diff --git a/include/wx/stream.h b/include/wx/stream.h index 488d1905dc..3b3486c1d1 100644 --- a/include/wx/stream.h +++ b/include/wx/stream.h @@ -1,7 +1,7 @@ ///////////////////////////////////////////////////////////////////////////// // Name: wx/stream.h -// Purpose: "wxWindows stream" base classes -// Author: Guilhem Lavaux +// Purpose: stream classes +// Author: Guilhem Lavaux, Guillermo Rodriguez Garcia, Vadim Zeitlin // Modified by: // Created: 11/07/98 // RCS-ID: $Id$ @@ -34,30 +34,39 @@ typedef wxOutputStream& (*__wxOutputManip)(wxOutputStream&); WXDLLEXPORT wxOutputStream& wxEndL(wxOutputStream& o_stream); -// --------------------------------------------------------------------------- -// wxStream: base classes -// --------------------------------------------------------------------------- +// ---------------------------------------------------------------------------- +// constants +// ---------------------------------------------------------------------------- enum wxStreamError { - wxSTREAM_NO_ERROR = 0, - wxSTREAM_NO_ERR = wxSTREAM_NO_ERROR, - wxSTREAM_NOERROR = wxSTREAM_NO_ERROR, - - wxSTREAM_EOF, - - wxSTREAM_WRITE_ERROR, - wxSTREAM_WRITE_ERR = wxSTREAM_WRITE_ERROR, - - wxSTREAM_READ_ERROR, - wxSTREAM_READ_ERR = wxSTREAM_READ_ERROR + 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 + wxSTREAM_PIPE_ERROR // broken pipe: the other half was closed }; // compatibility -#define wxStream_NOERROR wxSTREAM_NOERROR -#define wxStream_EOF wxSTREAM_EOF -#define wxStream_WRITE_ERR wxSTREAM_WRITE_ERROR -#define wxStream_READ_ERR wxSTREAM_READ_ERROR +#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 WXDLLEXPORT wxStreamBase { @@ -67,80 +76,168 @@ public: // error testing wxStreamError GetLastError() const { return m_lasterror; } - bool IsOk() const { return LastError() == wxSTREAM_NOERROR; } - bool operator!() const { return LastError() != wxSTREAM_NOERROR; } + bool IsOk() const { return GetLastError() == wxSTREAM_NOERROR; } + bool operator!() const { return !IsOk(); } + // reset the stream state + void Reset() { m_lasterror = wxSTREAM_NOERROR; } + + // deprecated (doesn't make sense!), don't use 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: - // VZ: these functions are really pure virtual and shouldn't be declared - // in the base class because it creates ambiguties in stream classes - // deriving from both wxInputStream and wxOutputStream -#if 0 - virtual size_t OnSysRead(void *buffer, size_t bufsize); - virtual size_t OnSysWrite(const void *buffer, size_t bufsize); -#endif - virtual off_t OnSysSeek(off_t seek, wxSeekMode mode); virtual off_t OnSysTell() const; - friend class wxStreamBuffer; - size_t m_lastcount; wxStreamError m_lasterror; + + friend class wxStreamBuffer; }; -class WXDLLEXPORT wxInputStream : /* virtual */ public wxStreamBase +// ---------------------------------------------------------------------------- +// wxInputStream: base class for the input streams +// ---------------------------------------------------------------------------- + +class WXDLLEXPORT wxInputStream : public wxStreamBase { public: + // ctor and dtor, nothing exciting wxInputStream(); virtual ~wxInputStream(); - // is the stream at EOF? - virtual bool Eof() const; // 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); - wxInputStream& Read(wxOutputStream& stream_out); - // Position functions - virtual off_t SeekI(off_t pos, wxSeekMode mode = wxFromStart); - virtual off_t TellI() const; + // copy the entire contents of this stream into streamOut, stopping only + // when EOF is reached or an error occurs + wxInputStream& Read(wxOutputStream& streamOut); - // State functions - virtual size_t LastRead() { return wxStreamBase::m_lastcount; } - // Ungetch + // 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); - // Operators + + // 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); } + wxInputStream& operator>>(__wxInputManip func) { return func(*this); } protected: - // to be implemented in the derived classes (it should have been pure - // virtual) - virtual size_t OnSysRead(void *buffer, size_t bufsize); + // 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; - // Ungetch managers + // 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; - size_t m_wbacksize; - size_t m_wbackcur; - char *AllocSpaceWBack(size_t needed_size); - size_t GetWBack(void *buf, size_t bsize); + // the size of the buffer + size_t m_wbacksize; + + // the current position in the buffer + size_t m_wbackcur; friend class wxStreamBuffer; }; -class WXDLLEXPORT wxOutputStream : /* virtual */ public wxStreamBase +// ---------------------------------------------------------------------------- +// wxOutputStream: base for the output streams +// ---------------------------------------------------------------------------- + +class WXDLLEXPORT wxOutputStream : public wxStreamBase { public: wxOutputStream(); @@ -168,6 +265,10 @@ protected: friend class wxStreamBuffer; }; +// ============================================================================ +// helper stream classes +// ============================================================================ + // --------------------------------------------------------------------------- // A stream for measuring streamed output // --------------------------------------------------------------------------- @@ -224,6 +325,10 @@ protected: wxOutputStream *m_parent_o_stream; }; +// ============================================================================ +// buffered streams +// ============================================================================ + // --------------------------------------------------------------------------- // Stream buffer: this class can be derived from and passed to // wxBufferedStreams to implement custom buffering @@ -240,7 +345,6 @@ public: }; wxStreamBuffer(wxStreamBase& stream, BufMode mode); - wxStreamBuffer(BufMode mode); wxStreamBuffer(const wxStreamBuffer& buf); virtual ~wxStreamBuffer(); @@ -294,6 +398,10 @@ public: // 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); @@ -328,13 +436,12 @@ protected: // flags bool m_destroybuf, // deallocate buffer? - m_destroystream, // delete associated stream? m_fixed, m_flushable; }; // --------------------------------------------------------------------------- -// wxBufferedStreams +// wxBufferedInputStream // --------------------------------------------------------------------------- class WXDLLEXPORT wxBufferedInputStream : public wxFilterInputStream @@ -367,6 +474,10 @@ protected: wxStreamBuffer *m_i_streambuf; }; +// ---------------------------------------------------------------------------- +// wxBufferedOutputStream +// ---------------------------------------------------------------------------- + class WXDLLEXPORT wxBufferedOutputStream : public wxFilterOutputStream { public: diff --git a/src/common/stream.cpp b/src/common/stream.cpp index 26d3ab77cd..1dd1991d99 100644 --- a/src/common/stream.cpp +++ b/src/common/stream.cpp @@ -46,7 +46,7 @@ // ---------------------------------------------------------------------------- // the temporary buffer size used when copying from stream to stream -#define BUF_TEMP_SIZE 10000 +#define BUF_TEMP_SIZE 4096 // ============================================================================ // implementation @@ -80,6 +80,16 @@ void wxStreamBuffer::Init() m_fixed = TRUE; } +wxStreamBuffer::wxStreamBuffer(BufMode mode) +{ + Init(); + + m_stream = NULL; + m_mode = mode; + + m_flushable = FALSE; +} + wxStreamBuffer::wxStreamBuffer(wxStreamBase& stream, BufMode mode) { Init(); @@ -88,32 +98,13 @@ wxStreamBuffer::wxStreamBuffer(wxStreamBase& stream, BufMode mode) m_mode = mode; m_flushable = TRUE; - m_destroystream = FALSE; -} - -wxStreamBuffer::wxStreamBuffer(BufMode mode) -{ - Init(); - - wxASSERT_MSG(mode != read_write, wxT("you have to use the other ctor for read_write mode") ); - if ( mode == read ) - m_stream = new wxInputStream; - else if ( mode == write) - m_stream = new wxOutputStream; - else - m_stream = NULL; - - m_mode = mode; - - m_flushable = FALSE; - m_destroystream = TRUE; } wxStreamBuffer::wxStreamBuffer(const wxStreamBuffer& buffer) { - // doing this has big chances to lead to a crashwhen the source buffer is + // doing this has big chances to lead to a crash when the source buffer is // destroyed (otherwise assume the caller knows what he does) - wxASSERT_MSG( !buffer.m_destroybuf && !buffer.m_destroystream, + wxASSERT_MSG( !buffer.m_destroybuf, _T("it's a bad idea to copy this buffer") ); m_buffer_start = buffer.m_buffer_start; @@ -125,7 +116,6 @@ wxStreamBuffer::wxStreamBuffer(const wxStreamBuffer& buffer) m_stream = buffer.m_stream; m_mode = buffer.m_mode; m_destroybuf = FALSE; - m_destroystream = FALSE; } void wxStreamBuffer::FreeBuffer() @@ -137,9 +127,6 @@ void wxStreamBuffer::FreeBuffer() wxStreamBuffer::~wxStreamBuffer() { FreeBuffer(); - - if ( m_destroystream ) - delete m_stream; } wxInputStream *wxStreamBuffer::GetInputStream() const @@ -195,14 +182,15 @@ void wxStreamBuffer::SetBufferIO(size_t bufsize) void wxStreamBuffer::ResetBuffer() { - wxCHECK_RET( m_stream, _T("should have a stream in wxStreamBuffer") ); + if ( m_stream ) + { + m_stream->m_lasterror = wxStream_NOERROR; + m_stream->m_lastcount = 0; + } - m_stream->m_lasterror = wxStream_NOERROR; - m_stream->m_lastcount = 0; - if (m_mode == read && m_flushable) - m_buffer_pos = m_buffer_end; - else - m_buffer_pos = m_buffer_start; + m_buffer_pos = m_mode == read && m_flushable + ? m_buffer_end + : m_buffer_start; } // fill the buffer with as much data as possible (only for read buffers) @@ -315,7 +303,7 @@ void wxStreamBuffer::PutChar(char c) // if we don't have buffer at all, just forward this call to the stream, if ( !HasBuffer() ) { - outStream->OnSysWrite(&c, 1); + outStream->OnSysWrite(&c, sizeof(c)); } else { @@ -327,7 +315,7 @@ void wxStreamBuffer::PutChar(char c) } else { - PutToBuffer(&c, 1); + PutToBuffer(&c, sizeof(c)); m_stream->m_lastcount = 1; } } @@ -345,7 +333,7 @@ char wxStreamBuffer::Peek() } char c; - GetFromBuffer(&c, 1); + GetFromBuffer(&c, sizeof(c)); m_buffer_pos--; return c; @@ -360,7 +348,7 @@ char wxStreamBuffer::GetChar() char c; if ( !HasBuffer() ) { - inStream->OnSysRead(&c, 1); + inStream->OnSysRead(&c, sizeof(c)); } else { @@ -371,7 +359,7 @@ char wxStreamBuffer::GetChar() } else { - GetFromBuffer(&c, 1); + GetFromBuffer(&c, sizeof(c)); m_stream->m_lastcount = 1; } } @@ -381,16 +369,18 @@ char wxStreamBuffer::GetChar() size_t wxStreamBuffer::Read(void *buffer, size_t size) { - wxInputStream *inStream = GetInputStream(); - - wxCHECK_MSG( inStream, 0, _T("should have a stream in wxStreamBuffer") ); - // lasterror is reset before all new IO calls - m_stream->m_lasterror = wxStream_NOERROR; + if ( m_stream ) + m_stream->m_lasterror = wxStream_NOERROR; + size_t read; if ( !HasBuffer() ) { - m_stream->m_lastcount = inStream->OnSysRead(buffer, size); + wxInputStream *inStream = GetInputStream(); + + wxCHECK_MSG( inStream, 0, _T("should have a stream in wxStreamBuffer") ); + + read = inStream->OnSysRead(buffer, size); } else // we have a buffer, use it { @@ -421,10 +411,13 @@ size_t wxStreamBuffer::Read(void *buffer, size_t size) } } - m_stream->m_lastcount = orig_size - size; + read = orig_size - size; } - return m_stream->m_lastcount; + if ( m_stream ) + m_stream->m_lastcount = read; + + return read; } // this should really be called "Copy()" @@ -615,10 +608,8 @@ off_t wxStreamBuffer::Tell() const { off_t pos; - // only ask the stream for position if we have a real stream and not a - // dummy one which we created ourselves, otherwise we'd call - // wxStream::OnSysTell() which would always return wxInvalidOffset - if ( !m_destroystream ) + // ask the stream for position if we have a real one + if ( m_stream ) { pos = m_stream->OnSysTell(); if ( pos == wxInvalidOffset ) @@ -677,31 +668,19 @@ wxInputStream::~wxInputStream() free(m_wback); } -size_t wxInputStream::OnSysRead(void * WXUNUSED(buffer), - size_t WXUNUSED(bufsize)) +bool wxInputStream::CanRead() const { - return 0; + // we don't know if there is anything to read or not and by default we + // prefer to be optimistic and try to read data unless we know for sure + // there is no more of it + return m_lasterror != wxSTREAM_EOF; } bool wxInputStream::Eof() const { - wxInputStream *self = wxConstCast(this, wxInputStream); - - char c; - self->Read(&c, 1); - - // some streams can know that they're at EOF before actually trying to - // read beyond the end of stream (e.g. files) while others have no way of - // knowing it, so to provide the same behaviour in all cases we only - // return TRUE from here if the character really couldn't be read - if ( !self->LastRead() && GetLastError() == wxSTREAM_EOF ) - { - return TRUE; - } - - self->Ungetch(c); - - return FALSE; + // the only way the base class can know we're at EOF is when we'd already + // tried to read beyond it in which case last error is set accordingly + return GetLastError() == wxSTREAM_EOF; } char *wxInputStream::AllocSpaceWBack(size_t needed_size) @@ -730,7 +709,7 @@ char *wxInputStream::AllocSpaceWBack(size_t needed_size) return m_wback; } -size_t wxInputStream::GetWBack(void *buf, size_t bsize) +size_t wxInputStream::GetWBack(void *buf, size_t size) { if (!m_wback) return 0; @@ -738,10 +717,10 @@ size_t wxInputStream::GetWBack(void *buf, size_t bsize) // how many bytes do we have in the buffer? size_t toget = m_wbacksize - m_wbackcur; - if ( bsize < toget ) + if ( size < toget ) { // we won't read everything - toget = bsize; + toget = size; } // copy the data from the cache @@ -783,13 +762,13 @@ size_t wxInputStream::Ungetch(const void *buf, size_t bufsize) bool wxInputStream::Ungetch(char c) { - return Ungetch(&c, sizeof(char)) != 0; + return Ungetch(&c, sizeof(c)) != 0; } char wxInputStream::GetC() { char c; - Read(&c, 1); + Read(&c, sizeof(c)); return c; } @@ -811,6 +790,13 @@ wxInputStream& wxInputStream::Read(void *buf, size_t size) break; } + if ( p != buf && !CanRead() ) + { + // we have already read something and we would block in OnSysRead() + // now: don't do it but return immediately + break; + } + read = OnSysRead(p, size); if ( !read ) { @@ -825,7 +811,7 @@ wxInputStream& wxInputStream::Read(void *buf, size_t size) char wxInputStream::Peek() { char c; - Read(&c, 1); + Read(&c, sizeof(c)); if (m_lasterror == wxStream_NOERROR) { Ungetch(c); @@ -838,13 +824,17 @@ char wxInputStream::Peek() wxInputStream& wxInputStream::Read(wxOutputStream& stream_out) { char buf[BUF_TEMP_SIZE]; - size_t bytes_read = BUF_TEMP_SIZE; - while (bytes_read == BUF_TEMP_SIZE) + for ( ;; ) { - bytes_read = Read(buf, bytes_read).LastRead(); - bytes_read = stream_out.Write(buf, bytes_read).LastWrite(); + size_t bytes_read = Read(buf, WXSIZEOF(buf)).LastRead(); + if ( !bytes_read ) + break; + + if ( stream_out.Write(buf, bytes_read).LastWrite() != bytes_read ) + break; } + return *this; } @@ -913,7 +903,7 @@ size_t wxOutputStream::OnSysWrite(const void * WXUNUSED(buffer), void wxOutputStream::PutC(char c) { - Write(&c, 1); + Write(&c, sizeof(c)); } wxOutputStream& wxOutputStream::Write(const void *buffer, size_t size)