#include "wx/stream.h"
#include "wx/datstrm.h"
#include "wx/textfile.h"
+#include "wx/log.h"
// ----------------------------------------------------------------------------
// constants
m_buffer_pos = NULL;
m_buffer_size = 0;
- // there is nothing to destroy anyhow
- m_destroybuf = FALSE;
+ // if we are going to allocate the buffer, we should free it later as well
+ m_destroybuf = TRUE;
}
void wxStreamBuffer::Init()
off_t wxStreamBuffer::Tell() const
{
- off_t pos = m_stream->OnSysTell();
- if ( pos == wxInvalidOffset )
- return wxInvalidOffset;
+ 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 )
+ {
+ pos = m_stream->OnSysTell();
+ if ( pos == wxInvalidOffset )
+ return wxInvalidOffset;
+ }
+ else // no associated stream
+ {
+ pos = 0;
+ }
pos += GetIntPosition();
if (!temp_b)
return NULL;
- /* copy previous data (and free old buffer) if needed */
+ // copy previous data (and free old buffer) if needed
if (m_wback)
{
memmove(temp_b + needed_size, m_wback + m_wbackcur, toget);
free(m_wback);
}
- /* done */
+ // done
m_wback = temp_b;
m_wbackcur = 0;
m_wbacksize = needed_size + toget;
size_t wxInputStream::GetWBack(void *buf, size_t bsize)
{
- size_t toget = m_wbacksize-m_wbackcur;
-
if (!m_wback)
return 0;
- if (bsize < toget)
- toget = bsize;
+ // how many bytes do we have in the buffer?
+ size_t toget = m_wbacksize - m_wbackcur;
- memcpy(buf, (m_wback+m_wbackcur), toget);
+ if ( bsize < toget )
+ {
+ // we won't read everything
+ toget = bsize;
+ }
+
+ // copy the data from the cache
+ memcpy(buf, m_wback + m_wbackcur, toget);
m_wbackcur += toget;
- if (m_wbackcur == m_wbacksize)
+ if ( m_wbackcur == m_wbacksize )
{
+ // TODO: should we really free it here all the time? maybe keep it?
free(m_wback);
m_wback = NULL;
m_wbacksize = 0;
m_wbackcur = 0;
}
+ // return the number of bytes copied
return toget;
}
size_t wxInputStream::Ungetch(const void *buf, size_t bufsize)
{
+ if ( m_lasterror != wxSTREAM_NO_ERROR && m_lasterror != wxSTREAM_EOF )
+ {
+ // can't operate on this stream until the error is cleared
+ return 0;
+ }
+
char *ptrback = AllocSpaceWBack(bufsize);
if (!ptrback)
return 0;
+ // Eof() shouldn't return TRUE any longer
+ if ( m_lasterror == wxSTREAM_EOF )
+ m_lasterror = wxSTREAM_NO_ERROR;
+
memcpy(ptrback, buf, bufsize);
return bufsize;
}
bool wxInputStream::Ungetch(char c)
{
- void *ptrback = AllocSpaceWBack(1);
- if (!ptrback)
- return FALSE;
-
- *(char *)ptrback = c;
- return TRUE;
+ return Ungetch(&c, sizeof(char)) != 0;
}
char wxInputStream::GetC()
wxInputStream& wxInputStream::Read(void *buf, size_t size)
{
- size_t retsize = GetWBack(buf, size);
- if (retsize == size)
+ char *p = (char *)buf;
+ m_lastcount = 0;
+
+ size_t read = GetWBack(buf, size);
+ for ( ;; )
{
- m_lastcount = size;
- m_lasterror = wxStream_NOERROR;
- return *this;
+ size -= read;
+ m_lastcount += read;
+ p += read;
+
+ if ( !size )
+ {
+ // we read the requested amount of data
+ break;
+ }
+
+ read = OnSysRead(buf, size);
+ if ( !read )
+ {
+ // no more data available
+ break;
+ }
}
- size -= retsize;
- buf = (char *)buf + retsize;
- m_lastcount = OnSysRead(buf, size) + retsize;
return *this;
}
off_t wxInputStream::SeekI(off_t pos, wxSeekMode mode)
{
- /* Should be check and improve, just to remove a slight bug !
- I don't know whether it should be put as well in wxFileInputStream::OnSysSeek ? */
+ // RR: This code is duplicated in wxBufferedInputStream. This is
+ // not really a good design, but buffered stream are different
+ // from all other in that they handle two stream-related objects,
+ // the stream buffer and parent stream.
+
+ // I don't know whether it should be put as well in wxFileInputStream::OnSysSeek
if (m_lasterror==wxSTREAM_EOF)
m_lasterror=wxSTREAM_NOERROR;
- /* A call to SeekI() will automatically invalidate any previous call
- to Ungetch(), otherwise it would be possible to SeekI() to one
+ /* RR: A call to SeekI() will automatically invalidate any previous
+ call to Ungetch(), otherwise it would be possible to SeekI() to
one position, unread some bytes there, SeekI() to another position
and the data would be corrupted.
GRG: Could add code here to try to navigate within the wback
buffer if possible, but is it really needed? It would only work
when seeking in wxFromCurrent mode, else it would invalidate
- anyway...
- */
+ anyway... */
+
if (m_wback)
{
+ wxLogDebug( wxT("Seeking in stream which has data written back to it.") );
+
free(m_wback);
m_wback = NULL;
m_wbacksize = 0;
off_t wxInputStream::TellI() const
{
- /* GRG: Changed to make it compatible with the wback buffer */
off_t pos = OnSysTell();
if (pos != wxInvalidOffset)
wxInputStream& wxBufferedInputStream::Read(void *buf, size_t size)
{
- size_t retsize;
+ // reset the error flag
+ m_lasterror = wxStream_NOERROR;
+
+ // first read from the already cached data
+ m_lastcount = GetWBack(buf, size);
- retsize = GetWBack(buf, size);
- m_lastcount = retsize;
- if ( retsize == size )
+ // do we have to read anything more?
+ if ( m_lastcount < size )
{
- m_lasterror = wxStream_NOERROR;
- return *this;
- }
- size -= retsize;
- buf = (char *)buf + retsize;
+ size -= m_lastcount;
+ buf = (char *)buf + m_lastcount;
+
+ // the call to wxStreamBuffer::Read() below will reset our m_lastcount,
+ // so save it
+ size_t countOld = m_lastcount;
+
+ m_i_streambuf->Read(buf, size);
- m_i_streambuf->Read(buf, size);
+ m_lastcount += countOld;
+ }
return *this;
}
off_t wxBufferedInputStream::SeekI(off_t pos, wxSeekMode mode)
{
+ // RR: Look at wxInputStream for comments.
+
+ if (m_lasterror==wxSTREAM_EOF)
+ m_lasterror=wxSTREAM_NOERROR;
+
+ if (m_wback)
+ {
+ wxLogDebug( wxT("Seeking in stream which has data written back to it.") );
+
+ free(m_wback);
+ m_wback = NULL;
+ m_wbacksize = 0;
+ m_wbackcur = 0;
+ }
+
return m_i_streambuf->Seek(pos, mode);
}
off_t wxBufferedInputStream::TellI() const
{
- return m_i_streambuf->Tell();
+ off_t pos = m_i_streambuf->Tell();
+
+ if (pos != wxInvalidOffset)
+ pos -= (m_wbacksize - m_wbackcur);
+
+ return pos;
}
size_t wxBufferedInputStream::OnSysRead(void *buffer, size_t bufsize)
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