as either the event number if @c isIndexEventPosition is IS_EVENTNUM,
  *        or the position in the container
@@ -410,12 +541,14 @@ HepMcParticleLink::HepMcParticleLink (barcode_type barCode,
  * @param ctx Context of the store to reference.
  */
 inline
-HepMcParticleLink::HepMcParticleLink (barcode_type barCode,
+HepMcParticleLink::HepMcParticleLink (barcode_type uid,
                                       uint32_t eventIndex,
                                       EBC_EVCOLL evColl,
                                       PositionFlag positionFlag,
+                                      UniqueIDFlag uniqueIDFlag,
                                       const EventContext& ctx)
-  : HepMcParticleLink (barCode, eventIndex, evColl, positionFlag,
+  : HepMcParticleLink (uid, eventIndex, evColl,
+                       positionFlag, uniqueIDFlag,
                        Atlas::getExtendedEventContext(ctx).proxy())
 {
 }
@@ -535,8 +668,8 @@ HepMcParticleLink::operator bool() const
 inline
 bool HepMcParticleLink::operator== (const HepMcParticleLink& rhs) const
 {
-  return  (m_extBarcode.barcode()==rhs.m_extBarcode.barcode() &&
-           m_extBarcode.getEventCollection()==rhs.m_extBarcode.getEventCollection() &&
+  return  (m_extBarcode.getEventCollection()==rhs.m_extBarcode.getEventCollection() &&
+           ExtendedBarCode::compareUniqueID(*this, rhs) == 0 &&
            ExtendedBarCode::compareIndex (*this, rhs) == 0);
 }
 
@@ -562,24 +695,13 @@ bool HepMcParticleLink::operator< (const HepMcParticleLink& rhs) const
     int cmpIndex = ExtendedBarCode::compareIndex (*this, rhs);
     if (cmpIndex < 0) return true;
     if (cmpIndex == 0) {
-      return m_extBarcode.barcode() < rhs.m_extBarcode.barcode();
+      return ExtendedBarCode::compareUniqueID(*this, rhs);
     }
   }
   return false;
 }
 
 
-/**
- * @brief Return the barcode of the target particle.  0 for a null link.
- * FIXME: return type.
- */
-inline
-int HepMcParticleLink::barcode() const
-{
-  return int(m_extBarcode.barcode());
-}
-
-
 /**
  * @brief Return which collection we're targeting, as an enum.
  */
@@ -606,7 +728,7 @@ char HepMcParticleLink::getEventCollectionAsChar() const
 inline
 HepMcParticleLink::barcode_type HepMcParticleLink::compress() const
 {
-  return ( ((m_extBarcode.barcode()&0xFFFF) << 16) |
+  return ( ((m_extBarcode.uid()&0xFFFF) << 16) |
            eventIndex() );
 }
 

Generators/GeneratorObjects/src/HepMcParticleLink.cxx

@@ -95,16 +95,24 @@ HepMcParticleLink::ExtendedBarCode::eventCollectionFromChar (char evtColl)
 void HepMcParticleLink::ExtendedBarCode::print (std::ostream& os) const
 {
   os << "Event index " ;
-  index_type index, position;
-  eventIndex (index, position);
+  index_type event_number, position;
+  eventIndex (event_number, position);
   if (position != UNDEFINED) {
     os << position << " (position in collection) ";
   }
   else {
-    os << index;
+    os << event_number << " (event number) ";
   }
-  os << ", Barcode " << m_BC
-     << ", McEventCollection "
+  os << ", Unique ID " ;
+  barcode_type particle_id, particle_barcode;
+  uniqueID (particle_id, particle_barcode);
+  if (particle_barcode != UNDEFINED) {
+    os << particle_barcode << " (barcode) ";
+  }
+  else {
+    os << particle_id << " (id) ";
+  }
+  os << ", McEventCollection "
      << HepMcParticleLink::getLastEventCollectionName(this->getEventCollection())
      << "(" << eventCollectionAsChar (m_evtColl) << ")";
 }
@@ -145,7 +153,7 @@ HepMcParticleLink::HepMcParticleLink (const HepMC::ConstGenParticlePtr& part,
                                       IProxyDict* sg /*= SG::CurrentEventStore::store()*/)
   : m_store (sg),
     m_ptr (part),
-    m_extBarcode((nullptr != part) ? HepMC::barcode(part) : 0, eventIndex, evColl, positionFlag)
+    m_extBarcode((nullptr != part) ? part->id() : 0, eventIndex, evColl, positionFlag, IS_ID)
 {
   assert(part);
 
@@ -172,76 +180,150 @@ HepMC::ConstGenParticlePtr HepMcParticleLink::cptr() const
   if (!is_valid && !m_store) {
     return nullptr;
   }
-  if (is_valid) return *m_ptr.ptr();
-    if (0 == barcode()) {
-#if 0
-      MsgStream log (Athena::getMessageSvc(), "HepMcParticleLink");
-      log << MSG::DEBUG
-             << "cptr: no truth particle associated with this hit (barcode==0)."
-             << " Probably this is a noise hit" << endmsg;
-#endif
-      return nullptr;
-    }
-    IProxyDict* sg = m_store;
-    if (!sg) {
-      sg = SG::CurrentEventStore::store();
+  if (is_valid) {
+    return *m_ptr.ptr();
+  }
+  if (m_extBarcode.linkIsNull()) {
+    #if 0
+    MsgStream log (Athena::getMessageSvc(), "HepMcParticleLink");
+    log << MSG::DEBUG
+        << "cptr: no truth particle associated with this hit (barcode==0)."
+        << " Probably this is a noise hit" << endmsg;
+    #endif
+    return nullptr;
+  }
+  IProxyDict* sg = m_store;
+  if (!sg) {
+    sg = SG::CurrentEventStore::store();
+  }
+  if (const McEventCollection* pEvtColl = retrieveMcEventCollection(sg)) {
+    const HepMC::GenEvent *pEvt = nullptr;
+    index_type event_number, position;
+    m_extBarcode.eventIndex (event_number, position);
+    if (event_number == 0) {
+      pEvt = pEvtColl->at(0);
     }
-    if (const McEventCollection* pEvtColl = retrieveMcEventCollection(sg)) {
-      const HepMC::GenEvent *pEvt = nullptr;
-      index_type index, position;
-      m_extBarcode.eventIndex (index, position);
-      if (index == 0) {
-        pEvt = pEvtColl->at(0);
-      }
-      else if (position != ExtendedBarCode::UNDEFINED) {
-        if (position < pEvtColl->size()) {
-          pEvt = pEvtColl->at (position);
-        }
-        else {
-#if 0
-          MsgStream log (Athena::getMessageSvc(), "HepMcParticleLink");
-          log << MSG::WARNING << "cptr: position = " << position << ", McEventCollection size = "<< pEvtColl->size() << endmsg;
-#endif
-          return nullptr;
-        }
+    else if (position != ExtendedBarCode::UNDEFINED) {
+      if (position < pEvtColl->size()) {
+        pEvt = pEvtColl->at (position);
       }
       else {
-        pEvt = pEvtColl->find (index);
+        #if 0
+        MsgStream log (Athena::getMessageSvc(), "HepMcParticleLink");
+        log << MSG::WARNING << "cptr: position = " << position << ", McEventCollection size = "<< pEvtColl->size() << endmsg;
+        #endif
+        return nullptr;
       }
+    }
+    else {
+      pEvt = pEvtColl->find (event_number);
+    }
 
-      if (nullptr != pEvt) {
-        // Be sure to update m_extBarcode before m_ptrs;
-        // otherwise, the logic in eventIndex() won't work correctly.
-        if (position != ExtendedBarCode::UNDEFINED) {
-          m_extBarcode.makeIndex (pEvt->event_number(), position);
-        }
-        if (barcode() != 0) {
-         const HepMC::ConstGenParticlePtr p = HepMC::barcode_to_particle(pEvt,barcode());
+    if (nullptr != pEvt) {
+      // Be sure to update m_extBarcode before m_ptrs;
+      // otherwise, the logic in eventIndex() won't work correctly.
+      if (position != ExtendedBarCode::UNDEFINED) {
+        m_extBarcode.makeIndex (pEvt->event_number(), position);
+      }
+      if (event_number == 0) {
+        m_extBarcode.makeIndex (pEvt->event_number(), position);
+      }
+      if ( !m_extBarcode.linkIsNull() ) { // Check that either the ID or Barcode is non-zero or undefined
+        barcode_type particle_id, particle_barcode;
+        m_extBarcode.uniqueID (particle_id, particle_barcode);
+        if (particle_id == ExtendedBarCode::UNDEFINEDBC) {
+          // barcode to GenParticle
+          const HepMC::ConstGenParticlePtr p = HepMC::barcode_to_particle(pEvt,int(particle_barcode));
           if (p) {
+            int genParticleID = p->id();
+            if (genParticleID > -1) {
+              particle_id = static_cast<barcode_type>(genParticleID);particle_id = p->id();
+              m_extBarcode.makeID (particle_id, particle_barcode);
+            }
             m_ptr.set (p);
             return p;
           }
         }
-      } else {
-        MsgStream log (Athena::getMessageSvc(), "HepMcParticleLink");
-        if (position != ExtendedBarCode::UNDEFINED) {
-          log << MSG::WARNING
-            << "cptr: Mc Truth not stored for event at " << position
-            << endmsg;
-        } else {
-          log << MSG::WARNING
-            << "cptr: Mc Truth not stored for event with event number " << index
-            << endmsg;
+        else {
+          // id to GenParticle
+          const auto &particles = pEvt->particles();
+          if (particle_id-1 < particles.size()) {
+            const HepMC::ConstGenParticlePtr p = particles[particle_id-1];
+            if (p) {
+              m_ptr.set (p);
+              return p;
+            }
+          }
         }
       }
     } else {
       MsgStream log (Athena::getMessageSvc(), "HepMcParticleLink");
-      log << MSG::WARNING << "cptr: McEventCollection not found" << endmsg;
+      if (position != ExtendedBarCode::UNDEFINED) {
+        log << MSG::WARNING
+            << "cptr: Mc Truth not stored for event at " << position
+            << endmsg;
+      } else {
+        log << MSG::WARNING
+            << "cptr: Mc Truth not stored for event with event number " << event_number
+            << endmsg;
+      }
     }
+  } else {
+    MsgStream log (Athena::getMessageSvc(), "HepMcParticleLink");
+    log << MSG::WARNING << "cptr: McEventCollection not found" << endmsg;
+  }
   return nullptr;
 }
 
 
+/**
+ * @brief Return the id of the referenced GenParticle.
+ */
+int HepMcParticleLink::id() const
+{
+  // dummy link
+  if (!m_ptr.isValid() && !m_store) {
+    return 0; // TODO Decide if this is a good default - constant from MagicNumbers.h instead?
+  }
+
+  barcode_type particle_id, particle_barcode;
+  m_extBarcode.uniqueID (particle_id, particle_barcode);
+  if (particle_id == ExtendedBarCode::UNDEFINEDBC) {
+    (void) eventIndex(); // FIXME be careful to avoid an infinite loop of calls here
+  }
+  m_extBarcode.uniqueID (particle_id, particle_barcode);
+  if (particle_id != ExtendedBarCode::UNDEFINEDBC) {
+    return particle_id;
+  }
+  return 0;
+}
+
+
+/**
+ * @brief Return the barcode of the target particle.  0 for a null link.
+ * FIXME: return type.
+ */
+int HepMcParticleLink::barcode() const
+{
+  barcode_type particle_id, particle_barcode;
+  m_extBarcode.uniqueID (particle_id, particle_barcode);
+  if (particle_barcode != ExtendedBarCode::UNDEFINEDBC) {
+    return int(particle_barcode);
+  }
+  // dummy link
+  if (!m_ptr.isValid() && !m_store) {
+    return 0; // TODO Decide if this is a good default - constant from MagicNumbers.h instead?
+  }
+  // we will need to look up the barcode from the GenParticle
+  (void) eventIndex(); // FIXME be careful to avoid an infinite loop of calls here
+  if (cptr()) {
+    return HepMC::barcode(cptr());
+  }
+  return 0;
+  //return int(m_extBarcode.barcode());
+}
+
+
 /**
  * @brief Return the event number of the referenced GenEvent.
  *        0 means the first GenEvent in the collection.
@@ -282,13 +364,13 @@ HepMcParticleLink::index_type HepMcParticleLink::eventIndex() const
     }
   }
   // Don't trip the assertion for a null link.
-  if (barcode() == 0 ) {  // || barcode() == 0x7fffffff)
-    if (event_number != ExtendedBarCode::UNDEFINED) {
-      return event_number;
+  if ( m_extBarcode.linkIsNull() )
+    {
+      return (event_number != ExtendedBarCode::UNDEFINED) ? event_number : 0;
     }
-    return 0;
-  }
+  // Attempt to find the GenParticle
   cptr();
+  // Check if event_number is valid once more
   m_extBarcode.eventIndex (event_number, event_position);
   assert (event_number != ExtendedBarCode::UNDEFINED);
   return event_number;
@@ -302,17 +384,17 @@ HepMcParticleLink::index_type HepMcParticleLink::eventIndex() const
 HepMcParticleLink::index_type
 HepMcParticleLink::getEventPositionInCollection (const IProxyDict* sg) const
 {
-  index_type index, position;
-  m_extBarcode.eventIndex (index, position);
+  index_type event_number, position;
+  m_extBarcode.eventIndex (event_number, position);
   if (position != ExtendedBarCode::UNDEFINED) {
     return position;
   }
-  if (index == 0) {
+  if (event_number == 0) {
     return 0;
   }
 
   EBC_EVCOLL evColl = getEventCollection();
-  std::vector<index_type> positions = getEventPositionInCollection(index, evColl, sg);
+  std::vector<index_type> positions = getEventPositionInCollection(event_number, evColl, sg);
   return positions[0];
 }
 
@@ -322,14 +404,14 @@ HepMcParticleLink::getEventPositionInCollection (const IProxyDict* sg) const
  *        (first) GenEvent with a given event number
  */
 std::vector<HepMcParticleLink::index_type>
-HepMcParticleLink::getEventPositionInCollection (index_type index, EBC_EVCOLL evColl, const IProxyDict* sg)
+HepMcParticleLink::getEventPositionInCollection (index_type event_number, EBC_EVCOLL evColl, const IProxyDict* sg)
 {
   std::vector<index_type> positions; positions.reserve(1);
-  const int intIndex = static_cast<int>(index);
+  const int int_event_number = static_cast<int>(event_number);
   if (const McEventCollection* coll = retrieveMcEventCollection (evColl,sg)) {
     size_t sz = coll->size();
     for (size_t i = 0; i < sz; i++) {
-      if ((*coll)[i]->event_number() == intIndex) {
+      if ((*coll)[i]->event_number() == int_event_number) {
         positions.push_back(i);
       }
     }

Generators/GeneratorObjects/test/HepMcParticleLink_test.cxx

@@ -137,7 +137,7 @@ namespace MCTesting {
     HepMC::set_signal_process_vertex(evt, v3 );
     // the event is complete, we now print it out to the screen
 #ifdef GENP_DEBUG
-    evt->print();
+    std::cout << evt << std::endl;
 #endif
 
     // delete all particle data objects in the particle data table pdt
@@ -275,41 +275,47 @@ namespace MCTesting {
     std::copy_if( pEvent->particles().begin(), pEvent->particles().end(), std::back_inserter(theGammas), is_photon() );
 #else
     std::copy_if( pEvent->particles_begin(), pEvent->particles_end(),
-                    back_inserter(theGammas), is_photon() );
+                  back_inserter(theGammas), is_photon() );
 #endif
     ASSERT_EQ(1u, theGammas.size());
     HepMC::ConstGenParticlePtr pGamma(theGammas.front());
 #ifdef GENP_DEBUG
-    pGamma->print();
-    std::cout << "gamma barcode " << hex << HepMC::barcode(pGamma) << std::endl;
+    std::cout << pGamma << std::endl;
+    std::cout << "gamma barcode " << HepMC::barcode(pGamma) << std::endl;
 #endif
 
     HepMcParticleLink gammaLink1(pGamma);
-    HepMcParticleLink gammaLink2(HepMC::barcode(pGamma));
+    HepMcParticleLink gammaLink2(pGamma->id());
+    HepMcParticleLink gammaLink3(HepMC::barcode(pGamma), 0, EBC_MAINEVCOLL, HepMcParticleLink::IS_EVENTNUM, HepMcParticleLink::IS_BARCODE);
     HepMcParticleLink gammaLink11(pGamma, 1);
-    HepMcParticleLink gammaLink12(HepMC::barcode(pGamma), 1);
+    HepMcParticleLink gammaLink12(pGamma->id(), 1);
+    HepMcParticleLink gammaLink13(HepMC::barcode(pGamma), 1, EBC_MAINEVCOLL, HepMcParticleLink::IS_EVENTNUM, HepMcParticleLink::IS_BARCODE);
 
     std::stringstream out;
     out << "Testing HepMcParticleLink streamer "
-              << gammaLink1 << " --- " << gammaLink11 <<std::endl;
+        << gammaLink1 << " --- " << gammaLink11 <<std::endl;
 #ifdef HEPMC3
-    ASSERT_EQ(out.str(),"Testing HepMcParticleLink streamer Event index 0, Barcode 10005, McEventCollection CollectionNotSet(a) --- Event index 1, Barcode 10005, McEventCollection CollectionNotSet(a)\n");
+    ASSERT_EQ(out.str(),"Testing HepMcParticleLink streamer Event index 0 (event number) , Unique ID 5 (id) , McEventCollection CollectionNotSet(a) --- Event index 1 (event number) , Unique ID 5 (id) , McEventCollection CollectionNotSet(a)\n");
 #else
     ASSERT_EQ(out.str(),"Testing HepMcParticleLink streamer Event index 0, Barcode 10005, McEventCollection CollectionNotSet(a) --- Event index 1, Barcode 10005, McEventCollection CollectionNotSet(a)\n");
 #endif
 
 #ifdef GENP_DEBUG
-    std::cout << "link barcode " << hex << gammaLink1.barcode() << std::endl;
-    std::cout << "link index " << hex << gammaLink1.eventIndex() << std::endl;
-    std::cout << "link1 barcode " << hex << gammaLink11.barcode() << std::endl;
-    std::cout << "link1 index " << hex << gammaLink11.eventIndex() << std::endl;
+    std::cout << "link barcode " << gammaLink1.barcode() << std::endl;
+    std::cout << "link index " << gammaLink1.eventIndex() << std::endl;
+    std::cout << "link id " << gammaLink1.id() << std::endl;
+    std::cout << "link1 barcode " << gammaLink11.barcode() << std::endl;
+    std::cout << "link1 index " << gammaLink11.eventIndex() << std::endl;
+    std::cout << "link1 id " << gammaLink1.id() << std::endl;
 #endif
     ASSERT_EQ(*gammaLink1, *gammaLink2);
     ASSERT_EQ(gammaLink1, gammaLink2);
     ASSERT_EQ(gammaLink1.barcode(), HepMC::barcode(pGamma));
 
+    ASSERT_EQ(gammaLink1, gammaLink3);
     ASSERT_EQ(*gammaLink11, *gammaLink12);
     ASSERT_EQ(gammaLink11, gammaLink12);
+    ASSERT_EQ(gammaLink11, gammaLink13);
 
     ASSERT_EQ(*gammaLink1, *gammaLink11);
     ASSERT_NE( gammaLink1, gammaLink11 ); //FIXME weird! Can't check ptr...
@@ -330,9 +336,9 @@ namespace MCTesting {
     // still work.
     HepMcParticleLink testLink1a(particle1,0);
     ASSERT_TRUE( testLink1a.isValid() );
-    // A HepMcParticleLink built using the barcode and the position of
+    // A HepMcParticleLink built using the id and the position of
     // the GenEvent in the McEventCollection should still work.
-    HepMcParticleLink testLink1b(HepMC::barcode(particle1),0);
+    HepMcParticleLink testLink1b(particle1->id(),0);
     ASSERT_TRUE( testLink1b.isValid() );
   }
 
@@ -385,7 +391,7 @@ namespace MCTesting {
     // A HepMcParticleLink built using the barcode and the position of
     // the GenEvent.
     HepMcParticleLink testLink1b(HepMC::barcode(particle1),dummyIndex1, EBC_MAINEVCOLL,
-                                 HepMcParticleLink::IS_POSITION);
+                                 HepMcParticleLink::IS_POSITION, HepMcParticleLink::IS_BARCODE);
     ASSERT_TRUE( testLink1b.isValid() );
     ASSERT_EQ( HepMC::barcode(particle1), testLink1b.barcode());
     ASSERT_EQ( refEvtNum1, testLink1b.eventIndex());
@@ -400,9 +406,9 @@ namespace MCTesting {
     ASSERT_EQ( refEvtNum1, testLink1c.eventIndex());
     ASSERT_EQ( dummyIndex1, testLink1c.getEventPositionInCollection(sg));
     ASSERT_EQ(particle1,testLink1c.cptr());
-    // A HepMcParticleLink built using the barcode and the event_number of
+    // A HepMcParticleLink built using the id and the event_number of
     // the GenEvent.
-    HepMcParticleLink testLink1d(HepMC::barcode(particle1),event_number1);
+    HepMcParticleLink testLink1d(particle1->id(),event_number1);
     ASSERT_TRUE( testLink1d.isValid() );
     ASSERT_EQ( HepMC::barcode(particle1), testLink1d.barcode());
     ASSERT_NE( dummyIndex1, testLink1d.eventIndex());
@@ -460,7 +466,7 @@ namespace MCTesting {
     // A HepMcParticleLink built using the barcode and the position of
     // the GenEvent.
     HepMcParticleLink testLink2b(HepMC::barcode(particle2), dummyIndex2, EBC_MAINEVCOLL,
-                                 HepMcParticleLink::IS_POSITION);
+                                 HepMcParticleLink::IS_POSITION, HepMcParticleLink::IS_BARCODE);
     ASSERT_TRUE( testLink2b.isValid() );
     ASSERT_EQ( HepMC::barcode(particle2), testLink2b.barcode());
     ASSERT_EQ( refEvtNum2, testLink2b.eventIndex());
@@ -477,7 +483,7 @@ namespace MCTesting {
     ASSERT_EQ(particle2,testLink2c.cptr());
     // A HepMcParticleLink built using the barcode and the event_number of
     // the GenEvent.
-    HepMcParticleLink testLink2d(HepMC::barcode(particle2),event_number2);
+    HepMcParticleLink testLink2d(particle2->id(),event_number2);
     ASSERT_TRUE( testLink2d.isValid() );
     ASSERT_EQ( HepMC::barcode(particle2), testLink2d.barcode());
     ASSERT_NE( dummyIndex2, testLink2d.eventIndex());
@@ -533,7 +539,7 @@ namespace MCTesting {
     // A HepMcParticleLink built using the barcode and the position of
     // the GenEvent.
     HepMcParticleLink testLink3b(HepMC::barcode(particle3), dummyIndex3, EBC_MAINEVCOLL,
-                                 HepMcParticleLink::IS_POSITION);
+                                 HepMcParticleLink::IS_POSITION, HepMcParticleLink::IS_BARCODE);
     ASSERT_TRUE( testLink3b.isValid() );
     ASSERT_EQ( HepMC::barcode(particle3), testLink3b.barcode());
     ASSERT_EQ( refEvtNum3, testLink3b.eventIndex());
@@ -546,9 +552,9 @@ namespace MCTesting {
     ASSERT_NE( dummyIndex3, testLink3c.eventIndex());
     ASSERT_EQ( refEvtNum3, testLink3c.eventIndex());
     ASSERT_EQ(particle3,testLink3c.cptr());
-    // A HepMcParticleLink built using the barcode and the event_number of
+    // A HepMcParticleLink built using the id and the event_number of
     // the GenEvent. BROKEN
-    HepMcParticleLink testLink3d(HepMC::barcode(particle3),event_number3);
+    HepMcParticleLink testLink3d(particle3->id(),event_number3);
     ASSERT_TRUE( testLink3d.isValid() );
     ASSERT_EQ( HepMC::barcode(particle3), testLink3d.barcode());
     ASSERT_NE( dummyIndex3, testLink3d.eventIndex());
@@ -602,9 +608,9 @@ namespace MCTesting {
     ASSERT_EQ( refEvtNum4, testLink4a.eventIndex());
     ASSERT_EQ( dummyIndex4, testLink4a.getEventPositionInCollection(sg));
     ASSERT_EQ( particle4, testLink4a.cptr());
-    // A HepMcParticleLink built using the barcode and the event_number of
+    // A HepMcParticleLink built using the id and the event_number of
     // the GenEvent.
-    HepMcParticleLink testLink4b(HepMC::barcode(particle4),event_number4);
+    HepMcParticleLink testLink4b(particle4->id(),event_number4);
     ASSERT_TRUE( testLink4b.isValid() );
     ASSERT_EQ( HepMC::barcode(particle4), testLink4b.barcode());
     ASSERT_EQ( refEvtNum4, testLink4b.eventIndex());
@@ -623,7 +629,7 @@ namespace MCTesting {
     // A HepMcParticleLink built using the barcode and the position of
     // the GenEvent.
     HepMcParticleLink testLink4d(HepMC::barcode(particle4), dummyIndex4, EBC_MAINEVCOLL,
-                                 HepMcParticleLink::IS_POSITION);
+                                 HepMcParticleLink::IS_POSITION, HepMcParticleLink::IS_BARCODE);
     ASSERT_TRUE( testLink4d.isValid() );
     ASSERT_EQ( HepMC::barcode(particle4), testLink4d.barcode());
     ASSERT_EQ( refEvtNum4, testLink4d.eventIndex());
@@ -762,7 +768,7 @@ namespace MCTesting {
     // Link to a GenParticle which was not recorded to the
     // McEventCollection, even though other parts of the same GenEvent
     // were recorded.
-    HepMcParticleLink testLink6a(cutBarcode, refEvtNum1);
+    HepMcParticleLink testLink6a(cutBarcode, refEvtNum1, EBC_MAINEVCOLL, HepMcParticleLink::IS_EVENTNUM, HepMcParticleLink::IS_BARCODE);
     ASSERT_FALSE( testLink6a.isValid() );
     ASSERT_EQ( cutBarcode, testLink6a.barcode());
     ASSERT_EQ( refEvtNum1, testLink6a.eventIndex());
@@ -770,7 +776,7 @@ namespace MCTesting {
     ASSERT_EQ( cutParticlePtr, testLink6a.cptr());
 
     // Link to a GenEvent which was not recorded to the McEventCollection
-    HepMcParticleLink testLink6b(cutBarcode, refEvtNum5);
+    HepMcParticleLink testLink6b(cutBarcode, refEvtNum5, EBC_MAINEVCOLL, HepMcParticleLink::IS_EVENTNUM, HepMcParticleLink::IS_BARCODE);
     ASSERT_FALSE( testLink6b.isValid() );
     ASSERT_EQ( cutBarcode, testLink6b.barcode());
     ASSERT_EQ( refEvtNum5, testLink6b.eventIndex());
@@ -825,7 +831,7 @@ namespace MCTesting {
     // A HepMcParticleLink built using the barcode and the position of
     // the GenEvent.
     HepMcParticleLink testLink1b(HepMC::barcode(particle1), dummyIndex1, EBC_MAINEVCOLL,
-                                 HepMcParticleLink::IS_POSITION);
+                                 HepMcParticleLink::IS_POSITION, HepMcParticleLink::IS_BARCODE);
     ASSERT_TRUE( testLink1b.isValid() );
     ASSERT_EQ( HepMC::barcode(particle1), testLink1b.barcode());
     ASSERT_EQ( refEvtNum1, testLink1b.eventIndex());
@@ -840,9 +846,9 @@ namespace MCTesting {
     ASSERT_EQ( refEvtNum1, testLink1c.eventIndex());
     ASSERT_EQ( dummyIndex1, testLink1c.getEventPositionInCollection(sg));
     ASSERT_EQ(particle1,testLink1c.cptr());
-    // A HepMcParticleLink built using the barcode and the event_number of
+    // A HepMcParticleLink built using the id and the event_number of
     // the GenEvent.
-    HepMcParticleLink testLink1d(HepMC::barcode(particle1),event_number1);
+    HepMcParticleLink testLink1d(particle1->id(),event_number1);
     ASSERT_TRUE( testLink1d.isValid() );
     ASSERT_EQ( HepMC::barcode(particle1), testLink1d.barcode());
     ASSERT_NE( dummyIndex1, testLink1d.eventIndex());
@@ -864,7 +870,7 @@ namespace MCTesting {
     // A HepMcParticleLink built using the barcode and the position of
     // the GenEvent.
     HepMcParticleLink testLink2b(HepMC::barcode(particle2), dummyIndex2, EBC_MAINEVCOLL,
-                                 HepMcParticleLink::IS_POSITION);
+                                 HepMcParticleLink::IS_POSITION, HepMcParticleLink::IS_BARCODE);
     ASSERT_TRUE( testLink2b.isValid() );
     ASSERT_EQ( HepMC::barcode(particle2), testLink2b.barcode());
     ASSERT_EQ( refEvtNum2, testLink2b.eventIndex());
@@ -879,9 +885,9 @@ namespace MCTesting {
     ASSERT_EQ( refEvtNum2, testLink2c.eventIndex());
     ASSERT_EQ( dummyIndex2, testLink2c.getEventPositionInCollection(sg));
     ASSERT_EQ(particle2,testLink2c.cptr());
-    // A HepMcParticleLink built using the barcode and the event_number of
+    // A HepMcParticleLink built using the id and the event_number of
     // the GenEvent.
-    HepMcParticleLink testLink2d(HepMC::barcode(particle2),event_number2);
+    HepMcParticleLink testLink2d(particle2->id(),event_number2);
     ASSERT_TRUE( testLink2d.isValid() );
     ASSERT_EQ( HepMC::barcode(particle2), testLink2d.barcode());
     ASSERT_NE( dummyIndex2, testLink2d.eventIndex());

Generators/GeneratorObjectsTPCnv/src/HepMcParticleLinkCnv_p1.cxx

@@ -42,7 +42,8 @@ void HepMcParticleLinkCnv_p1::persToTrans( const HepMcParticleLink_p1* persObj,
     ( HepMcParticleLink::ExtendedBarCode( persObj->m_barcode,
                                           persObj->m_mcEvtIndex,
                                           evColl,
-                                          flag) );
+                                          flag,
+                                          HepMcParticleLink::IS_BARCODE) );
 }
 
 void HepMcParticleLinkCnv_p1::transToPers( const HepMcParticleLink* transObj,

Generators/GeneratorObjectsTPCnv/src/HepMcParticleLinkCnv_p2.cxx

@@ -26,7 +26,8 @@ void HepMcParticleLinkCnv_p2::persToTrans( const HepMcParticleLink_p2* persObj,
     ( HepMcParticleLink::ExtendedBarCode( persObj->m_barcode,
                                           persObj->m_mcEvtIndex,
                                           HepMcParticleLink::ExtendedBarCode::eventCollectionFromChar(persObj->m_evtColl),
-                                          flag) );
+                                          flag,
+                                          HepMcParticleLink::IS_BARCODE) );
 }
 
 void HepMcParticleLinkCnv_p2::transToPers( const HepMcParticleLink* transObj,

Generators/GeneratorObjectsTPCnv/test/HepMcParticleLinkCnv_p1_test.cxx

@@ -212,42 +212,48 @@ void test1()
   createMcEventCollectionInStoreGate(genPartList);
   assert ( genPartList.size() == 13 );
   // HepMcParticleLinks pointing at GenParticles in the first GenEvent in the McEventCollection
-  // By event_number
+  // By barcode + event_number
   HepMC::ConstGenParticlePtr particle1 = genPartList.at(0);
-  HepMcParticleLink trans1a(HepMC::barcode(particle1),particle1->parent_event()->event_number());
+  HepMcParticleLink trans1a(HepMC::barcode(particle1),particle1->parent_event()->event_number(),EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans1a);
-  // By position
-  HepMcParticleLink trans1b(HepMC::barcode(particle1),0,EBC_MAINEVCOLL,HepMcParticleLink::IS_POSITION);
+  // By id + event_number
+  HepMcParticleLink trans1b(particle1->id(),particle1->parent_event()->event_number());
   testit (trans1b);
+  // By barcode + position
+  HepMcParticleLink trans1c(HepMC::barcode(particle1),0,EBC_MAINEVCOLL,HepMcParticleLink::IS_POSITION,HepMcParticleLink::IS_BARCODE);
+  testit (trans1c);
+  // By id + position
+  HepMcParticleLink trans1d(particle1->id(),0,EBC_MAINEVCOLL,HepMcParticleLink::IS_POSITION);
+  testit (trans1d);
   // HepMcParticleLinks pointing at GenParticles in other GenEvents in the McEventCollection
   HepMC::ConstGenParticlePtr particle2 = genPartList.at(7);
-  HepMcParticleLink trans2(HepMC::barcode(particle2),particle2->parent_event()->event_number());
+  HepMcParticleLink trans2(HepMC::barcode(particle2),particle2->parent_event()->event_number(),EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans2);
   HepMC::ConstGenParticlePtr particle3 = genPartList.at(8);
-  HepMcParticleLink trans3(HepMC::barcode(particle3),particle3->parent_event()->event_number());
+  HepMcParticleLink trans3(HepMC::barcode(particle3),particle3->parent_event()->event_number(),EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans3);
   // HepMcParticleLinks pointing at filtered pileup truth
   HepMC::ConstGenParticlePtr particle4 = genPartList.at(12);
-  HepMcParticleLink trans4(HepMC::barcode(particle4),particle4->parent_event()->event_number());
+  HepMcParticleLink trans4(HepMC::barcode(particle4),particle4->parent_event()->event_number(),EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans4);
   // HepMcParticleLinks pointing at delta-ray (barcode=0 - not recorded in McEventCollection) using event_number
   int deltaRayBarcode(0);
-  HepMcParticleLink trans5a(deltaRayBarcode,particle1->parent_event()->event_number());
+  HepMcParticleLink trans5a(deltaRayBarcode,particle1->parent_event()->event_number(),EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans5a);
   // HepMcParticleLinks pointing at delta-ray (barcode=0 - not recorded in McEventCollection) using position
-  HepMcParticleLink trans5b(deltaRayBarcode,0,EBC_MAINEVCOLL,HepMcParticleLink::IS_POSITION);
+  HepMcParticleLink trans5b(deltaRayBarcode,0,EBC_MAINEVCOLL,HepMcParticleLink::IS_POSITION,HepMcParticleLink::IS_BARCODE);
   testit (trans5b);
   // Link to a GenParticle which was not recorded to the
   // McEventCollection, even though other parts of the same GenEvent
   // were recorded.
   const HepMcParticleLink::index_type refEvtNum1 = static_cast<HepMcParticleLink::index_type>(particle1->parent_event()->event_number());
   const int cutBarcode(210001);
-  HepMcParticleLink trans6a(cutBarcode, refEvtNum1);
+  HepMcParticleLink trans6a(cutBarcode, refEvtNum1,EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans6a);
   // Link to a GenEvent which was not recorded to the McEventCollection
   const int event_number5(460);
   const HepMcParticleLink::index_type refEvtNum5 = static_cast<HepMcParticleLink::index_type>(event_number5);
-  HepMcParticleLink trans6b(cutBarcode, refEvtNum5);
+  HepMcParticleLink trans6b(cutBarcode, refEvtNum5,EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans6b);
 }
 

Generators/GeneratorObjectsTPCnv/test/HepMcParticleLinkCnv_p2_test.cxx

@@ -211,42 +211,48 @@ void test1()
   createMcEventCollectionInStoreGate(genPartList);
   assert ( genPartList.size() == 13 );
   // HepMcParticleLinks pointing at GenParticles in the first GenEvent in the McEventCollection
-  // By event_number
+  // By barcode + event_number
   HepMC::ConstGenParticlePtr particle1 = genPartList.at(0);
-  HepMcParticleLink trans1a(HepMC::barcode(particle1),particle1->parent_event()->event_number());
+  HepMcParticleLink trans1a(HepMC::barcode(particle1),particle1->parent_event()->event_number(),EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans1a);
-  // By position
-  HepMcParticleLink trans1b(HepMC::barcode(particle1),0,EBC_MAINEVCOLL,HepMcParticleLink::IS_POSITION);
+  // By id + event_number
+  HepMcParticleLink trans1b(particle1->id(),particle1->parent_event()->event_number());
   testit (trans1b);
+  // By barcode + position
+  HepMcParticleLink trans1c(HepMC::barcode(particle1),0,EBC_MAINEVCOLL,HepMcParticleLink::IS_POSITION,HepMcParticleLink::IS_BARCODE);
+  testit (trans1c);
+  // By id + position
+  HepMcParticleLink trans1d(particle1->id(),0,EBC_MAINEVCOLL,HepMcParticleLink::IS_POSITION);
+  testit (trans1d);
   // HepMcParticleLinks pointing at GenParticles in other GenEvents in the McEventCollection
   HepMC::ConstGenParticlePtr particle2 = genPartList.at(7);
-  HepMcParticleLink trans2(HepMC::barcode(particle2),particle2->parent_event()->event_number());
+  HepMcParticleLink trans2(HepMC::barcode(particle2),particle2->parent_event()->event_number(),EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans2);
   HepMC::ConstGenParticlePtr particle3 = genPartList.at(8);
-  HepMcParticleLink trans3(HepMC::barcode(particle3),particle3->parent_event()->event_number());
+  HepMcParticleLink trans3(HepMC::barcode(particle3),particle3->parent_event()->event_number(),EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans3);
   // HepMcParticleLinks pointing at filtered pileup truth
   HepMC::ConstGenParticlePtr particle4 = genPartList.at(12);
-  HepMcParticleLink trans4(HepMC::barcode(particle4),particle4->parent_event()->event_number());
+  HepMcParticleLink trans4(HepMC::barcode(particle4),particle4->parent_event()->event_number(),EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans4);
   // HepMcParticleLinks pointing at delta-ray (barcode=0 - not recorded in McEventCollection) using event number
   int deltaRayBarcode(0);
-  HepMcParticleLink trans5a(deltaRayBarcode,particle1->parent_event()->event_number());
+  HepMcParticleLink trans5a(deltaRayBarcode,particle1->parent_event()->event_number(),EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans5a);
   // HepMcParticleLinks pointing at delta-ray (barcode=0 - not recorded in McEventCollection) using hard-scatter event position
-  HepMcParticleLink trans5b(deltaRayBarcode,0,EBC_MAINEVCOLL,HepMcParticleLink::IS_POSITION);
+  HepMcParticleLink trans5b(deltaRayBarcode,0,EBC_MAINEVCOLL,HepMcParticleLink::IS_POSITION,HepMcParticleLink::IS_BARCODE);
   testit (trans5b);
   // Link to a GenParticle which was not recorded to the
   // McEventCollection, even though other parts of the same GenEvent
   // were recorded.
   const HepMcParticleLink::index_type refEvtNum1 = static_cast<HepMcParticleLink::index_type>(particle1->parent_event()->event_number());
   const int cutBarcode(210001);
-  HepMcParticleLink trans6a(cutBarcode, refEvtNum1);
+  HepMcParticleLink trans6a(cutBarcode, refEvtNum1,EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans6a);
   // Link to a GenEvent which was not recorded to the McEventCollection
   const int event_number5(460);
   const HepMcParticleLink::index_type refEvtNum5 = static_cast<HepMcParticleLink::index_type>(event_number5);
-  HepMcParticleLink trans6b(cutBarcode, refEvtNum5);
+  HepMcParticleLink trans6b(cutBarcode, refEvtNum5,EBC_MAINEVCOLL,HepMcParticleLink::IS_EVENTNUM,HepMcParticleLink::IS_BARCODE);
   testit (trans6b);
 }