core/vsl/vsl_binary_io.h

Go to the documentation of this file.

// This is core/vsl/vsl_binary_io.h
#ifndef vsl_binary_io_h_
#define vsl_binary_io_h_
//:
// \file
// \brief Set of functions, and objects to perform binary IO
// \author Ian Scott, Tim Cootes (Manchester) March 2001
//
// You should include this file if you want to do binary_io
//
// Also included are a set of functions
// vsl_print_summary(vcl_ostream& os, bool b)
// for basic types to ensure that templated classes
// vsl_print_summaries can work with all types

#include <vcl_iosfwd.h>
#include <vcl_string.h>
#include <vcl_fstream.h>
#include <vcl_map.h>
#include <vcl_utility.h>
#include <vxl_config.h>

//: A binary output adaptor for any vcl_ostream
// Currently the main use of this is to encourage streams to be opened
// in binary mode (ie. without CR/LF conversion)
//
// This class also provide basic support for serialisation. This allows an
// object which has multiple pointers to it to be saved only once. During
// reloading, the pointers can be all set up again to point to the single
// object. vsl_b_ostream does not do the serialisation itself, but instead
// keeps records of unique identifiers to allow the user's code to perform
// serialisation safely. For instance, a smart pointer type object will have
// to know how to safely save whatever it is pointing to.
class vsl_b_ostream
{
 public:
  //: Create this adaptor using an existing stream
  // The stream (os) must be open (i.e. ready to receive insertions)
  // so that the
  // IO version and magic number can be written by this constructor.
  // User is responsible for deleting os after deleting the adaptor
  vsl_b_ostream(vcl_ostream *os);

  //: A reference to the adaptor's stream
  vcl_ostream& os() const;

  //: Virtual destructor.
  virtual ~vsl_b_ostream() {}

  //: Returns true if the underlying stream has its fail bit set.
  bool operator!() const;

  //: Clear the stream's record of any serialisation operations
  // Calling this function while outputting serialisable things to stream,
  // will mean
  // that a second copy of an object may get stored to the stream.
  virtual void clear_serialisation_records();


  //: Adds an object pointer to the serialisation records.
  // Returns a unique identifier for the object.
  //
  // \a pointer must be non-null, so you should handle null pointers separately.
  //
  // You can optionally add some user-defined integer with each record
  // If error checking is on, and the object pointer is null or already in the records,
  // this function will abort()
  virtual unsigned long add_serialisation_record(void *pointer, int other_data = 0);

  //: Returns a unique identifier for the object.
  // Returns 0 if there is no record of the object.
  virtual unsigned long get_serial_number(void *pointer) const;

  //: Set the user-defined data associated with the object
  // If there is no record of the object, this function will return 0.
  // However a retval of 0 does not necessarily imply that the object is
  // unrecorded.
  virtual int get_serialisation_other_data(void *pointer) const;

  //: Modify the user-defined data associated with the object
  // If there is no record of the object, this function will abort.
  virtual int set_serialisation_other_data(void *pointer, int other_data);

  //: The length of the b_stream header.
  // You can move to this offset from the start of the file to get to
  // the first real data item.
  static const vcl_streamoff header_length;

 protected:
  //: The member stream
  vcl_ostream *os_;

  // Design notes: IMS
  // I used to think that a pointer and class name were needed to identify an
  // object. This is true if class your_class{my_class A}; your_class B;
  // then &B = &(B.A).
  // However this case doesn't arise in serialisation situations, because you
  // can't have shared ownership of A.

  // I could have used the pointer itself as the unique identifier, but it is
  // unreasonable to expect this to work cross-platform when the platforms have
  // different pointer sizes.

  //: The type of the serialisation records
  typedef vcl_map<void *, vcl_pair<unsigned long, int>, vcl_less<void *> >
    serialisation_records_type;

  //: The serialisation records
  // Records a pointer, a unique identifier, and an integer
  // (user_defined data.)
  serialisation_records_type serialisation_records_;

  //: The version number of the IO scheme.
  static const unsigned short version_no_;
};


//: An adapter for a vcl_ofstream to make it suitable for binary IO
class vsl_b_ofstream: public vsl_b_ostream
{
 public:
  //: Create this adaptor from a file.
  // The adapter will delete the internal stream automatically on destruction.
  vsl_b_ofstream(const vcl_string &filename,
                 vcl_ios_openmode mode = vcl_ios_out | vcl_ios_trunc):
    vsl_b_ostream(new vcl_ofstream(filename.c_str(), mode | vcl_ios_binary)) {}

  //: Create this adaptor from a file.
  // The adapter will delete the internal stream automatically on destruction.
  vsl_b_ofstream(const char *filename,
                 vcl_ios_openmode mode = vcl_ios_out | vcl_ios_trunc) :
    vsl_b_ostream(new vcl_ofstream(filename, mode | vcl_ios_binary)) {}

  //: Virtual destructor.
  virtual ~vsl_b_ofstream();


  //: Close the stream
  void close();
};


//: An adaptor for any vcl_istream to make it suitable for binary input
// Currently the main use of this is to encourage file streams to be opened
// in binary mode (ie. without CR/LF conversion)
//
// This class also provide basic support for serialisation. During loading,
// multiple pointers to one object can be all set up again to point to the
// single object. vsl_b_ostream does not do the serialisation itself, but
// instead keeps records of unique identifiers to allow the user's code to
// perform serialisation safely. For instance, a smart pointer type object will
// have to know how to safely save whatever it is pointing to.
class vsl_b_istream
{
 public:
  //: Create this adaptor using an existing stream.
  // The stream (is) must be open (i.e. ready to be read from) so that the
  // IO version and magic number can be read by this constructor.
  // User is responsible for deleting is after deleting the adaptor
  vsl_b_istream(vcl_istream *is);

  //: A reference to the adaptor's stream
  vcl_istream & is() const;

  //: Virtual destructor.so that it can be overloaded
  virtual ~vsl_b_istream() {}

  //: Returns true if the underlying stream has its fail bit set.
  bool operator!() const;

  //: Clear the stream's record of any serialisation operations
  // Calling this function while inputting serialisable things from a stream,
  // could cause errors during loading unless the records were cleared at a
  // similar point during output.
  virtual void clear_serialisation_records();

  //: Adds record of object's unique serial number, and location in memory.
  // \a pointer must be non-null, so you should handle null pointers separately.
  //
  // Adding a null pointer or one that already exists will cause the function to abort(),
  // if debugging is turned on;
  //
  // You can also store a single integer as other data.
  // Interpretation of this data is entirely up to the client code.
  virtual void add_serialisation_record(unsigned long serial_number,
                                        void *pointer, int other_data = 0);

  //: Returns the pointer to the object identified by the unique serial number.
  // Returns 0 if no record has been added.
  virtual void * get_serialisation_pointer(unsigned long serial_number) const;

  //: Returns the user defined data associated with the unique serial number
  // Returns 0 if no record has been added.
  virtual int get_serialisation_other_data(unsigned long serial_number) const;

  //: Modify the user-defined data associated with the unique serial number
  // If there is no record of the object, this function will abort.
  virtual int set_serialisation_other_data(unsigned long serial_number,
                                           int other_data);


  //: Return the version number of the IO format of the file being read.
  unsigned short version_no() const;

 protected:
  //: The member stream
  vcl_istream *is_;

  //: The type of the serialisation records.
  typedef vcl_map<unsigned long, vcl_pair<void *, int>, vcl_less<unsigned long> >
    serialisation_records_type;

  //: The serialisation records,
  // The record takes a unique identifier of the object (which would be
  // stored on the stream) and returns the pointer to the object, and
  // an other_data integer.
  serialisation_records_type serialisation_records_;

  // The version number of the IO format of the file being read.
  unsigned short version_no_;
};


//: An adapter for a vcl_ifstream to make it suitable for binary IO
class vsl_b_ifstream: public vsl_b_istream
{
 public:
  //: Create this adaptor from a file.
  // The adapter will delete the stream automatically on destruction.
  vsl_b_ifstream(const vcl_string &filename, vcl_ios_openmode mode = vcl_ios_in):
    vsl_b_istream(new vcl_ifstream(filename.c_str(),
    mode | vcl_ios_binary)) {}

  //: Create this adaptor from a file.
  // The adapter will delete the stream automatically on destruction.
  vsl_b_ifstream(const char *filename, vcl_ios_openmode mode = vcl_ios_in):
    vsl_b_istream(new vcl_ifstream(filename, mode | vcl_ios_binary)) {}

  //: Virtual destructor.so that it can be overloaded
  virtual ~vsl_b_ifstream();

  //: Close the stream
  void close();
};

//: Write bool to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,bool b);
//: Read bool from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,bool& b);
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, bool b )
{  os << b; }

//: Write char to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,char n );
//: Read char from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,char& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, char n )
{  os << n; }

//: Write signed char to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,signed char n );
//: Read  signed char from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,signed char& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, signed char n )
{  os << n; }

//: Write  to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,unsigned char n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,unsigned char& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, unsigned char n )
{  os << n; }

//: Write  to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,const vcl_string& n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,vcl_string& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, const vcl_string& n )
{  os << n; }

//: Write  to vsl_b_ostream
// \deprecated in favour of vcl_string version.
void vsl_b_write(vsl_b_ostream& os,const char* s );
//: Read  from vsl_b_istream
// \deprecated in favour of vcl_string version.
// \note You must preallocate enough space at \p s for expected length of string.
// This function is easy to crash mith a malformed data file.
void vsl_b_read(vsl_b_istream& is,char* s );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, const char* s )
{  os << s; }


// Visual Studio .NET on a 32-bit platform can check for 64-bit
// portability issues. When these warnings (/Wp64) are turn on,
// passing a ptrdiff_t as an int triggers a warning. The __w64
// keyword suppresses that warning here, because it's not a problem.
// On a real 64-bit platform, there will presumably be an overloaded
// vsl_b_write for the 64-bit integral type. We don't want to suppress
// the warning (C4244) completely, because it is a useful warning.
// 08/20/2003: Added macro that defines whether or not attribute needs
//             to be used. A new version of MS .NET compiler required this change.
//             Add compilers as needed. This could be moved to vcl_compiler.h. 
//             [Nils Krahnstoever]
#ifdef VCL_VC_DOTNET
# define VCL_64BIT_ATTR __w64
#else
# define VCL_64BIT_ATTR /* */
#endif

//: Write  to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os, int VCL_64BIT_ATTR n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is, int VCL_64BIT_ATTR &n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, int VCL_64BIT_ATTR n )
{  os << int(n); }

#undef VCL_64BIT_ATTR

//: Write  to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,unsigned int n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,unsigned int& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, unsigned int n )
{  os << n; }

//: Write  to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,short n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,short& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, short n )
{  os << n; }

//: Write  to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,unsigned short n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,unsigned short& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, unsigned short n )
{  os << n; }

//: Write  to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,long n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,long& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, long n )
{  os << n; }

//: Write  to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,unsigned long n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,unsigned long& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, unsigned long n )
{  os << n; }

#if VXL_HAS_INT_64 && !VXL_INT_64_IS_LONG

//: Write  to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,vxl_int_64 n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,vxl_int_64& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, vxl_int_64 n )
{
#if defined(VCL_VC_6)  // IMS. This Hack could be replaced by code which
  os << "****";        // splits the 64bit int and doesn the right thing.
#else
  os << n;
#endif
}

//: Write  to vsl_b_ostream
void vsl_b_write(vsl_b_ostream& os,vxl_uint_64 n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,vxl_uint_64& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, vxl_uint_64 n )
{
#if defined(VCL_VC_6)  // IMS. This Hack could be replaced by code which
  os << "****";        // splits the 64bit int and doesn the right thing.
#else
  os << n;
#endif
}

#endif // VXL_HAS_INT_64

//: Write  to vsl_b_ostream
// Number is saved with ANSI/IEEE Standard 754-1985 single precision.
void vsl_b_write(vsl_b_ostream& os,float n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,float& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, float n )
{  os << n; }

//: Write  to vsl_b_ostream
// Number is saved with ANSI/IEEE Standard 754-1985 double precision.
void vsl_b_write(vsl_b_ostream& os,double n );
//: Read  from vsl_b_istream
void vsl_b_read(vsl_b_istream& is,double& n );
//: Print to a stream
inline void vsl_print_summary(vcl_ostream& os, double n )
{ os << n; }


#endif // vsl_binary_io_h_