o Added a Clone() method to InterchangeObject and derivatives

   that allows making a descriptor copy that is not owned by
   any other strucure. The caller must arrange to delete the
   object pointer returned.

 o While implementing the above it became obvious that the
   reference-to-a-pointer-to-the-dictionary idiom that is used
   throughout the lower levels of the MXF library was the
   cause of much more grief than it was originally designed to
   prevent. This was made even more obvious when I replaced all
   of it with simple pointers, which revealed several shadow
   instances of m_Dict that were only reliable while the object
   that held them was valid.

1 files changed, 28 insertions, 26 deletions

diff --git a/src/MXF.h b/src/MXF.h
index ee0be96..5cc883f 100755
--- a/src/MXF.h
+++ b/src/MXF.h
@@ -1,5 +1,5 @@
 /*
-Copyright (c) 2005-2018, John Hurst
+Copyright (c) 2005-2021, John Hurst
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -44,13 +44,13 @@ namespace ASDCP
       const ui32_t kl_length = ASDCP::SMPTE_UL_LENGTH + ASDCP::MXF_BER_LENGTH;
 
       //
-      typedef ASDCP::MXF::InterchangeObject* (*MXFObjectFactory_t)(const Dictionary*&);
+      typedef ASDCP::MXF::InterchangeObject* (*MXFObjectFactory_t)(const Dictionary*);
 
       //
       void SetObjectFactory(const UL& label, MXFObjectFactory_t factory);
 
       //
-      InterchangeObject* CreateObject(const Dictionary*& Dict, const UL& label);
+      InterchangeObject* CreateObject(const Dictionary* Dict, const UL& label);
 
 
       // seek an open file handle to the start of the RIP KLV packet
@@ -98,14 +98,14 @@ namespace ASDCP
 	      }
 	    };
 
-	  const Dictionary*& m_Dict;
+	  const Dictionary* m_Dict;
 
 	  typedef SimpleArray<PartitionPair>::iterator pair_iterator;
 	  typedef SimpleArray<PartitionPair>::const_iterator const_pair_iterator;
 
 	  SimpleArray<PartitionPair> PairArray;
 
-	RIP(const Dictionary*& d) : m_Dict(d) {}
+	RIP(const Dictionary* d) : m_Dict(d) {}
 	  virtual ~RIP() {}
 	  virtual Result_t InitFromFile(const Kumu::FileReader& Reader);
 	  virtual Result_t WriteToFile(Kumu::FileWriter& Writer);
@@ -137,7 +137,7 @@ namespace ASDCP
 	  mem_ptr<PacketList> m_PacketList;
 
 	public:
-	  const Dictionary*& m_Dict;
+	  const Dictionary* m_Dict;
 
 	  ui16_t    MajorVersion;
 	  ui16_t    MinorVersion;
@@ -153,7 +153,7 @@ namespace ASDCP
 	  UL        OperationalPattern;
 	  Batch<UL> EssenceContainers;
 
-	  Partition(const Dictionary*&);
+	  Partition(const Dictionary*);
 	  virtual ~Partition();
 	  virtual void     AddChildObject(InterchangeObject*); // takes ownership
 	  virtual Result_t InitFromFile(const Kumu::FileReader& Reader);
@@ -221,9 +221,9 @@ namespace ASDCP
 	    };
 
 	  Batch<LocalTagEntry> LocalTagEntryBatch;
-	  const Dictionary*& m_Dict;
+	  const Dictionary* m_Dict;
 
-	  Primer(const Dictionary*&);
+	  Primer(const Dictionary*);
 	  virtual ~Primer();
 
 	  virtual void     ClearTagList();
@@ -290,18 +290,20 @@ namespace ASDCP
       //
       class InterchangeObject : public ASDCP::KLVPacket
 	{
+	  ASDCP_NO_COPY_CONSTRUCT(InterchangeObject);
 	  InterchangeObject();
 
 	public:
-	  const Dictionary*& m_Dict;
+	  const Dictionary* m_Dict;
 	  IPrimerLookup* m_Lookup;
 	  UUID           InstanceUID;
 	  optional_property<UUID>  GenerationUID;
 
-	InterchangeObject(const Dictionary*& d) : m_Dict(d), m_Lookup(0) {}
-	  virtual ~InterchangeObject() {}
+	  InterchangeObject(const Dictionary* d);
+	  virtual ~InterchangeObject();
 
 	  virtual void Copy(const InterchangeObject& rhs);
+	  virtual InterchangeObject *Clone() const;
           virtual Result_t InitFromTLVSet(TLVReader& TLVSet);
 	  virtual Result_t InitFromBuffer(const byte_t* p, ui32_t l);
 	  virtual Result_t WriteToTLVSet(TLVWriter& TLVSet);
@@ -317,11 +319,9 @@ namespace ASDCP
       //
       class Preface : public InterchangeObject
 	{
-	  ASDCP_NO_COPY_CONSTRUCT(Preface);
 	  Preface();
 
 	public:
-	  const Dictionary*& m_Dict;
 	  Kumu::Timestamp    LastModifiedDate;
 	  ui16_t       Version;
 	  optional_property<ui32_t> ObjectModelVersion;
@@ -334,10 +334,13 @@ namespace ASDCP
 	  optional_property<Batch<UL> > ApplicationSchemes;
 	  optional_property<Batch<UL> > ConformsToSpecifications;
 
-	  Preface(const Dictionary*& d);
+	  Preface(const Dictionary* d);
+	  Preface(const Preface& rhs);
 	  virtual ~Preface() {}
 
+	  const Preface& operator=(const Preface& rhs) { Copy(rhs); return *this; }
 	  virtual void Copy(const Preface& rhs);
+	  virtual InterchangeObject *Clone() const;
           virtual Result_t InitFromTLVSet(TLVReader& TLVSet);
 	  virtual Result_t InitFromBuffer(const byte_t* p, ui32_t l);
 	  virtual Result_t WriteToTLVSet(TLVWriter& TLVSet);
@@ -351,7 +354,6 @@ namespace ASDCP
       class IndexTableSegment : public InterchangeObject
 	{
 	  IndexTableSegment();
-	  ASDCP_NO_COPY_CONSTRUCT(IndexTableSegment);
 
 	public:
 	  //
@@ -395,7 +397,6 @@ namespace ASDCP
 	      const char* EncodeString(char* str_buf, ui32_t buf_len) const;
 	    };
 
-	  const Dictionary*& m_Dict;
 	  ui64_t  RtFileOffset; // not part of the MXF structure: used to manage runtime index access 
 	  ui64_t  RtEntryOffset;
 
@@ -410,10 +411,13 @@ namespace ASDCP
 	  Array<DeltaEntry> DeltaEntryArray;
 	  Array<IndexEntry> IndexEntryArray;
 
-	  IndexTableSegment(const Dictionary*&);
+	  IndexTableSegment(const Dictionary*);
+	  IndexTableSegment(const IndexTableSegment&);
 	  virtual ~IndexTableSegment();
 
+	  const IndexTableSegment& operator=(const IndexTableSegment& rhs) { Copy(rhs); return *this; }
 	  virtual void Copy(const IndexTableSegment& rhs);
+	  virtual InterchangeObject *Clone() const;
 	  virtual Result_t InitFromTLVSet(TLVReader& TLVSet);
 	  virtual Result_t InitFromBuffer(const byte_t* p, ui32_t l);
 	  virtual Result_t WriteToTLVSet(TLVWriter& TLVSet);
@@ -434,11 +438,10 @@ namespace ASDCP
 	  OP1aHeader();
 
 	public:
-	  const Dictionary*&  m_Dict;
 	  ASDCP::MXF::Primer  m_Primer;
 	  Preface*            m_Preface;
 
-	  OP1aHeader(const Dictionary*&);
+	  OP1aHeader(const Dictionary*);
 	  virtual ~OP1aHeader();
 	  virtual Result_t InitFromFile(const Kumu::FileReader& Reader);
 	  virtual Result_t InitFromPartitionBuffer(const byte_t* p, ui32_t l);
@@ -470,11 +473,10 @@ namespace ASDCP
 	  OPAtomIndexFooter();
 
 	public:
-	  const Dictionary*&   m_Dict;
 	  Kumu::fpos_t        m_ECOffset;
 	  IPrimerLookup*      m_Lookup;
 	 
-	  OPAtomIndexFooter(const Dictionary*&);
+	  OPAtomIndexFooter(const Dictionary*);
 	  virtual ~OPAtomIndexFooter();
 	  virtual Result_t InitFromFile(const Kumu::FileReader& Reader);
 	  virtual Result_t InitFromPartitionBuffer(const byte_t* p, ui32_t l);
@@ -524,7 +526,7 @@ namespace ASDCP
       typedef std::map<const std::string, const label_traits, ci_comp> mca_label_map_t;
 
       bool decode_mca_string(const std::string& s, const mca_label_map_t& labels,
-			     const Dictionary*& dict, const std::string& language, InterchangeObject_list_t&, ui32_t&);
+			     const Dictionary* dict, const std::string& language, InterchangeObject_list_t&, ui32_t&);
 
       //
       class ASDCP_MCAConfigParser : public InterchangeObject_list_t
@@ -535,11 +537,11 @@ namespace ASDCP
 	protected:
 	  mca_label_map_t m_LabelMap;
 	  ui32_t m_ChannelCount;
-	  const Dictionary*& m_Dict;
+	  const Dictionary* m_Dict;
 
 	  
 	public:
-	  ASDCP_MCAConfigParser(const Dictionary*&);
+	  ASDCP_MCAConfigParser(const Dictionary*);
 	  bool DecodeString(const std::string& s, const std::string& language = "en-US");
 
 	  // Valid only after a successful call to DecodeString
@@ -553,7 +555,7 @@ namespace ASDCP
 	  AS02_MCAConfigParser();
 	  
 	public:
-	  AS02_MCAConfigParser(const Dictionary*&);
+	  AS02_MCAConfigParser(const Dictionary*);
 	};
 
     } // namespace MXF