zypp/base/fXstream.h

   1 /*---------------------------------------------------------------------\
   2 |                          ____ _   __ __ ___                          |
   3 |                         |__  / \ / / . \ . \                         |
   4 |                           / / \ V /|  _/  _/                         |
   5 |                          / /__ | | | | | |                           |
   6 |                         /_____||_| |_| |_|                           |
   7 |                                                                      |
   8 \---------------------------------------------------------------------*/
   9 #ifndef ZYPP_BASE_FXSTREAM_H
  10 #define ZYPP_BASE_FXSTREAM_H
  11
  12 #include <iosfwd>
  13 #include <iostream>
  14
  15 namespace zypp {
  16   namespace detail {
  17     /**
  18      * @short Common template to define ifgzstream/ofgzstream
  19      * reading/writing compressed files.
  20      *
  21      * Don't use fXstream directly, but @ref ifgzstream or
  22      * @ref ofgzstream. fXstream is just to avoid almost
  23      * duplicate code.
  24      **/
  25     template<class TBStream,class TStreamBuf>
  26     class fXstream : public TBStream
  27     {
  28     public:
  29
  30       using ZlibError = typename TStreamBuf::error_type;
  31       using stream_type = TBStream;
  32       using streambuf_type = TStreamBuf;
  33
  34       fXstream()
  35         : stream_type( nullptr )
  36       { this->init( &_streambuf ); }
  37
  38       explicit
  39         fXstream( const char * file_r )
  40         : stream_type( nullptr )
  41       { this->init( &_streambuf ); this->open( file_r ); }
  42
  43       virtual
  44         ~fXstream()
  45       {}
  46
  47       bool
  48       is_open() const
  49       { return _streambuf.isOpen(); }
  50
  51       void
  52       open( const char * file_r )
  53       {
  54         if ( !_streambuf.open( file_r, defMode(*this) ) )
  55           this->setstate(std::ios_base::failbit);
  56         else
  57           this->clear();
  58       }
  59
  60       void
  61       close()
  62       {
  63         if ( !_streambuf.close() )
  64           this->setstate(std::ios_base::failbit);
  65       }
  66
  67       /**
  68              * The last error returned retuned from zlib.
  69              **/
  70       ZlibError
  71       zError() const
  72       { return _streambuf.error(); }
  73
  74       //! Similar to ios::rdbuf.
  75       //! But it returns our specific type, not the generic streambuf *.
  76       const streambuf_type&
  77       getbuf() const
  78       { return _streambuf; }
  79
  80     private:
  81
  82       streambuf_type _streambuf;
  83
  84       std::ios_base::openmode
  85       defMode( const std::istream & )
  86       { return std::ios_base::in; }
  87
  88       std::ios_base::openmode
  89       defMode( const std::ostream & )
  90       { return std::ios_base::out; }
  91
  92     };
  93   }
  94 }
  95
  96 #endif