wxWidgets/include/wx/stream.h

541 lines
17 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: wx/stream.h
// Purpose: stream classes
// Author: Guilhem Lavaux, Guillermo Rodriguez Garcia, Vadim Zeitlin
// Modified by:
// Created: 11/07/98
// RCS-ID: $Id$
// Copyright: (c) Guilhem Lavaux
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_WXSTREAM_H__
#define _WX_WXSTREAM_H__
#if defined(__GNUG__) && !defined(__APPLE__)
#pragma interface "stream.h"
#endif
#include "wx/defs.h"
#if wxUSE_STREAMS
#include <stdio.h>
#include "wx/object.h"
#include "wx/string.h"
#include "wx/filefn.h" // for off_t, wxInvalidOffset and wxSeekMode
class WXDLLIMPEXP_BASE wxStreamBase;
class WXDLLIMPEXP_BASE wxInputStream;
class WXDLLIMPEXP_BASE wxOutputStream;
typedef wxInputStream& (*__wxInputManip)(wxInputStream&);
typedef wxOutputStream& (*__wxOutputManip)(wxOutputStream&);
WXDLLIMPEXP_BASE wxOutputStream& wxEndL(wxOutputStream& o_stream);
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
enum wxStreamError
{
wxSTREAM_NO_ERROR = 0, // stream is in good state
wxSTREAM_EOF, // EOF reached in Read() or similar
wxSTREAM_WRITE_ERROR, // generic write error
wxSTREAM_READ_ERROR // generic read error
};
// compatibility
#if WXWIN_COMPATIBILITY_2_2
#define wxStream_NOERROR wxSTREAM_NOERROR
#define wxStream_EOF wxSTREAM_EOF
#define wxStream_WRITE_ERR wxSTREAM_WRITE_ERROR
#define wxStream_READ_ERR wxSTREAM_READ_ERROR
#define wxSTREAM_NO_ERR wxSTREAM_NO_ERROR
#define wxSTREAM_NOERROR wxSTREAM_NO_ERROR
#define wxSTREAM_WRITE_ERR wxSTREAM_WRITE_ERROR
#define wxSTREAM_READ_ERR wxSTREAM_READ_ERROR
#endif // WXWIN_COMPATIBILITY_2_2
// ============================================================================
// base stream classes: wxInputStream and wxOutputStream
// ============================================================================
// ---------------------------------------------------------------------------
// wxStreamBase: common (but non virtual!) base for all stream classes
// ---------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxStreamBase
{
public:
wxStreamBase();
virtual ~wxStreamBase();
// error testing
wxStreamError GetLastError() const { return m_lasterror; }
bool IsOk() const { return GetLastError() == wxSTREAM_NO_ERROR; }
bool operator!() const { return !IsOk(); }
// reset the stream state
void Reset() { m_lasterror = wxSTREAM_NO_ERROR; }
// this doesn't make sense for all streams, always test its return value
virtual size_t GetSize() const { return 0; }
#if WXWIN_COMPATIBILITY_2_2
// deprecated, for compatibility only
wxStreamError LastError() const { return m_lasterror; }
size_t StreamSize() const { return GetSize(); }
#endif // WXWIN_COMPATIBILITY_2_2
protected:
virtual off_t OnSysSeek(off_t seek, wxSeekMode mode);
virtual off_t OnSysTell() const;
size_t m_lastcount;
wxStreamError m_lasterror;
friend class wxStreamBuffer;
DECLARE_NO_COPY_CLASS(wxStreamBase)
};
// ----------------------------------------------------------------------------
// wxInputStream: base class for the input streams
// ----------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxInputStream : public wxStreamBase
{
public:
// ctor and dtor, nothing exciting
wxInputStream();
virtual ~wxInputStream();
// IO functions
// ------------
// return a character from the stream without removing it, i.e. it will
// still be returned by the next call to GetC()
//
// blocks until something appears in the stream if necessary, if nothing
// ever does (i.e. EOF) LastRead() will return 0 (and the return value is
// undefined), otherwise 1
virtual char Peek();
// return one character from the stream, blocking until it appears if
// necessary
//
// if EOF, return value is undefined and LastRead() will return 0 and not 1
char GetC();
// read at most the given number of bytes from the stream
//
// there are 2 possible situations here: either there is nothing at all in
// the stream right now in which case Read() blocks until something appears
// (use CanRead() to avoid this) or there is already some data available in
// the stream and then Read() doesn't block but returns just the data it
// can read without waiting for more
//
// in any case, if there are not enough bytes in the stream right now,
// LastRead() value will be less than size but greater than 0. If it is 0,
// it means that EOF has been reached.
virtual wxInputStream& Read(void *buffer, size_t size);
// copy the entire contents of this stream into streamOut, stopping only
// when EOF is reached or an error occurs
wxInputStream& Read(wxOutputStream& streamOut);
// status functions
// ----------------
// returns the number of bytes read by the last call to Read(), GetC() or
// Peek()
//
// this should be used to discover whether that call succeeded in reading
// all the requested data or not
virtual size_t LastRead() const { return wxStreamBase::m_lastcount; }
// returns TRUE if some data is available in the stream right now, so that
// calling Read() wouldn't block
virtual bool CanRead() const;
// is the stream at EOF?
//
// note that this cannot be really implemented for all streams and
// CanRead() is more reliable than Eof()
virtual bool Eof() const;
// write back buffer
// -----------------
// put back the specified number of bytes into the stream, they will be
// fetched by the next call to the read functions
//
// returns the number of bytes really stuffed back
size_t Ungetch(const void *buffer, size_t size);
// put back the specified character in the stream
//
// returns TRUE if ok, FALSE on error
bool Ungetch(char c);
// position functions
// ------------------
// move the stream pointer to the given position (if the stream supports
// it)
//
// returns wxInvalidOffset on error
virtual off_t SeekI(off_t pos, wxSeekMode mode = wxFromStart);
// return the current position of the stream pointer or wxInvalidOffset
virtual off_t TellI() const;
// stream-like operators
// ---------------------
wxInputStream& operator>>(wxOutputStream& out) { return Read(out); }
wxInputStream& operator>>(__wxInputManip func) { return func(*this); }
protected:
// do read up to size bytes of data into the provided buffer
//
// this method should return 0 if EOF has been reached or an error occured
// (m_lasterror should be set accordingly as well) or the number of bytes
// read
virtual size_t OnSysRead(void *buffer, size_t size) = 0;
// write-back buffer support
// -------------------------
// return the pointer to a buffer big enough to hold sizeNeeded bytes
char *AllocSpaceWBack(size_t sizeNeeded);
// read up to size data from the write back buffer, return the number of
// bytes read
size_t GetWBack(void *buf, size_t size);
// write back buffer or NULL if none
char *m_wback;
// the size of the buffer
size_t m_wbacksize;
// the current position in the buffer
size_t m_wbackcur;
friend class wxStreamBuffer;
DECLARE_NO_COPY_CLASS(wxInputStream)
};
// ----------------------------------------------------------------------------
// wxOutputStream: base for the output streams
// ----------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxOutputStream : public wxStreamBase
{
public:
wxOutputStream();
virtual ~wxOutputStream();
void PutC(char c);
virtual wxOutputStream& Write(const void *buffer, size_t size);
wxOutputStream& Write(wxInputStream& stream_in);
virtual off_t SeekO(off_t pos, wxSeekMode mode = wxFromStart);
virtual off_t TellO() const;
virtual size_t LastWrite() const { return wxStreamBase::m_lastcount; }
virtual void Sync();
wxOutputStream& operator<<(wxInputStream& out) { return Write(out); }
wxOutputStream& operator<<( __wxOutputManip func) { return func(*this); }
protected:
// to be implemented in the derived classes (it should have been pure
// virtual)
virtual size_t OnSysWrite(const void *buffer, size_t bufsize);
friend class wxStreamBuffer;
DECLARE_NO_COPY_CLASS(wxOutputStream)
};
// ============================================================================
// helper stream classes
// ============================================================================
// ---------------------------------------------------------------------------
// A stream for measuring streamed output
// ---------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxCountingOutputStream : public wxOutputStream
{
public:
wxCountingOutputStream();
size_t GetSize() const;
bool Ok() const { return TRUE; }
protected:
virtual size_t OnSysWrite(const void *buffer, size_t size);
virtual off_t OnSysSeek(off_t pos, wxSeekMode mode);
virtual off_t OnSysTell() const;
size_t m_currentPos;
DECLARE_NO_COPY_CLASS(wxCountingOutputStream)
};
// ---------------------------------------------------------------------------
// "Filter" streams
// ---------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxFilterInputStream : public wxInputStream
{
public:
wxFilterInputStream();
wxFilterInputStream(wxInputStream& stream);
virtual ~wxFilterInputStream();
char Peek() { return m_parent_i_stream->Peek(); }
size_t GetSize() const { return m_parent_i_stream->GetSize(); }
wxInputStream *GetFilterInputStream() const { return m_parent_i_stream; }
protected:
wxInputStream *m_parent_i_stream;
DECLARE_NO_COPY_CLASS(wxFilterInputStream)
};
class WXDLLIMPEXP_BASE wxFilterOutputStream : public wxOutputStream
{
public:
wxFilterOutputStream();
wxFilterOutputStream(wxOutputStream& stream);
virtual ~wxFilterOutputStream();
size_t GetSize() const { return m_parent_o_stream->GetSize(); }
wxOutputStream *GetFilterOutputStream() const { return m_parent_o_stream; }
protected:
wxOutputStream *m_parent_o_stream;
DECLARE_NO_COPY_CLASS(wxFilterOutputStream)
};
// ============================================================================
// buffered streams
// ============================================================================
// ---------------------------------------------------------------------------
// Stream buffer: this class can be derived from and passed to
// wxBufferedStreams to implement custom buffering
// ---------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxStreamBuffer
{
public:
enum BufMode
{
read,
write,
read_write
};
wxStreamBuffer(wxStreamBase& stream, BufMode mode);
wxStreamBuffer(const wxStreamBuffer& buf);
virtual ~wxStreamBuffer();
// Filtered IO
virtual size_t Read(void *buffer, size_t size);
size_t Read(wxStreamBuffer *buf);
virtual size_t Write(const void *buffer, size_t size);
size_t Write(wxStreamBuffer *buf);
virtual char Peek();
virtual char GetChar();
virtual void PutChar(char c);
virtual off_t Tell() const;
virtual off_t Seek(off_t pos, wxSeekMode mode);
// Buffer control
void ResetBuffer();
// NB: the buffer must always be allocated with malloc() if takeOwn is
// TRUE as it will be deallocated by free()
void SetBufferIO(void *start, void *end, bool takeOwnership = FALSE);
void SetBufferIO(void *start, size_t len, bool takeOwnership = FALSE);
void SetBufferIO(size_t bufsize);
void *GetBufferStart() const { return m_buffer_start; }
void *GetBufferEnd() const { return m_buffer_end; }
void *GetBufferPos() const { return m_buffer_pos; }
size_t GetBufferSize() const { return m_buffer_size; }
size_t GetIntPosition() const { return m_buffer_pos - m_buffer_start; }
void SetIntPosition(size_t pos) { m_buffer_pos = m_buffer_start + pos; }
size_t GetLastAccess() const { return m_buffer_end - m_buffer_start; }
size_t GetBytesLeft() const { return m_buffer_end - m_buffer_pos; }
void Fixed(bool fixed) { m_fixed = fixed; }
void Flushable(bool f) { m_flushable = f; }
bool FlushBuffer();
bool FillBuffer();
size_t GetDataLeft();
// misc accessors
wxStreamBase *GetStream() const { return m_stream; }
bool HasBuffer() const { return m_buffer_size != 0; }
bool IsFixed() const { return m_fixed; }
bool IsFlushable() const { return m_flushable; }
// only for input/output buffers respectively, returns NULL otherwise
wxInputStream *GetInputStream() const;
wxOutputStream *GetOutputStream() const;
// deprecated, for compatibility only
wxStreamBase *Stream() { return m_stream; }
// this constructs a dummy wxStreamBuffer, used by (and exists for)
// wxMemoryStreams only, don't use!
wxStreamBuffer(BufMode mode);
protected:
void GetFromBuffer(void *buffer, size_t size);
void PutToBuffer(const void *buffer, size_t size);
// set the last error to the specified value if we didn't have it before
void SetError(wxStreamError err);
// common part of several ctors
void Init();
// init buffer variables to be empty
void InitBuffer();
// free the buffer (always safe to call)
void FreeBuffer();
// the buffer itself: the pointers to its start and end and the current
// position in the buffer
char *m_buffer_start,
*m_buffer_end,
*m_buffer_pos;
// the buffer size
// FIXME: isn't it the same as m_buffer_end - m_buffer_start? (VZ)
size_t m_buffer_size;
// the stream we're associated with
wxStreamBase *m_stream;
// its mode
BufMode m_mode;
// flags
bool m_destroybuf, // deallocate buffer?
m_fixed,
m_flushable;
private:
// Cannot use
// DECLARE_NO_COPY_CLASS(wxStreamBuffer)
// because copy constructor is explicitly declared above;
// but no copy assignment operator is defined, so declare
// it private to prevent the compiler from defining it:
wxStreamBuffer& operator=(const wxStreamBuffer&);
};
// ---------------------------------------------------------------------------
// wxBufferedInputStream
// ---------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxBufferedInputStream : public wxFilterInputStream
{
public:
// if a non NULL buffer is given to the stream, it will be deleted by it
wxBufferedInputStream(wxInputStream& stream,
wxStreamBuffer *buffer = NULL);
virtual ~wxBufferedInputStream();
char Peek();
wxInputStream& Read(void *buffer, size_t size);
// Position functions
off_t SeekI(off_t pos, wxSeekMode mode = wxFromStart);
off_t TellI() const;
// the buffer given to the stream will be deleted by it
void SetInputStreamBuffer(wxStreamBuffer *buffer);
wxStreamBuffer *GetInputStreamBuffer() const { return m_i_streambuf; }
// deprecated, for compatibility only
wxStreamBuffer *InputStreamBuffer() const { return m_i_streambuf; }
protected:
virtual size_t OnSysRead(void *buffer, size_t bufsize);
virtual off_t OnSysSeek(off_t seek, wxSeekMode mode);
virtual off_t OnSysTell() const;
wxStreamBuffer *m_i_streambuf;
DECLARE_NO_COPY_CLASS(wxBufferedInputStream)
};
// ----------------------------------------------------------------------------
// wxBufferedOutputStream
// ----------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxBufferedOutputStream : public wxFilterOutputStream
{
public:
// if a non NULL buffer is given to the stream, it will be deleted by it
wxBufferedOutputStream(wxOutputStream& stream,
wxStreamBuffer *buffer = NULL);
virtual ~wxBufferedOutputStream();
wxOutputStream& Write(const void *buffer, size_t size);
// Position functions
off_t SeekO(off_t pos, wxSeekMode mode = wxFromStart);
off_t TellO() const;
void Sync();
size_t GetSize() const;
// the buffer given to the stream will be deleted by it
void SetOutputStreamBuffer(wxStreamBuffer *buffer);
wxStreamBuffer *GetOutputStreamBuffer() const { return m_o_streambuf; }
// deprecated, for compatibility only
wxStreamBuffer *OutputStreamBuffer() const { return m_o_streambuf; }
protected:
virtual size_t OnSysWrite(const void *buffer, size_t bufsize);
virtual off_t OnSysSeek(off_t seek, wxSeekMode mode);
virtual off_t OnSysTell() const;
wxStreamBuffer *m_o_streambuf;
DECLARE_NO_COPY_CLASS(wxBufferedOutputStream)
};
#endif // wxUSE_STREAMS
#endif // _WX_WXSTREAM_H__