83 lines
2.6 KiB
C++
83 lines
2.6 KiB
C++
/////////////////////////////////////////////////////////////////////////////
|
|
// Name: wx/private/fileback.h
|
|
// Purpose: Back an input stream with memory or a file
|
|
// Author: Mike Wetherell
|
|
// Copyright: (c) 2006 Mike Wetherell
|
|
// Licence: wxWindows licence
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
|
|
#ifndef _WX_FILEBACK_H__
|
|
#define _WX_FILEBACK_H__
|
|
|
|
#include "wx/defs.h"
|
|
|
|
#if wxUSE_FILESYSTEM
|
|
|
|
#include "wx/stream.h"
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Backs an input stream with memory or a file to make it seekable.
|
|
//
|
|
// One or more wxBackedInputStreams can be used to read it's data. The data is
|
|
// reference counted, so stays alive until the last wxBackingFile or
|
|
// wxBackedInputStream using it is destroyed.
|
|
// ----------------------------------------------------------------------------
|
|
|
|
class WXDLLIMPEXP_BASE wxBackingFile
|
|
{
|
|
public:
|
|
enum { DefaultBufSize = 16384 };
|
|
|
|
// Takes ownership of stream. If the stream is smaller than bufsize, the
|
|
// backing file is never created and the backing is done with memory.
|
|
wxBackingFile(wxInputStream *stream,
|
|
size_t bufsize = DefaultBufSize,
|
|
const wxString& prefix = wxT("wxbf"));
|
|
|
|
wxBackingFile() : m_impl(NULL) { }
|
|
~wxBackingFile();
|
|
|
|
wxBackingFile(const wxBackingFile& backer);
|
|
wxBackingFile& operator=(const wxBackingFile& backer);
|
|
|
|
operator bool() const { return m_impl != NULL; }
|
|
|
|
private:
|
|
class wxBackingFileImpl *m_impl;
|
|
friend class wxBackedInputStream;
|
|
};
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// An input stream to read from a wxBackingFile.
|
|
// ----------------------------------------------------------------------------
|
|
|
|
class WXDLLIMPEXP_BASE wxBackedInputStream : public wxInputStream
|
|
{
|
|
public:
|
|
wxBackedInputStream(const wxBackingFile& backer);
|
|
|
|
// If the length of the backer's parent stream is unknown then GetLength()
|
|
// returns wxInvalidOffset until the parent has been read to the end.
|
|
wxFileOffset GetLength() const;
|
|
|
|
// Returns the length, reading the parent stream to the end if necessary.
|
|
wxFileOffset FindLength() const;
|
|
|
|
bool IsSeekable() const { return true; }
|
|
|
|
protected:
|
|
size_t OnSysRead(void *buffer, size_t size);
|
|
wxFileOffset OnSysSeek(wxFileOffset pos, wxSeekMode mode);
|
|
wxFileOffset OnSysTell() const;
|
|
|
|
private:
|
|
wxBackingFile m_backer;
|
|
wxFileOffset m_pos;
|
|
|
|
wxDECLARE_NO_COPY_CLASS(wxBackedInputStream);
|
|
};
|
|
|
|
#endif // wxUSE_FILESYSTEM
|
|
|
|
#endif // _WX_FILEBACK_H__
|