/project/jni/stlport/src/stdio_streambuf.h

  1/*
  2 * Copyright (c) 1999
  3 * Silicon Graphics Computer Systems, Inc.
  4 *
  5 * Copyright (c) 1999
  6 * Boris Fomitchev
  7 *
  8 * This material is provided "as is", with absolutely no warranty expressed
  9 * or implied. Any use is at your own risk.
 10 *
 11 * Permission to use or copy this software for any purpose is hereby granted
 12 * without fee, provided the above notices are retained on all copies.
 13 * Permission to modify the code and to distribute modified code is granted,
 14 * provided the above notices are retained, and a notice that the code was
 15 * modified is included with the above copyright notice.
 16 *
 17 */
 18
 19// This header is an extension.  It defines two streambufs:
 20// stdio_istreambuf, a read-only streambuf synchronized with a C stdio
 21// FILE object, and stdio_ostreambuf, a write-only streambuf
 22// synchronized with a C stdio FILE object.  Note that neither
 23// stdio_istreambuf nor stdio_ostreambuf is a template; both classes
 24// are derived from basic_streambuf<char, char_traits<char> >.
 25
 26// Note: the imbue() member function is a no-op.  In particular, these
 27// classes assume that codecvt<char, char, mbstate_t> is always an identity
 28// transformation.  This is true of the default locale, and of all locales
 29// defined for the C I/O library.  If you need to use a locale where
 30// the codecvt<char, char, mbstate_t> facet performs a nontrivial
 31// conversion, then you should use basic_filebuf<> instead of stdio_istreambuf
 32// or stdio_ostreambuf.  (If you don't understand what any of this means,
 33// then it's not a feature you need to worry about.  Locales where
 34// codecvt<char, char, mbstate_t> does something nontrivial are a rare
 35// corner case.)
 36
 37
 38#ifndef _STLP_STDIO_STREAMBUF
 39#define _STLP_STDIO_STREAMBUF
 40
 41#include <streambuf>
 42#include <cstdio>              // For FILE.
 43
 44_STLP_BEGIN_NAMESPACE
 45_STLP_MOVE_TO_PRIV_NAMESPACE
 46
 47// Base class for features common to stdio_istreambuf and stdio_ostreambuf
 48class stdio_streambuf_base :
 49  public basic_streambuf<char, char_traits<char> > /* FILE_basic_streambuf */ {
 50public:                         // Constructor, destructor.
 51  // The argument may not be null.  It must be an open file pointer.
 52  stdio_streambuf_base(FILE*);
 53
 54  // The destructor flushes the stream, but does not close it.
 55  ~stdio_streambuf_base();
 56
 57protected:                      // Virtual functions from basic_streambuf.
 58  streambuf* setbuf(char*, streamsize);
 59
 60  pos_type seekoff(off_type, ios_base::seekdir,
 61                   ios_base::openmode
 62                          = ios_base::in | ios_base::out);
 63  pos_type seekpos(pos_type,
 64                   ios_base::openmode
 65                          = ios_base::in | ios_base::out);
 66  int sync();
 67
 68protected:
 69  FILE* _M_file;
 70};
 71
 72class stdio_istreambuf : public stdio_streambuf_base {
 73public:                         // Constructor, destructor.
 74  stdio_istreambuf(FILE* __f) : stdio_streambuf_base(__f) {}
 75  ~stdio_istreambuf();
 76
 77protected:                      // Virtual functions from basic_streambuf.
 78  streamsize showmanyc();
 79  int_type underflow();
 80  int_type uflow();
 81  virtual int_type pbackfail(int_type c = traits_type::eof());
 82};
 83
 84class stdio_ostreambuf : public stdio_streambuf_base {
 85public:                         // Constructor, destructor.
 86  stdio_ostreambuf(FILE* __f) : stdio_streambuf_base(__f) {}
 87  ~stdio_ostreambuf();
 88
 89protected:                      // Virtual functions from basic_streambuf.
 90  streamsize showmanyc();
 91  int_type overflow(int_type c = traits_type::eof());
 92};
 93
 94_STLP_MOVE_TO_STD_NAMESPACE
 95_STLP_END_NAMESPACE
 96
 97#endif /* _STLP_STDIO_STREAMBUF */
 98
 99// Local Variables:
100// mode:C++
101// End: