Persistent.h

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/*
   For more information, please see: http://software.sci.utah.edu

   The MIT License

   Copyright (c) 2009 Scientific Computing and Imaging Institute,
   University of Utah.

   
   Permission is hereby granted, free of charge, to any person obtaining a
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///
///@file  Persistent.h
///@brief Base class for persistent objects...
///
///@author
///       Steven G. Parker
///       Department of Computer Science
///       University of Utah
///@date  April 1994
///

#ifndef CORE_PERSISTENT_H
#define CORE_PERSISTENT_H 1

#include <boost/utility/enable_if.hpp>
#include <boost/type_traits/is_base_of.hpp>
#include <Core/Persistent/PersistentFwd.h>
#include <map>
#include <string>
#include <boost/shared_ptr.hpp>

// for index and size types
#include <Core/Datatypes/Legacy/Base/Types.h>

#include <Core/Utils/Legacy/Assert.h>
#include <Core/Logging/LoggerFwd.h>

#include <Core/Persistent/share.h>

namespace SCIRun {

  typedef Persistent* (*PersistentMaker0)();

class SCISHARE PersistentTypeID {
public:
  PersistentTypeID();
  PersistentTypeID(const std::string& type, 
                     const std::string& parent,
                     PersistentMaker0 maker, 
                     Persistent* (*bc_maker1)() = 0, 
                     Persistent* (*bc_maker2)() = 0);
  std::string type;
  std::string parent;
  PersistentMaker0 maker;
  Persistent* (*bc_maker1)();
  Persistent* (*bc_maker2)();    
};

typedef boost::shared_ptr<PersistentTypeID> PersistentTypeIDPtr;
typedef boost::shared_ptr<Piostream> PiostreamPtr;

SCISHARE PiostreamPtr auto_istream(const std::string& filename,
                                   Core::Logging::LoggerHandle pr = Core::Logging::LoggerHandle());
SCISHARE PiostreamPtr auto_ostream(const std::string& filename, const std::string& type,
                                 Core::Logging::LoggerHandle pr = Core::Logging::LoggerHandle());


//----------------------------------------------------------------------
class SCISHARE Piostream {
    
  public:
    typedef std::map<Persistent*, int>          MapPersistentInt;
    typedef std::map<int, Persistent*>          MapIntPersistent;

    enum Direction {
      Read,
      Write
    };

    enum Endian {
      Big,
      Little
    };

    static const int PERSISTENT_VERSION;
    void flag_error() { err = 1; }
    
  protected:
    Piostream(Direction, int, const std::string &, Core::Logging::LoggerHandle pr);

    Direction dir;
    int version_;
    bool err;
    int file_endian;
    
    MapPersistentInt* outpointers;
    MapIntPersistent* inpointers;
    
    int current_pointer_id;

    bool have_peekname_;
    std::string peekname_;

    Core::Logging::LoggerHandle reporter_;
    bool backwards_compat_id_;
    bool disable_pointer_hashing_;
    virtual void emit_pointer(int& have_data, int& pointer_id);
  public:
    static bool readHeader(Core::Logging::LoggerHandle pr,
                           const std::string& filename, char* hdr,
                           const char* type, int& version, int& endian);
  private:
    virtual void reset_post_header() = 0;
  public:
    std::string file_name;

    virtual ~Piostream();

    virtual std::string peek_class();
    virtual int begin_class(const std::string& name, int current_version);
    virtual void end_class();
    virtual void begin_cheap_delim();
    virtual void end_cheap_delim();

    virtual void io(bool&);
    virtual void io(char&) = 0;
    virtual void io(signed char&) = 0;
    virtual void io(unsigned char&) = 0;
    virtual void io(short&) = 0;
    virtual void io(unsigned short&) = 0;
    virtual void io(int&) = 0;
    virtual void io(unsigned int&) = 0;
    virtual void io(long&) = 0;
    virtual void io(unsigned long&) = 0;
    virtual void io(long long&) = 0;
    virtual void io(unsigned long long&) = 0;
    virtual void io(double&) = 0;
    virtual void io(float&) = 0;
    virtual void io(std::string& str) = 0;
    virtual bool eof() { return false; }

    void io(Persistent*&, const PersistentTypeID&);

    bool reading() const { return dir == Read; }
    bool writing() const { return dir == Write; }
    bool error() const { return err; }

    int version() const { return version_; }
    bool backwards_compat_id() const { return backwards_compat_id_; }
    void set_backwards_compat_id(bool p) { backwards_compat_id_ = p; }
    virtual bool supports_block_io() { return false; } // deprecated, redundant.
    
    // Returns true if block_io was supported (even on error).
    virtual bool block_io(void*, size_t, size_t) { return false; }
    
    void disable_pointer_hashing() { disable_pointer_hashing_ = true; }

    SCISHARE friend PiostreamPtr auto_istream(const std::string& filename,
                                   Core::Logging::LoggerHandle pr);
    SCISHARE friend PiostreamPtr auto_ostream(const std::string& filename, 
                                   const std::string& type,
                                   Core::Logging::LoggerHandle pr);
};


//----------------------------------------------------------------------
class SCISHARE Persistent {

  public:
    virtual ~Persistent();
    virtual void io(Piostream&);

    //----------------------------------------------------------------------
    // Functions for managing the database of Persistent objects
    // Note all of these functions are static, to allow access from outside
    // the class

    static PersistentTypeIDPtr find_derived( const std::string& classname, 
                                        const std::string& basename );
    static bool is_base_of(const std::string& parent, const std::string& type);
  
    static void add_class(const std::string& type, 
                          const std::string& parent,
                          Persistent* (*maker)(),
                          Persistent* (*bc_maker1)() = 0,
                          Persistent* (*bc_maker2)() = 0);

    static void add_mesh_class(const std::string& type, 
                          Persistent* (*maker)(),
                          Persistent* (*bc_maker1)() = 0,
                          Persistent* (*bc_maker2)() = 0);                          

    static void add_field_class(const std::string& type, 
                          Persistent* (*maker)(),
                          Persistent* (*bc_maker1)() = 0,
                          Persistent* (*bc_maker2)() = 0);  
  private:
    // Mutex protecting the list, these are in the class so they will be 
    // initialized before any of the static functions can be called

    typedef std::map<std::string, PersistentTypeIDPtr>  MapStringPersistentID;
    static MapStringPersistentID* persistent_table_;  
    static Core::Thread::Mutex* persistent_mutex_;
    
    static void initialize();
};

//----------------------------------------------------------------------
inline void Pio(Piostream& stream, bool& data) { stream.io(data); }
inline void Pio(Piostream& stream, char& data) { stream.io(data); }
inline void Pio(Piostream& stream, signed char& data) { stream.io(data); }
inline void Pio(Piostream& stream, unsigned char& data) { stream.io(data); }
inline void Pio(Piostream& stream, short& data) { stream.io(data); }
inline void Pio(Piostream& stream, unsigned short& data) { stream.io(data); }
inline void Pio(Piostream& stream, int& data) { stream.io(data); }
inline void Pio(Piostream& stream, unsigned int& data) { stream.io(data); }
inline void Pio(Piostream& stream, long& data) { stream.io(data); }
inline void Pio(Piostream& stream, unsigned long& data) { stream.io(data); }
inline void Pio(Piostream& stream, long long& data) { stream.io(data); }
inline void Pio(Piostream& stream, unsigned long long& data) { stream.io(data); }
inline void Pio(Piostream& stream, double& data) { stream.io(data); }
inline void Pio(Piostream& stream, float& data) { stream.io(data); }
inline void Pio(Piostream& stream, std::string& data) { stream.io(data); }
inline void Pio(Piostream& stream, Persistent& data) { data.io(stream); }

SCISHARE void Pio_index(Piostream& stream, index_type* data, size_type sz);


template<class T>
void Pio(Piostream& stream, boost::shared_ptr<T>& data, typename boost::enable_if<typename boost::is_base_of<Persistent, T>::type>* = 0)
{
  stream.begin_cheap_delim();
  Persistent* trep = data.get();
  stream.io(trep, T::type_id);
  if(stream.reading())
  {
    data.reset(static_cast<T*>(trep));
  }
  stream.end_cheap_delim();
}

template<class T>
inline void Pio(Piostream& stream, T* data, size_type sz)
{
  if (!stream.block_io(data, sizeof(T), sz))
  {
    for (index_type i=0;i<sz;i++)
      stream.io(data[i]);
  }
}

template <typename Size>
inline void Pio_size(Piostream& stream, Size& size)
{
  long long temp = static_cast<long long>(size);
  stream.io(temp);
  size = static_cast<size_type>(temp);
}

template <typename Index>
inline void Pio_index(Piostream& stream, Index& index)
{
  long long temp = static_cast<long long>(index);
  stream.io(temp);
  index = static_cast<size_type>(temp);
}

} // End namespace SCIRun

#endif