include/wx/stream.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/stream.h
   3 // Purpose:     "wxWindows stream" base classes
   4 // Author:      Guilhem Lavaux
   5 // Modified by:
   6 // Created:     11/07/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Guilhem Lavaux
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_WXSTREAM_H__
  13 #define _WX_WXSTREAM_H__
  14
  15 #ifdef __GNUG__
  16 #pragma interface
  17 #endif
  18
  19 #include "wx/defs.h"
  20
  21 #if wxUSE_STREAMS
  22
  23 #include <stdio.h>
  24 #include "wx/object.h"
  25 #include "wx/string.h"
  26 #include "wx/filefn.h"  // for off_t, wxInvalidOffset and wxSeekMode
  27
  28 class WXDLLEXPORT wxStreamBase;
  29 class WXDLLEXPORT wxInputStream;
  30 class WXDLLEXPORT wxOutputStream;
  31
  32 typedef wxInputStream& (*__wxInputManip)(wxInputStream&);
  33 typedef wxOutputStream& (*__wxOutputManip)(wxOutputStream&);
  34
  35 WXDLLEXPORT wxOutputStream& wxEndL(wxOutputStream& o_stream);
  36
  37 // ---------------------------------------------------------------------------
  38 // wxStream: base classes
  39 // ---------------------------------------------------------------------------
  40
  41 enum wxStreamError
  42 {
  43     wxSTREAM_NO_ERROR = 0,
  44     wxSTREAM_NO_ERR = wxSTREAM_NO_ERROR,
  45     wxSTREAM_NOERROR = wxSTREAM_NO_ERROR,
  46
  47     wxSTREAM_EOF,
  48
  49     wxSTREAM_WRITE_ERROR,
  50     wxSTREAM_WRITE_ERR = wxSTREAM_WRITE_ERROR,
  51
  52     wxSTREAM_READ_ERROR,
  53     wxSTREAM_READ_ERR = wxSTREAM_READ_ERROR
  54 };
  55
  56 // compatibility
  57 #define wxStream_NOERROR    wxSTREAM_NOERROR
  58 #define wxStream_EOF        wxSTREAM_EOF
  59 #define wxStream_WRITE_ERR  wxSTREAM_WRITE_ERROR
  60 #define wxStream_READ_ERR   wxSTREAM_READ_ERROR
  61
  62 class WXDLLEXPORT wxStreamBase
  63 {
  64 public:
  65     wxStreamBase();
  66     virtual ~wxStreamBase();
  67
  68     // error testing
  69     wxStreamError GetLastError() const { return m_lasterror; }
  70     bool IsOk() const { return LastError() == wxSTREAM_NOERROR; }
  71     bool operator!() const { return LastError() != wxSTREAM_NOERROR; }
  72
  73     virtual size_t GetSize() const { return 0; }
  74
  75     // deprecated, for compatibility only
  76     wxStreamError LastError() const { return m_lasterror; }
  77     size_t StreamSize() const { return GetSize(); }
  78
  79 protected:
  80     // VZ: these functions are really pure virtual and shouldn't be declared
  81     //     in the base class because it creates ambiguties in stream classes
  82     //     deriving from both wxInputStream and wxOutputStream
  83 #if 0
  84     virtual size_t OnSysRead(void *buffer, size_t bufsize);
  85     virtual size_t OnSysWrite(const void *buffer, size_t bufsize);
  86 #endif
  87
  88     virtual off_t OnSysSeek(off_t seek, wxSeekMode mode);
  89     virtual off_t OnSysTell() const;
  90
  91     friend class wxStreamBuffer;
  92
  93     size_t m_lastcount;
  94     wxStreamError m_lasterror;
  95 };
  96
  97 class WXDLLEXPORT wxInputStream : /* virtual */ public wxStreamBase
  98 {
  99 public:
 100     wxInputStream();
 101     virtual ~wxInputStream();
 102
 103     // is the stream at EOF?
 104     virtual bool Eof() const;
 105
 106     // IO functions
 107     virtual char Peek();
 108     char GetC();
 109     virtual wxInputStream& Read(void *buffer, size_t size);
 110     wxInputStream& Read(wxOutputStream& stream_out);
 111
 112     // Position functions
 113     virtual off_t SeekI(off_t pos, wxSeekMode mode = wxFromStart);
 114     virtual off_t TellI() const;
 115
 116     // State functions
 117     virtual size_t LastRead() { return wxStreamBase::m_lastcount; }
 118
 119     // Ungetch
 120     size_t Ungetch(const void *buffer, size_t size);
 121     bool Ungetch(char c);
 122
 123     // Operators
 124     wxInputStream& operator>>(wxOutputStream& out) { return Read(out); }
 125 #if wxUSE_SERIAL
 126     wxInputStream& operator>>(wxObject *& obj);
 127 #endif
 128     wxInputStream& operator>>( __wxInputManip func) { return func(*this); }
 129
 130 protected:
 131     // to be implemented in the derived classes (it should have been pure
 132     // virtual)
 133     virtual size_t OnSysRead(void *buffer, size_t bufsize);
 134
 135     // Ungetch managers
 136     char *m_wback;
 137     size_t m_wbacksize;
 138     size_t m_wbackcur;
 139
 140     char *AllocSpaceWBack(size_t needed_size);
 141     size_t GetWBack(void *buf, size_t bsize);
 142
 143     friend class wxStreamBuffer;
 144 };
 145
 146 class WXDLLEXPORT wxOutputStream : /* virtual */ public wxStreamBase
 147 {
 148 public:
 149     wxOutputStream();
 150     virtual ~wxOutputStream();
 151
 152     void PutC(char c);
 153     virtual wxOutputStream& Write(const void *buffer, size_t size);
 154     wxOutputStream& Write(wxInputStream& stream_in);
 155
 156     virtual off_t SeekO(off_t pos, wxSeekMode mode = wxFromStart);
 157     virtual off_t TellO() const;
 158
 159     virtual size_t LastWrite() const { return wxStreamBase::m_lastcount; }
 160
 161     virtual void Sync();
 162
 163     wxOutputStream& operator<<(wxInputStream& out) { return Write(out); }
 164 #if wxUSE_SERIAL
 165     wxOutputStream& operator<<(wxObject& obj);
 166 #endif
 167     wxOutputStream& operator<<( __wxOutputManip func) { return func(*this); }
 168
 169 protected:
 170     // to be implemented in the derived classes (it should have been pure
 171     // virtual)
 172     virtual size_t OnSysWrite(const void *buffer, size_t bufsize);
 173
 174     friend class wxStreamBuffer;
 175 };
 176
 177 // ---------------------------------------------------------------------------
 178 // A stream for measuring streamed output
 179 // ---------------------------------------------------------------------------
 180
 181 class WXDLLEXPORT wxCountingOutputStream : public wxOutputStream
 182 {
 183 public:
 184     wxCountingOutputStream();
 185
 186     size_t GetSize() const;
 187     bool Ok() const { return TRUE; }
 188
 189 protected:
 190     virtual size_t OnSysWrite(const void *buffer, size_t size);
 191     virtual off_t OnSysSeek(off_t pos, wxSeekMode mode);
 192     virtual off_t OnSysTell() const;
 193
 194     size_t m_currentPos;
 195 };
 196
 197 // ---------------------------------------------------------------------------
 198 // "Filter" streams
 199 // ---------------------------------------------------------------------------
 200
 201 class WXDLLEXPORT wxFilterInputStream : public wxInputStream
 202 {
 203 public:
 204     wxFilterInputStream();
 205     wxFilterInputStream(wxInputStream& stream);
 206     virtual ~wxFilterInputStream();
 207
 208     char Peek() { return m_parent_i_stream->Peek(); }
 209
 210     size_t GetSize() const { return m_parent_i_stream->GetSize(); }
 211
 212     wxInputStream *GetFilterInputStream() const { return m_parent_i_stream; }
 213
 214 protected:
 215     wxInputStream *m_parent_i_stream;
 216 };
 217
 218 class WXDLLEXPORT wxFilterOutputStream : public wxOutputStream
 219 {
 220 public:
 221     wxFilterOutputStream();
 222     wxFilterOutputStream(wxOutputStream& stream);
 223     virtual ~wxFilterOutputStream();
 224
 225     size_t GetSize() const { return m_parent_o_stream->GetSize(); }
 226
 227     wxOutputStream *GetFilterOutputStream() const { return m_parent_o_stream; }
 228
 229 protected:
 230     wxOutputStream *m_parent_o_stream;
 231 };
 232
 233 // ---------------------------------------------------------------------------
 234 // Stream buffer: this class can be derived from and passed to
 235 // wxBufferedStreams to implement custom buffering
 236 // ---------------------------------------------------------------------------
 237
 238 class WXDLLEXPORT wxStreamBuffer
 239 {
 240 public:
 241     enum BufMode
 242     {
 243         read,
 244         write,
 245         read_write
 246     };
 247
 248     wxStreamBuffer(wxStreamBase& stream, BufMode mode);
 249     wxStreamBuffer(BufMode mode);
 250     wxStreamBuffer(const wxStreamBuffer& buf);
 251     virtual ~wxStreamBuffer();
 252
 253     // Filtered IO
 254     virtual size_t Read(void *buffer, size_t size);
 255     size_t Read(wxStreamBuffer *buf);
 256     virtual size_t Write(const void *buffer, size_t size);
 257     size_t Write(wxStreamBuffer *buf);
 258
 259     virtual char Peek();
 260     virtual char GetChar();
 261     virtual void PutChar(char c);
 262     virtual off_t Tell() const;
 263     virtual off_t Seek(off_t pos, wxSeekMode mode);
 264
 265     // Buffer control
 266     void ResetBuffer();
 267
 268     // NB: the buffer must always be allocated with malloc() if takeOwn is
 269     //     TRUE as it will be deallocated by free()
 270     void SetBufferIO(void *start, void *end, bool takeOwnership = FALSE);
 271     void SetBufferIO(void *start, size_t len, bool takeOwnership = FALSE);
 272     void SetBufferIO(size_t bufsize);
 273     void *GetBufferStart() const { return m_buffer_start; }
 274     void *GetBufferEnd() const { return m_buffer_end; }
 275     void *GetBufferPos() const { return m_buffer_pos; }
 276     size_t GetBufferSize() const { return m_buffer_size; }
 277     size_t GetIntPosition() const { return m_buffer_pos - m_buffer_start; }
 278     void SetIntPosition(size_t pos) { m_buffer_pos = m_buffer_start + pos; }
 279     size_t GetLastAccess() const { return m_buffer_end - m_buffer_start; }
 280     size_t GetBytesLeft() const { return m_buffer_end - m_buffer_pos; }
 281
 282     void Fixed(bool fixed) { m_fixed = fixed; }
 283     void Flushable(bool f) { m_flushable = f; }
 284
 285     bool FlushBuffer();
 286     bool FillBuffer();
 287     size_t GetDataLeft();
 288
 289     // misc accessors
 290     wxStreamBase *GetStream() const { return m_stream; }
 291     bool HasBuffer() const { return m_buffer_size != 0; }
 292
 293     bool IsFixed() const { return m_fixed; }
 294     bool IsFlushable() const { return m_flushable; }
 295
 296     // only for input/output buffers respectively, returns NULL otherwise
 297     wxInputStream *GetInputStream() const;
 298     wxOutputStream *GetOutputStream() const;
 299
 300     // deprecated, for compatibility only
 301     wxStreamBase *Stream() { return m_stream; }
 302
 303 protected:
 304     void GetFromBuffer(void *buffer, size_t size);
 305     void PutToBuffer(const void *buffer, size_t size);
 306
 307     // set the last error to the specified value if we didn't have it before
 308     void SetError(wxStreamError err);
 309
 310     // common part of several ctors
 311     void Init();
 312
 313     // init buffer variables to be empty
 314     void InitBuffer();
 315
 316     // free the buffer (always safe to call)
 317     void FreeBuffer();
 318
 319     // the buffer itself: the pointers to its start and end and the current
 320     // position in the buffer
 321     char *m_buffer_start,
 322          *m_buffer_end,
 323          *m_buffer_pos;
 324
 325     // the buffer size
 326     // FIXME: isn't it the same as m_buffer_end - m_buffer_start? (VZ)
 327     size_t m_buffer_size;
 328
 329     // the stream we're associated with
 330     wxStreamBase *m_stream;
 331
 332     // its mode
 333     BufMode m_mode;
 334
 335     // flags
 336     bool m_destroybuf,      // deallocate buffer?
 337          m_destroystream,   // delete associated stream?
 338          m_fixed,
 339          m_flushable;
 340 };
 341
 342 // ---------------------------------------------------------------------------
 343 // wxBufferedStreams
 344 // ---------------------------------------------------------------------------
 345
 346 class WXDLLEXPORT wxBufferedInputStream : public wxFilterInputStream
 347 {
 348 public:
 349     // if a non NULL buffer is given to the stream, it will be deleted by it
 350     wxBufferedInputStream(wxInputStream& stream,
 351                           wxStreamBuffer *buffer = NULL);
 352     virtual ~wxBufferedInputStream();
 353
 354     char Peek();
 355     wxInputStream& Read(void *buffer, size_t size);
 356
 357     // Position functions
 358     off_t SeekI(off_t pos, wxSeekMode mode = wxFromStart);
 359     off_t TellI() const;
 360
 361     // the buffer given to the stream will be deleted by it
 362     void SetInputStreamBuffer(wxStreamBuffer *buffer);
 363     wxStreamBuffer *GetInputStreamBuffer() const { return m_i_streambuf; }
 364
 365     // deprecated, for compatibility only
 366     wxStreamBuffer *InputStreamBuffer() const { return m_i_streambuf; }
 367
 368 protected:
 369     virtual size_t OnSysRead(void *buffer, size_t bufsize);
 370     virtual off_t OnSysSeek(off_t seek, wxSeekMode mode);
 371     virtual off_t OnSysTell() const;
 372
 373     wxStreamBuffer *m_i_streambuf;
 374 };
 375
 376 class WXDLLEXPORT wxBufferedOutputStream : public wxFilterOutputStream
 377 {
 378 public:
 379     // if a non NULL buffer is given to the stream, it will be deleted by it
 380     wxBufferedOutputStream(wxOutputStream& stream,
 381                            wxStreamBuffer *buffer = NULL);
 382     virtual ~wxBufferedOutputStream();
 383
 384     wxOutputStream& Write(const void *buffer, size_t size);
 385
 386     // Position functions
 387     off_t SeekO(off_t pos, wxSeekMode mode = wxFromStart);
 388     off_t TellO() const;
 389
 390     void Sync();
 391
 392     size_t GetSize() const;
 393
 394     // the buffer given to the stream will be deleted by it
 395     void SetOutputStreamBuffer(wxStreamBuffer *buffer);
 396     wxStreamBuffer *GetOutputStreamBuffer() const { return m_o_streambuf; }
 397
 398     // deprecated, for compatibility only
 399     wxStreamBuffer *OutputStreamBuffer() const { return m_o_streambuf; }
 400
 401 protected:
 402     virtual size_t OnSysWrite(const void *buffer, size_t bufsize);
 403     virtual off_t OnSysSeek(off_t seek, wxSeekMode mode);
 404     virtual off_t OnSysTell() const;
 405
 406     wxStreamBuffer *m_o_streambuf;
 407 };
 408
 409 #endif // wxUSE_STREAMS
 410
 411 #endif // _WX_WXSTREAM_H__
 412