dlib C++ Library - unserialize.h

// Copyright (C) 2016 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_uNSERIALIZE_Hh_
#define DLIB_uNSERIALIZE_Hh_
#include "unserialize_abstract.h"
#include "../serialize.h"
#include "../algs.h"
#include "vectorstream.h"
namespace dlib
{
 class unserialize : public std::istream
 {
 class mystreambuf : public std::streambuf
 {
 typedef std::vector<char>::size_type size_type;
 size_type read_pos; // buffer[read_pos] == next byte to read from buffer
 public:
 std::vector<char> buffer;
 std::istream& str;
 template <typename T>
 mystreambuf(
 const T& item,
 std::istream& str_
 ) :
 read_pos(0),
 str(str_) 
 {
 // put the item into our buffer.
 vectorstream vstr(buffer);
 serialize(item, vstr);
 }
 // ------------------------ INPUT FUNCTIONS ------------------------
 int_type underflow( 
 )
 {
 if (read_pos < buffer.size())
 return static_cast<unsigned char>(buffer[read_pos]);
 else
 return str.peek();
 }
 int_type uflow( 
 )
 { 
 if (read_pos < buffer.size())
 return static_cast<unsigned char>(buffer[read_pos++]);
 else
 return str.get();
 }
 std::streamsize xsgetn (
 char* s, 
 std::streamsize n
 )
 { 
 if (read_pos < buffer.size())
 {
 const size_type num = std::min<size_type>(n, buffer.size()-read_pos);
 std::memcpy(s, &buffer[read_pos], num);
 read_pos += num;
 return num;
 }
 else
 {
 return str.rdbuf()->sgetn(s,n);
 }
 return 0;
 }
 };
 public:
 template <typename T>
 unserialize (
 const T& item,
 std::istream& str 
 ) :
 std::istream(&buf),
 buf(item, str)
 {}
 private:
 mystreambuf buf;
 };
}
#endif // DLIB_uNSERIALIZE_Hh_